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UNDERSTANDING
TYPE 2 DIABETES

Fewer highs, fewer lows, better health

PROFESSOR MERLIN THOMAS

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‘Understanding Type 2 Diabetes is a terrific addition to your library if you have Type 2 and want to gain a deeper knowledge of it, or if you have just been diagnosed and don’t know where to start.

Diabetes Diet Choices, May 2014

Written by Professor Merlin Thomas from the world-renowned Baker IDI Heart and Diabetes Institute, Understanding Type 2 Diabetes offers clear and effective guidance on how to manage all aspects of diabetes.’

Diabetes Matters, April 2013

‘This book is a clear guide for any diabetic sufferer on how to manage all aspects of the disease. The text covers what diabetes is and how it comes about, what is the right diet for someone with diabetes and how to achieve it and how exercise can improve and maintain health. The medical aspects of diabetes care, such as the best ways to control your waistline, blood glucose, blood sugar and cholesterol, as well as how to prevent major complications, are all covered in the book.’

Australian Nurses Journal, April 2013

‘This book aims to help those living with diabetes manage the condition, giving you the knowledge you need to choose the right diet, exercise and medication, and prevent complications.’

Good Health Magazine, May 2013

Disclaimer

This book is a general guide only and should never be a substitute for the skill, knowledge and experience of a qualified medical professional dealing with the facts, circumstances and symptoms of a particular case. The nutritional, medical and health information presented in this book is based on the research, training and professional experience of the author, and is true and complete to the best of their knowledge. However, this book is intended only as an informative guide; it is not intended to replace or countermand the advice given by the reader’s personal physician or diabetes care team. Because each person and situation is unique, the author and the publisher urge the reader to check with a qualified healthcare professional before using any procedure where there is a question as to its appropriateness. Your diabetes practitioner or care team should be consulted before beginning any new treatment program, including diet, lifestyle and/or physical activity. The author, publisher and their distributors are not responsible for any adverse effects or consequences resulting from the use of the information in this book. It is the responsibility of the reader to consult a physician or other qualified healthcare professional regarding their personal care. This book contains references to products and procedures that may not be available everywhere. The intent of the information provided is to be helpful; however, there is no guarantee of results associated with the information provided. Use of drug brand names is for educational purposes only and does not imply endorsement.

CONTENTS

Introduction

 

1. What is diabetes?

2. Why did it happen to me?

3. A spoon less of sugar

4. Waist management

5. Get physical

6. Pills and injections

7. Swinging low

8. Under pressure

9. Eschew the fat

10. Diabetes in my heart

11. Diabetes in my sight

12. Diabetes on my feet

13. Diabetes in my kidneys

14. Diabetes in my bladder

15. Diabetes on my mind

16. Diabetes on my mood

17. Diabetes in my sleep

18. Diabetes in my bed

 

Acknowledgments

Resources

Index

INTRODUCTION

In ancient times there lived a king called Sisyphus. Because of his past excesses and hubris he was cursed by the Gods. His penance was to push an immense boulder up a steep hill, only to have it roll back down and the task to start all over again. Having diabetes often feels like this, the ripened fruit of our actions or inattention. Equally, the treatment regime for managing diabetes often feels like an appropriate punishment: boring ritualized repetition and relentless austerity to make up for our previous bad behaviour. But it’s really not like that at all.

First, your goals of understanding and managing your diabetes are achievable. With the application of good diabetes care, healthy nutrition and regular physical activity, most people with type 2 diabetes lead full and healthy lives. Your effort is never futile.

Second, managing diabetes is not as hard as it sounds. What might appear on the surface to be an enormous or complex undertaking can become quite effortless with practice and application.

Third, diabetes management is not a punishment. It is easy to fall into the trap of believing that some suffering is the price of good health, like the distasteful medicine you must swallow to get well. But dieting is not punishment for the nutritionally wicked, nor is exercise the castigation of the couch potato. These are positive steps that have their own rewards.

Fourth, diabetes management requires a careful coordination of physical activity, diet and medication. But this does not mean you have to do the same things every day or eat the same restrictive diet, trapped in a tedious and repetitive cycle of care. In fact, diabetes management can be very flexible, matching individual requirements and capabilities with diet, exercise or medications.

