Daily energy expenditure and cardiovascular risk in Masai, rural and urban Bantu Tanzanians.

BACKGROUND: Several studies have revealed that the Masai, pastoralists in Tanzania, have low rates of coronary heart disease despite a diet high in saturated fat. It has also been suggested that they may be genetically protected. Recent studies detailing other potential protective factors, however, are lacking. METHODS: A cross-sectional investigation of 985 Tanzanian men and women (130 Masai, 371 rural Bantu and 484 urban Bantu) with mean age of 46 (9.3) years. Anthropometric measures, blood pressure, serum lipids, and the reported dietary pattern and physical activity level were assessed. RESULTS: 82% of Masai subjects reported a high fat/low carbohydrate intake, whereas 77% of the rural Bantu subjects reported a low fat/high carbohydrate intake, while a high fat/high carbohydrate intake was the main dietary pattern of the urban Bantu group as, reported by 55%. The most conspicuous finding for the Masai was the extremely high energy expenditure, corresponding to 2565 kcal/day over basal requirements, compared with 1500 kcal/day in the rural and 891 kcal/day for the urban Bantu. Mean body mass index among the Masai was lower than the rural and urban Bantu. Mean systolic blood pressure of the Masai was also lower compared with their rural and urban Bantu counterparts. The Masai revealed a favourable lipid profile. CONCLUSION: The potentially atherogenic diet among the Masai was not reflected in serum lipids and was offset probably by very high energy expenditure levels and low body weight.

Physical activity and blood lipids in rural and urban Tanzanians.

BACKGROUND: Physical inactivity and raised blood lipids are two powerful risk factors for coronary heart disease (CHD). Incidence and mortality from CHD are expected to increase in developing countries. However, studies on the prevalence of cardiovascular risk factors in Africa are rare. In this study we examined the level of physical activity and serum lipids in rural and urban Tanzanians. METHODS: Rural and urban inhabitants, n=985, mean age 43.8 years [SD, +/-8.9] were investigated. Physical activity level (PAL) was assessed by an interview-administered questionnaire and blood samples were collected and analysed for serum lipids. RESULTS: The rural population (n=501) reported a substantially higher PAL than the urban population (n=484). They also had significantly lower mean weight, body mass index (BMI), T-cholesterol, LDL-cholesterol, and HDL-cholesterol, T-cholesterol/HDL-cholesterol ratio, triglycerides and Apolipoprotein A-1. CONCLUSION: This study demonstrates that the urban Tanzanians have a considerably lower physical activity level and a more unfavourable lipid pattern than rural Tanzanians. These findings underline the importance of undertaking preventive measures to counter the increasing incidence of CHD in urban African populations.

Determinants of hyperleptinaemia in an African population.

OBJECTIVE: To examine the determinants for elevated plasma leptin concentration in normal weight (NW), obese (OB), and morbidly obese (MO) individuals in Tanzania. DESIGN: Cross-sectional epidemiological study, the CARDIAC study. SETTING: Three areas in Tanzania; Dar es Salaam, urban (U), Handeni, rural (R) and Monduli, pastoralists (P), in August 1998. SUBJECTS: Five hundred and forty five participants from a random sample of 600 people aged 46-58 years. MAIN OUTCOME MEASURES: Plasma leptin concentrations, height, weight, body mass index (BMI), lipid profiles, haemoglobin A1c (HBA1c), and blood pressure (BP). RESULTS: Plasma leptin concentrations were higher in women than in men (women; 16.0 ng/mL, men; 3.1 ng/mL; p<0.0001). Women showed a higher mean body mass index (BMI), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) than men. In both genders, plasma leptin concentration, total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), triglycerides (TG), systolic BP (SBP) and diastolic BP (DBP) were significantly higher in OB than in NW participants. MO women had significantly higher leptin concentration, SBP and DBP compared with the other two groups. In NW men, log leptin concentrations showed a direct correlation with weight, BMI, HBA1c, TC, LDL-C, TG, SBP and DBP (all p<0.0001 except TG; p<0.001), while among NW women and OB men, weight and BMI correlated positively with log leptin (all p<0.05). OB women observed a positive correlation between log leptin and weight, BMI and LDL-C. Regression analysis indicated that among NW subjects, gender, BMI and TC explained 53.9% of the variation in log leptin. In OB subjects, gender, BMI and LDL-C explained 51.7% of the variability in leptin levels. No relationship was found between log leptin and CVD risk factors among MO subjects. CONCLUSION: The most important determinants for hyperleptinaemia in NW participants were gender, BMI, TC, while in addition to these LDL-C, was an important determinant of leptin concentration in OB individuals. In MO women, the high leptin concentrations did not reflect the amount of adipose stores.

Anthropometric growth in school children aged 9-15 years

Anthropometric measurements are presented for Dar es Salaam school children aged between 9-15 years. Girls are heavier than boys (P less than 0.001); and attain almost a plateau in standing height by 15 years age. In girls; sitting to standing height percent increase with age by about 0.2 percent years as compared to a 0.67 percent year decline in boys suggesting that; the increase in standing height with age in girls results from more trunk than leg height growth as compared to more leg than trunk height growth in boys. Boys have wider chest (P less than 0.001) than girls and become taller than girls after 14 years of age. Despite having similar onset of accelerated and trends of anthropometric growth about 60 percent of the subjects in this study have smaller standing height and weight than values reported in Caucasians of comparable age. It is recommended that further work is required to include children between 0-8 years of age also from rural areas so that comprehensive reference values could be constructed