Risk of Major Adverse Cardiovascular Outcomes in Families With MASLD: A Population-Based Multigenerational Cohort Study

BACKGROUND: Metabolic dysfunction-associated steatotic liver disease (MASLD) is a risk factor for cardiovascular disease. However, whether family members of individuals with MASLD also share an increased cardiovascular risk is unknown. METHODS: We created a nationwide multigenerational cohort study identifying all family members of Swedish adults diagnosed with biopsy-proven MASLD (1969-2017) and of matched general population comparators (by age, sex, calendar year, and county of residence). We calculated incidence rates and used Cox models to calculate adjusted hazard ratios (aHRs) and 95% CIs for incident major adverse cardiovascular events (MACE), including acute myocardial infarction, stroke, hospitalization for heart failure, or cardiovascular death. Cox models were adjusted for education, country of birth, diabetes, hypertension, obesity, dyslipidemia, chronic kidney disease, chronic obstructive pulmonary disease, and the Charlson comorbidity index. RESULTS: We identified 22 267 MASLD first-degree relatives (FDRs; parents, siblings, and offspring) and 5687 MASLD spouses, as well as 118 056 comparator FDRs and 29 389 comparator spouses without earlier cardiovascular disease. Overall, the mean age was 41.8 years (SD, 18.0), and 51.5% were females. Over a median of 24.6 years, the incidence rate for MACE was higher in MASLD FDRs than in comparator FDRs (65.0 versus 62.5/10 000 person-years; aHR, 1.06 [95% CI, 1.01-1.11]). MASLD FDRs had higher rates of acute myocardial infarction (23.0 versus 20.9/10 000 person-years; aHR, 1.09 [95% CI, 1.01-1.18]) and cardiovascular death (aHR, 1.09 [95% CI, 1.01-1.18]). Across generations of FDRs, the risk of MACE was uniformly increased with no differences by relationship (ie, parents, siblings, and offspring; P-interaction>0.05). MASLD spouses were also at an increased risk of MACE (117.6 versus 103.5/10 000 person-years; aHR, 1.09 [95% CI, 1.01-1.18]). CONCLUSIONS: First-degree relatives of individuals with biopsy-proven MASLD are at slightly higher risk of incident MACE, but absolute risks do not support early screening for cardiovascular disease. Shared lifestyle factors may be the main contributors, as spouses of MASLD patients also had higher risks of MACE.