Inclusion of ovarian morphology results in statistically significantly higher pooled prevalence estimates for PCOS. Heterogeneity in prevalence estimates for PCOS reflect the broad clinical spectrum of the condition, lack of standardization of the elements within each set of diagnostic criteria and the use of a range of diagnostic cut-offs, as well as potential differences between study populations. The use of different definitions for anovulation and clinical androgen excess did not appear to contribute to differences in the estimated prevalence of PCOS in this study. However, as the number of studies in most of the comparison groups was small, real differences may have been missed. Uncertainty surrounding the diagnosis of PCOS urgently needs to be addressed in order to provide clinicians and their patients with greater diagnostic certainty, and hence reduce inappropriate labelling and the potential psychological harm that may accompany misdiagnosis.

Despite interventions being mostly successful in retarding progression to overt diabetes, this did not result in reductions in all-cause or cardiovascular mortality, or myocardial infarction, with the possible exception of stroke.

Aims:The association between glucose lowering in diabetes mellitus and major cardiovascular (CV) outcomes is weak; indeed, some oral hypoglycemic agents are associated with increased CV events. Dipeptidyl peptidase-4 inhibitors (DPP-4 inhibitors) are a new class of oral hypoglycemic agent that may have beneficial CV effects. We undertook a systematic review and meta-analysis to appraise the CV safety and efficacy of DPP-4 inhibitors. Methods: Comprehensive search for prospective trials involving DPP-4 inhibitors. Trials included reported at least one of the outcomes examined, recruited minimum 100 patients and minimum follow-up 24 weeks. The risk ratio (RR) was calculated using the MantelHaenszel random-effects model for mortality and major cardiovascular (CV) outcomes. Results: Fifty trials enrolling 55,141 participants were included. Mean follow-up 45.3 weeks. DPP-4 inhibitors compared with all comparators (placebo and active) showed no difference in all-cause mortality (n = 50,982, RR = 1.01, 95% CI 0.91-1.13, P = 0.83), CV mortality (n = 48,151, RR = 0.97, 95% CI 0.85-1.11, P = 0.70), acute coronary syndrome (ACS) (n = 53,034 RR = 0.97, 95% CI 0.87-1.08, P = 0.59), or stroke (n = 42,737, RR = 0.98, 95% CI 0.81-1.18, P = 0.80), and a statistically significant increase in heart failure outcomes (n = 39,953, RR = 1.16, 95% CI 1.01-1.33, P = 0.04). Discussion: Treatment with DPP-4 inhibitors compared with placebo shows no increase in risk with regards to all-cause mortality, CV mortality, ACS, or stroke, but a statistically significant trend toward increased risk of HF outcomes. Conclusion: These findings suggest no cardiovascular harm (or benefit) with DPP-4 inhibitors; further large-scale CV outcome studies will resolve the issue of excess HF risk.