Are Lipid Values and BMI Related to Hospitalizations in the Hemodialysis Population?

Objective: To examine the relationship between lipid values and BMI (body mass index) on hospitalizations in hemodialysis (HD) patients. Design: Retrospective (2-year) study. Setting: Outpatient dialysis center in a large metropolitan city. Patients: This study used 158 HD patients stratified on the basis of ethnicity (non-Black and Black) and diabetic status (nondiabetic and diabetic). Intervention: Subjects were observed for 2 years. Body weight, BMI, lipid parameters, and hospitalization duration were determined 8 times (3-month intervals). Main outcome measures: Body weight, BMI, lipid parameters (serum triglyceride concentration, serum total cholesterol, high-density lipoprotein [HDL]-, low-density lipoprotein [LDL]-, very low-density lipoprotein [VLDL]- cholesterol concentrations, serum Apo-protein A1 [Apo-A1] concentration, and serum Apo-protein B [Apo-B] concentration), and morbidity data were recorded. Results: Hemodialysis subjects were hospitalized 2.3 ± 1.6 times over the 2-year experimental period. Length of hospital stay averaged 6.6 ± 0.5 days/hospitalization. Length of hospital stay was inversely related to HDL concentration (r = -0.21, P < .05, n = 89), but not significantly related to BMI in HD subjects. BMI was positively associated with LDL concentration (r = +0.28, P < .01, n = 97). Cholesterol concentration was directly associated With LDL concentration (r = +0.52, P < .01, n = 138), VLDL concentration (r = +0.47, P < .01, n = 139), and triglyceride concentration (r = +0.54, P < .01, n = 155). Mean concentration of HDL-cholesterol was inversely related serum triglyceride concentration (r = -0.43, P < .01, n = 140). Although Apo-A1 concentration was directly associated with HDL level (r = +0.39, P ( .01, n = 139), Apo-B was inversely related to HDL level (r = -0.37, P < .01, n = 138) and directly related to cholesterol concentration (r = +0.71, P < .01, n = 138), VLDL concentration (r = +0.87, P < .01, n = 138), and triglyceride concentration (r = +0.81, P < .01, n = 138). Conclusion: Cardiac disease remains the primary cause of morbidity and mortality in HD patients, and results of the present study suggest that dyslipidemias present in the HD population negatively impact cardiovascular profiles which, in turn, influence the frequency/duration of hospitalizations. Among all lipid parameters analyzed in the present study, increased LDL and decreased HDL concentrations were more strongly related to length of hospital stay than was BMI.