Variability of serum gonadotropin and dehydroepiandrosterone sulfate concentrations in women with polycystic ovary syndrome.

This study was designed to assess the variability of luteinizing hormone (LH), follicle-stimulating hormone (FSH) and dehydroepiandrosterone sulfate (DHEAS) levels over time in women with polycystic ovary syndrome (PCOS). Serum LH, FHS and DHEAS concentrations were determined for four consecutive monthly intervals in three groups of women: group 1, normal cycling women in the follicular phase (n = 9); group 2, normal cycling women in the luteal phase (n = 10); and group 3, women with PCOS (n = 11). For LH, DHEAS and the LH/FSH ratio, a histogram was constructed based on whether the subjects in each group had 0, 1, 2, 3 or 4 high values. In addition, the coefficient of variation (CV) for the four individual values of each hormone was determined for each subject to quantitatively assess the variability of measurement over time. Histographic analysis revealed that an elevated LH value or an elevated LH/FSH ratio in PCOS was inconsistent. For DHEAS, 9 of 11 PCOS subjects had either 0 (n = 7) or 4 (n = 2) high values, suggesting that such determinations are relatively consistent. We conclude that (1) isolated LH or LH/FSH measurements may not be sufficiently reproducible to be clinically useful despite evidence that LH values may be more stable in PCOS than in normal women and (2) a normal or high DHEAS value in PCOS is more likely to be consistently replicated, although the number of subjects studied limits the power of this conclusion.