Association between duration of oral contraceptive use and risk of hypertension: A meta‐analysis

A meta‐analysis was conducted to evaluate the association between duration of oral contraceptive use and risk of hypertension. Relevant studies published in English or Chinese were identified by a search of PubMed, Web of Science, Wanfang Database, and China National Knowledge Infrastructure to January 2017. Seventeen articles containing 24 studies with 270,284 participants were included in this meta‐analysis. The pooled relative risk of hypertension for the highest vs lowest category of oral contraceptive duration was 1.47 (95% confidence interval, 1.25–1.73), and excluding three studies with a relative risk >3.0 yielded a pooled relative risk of 1.26 (95% confidence interval, 1.11–1.44). A linear dose‐response relationship was found ( P nonlinearity =0.69) and the risk of hypertension increased by 13% (relative risk, 1.13; 95% confidence interval, 1.03–1.25) for every 5‐year increment in oral contraceptive use. The duration of oral contraceptive use was positively associated with the risk of hypertension in this meta‐analysis.