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.

Pulmonary function results in asbestos factory workers.

The pattern of lung function was assessed in a group of 159 male employees of the Dar es Salaam asbestos factory. The results were compared with a control group (N= 180) of age and sex matched from the same area but not exposed to asbestos. The mean age were 32.8, SD=8.9 and 33.1 SD=7.7 years in the asbestos workers and control groups respectively. Lung function indices showed an increase with age reaching peak values between 30-34 years of age. FVC and FEV(1) values were similar in the two groups. However, MMEF, PEF, V(75), V(50), and V(25) were significantly lower in asbestos factor workers than in the control group. Observed results were also compared with results computed from prediction equation for normal healthy subjects. Observed FVC and FEV(1) values were similar to predicted values while MMEF and PEF values were significantly lower ([P < 0.05]) and [P < 0.001] respectively) in asbestos factory workers than predicted values. The reduced flows suggest early airways dysfunction affecting peripheral airways more than large airways, a finding supported by the normal FVC and FEV(1) values. It is recommended that efforts should be directed at increasing awareness of employees on the risks associated with asbestos and frequent health monitoring to all factory workers should be instituted.