Finally, you are not alone with your burden. Diabetes management will harness the support of your doctor, diabetes educator, dietician, podiatrist and many other professionals that comprise your diabetes care team. Each person will help you manage your diabetes and make the task of managing diabetes not only feasible but also revitalising.

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Diabetes can sometimes feel like a curse to a lifetime of futile repetition. But it is not like this at all!

This book is your guide to diabetes and outlines the many opportunities you have to make a positive difference to your health. It begins by examining what diabetes is and how it comes about. It then goes on to describe the many practical changes you can make to your diet, and the potential strengths as well as weaknesses of these changes. It also looks at physical activity and the different ways exercise can be used to both maintain and improve your health. The book also explores the medical aspects of diabetes care, including practical ways to achieve control of your waistline, blood glucose, blood pressure and cholesterol levels, as well as the best means to avoid major complications. You can do this.

It is nothing like pushing a rock up a hill.

1

WHAT IS DIABETES?

Understand

Manage

The name glucose comes from the Greek word glukus, meaning ‘sweet’. Glucose is a sweet sugar. It is also the major sugar that circulates inside your blood, so the terms ‘glucose’ and ‘sugar’ are often used interchangeably when managing diabetes. But glucose is not the same thing as the white sugar used in cooking or in your coffee.

The human body runs on fuel, like the petrol in your car. Glucose is chiefly used to fuel chemical reactions inside your body. This is known as metabolism. Metabolism provides the vital energy for every cell to do what needs to be done. Every cell needs fuel for its metabolism. Most cells will eat anything that is available. But your brain is a very picky eater — it will only eat glucose.

However, the problem is that your brain has little stored glucose of its own. It can’t make glucose itself and won’t use any other fuel if glucose runs out. Instead, it must rely on the glucose dissolved in your blood being present all of the time to maintain continuous supply and continuous functioning. From the brain’s point of view, blood sugar is as important as the oxygen in the air you breathe: it can only function for a few minutes without either before it stops working altogether.

To guarantee your brain keeps running night and day, the body must ensure that glucose is always present in your blood in roughly the same concentration. To achieve this level of control is not easy. Some days you might eat a few pieces of cake, a sandwich or even a huge bowl of pasta. Other times you might eat hardly anything at all. Yet through it all, glucose levels will normally fluctuate only very slightly:

This amazing level of control is achieved thanks to an elaborate system of checks and balances that carefully regulates how much glucose is going into the blood and how much is going out.

In essence, diabetes is the state in which this balance fails and glucose levels rise.

Every time you eat or drink something that contains any carbohydrate (also known as carbs) your body gets a dose of sugar. Whether you are eating chocolate cake or spaghetti or drinking a Coke, the carbs contained in each product are broken down by your digestion into simple sugars, one of which is glucose.

As these sugars are digested and absorbed, they trigger the release of hormones, the most important of which is insulin. Hormones are chemical signals that communicate a message from one part of the body to another, usually via the bloodstream. Insulin is made and released by the beta-cells of the pancreas. The message insulin sends coordinates the body’s response to rising blood glucose levels. This message tells the cells of the liver, muscles and fat to take away glucose from the blood (and store it for later use). It also tells the liver to stop making and releasing any extra glucose, which is rendered unnecessary by having just had a sugary meal.

This is a proportional response. The greater the amount of sugar contained in a product and the faster it hits your system, the greater the amount of insulin that is released. This keeps glucose levels from rising too fast or too high. In contrast, a meal that is low in sugar or contains sugars that are only slowly digested will need to trigger a proportionally smaller insulin response to make sure glucose levels don’t drop too rapidly.

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Diabetes occurs when there is not enough insulin (or its functions) to keep glucose levels balanced.

The net result of this finely balanced system is that, in people without diabetes, glucose levels in the blood only rise slightly and very briefly following a meal, regardless of what they eat.

When you are not eating, such as at night, your brain still needs glucose to keep functioning. So to keep up with the brain’s unceasing demands, the liver slowly releases its glucose stores and also manufactures new glucose, which it releases into the blood like a kind of controlled drip feed for your hungry brain.

