A FEW YEARS AGO I visited Sri Lanka as the guest of the professor of medicine at Colombo University to witness their final examinations. His great interest was the prevalence of diabetes type 2 and heart disease in his patients. After the exams, we attended several funerals so that I could see how comparatively young many of the victims were.

When I wrote about this concept, there were angry protests. Times change. This year my wife and I were guests at a dinner given at the House of Lords by people of South Asian origin to publicise this racial characteristic, and its effect on mortality and morbidity. People from South Asia are 50 per cent more likely to die from coronary heart disease than the rest of the population and a third will develop diabetes type 2 between the ages of 40 and 65. Though Asian people in the UK comprise only 1 per cent of the population, they represent 12.9 of all kidney patients waiting for transplants.

Patients of African, as opposed to Indian sub-continent origins, are known to react differently to several drugs already used in the treatment of high blood pressure, so it is not surprising that the Association of Black Cardiologists welcomed a trial of a drug likely to be of special benefit to this group of patients. Interestingly, although high blood pressure is so common among those of African origin, once it is controlled they have less chance than European patients of developing kidney disease. Several forms of heart disease are more common in people of African origin, in particular one form of cardiomyopathy (enlarged heart). There are similar examples of a difference in the incidence of specific conditions according to origins, including thalassaemia from other branches of medicine.

This is not always dependent on colour. A simple example is that women whose origins are from the Highlands and Islands tend to have a later menopause. There are similarly proven differences of the metabolism of alcohol according to race and related not only to skin colour; some people of Jewish origin also have difficulty metabolising alcohol.