Screening Recommendations for Diabetes in Women with Polycystic Ovary Syndrome

Diabetes in polycystic ovary syndrome: given the connection of the two conditions, when should women with PCOS be considered for type 2 diabetes screening?

It has been noted that women with PCOS are at risk of developing a plenitude of other conditions due to it being an endocrine disorder and because of the hormone imbalance. In regards of developing diabetes, we are most worried about the coexistence of insulin resistance in these patients. Previous studies have found an increased risk of developing type 2 diabetes in women with PCOS who have overweight or obesity. What these studies lacked, were an adequate number of patients of healthy-weight women with PCOS.

The study wanted to compare women with and without PCOS and the incidence rate of type 2 diabetes, including the consideration of risk factors. Secondly, they also wanted to assess the development of type 2 diabetes in women with PCOS independent of BMI. The researchers focused on performing a community-recruited nationally representative population cohort due to lack of previous trials with this population and for generalizability. Data was extracted from the Australian Longitudinal Study on Women’s Health (ALSWH) database spanning 15 years (2000-2015). 7 self-reporting surveys were used every 3 years, surveying women answering questions in regards of PCOS and diabetes. The baseline cohort was formed from responses to Survey II, with 8,378 women responding to the PCOS questions, without preexisting type 2 diabetes. Divided from the baseline cohort, two cohorts were formed, women with PCOS (n =707) and non-PCOS (n = 7,671) to observe the incidence of type 2 diabetes by Survey VII, noted as the primary outcome. Confounders measured in the study were BMI, income, educational qualification, country of birth, occupation, family history of diabetes and smoking status.

To observe the relationship between categorical and continuous variables with type 2 diabetes, Chi-square test or independent Student t test was used. The incidence rate ratio (IRR) for type 2 diabetes in women with PCOS versus those without PCOS was calculated by BMI categories at Survey I. Potential predictors were analyzed using Cox proportional hazards model. The researchers also calculated the diabetes-free survival time from the year of entry into the study until report of type 2 diabetes or the end of follow-up.

The baseline characteristics determined women who developed type 2 diabetes were more likely to have PCOS, have overweight/obesity, and have a family history of type 2 diabetes. The mean incidence rate for type 2 diabetes in the PCOS cohort (4.19/1000 person-years) was significantly higher than in the non-PCOS cohort (1.02/1000 person-years) (P < 0.001). Between the groups, the Kaplan-Meier Survival Curve showed a significant difference in type 2 diabetes-free survival times (P < 0.001).

Looking across all BMI subgroups (healthy-weight, overweight, and obese) comparing both groups, women with PCOS in each subgroup had an increased incidence of type 2 diabetes. Furthermore, they determined the rate increased in both groups by class of BMI, with the PCOS group with an IR of 3.21, 4.67, 8.80, and the non-PCOS group with an IR of 0.69, 1.33, 3.72. Comparing each BMI subgroup, the highest IRR seen was in women with PCOS at healthy-weight (4.68) versus overweight (3.52) and obese (2.36). Finally, from the regression analysis, from the 8 covariates considered, 5 were considered as independent predictors, those being, BMI, education, family history of type 2 diabetes, ethnicity, and PCOS. Adjusting for all variables except PCOS found a 3.23-fold increased risk of type 2 diabetes compared to those without PCOS. Further looking at the outcome of type 2 diabetes from the association of PCOS and BMI, it was found not statistically significant (P = 0.352).

Knowing that PCOS status independently increases the risk for type 2 diabetes, specifically across all BMI subgroups evaluated in this study, should assert the importance of screening for type 2 diabetes in polycystic ovary syndrome  patients. Previous studies determined similar results in older women who have overweight or obesity with family history of type 2 diabetes, but this study proves PCOS status alone is enough for a 3.23-fold risk.

While this study was done in a large population, that was made to represent the general population of Australia, bias could have resulted due to self-reported surveys. Although these surveys were validated and found to be reliable, the authors still acknowledged the potential bias. Also, from the surveys, the researchers were only aware of the occurrence of PCOS and type 2 diabetes; they noted they were unaware of the specific timing and diagnosis, but the diagnosis came from physicians, meaning it should be validated. In conclusion, from the results described, the authors believe that guideline recommendations should be implemented for women with PCOS to be screened for type 2 diabetes at least every 3 years. This should be applied no matter the age, BMI or additional risk factors, just the occurrence of PCOS alone.

Practice Pearls:

• While some feel that PCOS is underdiagnosed, it is important for women to be aware of the symptoms and to report these at their visits.
• PCOS status alone increases the risk for developing type 2 diabetes.
• Guidelines should implement recommendations for proper screening of type 2 diabetes in women with PCOS.

Kakoly, Nadira, et al. The Impact of Obesity on the Incidence of Type 2 Diabetes Among Women With Polycystic Ovary Syndrome. Diabetes Care. 2019 April 1.

PCOS and Diabetes, Heart Disease, Stroke. Centers for Disease Control and Prevention. www.cdc.gov/diabetes/library/spotlights/pcos.html.

Emma Kammerer, L|E|C|O|M Bradenton School of Pharmacy, PharmD Candidate