Primary hypobetalipoproteinemia as a specific etiology of steatotic liver disease: A meta-analysis

BACKGROUND & AIMS Primary hypobetalipoproteinemia (HBL) is a rare genetic disorder characterized by low plasma levels of low-density lipoprotein cholesterol below the 5th percentile for age and sex. Individuals with primary HBL are prone to developing steatotic liver disease (SLD) due to impaired secretion of very-low-density lipoprotein from the liver. However, the prevalence of SLD in this population remains unclear, and we aimed to examine this topic. METHODS In this single-arm meta-analysis, we searched PubMed and Cochrane databases from inception to February 1, 2026, for observational studies reporting the prevalence of SLD (via histology or non-invasive assessment methods) in ≥10 participants with primary HBL. We performed a meta-analysis using a generalized linear mixed model with Clopper-Pearson intervals to estimate pooled proportions. RESULTS Of the 156 records screened, 8 studies (n=462) were eligible. Five of these studies assessed hepatic steatosis using ultrasound. The pooled prevalence of SLD in primary HBL was 57.75% (95% CI 45.81 to 68.84). No differences in SLD prevalence were found according to world region, center, or sample size. There were significant differences in SLD prevalence by diagnostic method (p<0.0001). The pooled prevalence rates were 66.26%, 40.62%, and 31.73% for ultrasound, transient elastography, and magnetic resonance imaging, respectively. Specifically in familial HBL, the pooled prevalence of SLD was 60.02%. CONCLUSIONS These data confirm the high burden of SLD in primary HBL and support its consideration as a specific etiology within the SLD spectrum, particularly for patients without traditional cardiometabolic risk factors. Future studies should explore the natural history, the SLD-associated risk of fibrosis, and treatment options tailored to this subgroup.