Is the APOA5 rs662799 C allele linked to higher triglycerides and lower HDL cholesterol?

APOA5 rs662799 (−1131T>C) is a common genetic marker linked to an atherogenic lipid pattern, most consistently elevated triglycerides. For a 53-year-old woman, it may help contextualize a lipid phenotype, but does not establish an individual’s current triglyceride or HDL-C level.

Clinical evidence

• C-allele carriage is robustly associated with higher fasting triglycerides. Meta-analyses of 37,859 and 51,868 participants found an approximately 0.30 mmol/L increase (95% CI 0.26–0.33) and standardized mean difference 0.31 (95% CI 0.27–0.34) versus TT/noncarrier groups.
• Cohort data suggest an allele-dose pattern: adjusted triglycerides were 1.08 mmol/L (TT), 1.26 mmol/L (CT), and 1.48 mmol/L (CC) in one Hong Kong Chinese cohort.
• HDL-C is modestly lower in carriers: pooled difference −0.05 mmol/L; another meta-analysis reported standardized mean difference −0.17 (95% CI −0.21 to −0.14), and one collaborative analysis found 3.5% lower HDL-C per C allele.
• C-allele carriage was also associated with metabolic syndrome (dominant model OR 1.33, 95% CI 1.16–1.53), with stronger evidence in East Asian populations.

Mechanistic interpretation

• ApoA-V promotes lipoprotein-lipase-mediated hydrolysis and clearance of VLDL and chylomicrons. Delayed postprandial triglyceride peaks and larger chylomicron/VLDL triglyceride responses in carriers fit impaired triglyceride-rich lipoprotein processing.
• The proposed rs662799-specific mechanism remains uncertain: promoter-function results conflict, APOA5 mRNA differences were not consistently observed, and strong linkage disequilibrium with functional variants such as rs2266788 complicates causal attribution.
• Lower HDL-C may accompany triglyceride-rich particle accumulation through triglyceride exchange, HDL remodeling, and catabolism, but this causal pathway has not been directly demonstrated for rs662799.

Bottom line

• The claim is well supported for higher triglycerides and modestly lower HDL-C; impaired triglyceride-rich lipoprotein metabolism is a biologically coherent, moderately supported explanation, strongest for triglycerides rather than HDL-C.