Are conventional cardiovascular risk factors predictive of two-year mortality in hemodialysis patients?

Background: In general population hypertension, diabetes mellitus, overweig ht, hyperlipidemia and smoking are well-established risk factors for cardio vascular disease. However, the effect of these conventional risk factors on cardiovascular disease and mortality of patients on hemodialysis is not we ll understood. Indeed, some risk factors such as high blood pressure, hyper lipidemia and excess weight have been recently claimed to correlate with im proved survival. Objective: This study was undertaken to define the prevale nce of these conventional risk factors in 453 hemodialysis patients, predom inantly African-Americans, to determine their influence on two-year surviva l. Result: High cholesterol was found in 30% of the patients, high LDL-chol esterol in 25% and high triglycerides in 16%. Lipoprotein(a) (LP(a)) was el evated in 68% of the patients. 31% of our patients had predialysis mean art erial blood pressure (MAP) over 114, and 25% were obese based on a body mas s index (BMI) over 30, 26% were diabetic and 25% were active smokers. Smoki ng was more common among our male and Caucasian patients. The aggregate sco re for the risk factors were 2.4 +/- 0.1 per patient, which increased to 3. 2 +/- 0.1 in patients with obesity or diabetes, to 3.0 +/- 0.1 with hyperte nsion and to 2.8 +/- 0.1 with active smoking. In multivariate Cox model ana lysis, prealbumin, body weight and blood pressure showed a positive correla tion with two-year survival whereas diabetes mellitus had a negative correl ation. Hyperlipidemia did not correlate to patients' two-year mortality. Sm oking was associated with higher mortality, but that did not reach statisti cal significance. Conclusion: Conventional risk factors at least over a two -year period do not readily account for the higher mortality of a group of predominantly African-American patients on hemodialysis. The lack of predic tion is speculated to be partly due to the overriding beneficial effects of better nutrition and due to the presence of other yet to be well-defined f actors such as hyperhomocysteinemia, oxidative stress, coronary calcificati on, hitherto unidentified uremic toxins or a combination of these factors.