Lipid Profiles and trans Fatty Acids in Serum Phospholipids of Semi-nomadic Fulani in Northern Nigeria.

The Fulani are semi-nomadic pastoralists of West Africa whose diet, culture, and economy are centred on cattle. Previous studies have shown that the Fulani of northern Nigeria derive 50% of their total calories from fat and 30% of their calories from milk, cheese, yogurt, and butter oil that contain significant amounts of trans fatty acids (TFAs), primarily vaccenic acid, which raise total serum cholesterol and low-density lipoproteincholesterol (LDL-C), and lower high-density lipoprotein-cholesterol (HDL-C). The study was conducted to know how the consumption of relatively large amounts of dairy products by adult Fulani affected the TFA content of their serum phospholipids. Blood samples were collected from 22 male and 29 female Fulani, aged 35-60 years, who were living in rural areas of Gombe state in northeastern Nigeria. The total serum phospholipid fraction was isolated, and its fatty acid composition was determined. Surprisingly, vaccenic acid was not detected, and three other TFAs—18:1-t6, 18:1-t9, and 18:2-t9,t12—together accounted for only 0.16% of the total fatty acid. The mean serum total cholesterol, LDL-C, and triglyceride concentrations of the subjects were within the normal range for populations in developed countries; however, at 32 mg/dL, the mean serum HDL-C concentration of the Fulani males was slightly below the lower limit of the reference range. No correlations were observed between the total TFA percentage or that of the three individual TFAs and any of the parameters of the serum lipid profile. These findings indicate that, with respect to TFAs at least, the fatty acid pattern of the serum phospholipids of Fulani pastoralists does not reflect the high TFA content of their traditional diet. Despite the consumption of rumenic acid-rich dairy products, for unknown reasons, the semi-nomadic Fulani manage to maintain a low level of TFAs in their blood and a relatively healthful serum lipid profile. While the mechanism that accounts for this disconnect between the consumption of TFAs by Fulani pastoralists and the proportion of TFAs in their serum phospholipids is obscure, possibilities include discrimination against rumenic acid during the process of triglyceride synthesis and chylomicron synthesis in the intestine and the preferential oxidation of TFAs by Fulani the people compared to other ethnic groups.

Nutritional factors associated with anaemia in pregnant women in northern Nigeria.

This study was conducted to assess the relative contribution of iron, folate, and B 12 deficiency to anaemia in pregnant women in sub-Saharan Africa. In total, 146 pregnant women, who attended two antenatal clinics in Gombe, Nigeria, were recruited into the study. The majority (54%) of the women were in the third trimester. Blood samples were obtained for determination of haematocrit and for measurement of serum iron, total iron-binding capacity, ferritin, folate, vitamin B12, and homocysteine. Malaria was present in 15 (9.4%) women. Based on a haemoglobin value of<105 g/L, 44 (30%) women were classified as anaemic. The major contributing factor to anaemia was iron deficiency based on the serum concentration of ferritin (<10 ng/mL). The mean homocysteine concentration for all subjects was 14.1 pmol/L, and homocysteine concentrations were inversely correlated with concentrations of folate and vitamin B 12. The serum homocysteine increased markedly at serum vitamin B12 levels below 250 pmol/L. The most common cause of anaemia in the pregnant women in northern Nigeria was iron deficiency, and the elevated concentrations of homocysteine were most likely due to both their marginal folate and vitamin B12 status.

Risk factors for cardiovascular disease and diet of urban and rural dwellers in northern Nigeria.

Over the last 30 years, cardiovascular diseases (CVDs), including stroke and myocardial infarction, have increased in developing countries. Serum lipids and diet of the Fulani, a rural Nigerian population, were previously studied. Despite their consumption of a diet rich in saturated fat, the overall blood lipid profiles of Fulani men and women are generally favourable. However, Fulani males in the same study had mean serum levels of homocysteine, an emerging risk factor for CVD, that exceeded the upper limit of the homocysteine reference range. The authors were interested in knowing if these findings in the Fulani nomads were representative of the biochemical parameters of CVD risk in other ethnic groups in the same region of Nigeria. To address this question, the nutrient content of diets of 55 men, aged 20-75 years, and 77 women, aged 20-70 years, who were inhabitants of a large urban centre in northern Nigeria, was assessed, and their serum levels of total cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides, and homocysteine were determined. These data were compared with those of the same rural Fulani population studied previously. Urban subjects consumed more calories than rural subjects (men: 2061 vs 1691 kcal; women: 1833 vs 1505 kcal) and had a significantly higher mean body mass index (BMI) and percentage of body fat than rural subjects. Both urban males and females had carbohydrate intakes that were greater than those of Fulani pastoralists (men: 56% vs 33% total calories; women: 51% vs 38% total calories), but had a significantly lower dietary intake of total fat and saturated fat (men: 36% vs 51% of total calories; women: 40% vs 51% of total calories). With the exception of HDL-cholesterol levels, which were significantly lower in the rural population, the blood lipid profiles of rural subjects were more favourable compared to those of urban subjects. Both urban and rural males had homocysteine levels above the upper limit of the reference range for healthy adults (urban males--12.7 micromol/L; rural males-15.2 micromol/L). The dietary intakes of folate and vitamin B12 were lower for rural Fulani subjects, and this was reflected in their significantly lower serum concentrations of these two vitamins. Results of this study suggest that, although the lipid profiles of urban and rural men and women in northern Nigeria indicate a relatively low risk for CVD, their elevated serum homocysteine levels are a cause for concern. The high homocysteine levels among rural men and women could be explained in part at least by their marginal status with respect to folate and vitamin B12.

Serum lipid profiles and homocysteine levels in adults with stroke or myocardial infarction in the town of Gombe in northern Nigeria.

While the incidence of infectious diseases has been on the decline in developing countries, the toll of cardiovascular diseases, including stroke and myocardial infarction, has been increasing. The impression of physicians in certain regions of the western Sahel, including the state of Gombe in northeastern Nigeria, is that macrovascular disease in the indigenous population is on the rise. This study was, therefore, undertaken to compare well-established risk factors for cardiovascular disease in a group of 53 men (n=34) and women (n=19) in the town of Gombe who had suffered a stroke or heart attack with the corresponding parameters in 48 age- and gender-matched healthy adults living in the same environment. The parameters of cardiovascular diseases considered were: overweight and obesity, blood pressure, lipid profiles, and homocysteine. While the male and female patients who had suffered stroke (n=48) or heart attack (n=5) were borderline hypertensive, their mean body mass index values were not different from the corresponding values of their control groups. Although the serum homocysteine levels of the patients and controls were not significantly different, 85% of the stroke patients had serum homocysteine levels greater than 10 microM. These high homocysteine levels could not be accounted for by sub-optimal folate or vitamin B 12 status. The serum levels of HDL-cholesterol and triglyceride were not significantly different between the male and female patients and their respective controls. However, the males, but not the females, with macrovascular disease had significantly higher levels of total cholesterol (161 vs 137 mg/dL, p=0.04) and LDL-cholesterol (91 vs 70 mg/dL, p=0.02). In addition, both female and male stroke/myocardial infarction patients exhibited an elevated LDL-cholesterol/HDL-cholesterol ratio. These results indicate that blood pressure and the LDL-cholesterol/HDL-cholesterol ratio are associated with stroke and myocardial infarction in adults in northern Nigeria, thereby creating potential opportunities for possible public-health interventions.

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.