The Impact of Obesity on the Incidence of Type 2 Diabetes Among Women With Polycystic Ovary Syndrome

• Published in: Diabetes care Vol. 42; no. 4; pp. 560 - 567
• Main Authors: Kakoly, Nadira S., Earnest, Arul, Teede, Helena J., Moran, Lisa J., Joham, Anju E.
• Format: Journal Article
• Language: English
• Published: United States American Diabetes Association 01.04.2019
• Subjects: Adolescent; Adult; Age; Australia - epidemiology; Body mass; Body Mass Index; Body Weight; Cohort Studies; Correlation analysis; Diabetes; Diabetes mellitus; Diabetes mellitus (non-insulin dependent); Diabetes Mellitus, Type 2 - complications; Diabetes Mellitus, Type 2 - epidemiology; Female; Genetics; Health risks; Humans; Incidence; Longitudinal Studies; Obesity; Obesity - complications; Obesity - epidemiology; Overweight - complications; Overweight - epidemiology; Polycystic ovary syndrome; Polycystic Ovary Syndrome - complications; Polycystic Ovary Syndrome - epidemiology; Research design; Risk; Risk analysis; Risk factors; Subgroups; Survival analysis; Womens health; Young Adult; Australia
• ISSN: 0149-5992; 1935-5548; 1935-5548
• DOI: 10.2337/dc18-1738

The nature of the independent relationship between polycystic ovary syndrome (PCOS) and type 2 diabetes remains unclear. Few studies have aimed to clarify this relationship independent of obesity in longitudinal population-based cohorts. We used the Australian Longitudinal Study on Women's Health (ALSWH) (2000-2015) database to estimate nationwide incidence rates and predictors of type 2 diabetes among women aged 18-42 using person-time and survival analysis. Over a follow-up of 1,919 person-years (PYs), 186 women developed type 2 diabetes. The incidence rate was 4.19/1,000 PYs and 1.02/1,000 PYs ( < 0.001) in PCOS and control subjects. On subgroup analyses across healthy-weight, overweight, and obese categories of women, the incidence rates for type 2 diabetes were 3.21, 4.67, and 8.80, whereas incidence rate ratios were 4.68, 3.52, and 2.36 ( < 0.005) in PCOS versus age-matched control subjects. PCOS was one of the most influential predictors for type 2 diabetes in the entire cohort (hazard ratio 3.23, 95% CI 2.07-5.05, < 0.001) adjusting for BMI, education, area of residence, and family history of type 2 diabetes. Women with PCOS are at an increased risk of type 2 diabetes, irrespective of age and BMI. The incidence of type 2 diabetes increases substantially with increasing obesity; yet, PCOS adds a greater relative risk in lean women. Based on the overall moderate absolute clinical risk demonstrated here, guideline recommendations suggest type 2 diabetes screening every 1-3 years in all women with PCOS, across BMI categories and age ranges, with frequency influenced by additional type 2 diabetes risk factors.