Increased risk of diabetes across the reproductive age range in women with PCOS: A territory-wide retrospective analysis from the Hong Kong diabetes surveillance database

Abstract

OBJECTIVE: Polycystic Ovary Syndrome (PCOS) is associated with insulin resistance, hyperandrogenism, and dyslipidemia, but the progression of type 2 diabetes mellitus in Chinese women with PCOS have only been investigated in clinic-based study population. Therefore, a population-based longitudinal study can help establish the overall risk of diabetes progression in Chinese women with PCOS. METHODS: This territory-wide, retrospective cohort study evaluated data extracted from the Hong Kong Diabetes Surveillance Database (HKDSD) between year 2000 and 2019. The subjects were women with PCOS (n=3978) identified based on the ICD-9 code for PCOS diagnosis, whilst women without PCOS served as controls (n=39780). Women with PCOS were age-matched at a ratio of 1:10 to a set of non-PCOS controls. Primary outcome was the first record of incident diabetes. Crude rates for diabetes were presented, and time to diabetes was analyzed using Cox proportional hazard models. RESULTS: The mean follow-up was 6.3 ± 4.2 and 7.0 ± 4.3 years in women with PCOS (baseline mean age: 28.53 ± 7.39 years old) and controls (baseline mean age: 28.93 ± 7.62 years old), respectively. In the cohort of women with PCOS, the crude incidence rate of diabetes was 21.48 per 1000 person-years (95% CI 19.56 -23.40) compared with 3.51 (95% CI 3.29-3.73) in the control cohort. The crude hazard ratio for the development of diabetes in Chinese women with PCOS was 6.25 (95% CI: 5.60-6.98, p<0.001). All participants were further stratified by age groups (≤19, 20-29, 30-39 and ≥40 years old). The incidence rate of diabetes was significantly higher in women diagnosed with PCOS than that of the age-matched control cohort, especially if PCOS was diagnosed at a younger age. Although the excess risk of developing diabetes decreased with increasing age at diagnosis, it remained significantly higher in women with PCOS across all age groups. Nevertheless, diabetes was diagnosed on average 5 years earlier in women with PCOS compared to control counterpart (mean onset of diabetes in PCOS: 34.65 ± 8.13 vs control: 39.61 ± 9.38, p<0.001). CONCLUSIONS: The risk of developing diabetes is markedly increased in Chinese women with PCOS compared with women without PCOS. Women diagnosed with PCOS at a younger age have the highest relative risk of developing diabetes when compared to non-PCOS women, suggesting regular glycaemic status screening might be required in order to detect diabetes at an early stage.