To make this happen before glucose levels in the blood start to fall, the pancreas immediately stops releasing insulin and starts making other hormones such as glucagon. These hormones send a different message. They say that any unnecessary uptake of glucose must now stop, leaving any glucose for your fussy brain. Also, the brakes that insulin has placed on the liver’s glucose production should be removed, to start the drip feed.

Again, the rate at which glucose is released into the blood is finely balanced to match the rate at which the body (and in particular the brain) uses glucose. So glucose levels in the blood don’t fall very much, if at all, between meals in people who do not have diabetes. Even if you skip a meal, or wish to fast for several days, glucose levels always remain sufficient for the brain to keep working.

So in people without diabetes, day and night, feeding or fasting, the levels of glucose in their blood do not rise or fall much at all, balanced by the actions of insulin and other hormones.

Diabetes only occurs when there is not enough insulin to keep this balance and maintain glucose levels under tight control.

How and why this happens is complicated. Many different factors can contribute to the decline and loss of insulin’s functions, leading ultimately to the development of type 2 diabetes. These are discussed in detail in Chapter 2.

DIABETES AND GLUCOSE CONTROL

Not having enough insulin has major consequences for glucose control.

In diabetes, glucose levels in the blood can rise excessively after a meal

The job of insulin is chiefly to coordinate your body to deal with the sugars in your meal. So one of the first signs that insulin is not doing this job is a rise in your glucose level after a meal, especially one rich in carbohydrate. This is when you need to make the greatest amount of insulin to cope with the extra glucose entering your blood, so this is also when any limited capacity for insulin production is first challenged.

One simple way to test for type 2 diabetes is an oral glucose tolerance test (OGTT). This test involves drinking a large amount of glucose and then determining how quickly it is cleared from your blood and glucose balance is restored. It is essentially a ‘road test’ of your pancreas to see if it can rev up and handle the (sugar) hills. An OGTT is usually performed in the morning after having not eaten anything overnight. Drinking water beforehand is allowed, but no coffee, tea or juice, which can upset the results. At the start of the OGTT a blood sample is drawn. You are then given a sweet solution (containing 75g of glucose) to drink within 5 minutes. A further blood sample is drawn 2 hours later and the glucose level is measured.

In healthy people, the glucose level in their blood 2 hours after drinking this big wallop of glucose will be below 7.8 mmol/L (140mg/dL). This means they quickly made enough insulin to efficiently put all this sugar away.

If your glucose level is above 11 mmol/L (198 mg/dL) 2 hours after drinking the glucose, insulin has not done its job. This indicates a diagnosis of diabetes.

If glucose levels are modestly elevated (between 7.8 and 11 mmol/L) (140.4 and 198 mg/dL) then impaired glucose tolerance is said to exist. This is also known as pre-diabetes, as without significant changes in diet and lifestyle most people with these intermediate levels ultimately go on to develop fullblown diabetes.

In diabetes, glucose levels in the blood can stay elevated even when you are not eating

Most of the glucose in your blood does not come from your diet. It has been made and released by your liver. As detailed earlier in this chapter, in the healthy human body the production of glucose is perfectly in tune with the glucose levels in your blood and the rate at which it is used up. So glucose levels in the blood do not usually fall very much when you are not eating, because glucose production springs into action.

Equally, if glucose levels are too high or sugar is coming into the body after a meal, unnecessary glucose production by the liver should be shut down, so balancing the system. But in type 2 diabetes this shutdown does not happen very well. This is partly because there is not enough insulin (function) to stop glucose production. In addition, the signals that drive glucose production, like glucagon and free fat in the blood, fail to be adequately suppressed.

Without the right signals, your liver mistakenly believes you are hungry all the time and need more glucose in your blood, even when you have just eaten.

So diabetes is like a state of anarchy (literally out of control). Even though glucose levels may be already high in the blood, in diabetes extra glucose is still made by the anarchic liver and released into the blood. Consequently, glucose levels become and remain elevated in people with type 2 diabetes even if they are on a stringent diet or are eating almost nothing at all. Indeed, most people are first diagnosed with type 2 diabetes because they are found to have a glucose level greater than 7 mmol/L (126 mg/dL) on a routine blood test taken when they were not eating (e.g. before a meal).

