Serum Leptin Levels in Premature Pubarche and Prepubertal Girls With and Without Obesity

Abstract

ABSTRAGTLeptin can be regarded as a marker of the nutritional status of the body. This study was performed to determine the correlation of leptin levels with insulin (I) and androgens in girls with premature pubarche (PP) and prepubertal controls (C) with (OB) or without (nOB) obesity. We studied 25 girls with PP and 14 C; girls were dived into two subgroups according to body mass index (BMI): OB (18 PP and 8 C) and nOB (7 PP and 6 C). Obesity was defined as BMI >95 th percentile for chronological age. Serum levels of leptin, I, glucose (G), DHEAS, testosterone, androstenedione (A), Cortisol, SHBG, IGFBP-1 and lipid profile were measured. The fasting G to I ratio (FGIR) was calculated and FGIR <7 was considered as suggestive of I resistance (IR). Data were analyzed comparing PP vs C and OB vs nOB. Serum DHEAS (0.60 ± 0.45 vs 0.18 ± 0.22 μg/ml) and A (895.5 ± 420.4 vs 457.0 ± 352.1 pg/ml) levels were significantly higher in PP than C. Other hormonal and metabolic parameters were similar. Serum leptin (30.8 ± 18.3 vs 8.1 ± 5.9 ng/ml), A (841.8 ± 471.1 vs 522.5 ± 317.2 pg/ml), DHEAS (0.53 ± 0.44 vs 0.31 ± 0.39 pg/ml), G (88.4 ± 8.8 vs 80.2 ± 8.1 mg/dl), I (13.5 ± 7.7 vs 5.1 ± 3.7 μϋ/ml) and total cholesterol (TC) (180.5 ± 30.9 vs 161.8 ± 29.5 mg/dl) levels were greater in the OB than in the nOB group. IR was observed in 10 girls with OB and in one with nOB. Leptin was correlated with BMI (r = 0.83), SHBG (r = -0.44), IGFBP-1 (r = -0.47), I (r = 0.37), A (r = 0.48) and TC (r = 0.36), but in multiple regression analysis only with BMI (r 2 = 0.72, ρ <0.001). Girls with PP and prepubertal OB girls showed elevated leptin levels independent of I and androgen levels. Girls with OB had a greater degree of hyperandrogenism and IR. As obesity, IR and hyperandrogenism are common findings in polycystic ovary syndrome (PCOS), which is more prevalent in young women with a history of PP, a role of leptin in PCOS can be suggested. In addition, girls with PP could be considered a population at risk for plurimetabolic syndrome. KEY WORDSleptin, insulin, androgens, obesity, premature pubarche

The Effect of Exercise on Leptin, Insulin, Cortisol and Lipid Profiles in Obese Children

“…20,37,38 Insulin and, less remarkably, cortisol were found to have significant positive effects on serum leptin, whereas dehydroepiandrostenedione had a weaker negative influence in a multiple regression analysis using BMI as an index of degree of body fat. 39 These findings are in agreement with experimental data that demonstrate that both insulin and cortisol are stimulators of leptin expression in cultured human adipocytes. 40,41 The findings of the present study are consistent with studies demonstrating that insulin secretion is decreased in response to exercise, particularly in children, thereby increasing the peripheral consumption of glucose.…”

Are Growth Factors and Leptin Involved in the Pathogenesis of Premature Adrenarche in Girls?

“…L'Allemand et al 19 reported that the BMI of PA patients was higher than that of the control group and leptin values were similar to those in the control group. Recently, it was reported that serum leptin levels of obese PA patients are higher than in a non-obese PA group independent of insulin and androgen levels 34 . Recently, it was reported that serum leptin levels of obese PA patients are higher than in a non-obese PA group independent of insulin and androgen levels 34 .…”

Candidate Genes Associated With Polycystic Ovary Syndrome in Asian Populations: A Research Review

“…The epigenetic mechanisms involved in PCOS may yield new insights into the pathophysiology of the disorder [20]. Girls with premature pubarche (PP) could be considered a population at risk for plurimetabolic syndrome [21].…”