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In memory of my mother, Mollie Anne McDonald Souter,
who lived well with her Type 2 diabetes for many years

I would like to thank Isabel Atherton, my wonderful agent at Creative Authors for helping to bring another book in this series to fruition. Thanks also to Claire Plimmer at Summersdale who commissioned this and the previous titles, and to Anna Martin who has skilfully guided it through the various stages towards publication. Thanks to Ellie Clarke for doing the initial edit to knock the rough edges off the manuscript and to Lyn Coutts my copy-editor for smoothing it still further. I am grateful for the many helpful suggestions that have been made at every stage, which have helped to make it a more readable and accessible book.

If you have recently been diagnosed with Type 2 diabetes, you may be thinking that you have been given bad news. You may think life as you have enjoyed it is at an end and that you are faced with a future of deterioration. This does not have to be the case at all. Type 2 diabetes is a condition to take seriously, but the diagnosis gives you the opportunity to get it under control and to reduce your risk of developing complications. Indeed, control it well and you will probably feel better than you have done for some time.

You may not, in fact, have been diagnosed with the condition, but been told that you have pre-diabetes. This means that you are at risk of developing it, but as yet you have not done so. The very good news is that you can reverse that risk and prevent yourself from developing Type 2 diabetes.

Diabetes is a condition that is increasing in incidence every year around the globe. It is linked with rising obesity levels, greater inactivity and the consumption of a diet that frankly predisposes people to develop diabetes.

As we shall see in Chapter 1 (An overview of diabetes) diabetes mellitus is a lifelong disorder of carbohydrate metabolism that occurs when the pancreas does not produce enough insulin, or when the body does not respond to its own insulin. While I am going to consider the different types, the overall emphasis of the book is on understanding and dealing with Type 2 diabetes.

The book falls naturally into two parts. Part 1 is about understanding Type 2 diabetes, beginning with some background information about the way the body’s metabolism works and how the body handles glucose. Then we shall look at how things can go wrong and what sort of complications can occur. This is important, because Type 2 diabetes can affect many of the body’s systems, particularly the circulation and heart, the eyes, the kidneys and the nervous system. You need to know about all of these in order to reduce your risk of developing such complications.

Part 2 will look at how diabetes is diagnosed and how you and your doctor can keep it under control. We will look at the tests and investigations you should have, and we will look at the way that diet, exercise and possibly drugs can maximise your health.

The diagnosis is not bad news; it is a warning that things are not working as they should, and by altering lifestyle and developing a positive attitude towards the condition and your future, you can live well with your Type 2 diabetes.

Type 2 diabetes does not always produce the common symptoms, such as increased thirst. This is very important, because many people with Type 2 diabetes have no symptoms at all, or are not particularly bothered by them for years. They may not know that they have diabetes until they have a blood-glucose test done on routine examination at their doctor’s surgery. Because of this tendency for the condition to smoulder on unrecognised, if you believe that you are at risk of developing it, you should have a blood test.

Diabetes mellitus is a lifelong disorder of carbohydrate metabolism that occurs when the pancreas does not produce enough insulin or when the tissues do not respond to the body’s own insulin.

The characteristic feature of diabetes in an undiagnosed or untreated form is excess thirst and increased tendency to pass urine. This is the result of raised blood-glucose levels. Over time this can lead to serious damage to various body systems.

There are two main types of diabetes, which make up the vast majority of cases. They share the name diabetes mellitus, but each type has its own features, causes and indicated treatments.

Both types affect the blood-glucose levels and both produce complications unless they are adequately treated. These complications can significantly impair health and even lead to early death.

This is characterised by lack of insulin production. It used to be called juvenile onset diabetes or insulin dependent diabetes. This was because it tended to occur in children and young adults. It requires treatment with insulin.

It is an autoimmune condition in which the immune system attacks the insulin-producing cells in the pancreas. There is therefore a deficiency of insulin and the individual will have to take insulin injections for the rest of his or her life. It is not possible at this stage in time to prevent Type 1 diabetes from developing. Type 1 diabetes accounts for about ten per cent of all diabetes cases worldwide.

It used to be called maturity onset diabetes, or insulin independent diabetes. This was because it tended to occur in adults who are overweight. The treatment usually involves dietary control and possibly oral hypoglycaemic drugs to lower the blood-glucose.

It is perfectly possible to prevent Type 2 diabetes. Type 2 diabetes accounts for about 90 per cent of all diabetes cases worldwide.

