In women with PCOS, raised serum LH concentration is associated with lower age and BMI; converse associations are identified in women with IR. Our initial analysis of women with PCOS showed a 2030% overlap of women with both raised serum LH concentration and IR. To investigate further the relationship between LH and IR we analysed endocrine data from a group of women diagnosed with PCOS by Rotterdam criteria. Notes of 241 women identified as having PCOS were reviewed; median age 26; IQR 2131 years. Serum LH concentration (≥10 U/L) and LH/FSH ratio (≥2) were identified in 26.8% and 24.3% women respectively. HOMA-IR >1, >2 or >3 was found in 92%, 66% and 48% women respectively. LH >10 U/L and HOMA-IR >1 was found in 30.5%; LH/FSH >2 and HOMA-IR >1 in 21.7%. By linear regression, LH was inversely related to HOMA-IR, β coefficient −0.08, 95% CI −0.16, −0.01 and P=0.02. By multivariate (stepwise) linear regression analysis the independent predictors of LH were identified as androstenedione, β coefficient 0.25 (0.08, 0.41) P<0.01 and BMI, β coefficient −0.15 (−0.24, −0.06) P= 0.001. Predictors for HOMA-IR were identified as BMI, β coefficient 0.11 (0.07, 0.16) P<0.001 and free testosterone index, β coefficient 0.17 (0.12, 0.23) P<0.001. Multivariate analysis of LH/HOMA-IR showed BMI, β coefficient −0.25, 95% CI −0.31, −0.18 P<0.001, and androstenedione, β coefficient 0.20, 95% CI 0.08, 0.31, P=0.001, to be independent predictive factors. There is an overlap of raised LH and IR in 2030% women. A significant, inverse relationship between LH and IR is identified. Both LH and IR are significantly associated with hyperandrogenism, through raised androstenedione and free testosterone index respectively. BMI, but not age, is the single most significant determinant of LH, IR and LH/HOMA-IR.
Declaration of interest: There is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported.
Funding: No specific grant from any funding agency in the public, commercial or not-for-profit sector.