[Polycystic ovary syndrome: relationship of insulin tissular sensitivity, LH secretion and ovarian morphophysiologic changes].
BACKGROUND: Insulin resistance to LH hypersecretion are recognized features of polycystic ovary syndrome. Previous studies have suggested that both defects are independent from each other. AIM: To examine the relationship between insulin sensitivity and LH secretion in women with polycystic ovary syndrome. PATIENTS AND METHODS: Eighteen women with clinical and biochemical evidence of hyperandrogenism, normal oral glucose tolerance test and polycystic ovaries on ultrasonography, were studied. Insulin sensitivity was assessed using the insulin tolerance test. LH secretion was studied integrating LH values of blood samples taken every 10 minutes for 6 h. Testosterone, testosterone index, SHBG and IGFBP-1 were measured in three selected samples and ovarian volume was assessed by ultrasound. RESULTS: Insulin sensitivity ranged from 0.06 to 0.75 and the area under the curve for LH, from 532 to 8.517 IU/L/6 h. No correlation was found between these two parameters and between each parameter and ovarian volume or androgen concentration. Positive correlations were observed between insulin sensitivity and SHBG concentrations (r = 0.612 p < 0.01) and IGFBP-1 concentrations (r = 0.588 p < 0.001). When compared to patients body mass index of less than 30 kg/m2, patients with body mass index over 30 kg/m2 had significantly lower insulin sensitivity and higher LH levels. In the latter a positive correlation between insulin sensitivity and the area under the curve for LH was observed (r = 0.683 p < 0.02). CONCLUSIONS: Obese polycystic ovary syndrome patients exhibited an inverse correlation between insulin resistance and LH hypersecretion, suggesting a relationship between both defects.