THE CONSEQUENCES OF HIGH GLUCOSE

High glucose levels usually start out as a silent problem. Most people are completely unaware they have type 2 diabetes. Yet glucose levels have usually been elevated in the blood for an average of 5 to 10 years before a diagnosis of type 2 diabetes is first made.

The most common symptoms associated with type 2 diabetes are easily dismissed as a signs of getting old or other problems. These may include:

All of these symptoms are caused by having high glucose levels in your blood. They are not permanent or a sign of damage. When diabetes is treated and glucose control is restored most of these symptoms will go away. This is one reason why you and your diabetes care team will be working to keep your glucose levels as close to normal as possible.

There is no symptom here that is particularly unique to type 2 diabetes. It is very easy to simply explain these symptoms away, ignore them or misattribute them to other conditions. This is why today it is recommended that all people at risk for type 2 diabetes should have regular blood tests to look for diabetes regardless of how they feel.

GLUCOSE MONITORING USING HbA1c

The most common way to get a handle on your glucose control is for a doctor to measure your haemoglobin A1c (also known as HbA1c or A1c). The test for this involves having a blood sample taken and sent away to a clinical laboratory. The HbA1c shows the amount of glucose that is stuck onto a protein — haemoglobin — in your red blood cells. The higher your glucose levels have been during the previous 3 to 4 months, the more glucose will be stuck to the haemoglobin and the higher your HbA1c will be. This means that taking a blood test to measure your HbA1c is one way to confirm if you have diabetes.

In people without diabetes, their HbA1c is almost always less than 6 per cent (or 48 mmol/mol in the new units for this test now used by many doctors). By comparison, without treatment, people with type 2 diabetes usually have an HbA1c of greater than 6.5 per cent (50 mmol/mol). An HbA1c greater than 8 per cent (64 mmol/mol) suggests persistently elevated glucose levels and generally indicates your blood glucose is not well controlled and the risk of complications is increased.

Your HbA1c will be measured when you are diagnosed with type 2 diabetes and then at least twice a year thereafter. It is also common to measure your HbA1c about 3 months after starting any new treatment to lower your glucose levels, as it takes this long for its full effect to be seen on your HbA1c.

Often the first step in diabetes management will be to set an appropriate target for your HbA1c. Usually, getting and keeping the HbA1c to less than 7 per cent (53 mmol/mol) is the goal. This is not quite as good as people without diabetes, who normally run an HbA1c less than 6 per cent. However, achieving an HbA1c of less than 7 per cent (53 mmol/mol) will eliminate most of the symptoms caused by high glucose levels in people with diabetes. In addition, improving glucose control beyond this level does not appreciably reduce your risk from the complications of diabetes detailed later in this book, while exposing you to the burden of additional treatment.

However, sometimes even aiming for this level of glucose control is not the right thing for you to do. The right target for your HbA1c should take into account your age, lifestyle, work practices, the treatment you are receiving and its side effects, and a host of other factors. This kind of careful individualised assessment of the adequacy of your current level of glucose control, and the value and safety of going lower, will be made almost every time you see your physician or diabetes care team.

MONITORING USING BLOOD GLUCOSE LEVELS

Another way to come to grips with your glucose control is to directly measure and monitor your own blood glucose levels using a blood glucose meter. This is known as self-monitoring. Most good hospitals and many diabetes practices have educator nurses who will teach you this technique. The glucose test involves pricking your finger to release a drop of blood. (It is not very painful or particularly complicated to do.) The drop of blood is then applied to a plastic strip and placed in a small machine that measures the glucose level in the blood.

When glucose levels are under good control, most of the results from self-monitoring will be between:

Testing your own blood glucose levels is a practical way to make sure that your diabetes management is on track. Self-monitoring also enables you to find out how different foods and activities affect your own individual blood glucose levels, and makes it easier to develop and modify diet and lifestyle plans that best suit your individual needs. In addition, self-monitoring provides valuable and prompt feedback about anything you might be doing to improve your glucose control, such as changes in your medication, physical activity, diet or lifestyle. Blood glucose monitoring can also be a useful way to reduce the risk of hypoglycaemia (see Chapter 5).