This is diabetes that starts during pregnancy and goes away at the end of the pregnancy. It is usually discovered in the middle trimester of pregnancy.

The main reason why the older names are no longer used is simply because we are seeing increasing incidence of the following diabetes variants around the world. We see Type 1 developing in adults and we see Type 2 developing in children. In some countries, Type 2 accounts for almost half of newly diagnosed diabetes in children and adults.

OTHER LESS COMMON TYPES OF DIABETES

There are other less common types of diabetes. Cumulatively, they account for a mere two per cent of diabetes cases.

MODY (maturity-onset diabetes of youth) – this is caused as a result of mutations affecting beta cells of the islets of Langerhans, which are the insulin-producing cells in the pancreas. (See Chapter 3: So what happens in diabetes?) • Neonatal hypoglycaemia – a type of diabetes that occurs before the age of six months and is usually due to a genetic mutation. • Diabetes as part of other endocrine (hormonal) diseases, for example: Cushing’s syndrome, acromegaly and thyrotoxicosis.
Pancreatic disease – for example: cystic fibrosis (a disorder in which the lungs and digestive system get clogged with sticky mucus) and haemochromatosis (a disorder in which the body stores excess iron).
Iatrogenic diabetes – meaning ‘doctor-induced’ from long-term steroid drug use or HIV drug treatment, for example.

There are several possible complications from diabetes that may be divided into groups.

1. Macro-vascular – disease of large blood vessels, for example: coronary arteries (angina and heart attacks), peripheral arteries (intermittent claudication) and cerebral arteries (strokes).

2. Micro-vascular – disease of small blood vessels, for example: diabetic retinopathy (blood vessels in the retinae of the eyes), nephropathy (blood vessels in the kidneys) and neuropathy (blood vessels to the small tissues and the nerves).

Women who are already diabetic before they conceive a child are five times more likely to have babies with congenital heart disease than women without diabetes.

Babies born to women who develop gestational diabetes do not have the same risk because the condition tends to occur in the middle trimester after the baby’s heart and organs have developed.

Diabetes is a serious condition that can lead to early death if it is not carefully managed.

KEY POINT

Cardiovascular disease, including heart attacks and strokes accounts for 50–80 per cent of deaths in people with diabetes.

This is a very important condition. It is when the blood-glucose level is higher than normal, but not high enough to be diagnosed as diabetes. It is a state that increases the risk of diabetes.

It is estimated that there are around seven million people in the UK with pre-diabetes. The good news is that with alteration of lifestyle consisting of a healthy diet, regular physical activity, maintaining a normal body weight and avoiding tobacco use Type 2 diabetes can be avoided.

The likelihood of developing Type 2 diabetes is also influenced by genetics and environmental factors. Research¹ has shown that if:

A lot of attention has been paid to changes in lifestyle, as many countries have adopted Western diets, with drastic increase in diabetes and increased incidence of heart disease and stroke. This has been particularly apparent in certain ethnic groups, such as some Native Americans and indigenous Australians.

The risk of diabetes is increased for some ethnic groups and reduced for others. Type 2 diabetes is six times more prevalent in people of South Asian ancestry² and three times more likely to occur in people of African and Afro-Caribbean ancestry.

There seems to be a clear link between obesity and diabetes. It has been observed that as the incidence of obesity rises, so too does the incidence of diabetes.

In Japan, the incidence of diabetes is relatively low. However, among Japanese people who emigrated to the USA and adopted a Western lifestyle and diet, the incidence of both obesity and diabetes rose. Interestingly, in sumo wrestlers in Japan, who have to maintain body bulk in order to compete in this traditional sport, diabetes rates are significantly above normal.

KEY POINTS

Risk factors for Type 2 diabetes include:

large waist (over 94 centimetres for men and 80 centimetres for women) or being overweight.
being of African, Afro–Caribbean or South Asian origin.
a family history of the condition.
being over 40 years old, or over 25 if of African, Afro-Caribbean or South Asian origin, or from an ethnic minority group.

Diabetes mellitus is an important condition for both the individual and for society. It is important to the individual because it can affect his or her overall health. It predisposes people to other conditions and has many potential complications. If it is poorly controlled it can lead to early death.

The number of people suffering from diabetes is increasing every year. This seems to be the result of social changes in dietary habits with overconsumption of energy-rich foods, rising levels of obesity and more sedentary lifestyles.

