Circadian leptin, insulin and cortisol rhythms in obese subjects.

Autor: Lazreg, TaheniBen, Zaouali, Monia, Chaieb, Molka, Dallel, Nada, Chaieb, Larbi, Tabka, Zouhaier, Zbidi, Abdelkarim
Předmět:
Zdroj: Biological Rhythm Research; Feb2007, Vol. 38 Issue 1, p9-17, 9p, 2 Charts, 4 Graphs
Abstrakt: The recent discovery of leptin, the product of the “ob” gene has greatly advanced the understanding of body adiposity and energy balance regulation. Serum leptin levels follow a circadian rhythm, which seems to be regulated predominantly by insulin increases levels and the circadian rhythm of cortisol. The aims of this study were to: (1) determine the effect of obesity on leptin 24 hours pattern; (2) determine the biological rhythm of leptin, insulin and cortisol. Thirteen subjects (10 women, three men) participated in this study. Serum samples were drawn at four hour intervals for a total of 24 hours. Leptin showed diurnal rhythmicity with peaks at 04.00 h (91.7±12.9 ng/ml) and troughs at 12.00 h (73.1±9.7 ng/ml). There was a strong association between leptin levels and BMI (r = 0.34; p < 0.001). The high levels of leptin may contribute to leptin resistance in obesity. Our data show the negative correlation over time between leptin and cortisol (r = -0.28, p = 0.005), and we demonstrate also that leptin and insulin are not correlated over time. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index