Association between polycystic ovary syndrome and the risk of stroke and all-cause mortality: insights from a meta-analysis

Many epidemiologic literatures have investigated the link between PCOS and long-term stroke risk and all-cause mortality, but the results are surprisingly conflicting. A meta-analysis was performed to examine the link between polycystic ovary syndrome (PCOS) and the risk of stroke, death from any cause, and assessed whether BMI might explain a higher risk of stroke. We searched the PUBMED, EMBASE, and Cochrane Library databases with no restrictions. Nine Cohort studies were identified, involving a total of 237,647 subjects. Compared with those without PCOS, subjects with PCOS were significantly associated with a increased risk of developing stroke (OR=1.36; 95% CI 1.09-1.70; p=.007). However, no significant association was observed between PCOS and all-cause death (OR=1.21; 95% CI 0.88-1.66; p=.25). Moreover, after pooling the five studies with risk estimates adjusted for BMI, the association between PCOS and stroke was slightly attenuated, although the odds ratios did not reach statistical significance (OR=1.24; 95%CI 0.98-1.59). In conclusion, PCOS is associated with significant increased risk for stroke, while there is no consistent evidence to indicate that PCOS influences all-cause death outcomes. Increased BMI is an important contributor to the relationship between PCOS and stroke risk. Further study is needed to clarify which subgroups of subjects with the PCOS are at higher risk for stroke and should focus on developing reliable device for risk stratification.