‘Diabesity’ is a 21st century epidemic that makes avoidance of weight gain a key consideration in strategies to manage diabetes. But the well-established relationship between diabetes, obesity and insulin therapy should not deter healthcare professionals from early therapeutic intervention in diabetic patients, nor those patients from complying with their insulin regimens, a new report stresses.

Written by four diabetes experts with sponsorship from Novo Nordisk, the Weight of the World report was launched at last week’s 43rd annual meeting of the European Association for the Study of Diabetes (EASD) in Amsterdam. It coincided with new clinical data confirming that Novo Nordisk’s long-acting insulin analogue, Levemir (insulin detemir), was consistently associated with less marked weight gain or even weight loss compared with other basal insulins.

The prevalence of diabetes has expanded beyond all expectations. In 1994 it was forecast that the number of diabetics worldwide would reach 239 million by 2010. Instead, there are already 246 million people living with diabetes and the global tally is now projected to rise from 171 million in 2000 to 380 million in 2025. Some 85-95% of these cases are type 2 diabetes, where overweight/obesity is the most prominent risk factor.

In western countries 90% of type 2 diabetes is associated with weight gain, the report notes. Globally, 58% of type 2 diabetes can be attributed to a body mass index (BMI) of more than 21kg/m2. The diabesity phenomenon is being driven by galloping obesity rates in both adults and children. In 2005, 400 million adults were defined as obese (BMI of over 30kg/ m2) worldwide, a figure that is expected to reach 700 million by 2025. About one in 10 children worldwide are already overweight or obese, with rates of double the global average in Europe and three times the average in North and South America.

What this adds up to in health and economic terms is a disaster in waiting. Already diabetes is associated with more than 300 million deaths per year around the world, doubling the risk of death compared with people of a similar age without diabetes. Obesity and diabetes in combination increase the risk of death seven-fold versus people with no medical conditions.

Moreover, the human cost comes with a punishing financial burden: the World Health Organization estimates that up to 15% of annual health budgets are spent on diabetes and co-morbidities. Worldwide, diabetes already costs health systems as much as €170 billion and by 2025 the bill is forecast to hit €220 billion.

Doctor's dilemma

It is against this alarming backdrop that the report examines what it calls “the doctor’s dilemma: the tussle between glycaemic control and weight gain”. Whereas insulin is traditionally linked to weight increases, as indeed are some oral antidiabetics, weight gain itself can undermine the patient’s ability to achieve blood glucose targets while aggravating the risk of associated conditions such as heart disease, discouraging adherence to diabetes medication and threatening psychological well-being. The relationship is further complicated by factors such as diabetes patients over-eating to ward off the fear of hypoglycaemia.

Although the report argues that weight control should be considered a fundamental aspect of diabetes management throughout the progression of the disease, it also contends that weight gain is no longer a given of insulin therapy. In particular, it says, neither healthcare professionals nor patients should regard the potential for weight gain as justification for initiating insulin therapy as a last resort.

As Dr Vivian Fonseca, one of the report authors and head of the endocrinology section at Tulane University Medical Centre in New Orleans, US, commented in Amsterdam: “I often see [diabetes] patients who should have started insulin three years ago”.