Stroke Risk and Serum Uric Acid Levels: Does Gender Play a Role?

Results of a meta-analysis published in the Journal of the American Heart Association¹ found no indication of gender-specific effects of elevated serum uric acid (UA) levels on stroke risk. The investigators did find a moderately increased risk of stroke in association with high serum UA levels, but it was equally distributed between men and women.

Previous studies have produced contradictory evidence of a link between serum UA and stroke risk,^2-6 and 2 studies specifically pointed to greater risks in women compared with men.^3,7 Chongke Zhong, MD, from the Medical College of Soochow University, Suzhou, China, and colleagues undertook the current study to provide a systematic analysis to evaluate a gender bias.

The investigators conducted a literature search of 3 main medical databases of all relevant studies reported by September, 2016, starting in 1965 for PubMed and Embase and in 1986 for Web of Science, specifically looking for trials that reported gender-specific results of serum UA levels associated with stroke.

The main analysis evaluated a total of 13 studies,^2-14 including 11 prospective cohort studies that reported an increased risk of serum UA tied to stroke outcomes in men and 10 that supported increased risk in women. The total number of patients in the cohorts was 12,494 and 10,229, respectively.

The relative risk (RR) of ischemic stroke associated with every 1 mg/dL increase of serum UA was slightly higher in men than in women (1.13 [CI 95%,1.08-1.17] vs 1.12 [CI 95%, 1.06-1.18]). Conversely, RR of hemorrhagic stroke was marginally increased in women compared with men (1.07 CI 95% 1.01-1.14 vs 1.05, CI 95% 0.97-1.14, respectively).

Moderate heterogeneity was observed in the men and none in the women. For both types of stroke, a significant nonlinear trend toward higher stroke risk was seen with men but not women with elevated serum UA levels.

The risk of future stroke was similar in both groups, with no significant difference attributed to gender. Overall, the investigators found a 10% increase in stroke risk for men (RR = 1.10 [1.05-1.14]) and an 11% increase for women (RR = 1.11 [1.09-1.13]) associated with each 1 mg/dL increase in serum UA, consistent with 2 previous meta-analyses suggesting a potential effect of hyperurecemia on mortality.^15,16 The nonlinear association observed only in men became most significant at serum UA levels above 6 mg/dL, increasing more sharply at higher levels.

References

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