It is not essential to monitor your own glucose levels. However, most people with type 2 diabetes are encouraged to monitor when there are adequate resources, support and assessment.

A strategic plan for blood glucose monitoring will usually be developed in conjunction with your physician or diabetes care team. The frequency of self-monitoring will always need to be different for different people and different situations. For example, people with very stable glucose control may need to monitor less often than those starting out on a new treatment regimen, or those troubled by lots of highs and/or lows. How often you need to test may range from once or twice a week to many times a day, timed to coincide with key problem periods. More testing will usually be undertaken if you are unwell, because this is commonly the time that glucose control, as well as other aspects of your health, goes awry.

A new way to monitor glucose levels has recently become more widely available. This is known as continuous glucose monitoring (CGM) and involves wearing a small device that is able to measure glucose levels every 5 minutes. It can be worn for up to 6 days and can track changes in your glucose levels throughout the day and night. Some devices also have alarms for glucose highs and lows. These devices can provide a very accurate picture of your daily fluctuations in blood glucose control and help find the best approach to tackling your own individual glucose control problems.

At present, CGM devices are mostly used only for brief periods, and give a brief snapshot of glucose control over a few days. However, some people are starting to use this technology every day. It is likely that the future management of diabetes will increasingly involve continuous blood glucose monitoring.

2

WHY DID IT HAPPEN TO ME?

Understand

Manage

Diabetes is a simple disease. It occurs when there is not enough insulin (or not enough of its functions) to keep your glucose levels under control. Insulin is a hormone made and released by the beta-cells of the pancreas. Its job is to coordinate the body’s response to rising blood glucose levels in the blood. Diabetes develops only when it can’t do this anymore. But while diabetes is a simple problem, the reasons diabetes comes about are much more complex.

Many different factors can contribute to the decline and loss of insulin’s functions, leading ultimately to the development of diabetes.

In some people, the immune system can inadvertently destroy the insulin-producing beta-cells of the pancreas. This is called type 1 diabetes. Type 1 diabetes accounts for around 8 to 10 per cent of all people with diabetes. It can occur at any age, not just in children and adolescents. Type 1 diabetes used to be known as insulin-dependent diabetes because the ability to make insulin is completely lost and insulin injections are always needed to survive. However, people with other forms of diabetes may also need insulin to control their glucose levels, so this name has become largely obsolete.

The most common form of diabetes is type 2 diabetes, which accounts for over 90 per cent of all diabetes in adults and is the sole topic of this book. In type 2 diabetes, the capacity to produce enough insulin to adequately control your glucose levels is progressively exhausted over many years (probably at least 20 years). By the time type 2 diabetes is finally diagnosed it may be that over half of the insulin-producing beta-cells in the pancreas have been lost.

WHAT CAUSES TYPE 2 DIABETES?

Broadly, there are three key factors that combine to prevent the beta-cells of the pancreas doing their job to make enough insulin to keep blood glucose levels under control. These act to a greater or lesser extent in different people, but collectively mean that the capacity for insulin production eventually fails to keep up with demands, and glucose levels start to rise.

Too much work can be exhausting for the pancreas

The beta-cells of the pancreas make insulin in proportion to the amount of sugar in a meal and how quickly it is digested and absorbed (known as the glycaemic load or GL — see Chapter 3). If you regularly eat a diet rich in sugars, especially those that are rapidly digested, your pancreas will have to make more insulin more quickly. And these demands to make more and more insulin eventually take their toll. People who habitually eat this kind of unhealthy sugar-rich diet have a higher risk of developing type 2 diabetes.

The pancreas will also have to work harder if the cells of the body become less sensitive to insulin (known as insulin resistance).

Resistance to the actions of insulin is a common early finding in people who ultimately develop type 2 diabetes. If there is resistance to insulin’s actions, much more insulin must be made and released every time sugar is eaten to compensate and keep glucose under control. So insulin levels in type 2 diabetes initially run higher than normal. For a while this is possible, but not forever.

