Serum lipid profiles and risk of cardiovascular disease in three different male populations in northern Nigeria

The Fulani of northern Nigeria are indigenous semi-nomadic pastoralists whose diet consists largely of dairy products. Despite their consumption of relatively large amounts of saturated fats, an earlier study showed that their total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL) and serum triglyceride levels fall within the reference range of values for North Americans. Men in the cities of Jos and Abuja, two populations who also reside in northern Nigeria, differ from the Fulani with regard to diet and activity level. Males in both Jos and Abuja have diets consisting of high protein or carbohydrate and are more sedentary than the Fulani subjects. The main aims of the study were to measure the concentrations of various lipids in the blood serum of male urban dwellers in Jos and Abuja and to compare their blood lipid profiles with those of the rural Fulani (mean age 33.9 years). Blood serum samples from 118 men in Jos (mean age 37.9 years) and 77 men in Abuja (mean age 34.4 years) were analyzed for total cholesterol, triglycerides, LDL, HDL, homocysteine, folate, and vitamin B12. In addition to height and weight, systolic and diastolic blood pressures were measured. The mean total cholesterol, triglyceride, HDL and LDL values for the three groups of subjects fell within or close to the accepted range of values for North Americans. However, the Fulani males had HDL values (mean, 33.9 mg/dL) below the range of values prescribed for North Americans (>40 mg/dL). Moreover, the Fulani men and the men in Abuja had a total cholesterol/ HDL ratio of 4.2 and 4.0 respectively, which exceed the accepted value (< or =3.5) prescribed by the Columbia University. In all three populations, the incidence ofhomocysteinaemia (serum homocysteine > 12.4 micromol/L) was very high. Their mean homocysteine levels ranged from 14.7 to 16.7 pmol/L and could not be accounted for by folate or vitamin B12 status. The mean blood pressures of the Abuja (127/77 mm Hg) and the Fulani (120/74 mm Hg) men were within the normotensive range (<130/85 mm Hg). However, the mean blood pressures of the Jos males (131/85 mm Hg) indicated borderline hypertension. These data indicate that, with regard to serum lipids, urban and rural adult Nigerian males have generally favourable risk factors for cardiovascular disease when compared with healthy North Americans. All three sub-populations, however, have levels of homocysteine that are cause for concern vis-à-vis their overall health status.