Importance of plasma leptin in predicting future weight gain in obese children: a two-and-a-half-year longitudinal study.
OBJECTIVE
To determine whether relatively low leptin levels predict changes in adiposity in prepubertal and pubertal obese children.


METHODS
In a biracial cohort of 68 obese children (33 male and 35 female; 46 Caucasians and 22 African-Americans, age range 7-18 y), we measured at baseline fasting insulin and leptin levels, height and weight and calculated body mass index (kg/m(2)) and expressed body mass index as (BMI) Z-score. After a 2.5-y follow-up, anthropometric measurements were repeated and changes in weight gain were calculated as changes in BMI Z-score.


RESULTS
At baseline obese preadolescent boys and girls had similar age and BMI Z-score, fasting insulin and leptin levels. After an average follow-up of 2.5 y, mean weight change calculated by changes in BMI Z-score from baseline was similar in both groups. In obese adolescent boys and girls at baseline, no significant gender differences were observed for BMI Z-score and insulin levels. In contrast, plasma leptin levels were significantly higher in obese girls compared with obese adolescent boys. At follow-up, there was no significant difference in change in BMI Z-score between obese boys and girls. Multiple linear regression analysis revealed that high basal leptin levels were positively associated with greater changes in BMI Z-score only in girls (r(2)=0.18, P<0.02), after adjusting for basal BMI Z-score, Tanner stage, years of follow-up and basal insulin. High basal leptin levels in girls explained 18% of the weight gain.


CONCLUSIONS
High leptin levels are associated with excessive future weight gain only in girls.
Savoye
M
M
Department of Pediatrics and The Children's General Clinical Research Center and the Yale University School of Medicine, New Haven, Connecticut 06520, USA.
Dziura
J
J
Castle
J
J
DiPietro
L
L
Tamborlane
W V
WV
Caprio
S
S
D000293:Adolescent; D015992:Body Mass Index; D002648:Child; D005215:Fasting; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D020738:Leptin / Q000097:blood*; D016014:Linear Models; D008137:Longitudinal Studies; D008297:Male; D009765:Obesity / Q000097:blood*; D010641:Phenotype; D011627:Puberty; D012727:Sex Characteristics; D015430:Weight Gain
D007328:Insulin; D020738:Leptin