RELATIONSHIP OF GLUCOSE-INTOLERANCE TO CORONARY RISK IN AFRO-CARIBBEAN COMPARED WITH EUROPEANS

Afro-Caribbeans have low mortality rates from coronary heart disease, despite a high prevalence of diabetes mellitus. We examined 1166 Afro-Caribbean and European men and women aged 40-64 years in a community survey in London, UK. Prevalence of glucose intolerance (combining impaired glucose tolerance, new and known diabetes) was 31% in Afro-Caribbeans and 14% in Europeans (p<0.001). In men, the prevalence of probable coronary heart disease was 6% in Afro-Caribbeans and 13 % in Europeans (p < 0.01). Triglyceride was lower in Afro-Caribbeans than Europeans; in men, HDL cholesterol was higher. Afro-Caribbean men were less centrally obese, while Afro-Caribbean women were more centrally obese than their European counterparts. Fasting and 2-h insulin levels were higher in Afro-Caribbeans than Europeans. Glucose intolerance was associated with high triglyceride, low HDL cholesterol and central obesity in European but not in Afro-Caribbean men. In Europeans, fasting triglyceride was 1.49 mmol/l in normoglycaemic and 1.89 mmol/l in glucose intolerant men (p < 0.05), in Afro-Caribbean men triglyceride was 1.08 and 1.22 mmol/l, respectively. Waist hip ratio was 0.94 in normoglycaemic, and 0.98 in glucose intolerant European men (p < 0.001). In Afro-Caribbean men, waist hip ratio was 0.93 in both groups. At each level of insulin, glucose or central obesity, triglyceride was lower in Afro-Caribbean men and women than in Europeans. We speculate that despite high insulin levels, Afro-Caribbeans have a favourable lipoprotein pattern which persists in the presence of glucose intolerance, and may be related to body fat distribution. This could begin to explain their low rates of coronary heart disease.