Polycystic Ovary Syndrome, Combined Oral Contraceptives, and the Risk of Dysglycemia: A Population-Based Cohort Study With a Nested Pharmacoepidemiological Case-Control Study
Research Design and Methods: Utilizing a large UK primary care database (The Health Improvement Network, THIN; 3.7 million patients from 787 practices), we carried out a retrospective population-based cohort study to determine dysglycemia risk (64,051 women with PCOS, 123,545 matched controls), as well as a nested pharmaco-epidemiological case-control study to investigate COCP use in relation to dysglycemia risk (2407 women with PCOS with [=cases] and without [=controls] a diagnosis of dysglycemia during follow-up). Cox models were used to estimate the unadjusted and adjusted hazard ratio and conditional logistic regression was used to obtain adjusted odds ratios (aORs).
Results: The adjusted hazard ratio for dysglycemia in women with PCOS was 1.87 (95% CI 1.78-1.97, p<0.001; adjustment for age, social deprivation, BMI, ethnicity, and smoking), with increased rates of dysglycemia in all BMI subgroups. Women with PCOS and COCP use had a reduced dysglycemia risk (aOR 0.72, 95% CI 0.59 to 0.87).
Conclusions: In this study limited by its retrospective nature and the use of routinely collected electronic general practice record data, which does not allow to exclude the impact of prescription-by-indication bias, women with PCOS exposed to COCPs had a reduced risk of dysglycemia across all BMI subgroups. Future prospective studies should be considered to further understand these observations and potential causality.