Diabetes throws a significant load on the heath resources of all countries and, since so many people who are diagnosed with it are of working age, it can have a huge impact on a country’s economy.

Most deaths are likely to take place in countries with limited resources where there are not facilities for renal dialysis or complex surgery. Indeed, insulin is not available in many of the poorest countries. This accounts for the high mortality rates in those countries.

About 80 per cent of all people with diabetes live in the poorest countries. By comparison, around 80 per cent of the money spent on diabetes care occurs in the richest countries.

KEY POINTS

Globally, there are about 347 million people with diabetes – this is a prevalence of just under five per cent of the world’s population.³
The International Diabetes Federation state that the countries with the greatest numbers of diabetics are respectively China, India, USA, Russia and Brazil.
The International Diabetes Federation states that the countries with the highest prevalence rates are Saudi Arabia, Nauru and Mauritius.
More than 80 per cent of diabetic deaths occur in low- and middle-income countries.⁴
The World Health Organization (WHO) predicts that diabetes deaths will double between 2005 and 2030.
WHO predicts that diabetes will become the seventh leading cause of death in the world by 2030.

Note: Prevalence means the number of people with a specific condition at a specified time divided by the total population.

The UK has a population of 63 million, the third largest in the European Union.⁵ According to the charity Diabetes UK, there are around 850,000 people in the UK who have undiagnosed diabetes.

KEY POINTS

Currently there are over 3.1 million people aged 16 or over with diabetes in the UK.
By 2030 it is predicted that there will be over 4.6 million people aged 16 or over with diabetes in the UK.
Six per cent of adults have diabetes.
85–90 per cent of all diabetics have Type 2 diabetes.
Ten per cent of all diabetics have Type 1 diabetes.
Two to five in every 100 women giving birth in England and Wales develops gestational diabetes.

Diabetes UK estimates that around ten per cent of the NHS annual budget is used to fund treatment of diabetes, equating to about £9 billion per year.

Having diabetes should not stop you from enjoying life and being successful in your chosen field.

Medical writers have been aware of this condition for at least 4,000 years. Its nature and its cause, however, remained a mystery for centuries.

The fact that writers in different cultures observed and advised about this condition makes it clear that diabetes has affected people around the world throughout history. As we will see in this chapter, it is not a condition restricted to the modern world. Having said that, contemporary lifestyles may be making diabetes more common than it was in the past.

In 1862, Edwin Smith, a young amateur Egyptologist and adventurer, purchased two papyri in Luxor. It is unclear from whom he bought them, but it is said that they had been found between the legs of a mummy in the El-Asasif area of the Theban necropolis on the other side of the Nile from Luxor.

Both these papyri dated to about 1,534 BCE, but were thought to be copies of far older texts. One became known as the Edwin Smith papyrus and is the oldest known surgical text in the world. The other was eventually purchased by German Egyptologist Georg Ebers in 1872. This papyrus is a medical text outlining the state of Egyptian knowledge about medicine and the treatment of over 700 afflictions.

The Ebers papyrus is thought to have been written by a physician called Hesy-Ra, who mentions several types of urinary problem, some of which almost certainly refer to urinary infections like cystitis, where the main symptom is frequent micturition, or passage of urine. He makes a distinction between the frequent passage of urine with pain (which would have been from urinary infections) and the frequent passage of a lot of urine without pain, which we call polyuria. The latter is almost certainly a description of diabetes. The treatment advised by Hesy-Ra included a liquid extract of bones together with grain, grit, wheat, green lead and earth. Unfortunately, it is unlikely that the treatment would have had any beneficial effect.

The Indian surgeon and physician Sushruta (600–501 BCE) wrote a textbook called Sushruta-samhita, which means Sushruta’s compendium. In it he details 650 drugs used by doctors of his time. In addition, he detailed many operations using 42 surgical techniques and over 120 surgical instruments. He gave instructions on how to surgically repair the nose (cutting off the nose being the penalty for adultery and other transgressions) and also how to do a lithotomy, the operation to remove urinary stones. He is recognised as the father of plastic surgery.

He describes the symptoms of diabetes, which he called madhumeh, to describe the sweetness and stickiness of the patient’s urine. Madu is used in several Indo-Aryan languages to mean honey or sweet.

