Correlations among serum leptin levels, complete blood count parameters and peripheral CD34(+) cell count in prepubertal obese children.

Leptin is a hormone produced by adipocytes that helps reduce body weight by depressing appetite and increasing metabolic activity. Leptin also promotes early hematopoiesis. The main aim of this study was to compare complete blood count (CBC) parameters and peripheral blood CD34(+) cell counts in prepubertal obese and nonobese children. Relationships between leptin levels and CBC parameters and peripheral CD34(+) progenitor cell counts in the obese group were also investigated. Thirty one healthy, prepubertal, obese children and 30 nonobese, age-matched prepubertal controls were included in the study. A fasting blood sample was collected from each subject, and CBC findings, serum leptin level, and peripheral blood CD34(+) progenitor cell count were recorded. In the obese group, the mean results for body mass index (BMI), BMI standard deviation score (BMI SDS), and serum leptin level were significantly higher than the corresponding control findings. There were no significant differences between the groups with respect to CBC parameters and CD34(+) cell percentage. In both the obese and control groups, the girls' serum leptin levels were significantly higher than the boys'. In the obese group, serum leptin level was strongly correlated with BMI and with BMI SDS (Pearson correlation coefficients r=0.70, p<0.001, and r=0.59, p<0.001, respectively) in both girls and boys. None of the CBC parameters nor CD34(+) progenitor cell percentage was correlated with leptin, BMI, or BMI SDS. The results indicate that serum leptin levels in obese children are positively correlated with BMI. However, in contrast to adults, high leptin level in childhood obesity does not seem to be associated with altered CBC parameters or increased peripheral CD34(+) progenitor cell count.