Anemia is a potential nontraditional risk factor for cardiovascular disease (CVD). This study evaluated whether anemia is a risk factor for adverse outcomes in people with diabetes and whether the risk is modified by the presence of chronic kidney disease (CKD). Persons with diabetes from four community-based studies were pooled: Atherosclerosis Risk in Communities, Cardiovascular Health Study, Framingham Heart Study, and Framingham Offspring Study. Anemia was defined as a hematocrit <36% in women and <39% in men. CKD was defined as an estimated GFR of 15 to 60 ml/min per 1.73 m 2 . Study outcomes included a composite of myocardial infarction (MI)/fatal coronary heart disease (CHD)/stroke/death and each outcome separately. Cox regression analysis was used to study the effect of anemia on the risk for outcomes after adjustment for potential confounders. The study population included 3015 individuals: 30.4% were black, 51.6% were women, 8.1% had anemia, and 13.8% had CKD. Median follow-up was 8.6 yr. There were 1215 composite events, 600 MI/fatal CHD outcomes, 300 strokes, and 857 deaths. In a model with a CKD-anemia interaction term, anemia was associated with the following hazard ratios (95% confidence intervals) in patients with CKD: 1.70 (1.24 to 2.34) for the composite outcome, 1.64 (1.03 to 2.61) for MI/fatal CHD, 1.81 (0.99 to 3.29) for stroke, and 1.88 (1.33 to 2.66) for all-cause mortality. Anemia was not a risk factor for any outcome in those without CKD (P > 0.2 for all outcomes). In persons with diabetes, anemia is primarily a risk factor for adverse outcomes in those who also have CKD.
Left ventricular hypertrophy (LVH) and anemia are highly prevalent in moderate chronic kidney disease (CKD). Because anemia may potentiate the adverse effects of LVH on cardiovascular outcomes, the effect of both anemia and LVH on outcomes in CKD was examined. Data from four community-based longitudinal studies were pooled: Atherosclerosis Risk in Communities Study, Cardiovascular Health Study, Framingham Heart Study, and Framingham Offspring Study. Serum creatinine levels were calibrated indirectly across studies, and GFR was estimated using the Modification of Diet in Renal Disease equation. CKD was defined as GFR between 15 and 60 ml/min per 1.73 m 2 . LVH was based on electrocardiogram criteria. Anemia was defined as hematocrit <36% in women and 39% in men. The primary outcome was a composite of myocardial infarction, stroke, and death; a secondary cardiac outcome included only myocardial infarction and fatal coronary heart disease.
SummaryBackground and objectives There are few data on risk factors for sudden cardiac death (SCD) in patients undergoing hemodialysis (HD). The study objective was to identify predictors associated with various causes of death in the Hemodialysis (HEMO) Study and to develop a prediction model for SCD using a competing risk approach.Design, setting, participants, & measurements In this analysis of 1745 HEMO participants, all-cause mortality was classified as SCD, non-SCD, and noncardiac death. Predictors for each cause of death were evaluated using cause-specific Cox proportional hazards models, and a competing risk approach was used to calculate absolute risk predictions for SCD.Results During a median follow-up of 2.5 years, 808 patients died. Rates of SCD, non-SCD, and noncardiac death were 22%, 17%, and 61%, respectively. Predictors of various causes of death differ somewhat in HD patients. Age, diabetes, peripheral vascular disease, ischemic heart disease, serum creatinine, and alkaline phosphatase were independent predictors of SCD. The 3-year C-statistic for SCD was 0.75 (95% confidence interval, 0.70-0.79), and calibration was good (x 2 =1.1; P=0.89). At years 3 and 5 of follow-up, the standard Cox model overestimated the risk for SCD as compared with the competing risk approach on the relative scale by 25% and 46%, respectively, and on the absolute scale by 2% and 6%, respectively.Conclusions Predictors of various causes of death differ in HD patients. The proposed prediction model for SCD accounts for competing causes of death. External validation of this model is required.
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