Diabetes - a hidden danger

Everyone has heard of it and almost everyone knows someone who has it, yet diabetes is still a hidden disease. It is estimated that half of those with diabetes remain as yet undiagnosed. And current predictions are that the number suffering from one form of diabetes will double by 2010.

The best known form (type I diabetes), which is insulin-dependent, occurs when little or no insulin is produced by the pancreas. It is usually diagnosed in childhood or adolescence. Treatment involves insulin injections, regular monitoring of blood glucose levels and a healthy diet.

But the huge increase is in the lesser known form (type II diabetes), which is not insulin dependent. This type of diabetes occurs when the pancreas doesn't produce enough insulin or can't properly use the insulin that is produced. Type II diabetes is a chronic progressive disease, accounting for an estimated 90 per cent of all those with diabetes. More than 100,000 Irish people have been diagnosed with diabetes and it's estimated there are a further 100,000 undiagnosed cases.

Dr Tony O'Sullivan is a GP who has type I diabetes. As honorary secretary of the Diabetes Federation of Ireland and chairman of the Irish College of General Practitioners (ICGP) task group on diabetes, he brings his personal experience of diabetes and his professional expertise to his work. He says diabetes-related problems are the fourth biggest killer in Ireland, and diabetes is the most important health problem not to have received strategic attention from the Department of Health.

About 10 per cent of the health budget is estimated to be taken up with diabetes-related problems.

It's a complex scenario. First, many sufferers of type II diabetes are discovered only when they turn up at coronary care units with angina or following heart attacks. "Up to 50 per cent of those who present at coronary care units have diabetes or impaired glucose tolerance, which is a pre-diabetes state," says Prof Gerald Tomkin, endocrinologist and chairman of the Diabetes Federation of Ireland. Other cases of diabetes are discovered when sufferers develop complications directly associated with the disease, such as kidney disease, foot ulcers or blurred vision.

If these people were diagnosed at an earlier stage - when they had impaired glucose tolerance - many complications could have been avoided.

The symptoms of both types of diabetes are an unquenchable thirst, frequent desire to pass urine, extreme tiredness, genital itching and blurred vision. Diabetes is diagnosed following a blood test to check glucose levels. So why aren't people with diabetes being picked up earlier? "Individuals with type II diabetes can have diabetes for five to seven years without presenting to their GPs with symptoms, so we can't rely on patients themselves to pick up cases of diabetes at an early stage," says Dr O'Sullivan.

He points to the need for all GPs to take high-risk factors for diabetes into consideration and give those patients who are at risk an annual blood glucose test for diabetes. The ICGP has made a proposal to the Department of Health that GPs should be given a financial incentive to test their patients for diabetes. "Doctors will pick up one case of diabetes for every 20 or so they test. The risk factors are high blood pressure, high cholesterol levels, over 50, overweight, a family history of diabetes and, for mothers, having had a baby over 9lbs weight," says Dr O'Sullivan.

Recent studies point to obesity as the most important risk factor in type II diabetes, and much has been written about the increase in this form of diabetes being directly linked to our increasingly sedentary lifestyles.

"The more fat cells in the body, the more insulin-resistant the body becomes. This is particularly so if the fat is in the abdomen. Diabetes is 15 times more likely to occur in those who put on more than 20lbs in middle age," says Prof Tomkin.

Researchers at the University of Pennsylvania School of Medicine recently discovered a new hormone, resistin, which is released by fat cells and interferes with the uptake of insulin. This hormone was found to promote insulin resistance.

Two recent studies reported in the New England Journal of Medicine reiterated the crucial link between diet and lifestyle in reducing the risk of diabetes. The Finnish Diabetes Prevention Study found that the risk of type II diabetes was reduced by 58 per cent in a group of overweight 55-year-olds who were given individualised counselling aimed at reducing their weight and their intake of saturated fats and increasing their physical activity and intake of fibre.

The good news is that type II diabetes sufferers are less likely to develop medical complications if they undertake crucial changes in their diet and levels of exercise, but the bad news is that many sufferers are not undertaking these changes.

A recent Irish survey on those suffering from type II diabetes found that two-thirds of sufferers are not taking any exercise to manage their diabetes. The same survey found that 46 per cent of female sufferers and 30 per cent of male sufferers are not following diet programmes. And one quarter of all sufferers are not monitoring their blood glucose levels.

Dr O'Sullivan believes that lifestyle factors can only be addressed as part of a public health education campaign.

"People haven't yet made the link between healthy living and good health," he says. "They don't realise that a healthy lifestyle will protect them against diabetes, cancer and heart disease."

Wednesday is World Diabetes Day. This year's theme is diabetes and cardiovascular disease. The National Federation of Diabetes will launch its new website, www.diabetes.ie, and a new helpline:1850 909909 on the day.