Complications > Cardiovascular disease

To say that the diabetes world has been rocked by recent revelations about cancer might be too strong a term; but it certainly has been shaken. A growing bank of data over the last few years has put cancer very much 'on the radar’ of diabetes clinicians and researchers alike. Andrew Renehan tells the stories behind the headlines.

Rates of diabetes continue to increase rapidly around the world. The current prevalence of about 5.1% is set to rise to 6.3% by 2025 – 333 million people with the condition. Further huge numbers of people are unaware that they have undiscovered diabetes and pre-diabetes conditions. The number of people with impaired glucose tolerance will increase from 314 million to 472 million over the next 15 years or so. These people are at dangerously high risk both for future diabetes complications and early death through cardiovascular disease.

Recently, two clinical trials addressed the role of tight blood glucose control on cardiovascular risk in people with type 2 diabetes: the Action to Control Cardiovascular Risk in Diabetes (ACCORD) study and the Action in Diabetes and Vascular Disease (ADVANCE) trial. The ACCORD study included 10,251 people with type 2 diabetes and was designed to determine whether intensive blood glucose control (HbA1c below 6%) as compared to a conventional approach (HbA1c between 7% and 7.9%) would result in favourable cardiovascular outcomes in people with type 2 diabetes at high vascular risk.

The metabolic syndrome is becoming a global public health issue. Those affected have higher risk of suffering a heart attack or stroke – as well as of dying from such an event – compared with people without the syndrome. This cluster of factors is closely linked with the worldwide increases in type 2 diabetes, cardiovascular disease and other chronic diseases. The resulting premature deaths and disabilities are set to cripple health budgets in both developed and developing countries. Criteria for diagnosis of the metabolic syndrome entail a combination of cardio-metabolic risk factors.

After World War II, chronic diseases, cardiovascular diseases in particular, became a major public health problem in industrialized countries. These diseases were perceived as diseases of affluence. Finland was hit hard: in the 1960s, Finland had the world’s highest rate of deaths from coronary heart disease. Middle-aged men were dying in great numbers. The rates were even higher in the east of the country – the highest figures being in the Province of North Karelia.

Discussing the sensitive issue of long-term complications is difficult for people with diabetes and the healthcare providers who work with them. Consequently, this area of diabetes management is often not handled well. In some situations, healthcare providers are reluctant to impose 'unpleasant' information on people who might be struggling to cope with diabetes; in others, the potential risk of developing complications might be used as a threat in an attempt to scare people into following medical advice.

People with type 2 diabetes suffer badly from heart disease, strokes, and damage to the blood supply to their feet. Indeed, these cardiovascular conditions are the major causes of ill-health and death in people with the condition. A significant proportion of that ill-health is preventable, including by attention to the levels of fats and sugar in the blood, the clotting tendency of the blood, and blood pressure. Raised blood pressure is also responsible for worsening of eye damage and kidney damage in people with type 2 diabetes, and is therefore particularly well worth treating.

In the late 20th century obesity became an epidemic. The importance of obesity as a risk factor for a number of conditions, including type 2 diabetes, cardiovascular disease, hypertension, gallstones and certain cancers, is well documented. Often associated with insensitivity to insulin, obesity is clearly a key factor in the development of the metabolic syndrome – a risk for both diabetes and cardiovascular disease. In this article, Robert Eckel and Scott Grundy explore the underlying causes of obesity and insensitivity to insulin.

As the number of children with obesity continues to grow, the health implications of the condition are becoming increasingly evident: an unprecedented epidemic of type 2 diabetes is emerging in obese and overweight young people. At the time of diagnosis of diabetes, cardiovascular disease may already be present, even in young adults. The close association between type 2 diabetes and cardiovascular disease led to the hypothesis that the two may arise from a common antecedent, the metabolic syndrome – a cluster of metabolic disorders.