Fasting ghrelin levels in physically active women: relationship with menstrual disturbances and metabolic hormones.

Recent findings support a role for ghrelin in the regulation of energy homeostasis and possibly reproductive function. The primary purpose of this study was to test whether differences in fasting ghrelin levels exist in exercising women with differing menstrual and metabolic status. Menstrual cycle status was defined as sedentary ovulatory (SedOvul; n = 10, cycles = 26), exercising ovulatory (ExOvul; n = 11, cycles = 22), exercising luteal phase defect/anovulatory (ExLPD/Anov; n = 11, cycle = 27), and exercising amenorrheic (ExAmen; n = 8, cycle = 16). Subjects were 27.7 +/- 1.2 yr of age, weighed 60.2 +/- 3.3 kg, and had menstrual cycle lengths of 28.4 +/- 0.9 d. Blood was collected during the follicular phase (d 2-9) of each menstrual cycle and analyzed for total ghrelin, insulin, total T(3), and leptin. Ghrelin was significantly elevated by approximately 85% in the ExAmen category (725.5 +/- 40.8 pmol/liter) when compared with all other categories (P < 0.001; SedOvul = 393.6 +/- 32.0 pmol/liter, ExOvul = 418.9 +/- 34.8 pmol/liter, and ExLPD/Anov = 381.1 +/- 314 pmol/liter). Leptin levels were lower in all groups vs. SedOvul (P < 0.001). Insulin was lower in both the ExLPD/Anov and ExAmen categories vs. SedOvul and ExOvul (P < 0.018), and total T(3) was lower in ExAmen compared with all other groups (P < 0.001), with concentrations in ExLPD/Anov and ExOvul exceeding those in SedOvul (P < 0.05). These data clearly indicate a metabolic hormonal profile consistent with chronic energy deficiency in exercising women across a range in menstrual status and introduces ghrelin as a potential supplementary indicator that uniquely discriminates amenorrheic athletes from athletes with other menstrual disturbances.