LOW-PREVALENCE OF RISK-FACTORS FOR CORONARY HEART-DISEASE IN RURAL TANZANIA

A community-based survey was used to assess the prevalence of risk factors for coronary heart disease (CHD) in rural Tanzanians. In all, 8581 subjects (3705 men, 4876 women) aged greater-than-or-equal-to 15 years in eight villages in three regions in rural Tanzania representing a range of socioeconomic deprivation were studied. The main outcome measures were serum cholesterol and triglyceride level, blood pressure and prevalence of dyslipidaemia, hypertension, smoking, overweight, impaired glucose tolerance (IGT) and diabetes; as well as ECG changes. Mean serum cholesterol levels in men were 4.2, 3.4 and 3.7 mmol/l, and in women 4.4 3.6 and 3.9 mmol/l in Kilimanjaro, Morogoro and Mara regions respectively. In Kilimanjaro region 17.4% of men and 19.0% of women had values above 5.2 mmol/l compared with only 5.0% and 6.7% in Morogoro region and 4.8% and 6.9% respectively in Mara region. Systolic and diastolic blood pressures increased with age in both men and women in all three regions with the most marked increase in Kilimanjaro region and the smallest rise in Mara region. Mean age-adjusted values were highest in Kilimanjaro region (124/75 mm Hg, and 125/76 mm Hg in men and women respectively) and lowest in Mara region (120/70 mm Hg in men and 118/68 mm Hg in women). Hypertension was found in 6.6% of men and 7.5% of women in Kilimanjaro region, 3.3% and 4.7% in Morogoro, and 2.6% and 3.4% in Mara region. Cigarette smoking was found in 42.6% of men in Kilimanjaro region, 28.2% of Morogoro region and 8.6% in Mara region. Less than 4% of women smoked in all three regions. Only 2.4-4.0% of men, and 7.9-10.5% of women were overweight or obese. ST,T and Q,QS changes on ECG were recorded in 7.8% and 2.7% of men, and 17.4% and 3.7% of women aged greater-than-or-equal-to 40 years. Diabetes was found in 0.6-0.8% as previously reported. The proportion of men with two or more risk factors for CHD ranged from 0.2% in Mara region to 4.6% in Kilimanjaro region. For women the corresponding figures ranged from 0% in Mara region to 1.1% in Morogoro region. The proportion was increased in those with IGT (9.3%) and diabetes (14.1%). Similarly those with ischaemic (Q,QS) changes on ECG had a twofold increase in risk factors. Cardiovascular risk factor levels make it unlikely that CHD will emerge as a significant health problem among rural Tanzanians in the near future.