Cigarette smoking, alcohol use, and physical activity in relation to serum leptin levels in a multiethnic population: The Miami Community Health Study.
OBJECTIVE
To examine the correlates of plasma leptin, including fasting insulin, adiposity, and several health habits and behaviors among a nondiabetic multiethnic population.


METHODS
A cross-sectional study was conducted among 25-44 year old African-Americans (n = 126), Cuban-Americans (n = 107), and non-Hispanic whites (n = 189) randomly selected from Dade County Florida. Fasting leptin levels were correlated with fasting insulin, percent body fat, smoking, alcohol use, and physical activity within each sex. Multiple linear regression and analysis of covariance were used to estimate the independent determinants of plasma leptin concentration separately among men and women.


RESULTS
Stepwise linear regression analyses revealed statistically significant associations of leptin with percent body fat, fasting insulin, cigarette smoking, and physical activity (both inversely) among men (p < 0.05 for each). Among women, percent body fat, fasting insulin (both positively), cigarette smoking, and alcohol use (inversely) were independent predictors of leptin levels explaining over 70% of the variance. Analyses of covariance revealed that women had higher adjusted mean leptin levels than men (13.1 ng/ml vs. 5.9 ng/ml; p < 0.001), whereas no separate effect of ethnicity was noted.


CONCLUSIONS
Although adiposity was the strongest correlate of leptin levels, fasting insulin and several health habits and behaviors were independently associated with leptin. After adjustment for these factors, women had significantly higher mean leptin levels than men. The independent association among leptin and insulin levels is intriguing and suggests additional avenues for epidemiologic research.
SUNY at Buffalo, Department of Social and Preventive Medicine, NY 14214, USA.
R P
RP
Donahue
P
P
Zimmet
J A
JA
Bean
M
M
Decourten
R A
RA
DeCarlo Donahue
G
G
Collier
R B
RB
Goldberg
R J
RJ
Prineas
J
J
Skyler
N
N
Schneiderman
D000328:Adult; D000367:Age Factors; D000428:Alcohol Drinking / Q000097:blood / Q000208:ethnology*; D000704:Analysis of Variance; D015415:Biomarkers / Q000097:blood; D001824:Body Constitution; D015331:Cohort Studies; D003431:Cross-Cultural Comparison; D003430:Cross-Sectional Studies; D005006:Ethnicity / Q000706:statistics & numerical data; D015444:Exercise; D005260:Female; D005431:Florida / Q000453:epidemiology; D006306:Health Surveys; D006801:Humans; D020738:Leptin; D008019:Life Style / Q000208:ethnology*; D016014:Linear Models; D008297:Male; D009765:Obesity / Q000097:blood / Q000208:ethnology; D011506:Proteins / Q000032:analysis*; D012737:Sex Factors; D012907:Smoking / Q000097:blood / Q000208:ethnology*
D015415:Biomarkers; D020738:Leptin; D011506:Proteins