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.


METHODS
Cross-sectional epidemiological study, the CARDIAC study.


METHODS
Three areas in Tanzania; Dar es Salaam, urban (U), Handeni, rural (R) and Monduli, pastoralists (P), in August 1998.


METHODS
Five hundred and forty five participants from a random sample of 600 people aged 46-58 years.


METHODS
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.


CONCLUSIONS
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.
Njelekela
M
M
Department of Human and Environmental Science, Graduate School of Human and Environmental Studies, Kyoto University, Kyoto 606-8501, Japan.
Kuga
S
S
Hiraoka
J
J
Masesa
Z
Z
Ntogwisangu
J
J
Mashalla
Y
Y
Ikeda
K
K
Mtabaji
J
J
Nara
Y
Y
Yamori
Y
Y
Tsuda
K
K
D015992:Body Mass Index; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D020738:Leptin / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000097:blood* / Q000150:complications; D009767:Obesity, Morbid / Q000097:blood* / Q000150:complications; D012307:Risk Factors; D013636:Tanzania
D020738:Leptin