Women have lower NAFLD risk but higher progression

Women have a lower risk for developing nonalcoholic fatty liver disease than men, but they have a higher risk for advanced fibrosis once it is established, according to study results.

Maya Balakrishnan, MD MPH, of the section of gastroenterology and hepatology at Baylor College of Medicine, and colleagues wrote that while differences in prevalence and severity between men and women have been observed in other chronic liver diseases, the effect of sex on risk and clinical course of NAFLD has not been clarified.

“Studies to date have reported mixed results where some studies show greater NAFLD prevalence among men compared to women while others report greater prevalence of nonalcoholic steatohepatitis (NASH) — the progressive subtype of NAFLD — among women,” they wrote. “Knowing whether and how [sex] influences the risk and severity of NAFLD is important for risk stratification, risk modification as well as prognostication.”

Investigators searched the literature for studies that reported sex-stratified NAFLD prevalence among population-based samples and either NASH or advanced fibrosis among patients with biopsy-proven NAFLD.

In their meta-analysis, researchers included 54 studies comprising sample sizes of 62,239 for NAFLD, 5,428 for NASH and 6,444 for advanced fibrosis.

Balakrishnan and colleagues found that women had a lower risk for NAFLD than men (pooled risk ratio [RR] = 0.81; 95% CI, 0.68–0.97) but a similar risk for NASH. Additionally, women had a higher risk for advanced fibrosis compared with men (RR = 1.56; 95% CI, 1.12–1.68).

Researchers also found that age impacted the effect of sex on the severity of NAFLD. Among women in study populations with an average age of at least 50 years, the risk for NASH (RR = 1.17; 95% CI, 1.01–1.36) and advanced fibrosis (RR = 1.56; 95% CI, 1.36–1.8) were higher, while differences between men and women were attenuated in younger populations.

“Given the higher risk of advanced fibrosis observed among women compared to men with NAFLD in our meta-analysis, it is plausible that cirrhosis and its complications may occur with greater frequency among women than in men,” Balakrishnan and colleagues wrote. “Thus, women with NAFLD should be evaluated for NASH and fibrosis as vigorously as men.”