Insulin resistance is like driving your car with the handbrake still partly on. You can still get to your destination but it takes much more effort. Eventually, all that revving damages your engine and the car can no longer make it down the street. In the same way, type 2 diabetes occurs when you reach a point that your pancreas simply can no longer make enough insulin to overcome the resistance.

The most common cause of insulin resistance is being overweight or inactive, and especially both. But these are not the only causes. In every pregnancy, hormones and other factors normally cause resistance to the actions of insulin. This means that insulin production in pregnant women needs to be almost doubled to keep glucose levels under control. Most women’s bodies can capably do this. However, some women do not have the kind of extra capacity to double their insulin production, especially older and/or overweight women. And when there is not enough insulin (function) to keep metabolism under control, glucose levels will inevitably rise. When this happens during pregnancy it is known as gestational diabetes.

Although glucose levels usually return to normal after giving birth, women with gestational diabetes are four times more likely to eventually develop type 2 diabetes as they age when compared to those who have a diabetes-free pregnancy. Many people think of a 9-month pregnancy as a kind of road test of your pancreas, for what might happen in the future should you remain overweight or inactive over much longer periods.

Another condition associated with type 2 diabetes is polycystic ovarian syndrome, or PCOS. PCOS affects between 5 and 10 per cent of all women. It can cause women to experience irregular periods, acne, and excessive facial hair and weight gain. Having PCOS also makes you more likely to develop type 2 diabetes, which may affect up to 40 per cent of women with PCOS by the time they are 40 years old. This is partly because those women with PCOS also have greater resistance to the (glucose-lowering) actions of insulin.

Some medicines used in the treatment of other diseases may also cause type 2 diabetes in some people through making the body more resistant to the effects of insulin. These include steroid pills (especially in high doses), some diuretics and antipsychotics used in the treatment of mental illness.

Too much fat in all the wrong places

Most people develop type 2 diabetes because they cannot safely contain the excess energy from their diet and a toxic waist starts to accumulate.

Most of the excess energy from your diet is stored as fat. The equation is simple: if you eat it and you’ll don’t burn it in your metabolism or physical activities, then you store it. Energy is too precious a thing for the body to waste.

Your fat normally turns over about 10 per cent of its energy stores every day. This means it always has plenty in reserve in case of extra requirements, such as if you miss a meal or need to be more active than usual.

The body initially stores its fat mostly under the skin, in the thighs, buttocks and breasts (known as peripheral fat). These depots are very efficient at impounding fat and keeping it safe until its energy is needed. This is partly because peripheral fat is sensitive to the signals that regulate metabolism, the most important of which is insulin, which promotes fat storage.

Peripheral fat is not unhealthy. If you remove all this fat from under your skin (e.g. by liposuction) you do not become any healthier or reduce your chances of developing type 2 diabetes. In fact, it is thought that having this kind of healthy fat might prevent the dangerous spill-over of fat into other tissues. Transplanting peripheral fat into people who have an abnormal deficiency of fat tissue (known as lipodystrophy) can actually improve their health.

However, the problem comes when these peripheral fat stores are filled up or stop listening to insulin. If they can no longer act as an efficient energy reservoir, what do you do with all the extra energy now? You can’t afford to waste it. So you need to build additional storage capacity outside of where fat is normally stored. This is known as ectopic fat. Most of these new ‘dump sites’ are around the internal organs (also known as visceral fat) or inside them (known as steatosis).

The easiest way to determine whether you have any of this ectopic fat is to place a tape measure around your waist, two finger breadths above the top of your hip bone.

In people of a European, white, Caucasian background, a healthy waist circumference is considered to be

In people of an Asian, Indian or Middle Eastern background, a healthy waist circumference is considered to be

Few people with a waist circumference persistently in the healthy reference range will develop type 2 diabetes. But as your waistline increases beyond these levels, the chances that you might develop type 2 diabetes will significantly increase. Today, over half of all adults exceed these measurements. Some by quite a bit. This is the dominant reason type 2 diabetes is increasing exponentially around the world.

