Effect of chronic hypoxia on leptin, insulin, adiponectin, and ghrelin

The endocrine system plays an important role in the adaptation to hypoxia. The aim of this study was to assess the effect of chronic hypoxia on insulin, adiponectin, leptin, and ghrelin levels in a neonatal animal model. Sprague-Dawley rats were placed in a normobaric hypoxic environment at birth. Controls remained in room air. Rats were killed at 2 and 8 weeks of life. Insulin, adiponectin, leptin, and ghrelin were measured. At 2 weeks of life, there was no significant difference in insulin, adiponectin, and leptin levels between the hypoxic and control rats. The only statistically significant difference was found in ghrelin levels, which were lower in the hypoxic group (3.19 +/- 3.35 vs 24.52 +/- 5.09 pg/mL; P < .05). At 8 weeks of life, insulin was significantly higher in the hypoxic group (0.72 +/- 0.14 vs 0.44 +/- 0.26 ng/mL; P < .05) and adiponectin was significantly lower (1257.5 +/- 789.5 vs 7817.3 +/- 8453.7 ng/mL; P < .05). Leptin and ghrelin did not show significant difference in this age group, but leptin level per body weight was higher in the hypoxic group. Finally, we conclude that 2 weeks of continuous neonatal hypoxic exposure leads to a decrease in plasma ghrelin only with no significant change in insulin, adiponectin, and leptin and that 8 weeks of hypoxia leads to a decrease in adiponectin with an increase in insulin despite a significant decrease in weight. (C) 2008 Elsevier Inc. All rights reserved.