Risk Factors for Coronary Heart Disease in a Population with a High Prevalence of Obesity and Diabetes: A Case-Control Study of the Polynesian Population of Western Samoa 3

Abstract

Objective To evaluate anthropometric, haemodynamic and biochemical risk markers for coronary heart disease (CHD) in the Polynesian population of Western Samoa in a case-control study of 43 cases of CHD compared with 90 age- (mean 53 years) and sex-matched controls.

Methods Cases were identified on the basis of a 12-lead electrocardiogram and clinical history.

Results More than 60% of the participants had a body mass index ≥ 30 kg/m₂ and nearly 80% had central obesity. Both diabetes mellitus (17%) and impaired glucose tolerance (9%) were also common in this population. Nineteen per cent of the population were hypertensive and both antihypertensive therapy (21 versus 1%, P<0.001, risk 23.6) and hypertension (35 versus 11%, P<0.01, risk 4.3) were significantly more common among cases than they were among controls. In addition, the plasma high-density lipoprotein cholesterol level was lower (1.00±0.09 versus 1.24±0.05 mmol/l, P<0.05) and the plasma urate level was higher (0.42±0.02 versus 0.37±0.01 mmol/l, P<0.05) in the female cases than they were in their respective controls. Low-density lipoprotein (LDL) particle sizing did not reveal an excess of small LDL particles to be a feature of CHD cases, but more than 70% both of cases and of controls had multiple LDL species. The response of the triglyceride level to a fat-rich meal was the same for CHD cases and controls.

Conclusion The population studied had a high prevalence of several risk factors for CHD, including obesity and non-insulin-dependent diabetes mellitus; however, the most prominent factor relating to CHD within the community was the presence of hypertension.