Effect of Obesity, Serum Lipoproteins, and Apolipoprotein E Genotypes on Mortality in Hospitalized Elderly Patients

Background: The aim of this study was to investigate the relationship among apolipoprotein E (APOE) polymorphism, body mass index (BMI), and dyslipidemia and how these factors modify overall mortality in a cohort of hospitalized elderly patients. Methods: Plasma concentrations of total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), BMI, and APOE genotype were evaluated in 1,012 hospitalized elderly patients, who were stratified into three groups according to their baseline BMI and APOE allele status. Multivariate logistic regression analysis was used to assess whether APOE genotype, BMI, and dyslipidemia are associated with mortality, adjusting for potential confounders. Interaction analysis was also performed. Results: Obese patients have significantly higher levels of TC and LDL-C compared to normal-weight and overweight subjects, for both sexes. APOE epsilon 4 carriers have significantly higher levels of TC and LDL-C compared with epsilon 2 and epsilon 3 carrier both in males and females. Interaction analysis showed that women with TC < 180 mg/dL, LDL-C < 100 mg/dL, normal weight, and epsilon 3 carrier (odds ratio [OR] = 3.42, 95% confidence interval [CI] 1.36-8.60) and men with LDL-C < 100 mg/dL, HDL-C < 40 mg/dL, and epsilon 3 carrier (OR = 1.97, 95% CI 1.04-3.74) were at highest risk of mortality. Conclusions: In elderly hospitalized patients, obesity and APOE genotype influence the lipid profile and mortality risk. A significant interaction among BMI, dyslipidemia, and APOE genotype was observed that could identify elderly patients with different risks of mortality.