Another Indian physician called Charaka, who is thought to have flourished sometime between the second century BCE and the second century CE, refined Sushruta’s observations. He wrote the Charakasamhita, meaning Charaka’s compendium, and in it differentiates between two types of diabetics. One group, who were thin and young and another group who were older and fatter. He also noted that the older group lived longer. This was the first attempt to divide diabetics into two groups, basically Type 1 and Type 2.

Remarkably, Charaka suggested a test: if the urine of such a patient was poured near an anthill it would attract ants!

Aretaeus of Cappadocia first used the word ‘diabetes’ in the second century CE to indicate this condition. The word was derived from dia meaning ‘through’ and betes meaning ‘passing’, likening the passing through of urine to a siphon action. He also described the characteristic of the disease, which causes ‘a melting down of the flesh and limbs into the urine.’ He thought that it was a disorder of kidney function.

Claudius Galenus of Pergamum (circa 130–200 CE) was a famous second-century Greek physician practising in the Roman Empire. He described the excessive passage of urine, which he called diarrhoea urinosa, and the extreme thirst as dipsakos.

The sweetness of the urine of diabetics was noted by the Chinese physician Chen Chuan in the seventh century CE. At about the same time the Japanese physician Li Hsuan noted that the sweet urine of these patients would attract dogs. He also noted that diabetic patients were more likely to develop infections, including boils and sores and a respiratory disorder that was like tuberculosis.

Both Chen Chuan and Li Hsuan recommended that it should be treated by abstinence from sex and from wine and the avoidance of salty food, which would make the thirst worse. This is perfectly logical, of course, but focusing on the avoidance of sugar and sweets would have been more effective.

In the tenth century CE, the great Persian polymath known as Avicenna (980–1037 CE) pushed the frontiers of medicine on several fronts.

An astute clinician, he wrote that diabetes was associated with two specific complications. Firstly, there was a ‘fall down’ of sexual function. Secondly, people with this condition were prone to develop gangrene of their extremities. As we shall see later in this book, these are definite complications.

He also improved the method of giving medication by coating his pills in silver or gold leaf. In an age of alchemy, precious metals were thought to enhance the effectiveness of medicines. This also reduced the bitter taste of many medicines.

For diabetes, he advocated a mixture of herbs including lupin, fenugreek and zedoary (white turmeric) seeds. These do, in fact, have mild hypoglycaemic effects (they lower blood-sugar) so they would have had some positive consequence.

The Renaissance – discoveries about the cause and the first effective treatment

This period of time saw an explosion in science, philosophy, art and literature.

Doctors like William Harvey (1578–1657) studied anatomy and started to give an explanation for the way that the body worked. He was a physician and anatomist who fought in the English Civil War and who was court physician to three kings of England. After graduating from Cambridge University, he went to study medicine and anatomy at the University of Padua in Italy. In 1616 he announced his discovery of the circulation of the blood, and in 1628 he published his work Exercitatio Anatomica de Motu Cordis et Sanguinis in Animalibus (An Anatomical Exercise on the Motion of the Heart and Blood in Animals). It was the most significant piece of medical research ever written and laid the foundation for the scientific study of medicine.

Dr Thomas Willis (1621–1675) was another anatomist who, like Harvey, was deeply interested in the body’s blood supply. He published several books in the 1660s, the most significant being a work about the brain. In it he described the circle of blood vessels at the base of the brain, which were formed from major arteries travelling up the front of the neck to join with ones from the back of the neck to produce an arterial circle which gave off branches to supply blood to the various areas of the brain. This is called the Circle of Willis.

Dr Willis was also intrigued by diabetes. He referred to it as ‘the pissing evil’, but went on to state that diabetic urine was ‘wonderfully sweet as if it were imbued with honey or sugar’ since tasting patients’ urine was an art that most physicians practiced in his day. He added the Latin word mellitus, meaning ‘honey-sweet’. Hence, the name diabetes mellitus literally means the honey-sweet syphon, which effectively describes the symptoms of excessive urination of sweet urine.

Dr Thomas Sydenham (1624–1689) wrote a textbook Observationes Medicae, the major text for two centuries, in which he proposed that diabetes was not merely a disorder of the urinary system (as had been thought until then) but was in actuality a systemic disorder. This means that it affects many of the body’s systems.

In 1776 Liverpool physician Dr Matthew Dobson performed a series of experiments and discovered that there was a sweet-tasting substance in both the urine and the blood serum of patients with diabetes. When he evaporated the urine and the blood serum he was able to identify that the sweetness was due to the presence of sugar.