INFLUENCE OF 3-WEEK FASTING ON GONADOTROPIN PULSATILITY IN OBESE MENSTRUATING WOMEN

OBJECTIVE: To evaluate the influence of three-week fasting on gonadotr opin pulsatility in extremely obese women of reproductive age. DESIGN: Prospective study of 21-day fasting (400 kcal/day), under medical sup ervision. SUBJECTS: 20 females, average age of 35.1 +/- 5.9 y, and ave rage BMI of 41.19 +/- 8.39 kg/m(2), with regular menstrual cycles (26- 34 days). The mean weight loss was 12.5 +/- 3.23 kg. MEASUREMENTS: Blo od samples for LH and FSH were taken between 4th and 7th day of the me nstrual cycle, before and in the first cycle immediately after weight reduction, for 6 h, starting at 09.00 with 10 min intersample interval s. Pulsatility analysis was done using Pulsar program. Statistical ana lysis was done using Wilcoxon's matched pairs signed ranking test and McNemar's test. RESULTS: There was no statistically significant differ ence (p > 0.05) in LH and FSH pulsatile secretion before and after die t including the number of pulses, amplitudes. interpulse intervals and peak lengths. There were no disturbances of menstrual cycle during or after the diet. CONCLUSION:These results suggest that a 21-day fast, accompanied with significant weight loss, does not affect gonadotropin pulse pattern in follicular phase and normal menstrual cycle length i n extremely obese females of reproductive age, compared with the patte rn before diet.