Associations Between Reproductive and Hormone-Related Factors and Risk of Nonalcoholic Fatty Liver Disease in a Multiethnic Population

Background & Aims: Despite apparent differences between men and women in the prevalence and incidence of nonalcoholic fatty liver disease (NAFLD), there are limited epidemiologic data regarding the associations of reproductive and hormone-related factors with NAFLD. We examined the associations of these factors and exogenous hormone use with NAFLD risk in African American, Japanese American, Latino, Native Hawaiian, and white women. Methods: We conducted a nested case–control study (1861 cases and 17,664 controls) in the Multiethnic Cohort Study. NAFLD cases were identified using Medicare claims data; controls were selected among participants without liver disease and individually matched to cases by birth year, ethnicity, and length of Medicare enrollment. Reproductive and hormone-related factors and covariates were obtained from the baseline questionnaire. Multivariable logistic regression was used to calculate odds ratios (ORs) and 95% CIs. Results: Later age at menarche was associated inversely with NAFLD (P_trend =.01). Parity, regardless of number of children or age at first birth, was associated with increased risk of NAFLD (OR, 1.25; 95% CI, 1.05–1.48). Oral contraceptive use also was linked to increased risk of NAFLD (OR, 1.14; 95% CI, 1.01–1.29; duration of use P_trend =.04). Compared with women with natural menopause, those with oophorectomy (OR, 1.41; 95% CI, 1.18–1.68) or hysterectomy (OR, 1.33; 95% CI, 1.11–1.60) had an increased risk of NAFLD. A longer duration of menopause hormone therapy (only estrogen therapy) was linked with an increasing risk of NAFLD (OR per 5 years of use, 1.08, 95% CI, 1.01–1.15). Conclusions: Findings from a large multiethnic study support the concept that menstrual and reproductive factors, as well as the use of exogenous hormones, are associated with the risk of NAFLD.