By Zubeida Mustafa
There was a time when diabetes mellitus was regarded as the rich man’s disease. Not so any more. In fact, the data collected by epidemiologists indicate that today there is a higher incidence of this disorder in the developing countries.
Dr Peter Bennett, who is the head of the Epidemiology and Clinical Research Branch of the National Institute of Diabetes, Digestive and Kidney Diseases of the National Institute of Health, USA, has been investigating the prevalence of diabetes among the Pima Indians in America. His studies have extended.to other societies as well. “Surveys conducted over the last 15 to 20 years give very clear evidence that diabetes has been on the rise in the Third World,” Dr Bennett told me recently. He was in Karachi to attend the Regional Congress of the International Diabetes Federation.
Another significant finding to emerge from recent research is that this disease is more common in some races than in others. In America, Dr Bennett observed, 50 per cent of the Pima Indians above 35 years of age suffer from diabetes. But only four per cent of Americans of European origin have this disorder. Its incidence is higher among the American blacks.
Dr Bennett has found that the incidence of diabetes in a community increases when it is in.the process of development and slows down as higher levels of progress have been attained. Thus, the people of the same race who might be showing a low level of incidence of diabetes in underdeveloped societies become susceptible to the disease when they migrate to the more developed countries.
Dr Bennett said that in India about two to three per cent of the people have diabetes. But 10-15 per cent of the Indians who have moved to the US are diabetic. Interestingly, the more affluent people living in the suburbs of New Delhi also have a higher incidence of the disease (12-14 per cent).
From all this epidemiological data, the conclusion that can be clearly drawn is that the two factors that determine the incidence of diabetes are lifestyle and the genetic susceptibility of a people to the disease. This also leads the medical profession to believe that diabetes is preventible.
Dr Bennett spoke emphatically of “the advances in our ability to control diabetes, especially the complications that can set in”. He identified lifestyle as the most important element in the prevention of diabetes. “Even if one is genetically susceptible to diabetes, a healthy lifestyle can still ward off the disease. I believe that diet which cuts down caloric intake and exercise which increases activity level and makes a person lose weight invariably reduce the sugar level. They also slow down the development of long-term complications affecting the eyes, kidneys and heart,” Dr Bennett said.
Diabetes is on the increase in developing countries because of the changes that people are experiencing in their lifestyle. When societies are in a state of underdevelopment, their members tend to be more active and their caloric intake does not exceed their need. When they become highly developed these societies show a greater degree of health awareness. Their diet is more varied and balanced and their fibre intake in the form of fruits and vegetables is higher. Their lifestyle might be sedentary and unhealthy but leisure activities such as exercising in health clubs and sports help people lose weight.
“It is in the intermediate stage that the greatest problems are encountered,” Dr Bennett said. “People cease being as active as before and they also eat more, tending to become obese,” he observed.
As far as the genetic factor is concerned, Dr Bennett felt that the medical profession was not at the stage where it could offer much guidance for genetic counselling. “We are trying to identify specific genetic markers but at present we cannot determine for sure the individual who has the susceptibility. ‘We can only offer broad observations. Thus we know that if both parents have the disease the likelihood of their child also having it is as high as 70 per cent. In such a caase, it makes good sense to make the child himself aware of his vulnerability, so that he takes precautions against diabetes.”
“In the absence of any cure for diabetes, the focus will have to be on prevention. The twin factors which help diabetics (as also healthy people) are diet and exercise,” Dr Bennett said. Next year we should learn more about this when WHO releases the report of its study group on diabetes.
Source: Dawn 30-12-1992