Apoprotein B/apoprotein A-1 ratio and mortality among prevalent dialysis patients

Abstract

Background and objectives In dialysis patients, the associations between apoprotein profile and all-cause or cardiovascular disease (CVD)-related mortality are not well known. We, therefore, investigated whether apoprotein levels are associated with these events. Design, setting, participants, & measurements We undertook a prospective observational cohort study of prevalent hemodialysis patients aged ≥18 years (n=1081), who were followed for 4 years (2011–2014). Outcomes were all-cause and CVD-related mortality. Predictors used were baseline apoprotein levels, particularly the apoprotein B (apo B)/apoprotein A-1 (apo A-1) ratio. A Cox regression analysis was used to calculate the hazard ratios (HRs) for mortality. Apo A-1, apo B, and apo B/ apo A-1 ratio were analyzed with adjustments in three models: model 1, basic adjustment for age and sex; model 2, basic adjustments plus dialysis conditions (dialysis vintage, mean predialysis systolic blood pressure, dry weight, and mean intradialytic weight gain); and model 3, model 2 plus metabolic and inflammatory conditions (basal kidney disease, serum albumin, C-reactive protein level, and statin use). Results Of the 1081 patients included in the study, 203 deaths were recorded, 92 of which were related to CVD. The apo B/ apo A-1 ratio was significantly associated with all-cause and CVD-related mortality when analyzed by 1-SD increments or quartile IV versus I in all models. In model 3, HRs and 95% confidence intervals (95% CIs) for 1-SD increments of apo B/ apo A-1 ratio for all-cause mortality or CVD-related mortality were: HR, 1.16 (95% CI, 1.00 to 1.35), or HR, 1.38 (95% CI, 1.11 to 1.71), respectively, and for quartile IV versus I: HR, 1.65 (95% CI, 1.05 to 2.57), or HR, 2.56 (95% CI, 1.21 to 5.40), respectively. Apo A-1 was significantly associated with both mortalities in models 1 and 2. However, apo B was only significantly associated with CVD-related mortality in model 3. Conclusions Apoprotein measurement, especially the apo B/apo A-1 ratio, was significantly associated with all-cause and CVD-related mortality in prevalent dialysis patients.