Today, at least three out of four people with type 2 diabetes have abdominal obesity, defined by a waist circumference that is:

Diabetes is not inevitable if you have a waist of this size, but it does become more likely. For example, when compared to people with a healthy waist circumference, developing diabetes in the next 5 years is four times more likely if you have abdominal obesity.

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Most people develop type 2 diabetes because they cannot safely store the excess energy from their diet and a ‘toxic waist’ starts to accumulate.

This girth implies that there is probably a large amount of ectopic fat in the body and it is definitely worth doing something about it. In fact, if you specifically measure the amount of (ectopic) fat in the liver (known as fatty liver or hepatic steatosis) you find the same sort of numbers — that is, at least three out of four people with type 2 diabetes also have too much fat in their liver.

The problem with ectopic fat is that it is not very good at its job. It is really a makeshift solution to the ‘problem of fat storage’ when all other options are exhausted. And in not doing its job very well, a number of things can go wrong.

In particular, unlike healthy fat, ectopic fat is far less efficient at safekeeping its fat stores. It tries really hard to compensate and is much more metabolically active than peripheral fat, but it is just not very good at it. So instead of being efficiently stored, free fat leaches out into the tissues and the blood, particularly after a meal, when fat levels should normally be going down.

These free floating fats and their by-products are directly toxic in many parts of the body, including the beta-cells of the pancreas. Free fat is only supposed to be a drip feed, released into the blood in carefully regulated amounts when you are not eating, in order to spare the glucose for the brain. But if your fat is not safely stored, and levels are high in the blood, it is a free meal for cells, which get fatter themselves as a result. So cells like the beta-cells of the pancreas accumulate ectopic fat in great globules that ultimately distort the way they function. Cells that are eating fat also don’t need glucose for fuel, so glucose utilization falls.

This excessive flux of free fat through a cell’s metabolism also causes problems, as toxic by-products are generated through inefficiency. The best known of these by-products are free radicals (also known as reactive oxygen species), which react with and damage anything they come into contact with.

Cells that are stuffed full of fat also don’t respond well to insulin. This is particularly the case when ectopic fat accumulates in the cells of the liver. As detailed above, insulin resistance in the liver forces the pancreas to have to make much more insulin to bring glucose production by the liver back under control. And this means more work for the beta-cells of the pancreas, which are already feeling the strain.

Finally, fat is not a lifeless lump of lard. In fact, it is a dynamic regulator of health and wellbeing. All fat, but especially ectopic fat, is able to produce a range of chemicals (known as adipokines) that railroad healthy functioning. In fact, fat tissue is the largest producer of hormones in the human body. People with type 2 diabetes often have high levels of adipokines in their blood, chiefly because they also have high levels of ectopic fat.

You also need to be susceptible

There are a great many people who are overweight, some of them extremely so. But only some develop type 2 diabetes. This is because you also often need a third factor to be present for type 2 diabetes to occur.

To develop type 2 diabetes, you also need to be susceptible either to developing ectopic fat or your beta-cells must be susceptible to exhaustion.

Some people are better than others at safely setting aside any excess energy from their diet as healthy peripheral fat. This might be because they have a bigger storage capacity or are more able to expand it when needed, rather than dumping fat inappropriately around their organs. What determines when the peripheral fat store reaches its capacity (in essence its size and expandability) may be different in different people depending on their age, gender, race, genes and a host of other factors.

For example, people of Indian or Asian descent are generally more prone to lay down fat around their internal organs if they eat too much or are inactive. This is because Asian people have an inherently smaller storage capacity in their peripheral fat. This is one reason why type 2 diabetes seems to occur in much thinner people from Asia than it does in the West. However, if you look on the inside those with diabetes are just as likely to have excess fat whether they are of Indian, Asian or European heritage.

Diabetes also doesn’t affect everyone who has resistance to the effects of insulin or affect everyone who is eating a bad diet. This appears to be because some people remain quite capable of making enough insulin to control their glucose levels even though they may need to make very large amounts of insulin in the face of stiff insulin resistance or dietary excesses. By contrast, other people simply can’t sustain this extra workload for long and eventually there is not enough insulin (function) to keep glucose levels under control, and type 2 diabetes develops.

There are a number of different factors that make your pancreas susceptible to the effects of too much work or too much fat.

In the family

Type 2 diabetes tends to run in families. One in every three people with type 2 diabetes also has a close family member with type 2 diabetes. If either of your parents, your brother or your sister has type 2 diabetes, you are five to six times more likely to develop type 2 diabetes yourself. If three family members have type 2 diabetes, you are over fifteen times more likely to develop type 2 diabetes yourself than someone without a family history. The reason that type 2 diabetes runs in families is partly due to similar diet, lifestyle habits and exposure to environmental factors. It may also be partly determined by your genes.

Genes are the basic instructions encoded in your DNA that are used to determine how your body works. These gene instructions are passed down from parents to their children, who all share similar genes. In some cases, the genes you inherit may increase your risk of type 2 diabetes. Most of these genes appear to influence how well beta-cells handle the stress of having to make more insulin. But while genes are important in some families, overall they explain only a small fraction of why most people develop type 2 diabetes.

During early development

Susceptibility to type 2 diabetes may also be acquired during your life, particularly during your early development in your mother’s womb. For example, babies very small for their age have an increased risk of developing type 2 diabetes when they grow up. This is probably because the same thing that restricts the growth of a baby also restricts the development of the pancreas and ultimately its capacity to take the strain of controlling glucose levels during adulthood. A mother’s high glucose levels during pregnancy can also increase the risk of type 2 diabetes in her children, partly because their beta-cells become more susceptible to damage.

Increased susceptibility with ageing

Some people develop type 2 diabetes only when they are very old, without having been very overweight or inactive during their life. This is probably because the regenerative capacity of the pancreas is not limitless, and the ability to make insulin slowly declines with time in everyone. But ageing just brings you closer to the edge — usually something else is also required to push you over. Whether ‘getting old’ will result in type 2 diabetes is determined by how great the demands are for insulin production and how great this capacity has already been reduced by other factors. Of those people who develop type 2 diabetes in their eighties, it is often suggested that it was probably always going to happen no matter what, given enough time. But if these same people had been overweight and inactive during their lives, it would probably have happened much earlier.

TYPE 2 DIABETES: THREE STRIKES AND YOU’RE OUT

Type 2 diabetes will affect at least one in every three people at some point during their lifetime. But it will not affect everyone.

There are many people who are overweight who don’t get diabetes. There are many who have a poor diet or the wrong genes, and they don’t get diabetes either. To get type 2 diabetes you need all three things to happen.

Type 2 diabetes is made more likely if any one of these factors is increased. For example, an unhealthy diet will increase the work of the pancreas and increase the risk of diabetes. Similarly, being overweight can increase your risk of diabetes even without a strong family history. Equally, some people have a strong family history of diabetes so it doesn’t take much extra work or being very overweight for diabetes to occur. Of course, if more than one of these factors is increased, your risk will multiply and diabetes will become both more likely and more likely to occur at an earlier age.

At the same time, the best ways to prevent and treat diabetes will target these important areas. For example, changes in the amount and types of sugar and fibre in your diet can reduce the strain on your pancreas to produce large amounts of insulin (see Chapter 3). Getting rid of any extra fat in your body through diet (Chapter 4) and increased physical activity (Chapter 5) will reduce its limiting effects on your metabolism and reduce insulin resistance. Some medicines will also help to protect the beta-cells and make them more able to compensate for the demands of glucose control.

In its early stages, diabetes is reversible. For example, gastric bypass surgery dramatically reduces food intake and causes a great decline in the amount of ectopic fat in your body (see Chapter 4). This is able to ‘cure’ type 2 diabetes such that many people having this procedure can keep control of their glucose levels without the need for any medications. It requires complicated, invasive major surgery that is not an answer for the over 430 million people worldwide with type 2 diabetes. But it does illustrate that once you understand some of the factors involved in the development of diabetes (like ectopic fat), and target them early enough, anything is possible.

3

A SPOON LESS OF SUGAR

Understand