Associations between Body Mass Index in Hemodialysis Patients and Comorbidity, Dialysis Adequacy, Blood Pressure Control, Vascular Access Type, and Hospital Admission Rate

Abstract

Higher body mass index (BMI) is associated with various comorbidities. In hemodialysis (HD) patients, BMI affects dialysis adequacy and blood pressure (BP) control and is associated with serious comorbidities. This is a cross-sectional observational study that took place at King Abdulaziz Medical City, Riyadh, Saudi Arabia. A total of 262 adult patients on HD for at least six months were recruited to this study. Chart review was used to retrospectively collect patients' data. Categorical variables were compared using Chi-square test of proportions, whereas analysis of variance was used between categorical and continuous variables. P <0.05 was considered statistically significant. Only 17 (6.5%) patients were underweight, 90 (34.4%) had normal weight, 65 (24.8%) were overweight, and 90 (34.4%) were obese. Diabetes mellitus was the most common cause of chronic kidney disease. A significant relationship was found between BMI and dialysis adequacy (P = 0.004) with 54 (60%) obese patients having inadequate dialysis. The mean postdialysis systolic BP was the lowest in the obese BMI category (129.71 ± 18.38 mmHg, P = 0.037). The obese category scored least on the Charlson Comorbidity Index (CCI) reflecting lower risk of mortality than the other three BMI categories. Despite having the lowest overall rate of hospitalization in the previous 12 months, obese patients had higher rates of hospitalization from sepsis compared to the other three groups (P = 0.048). Despite having reduced dialysis adequacy, obese HD patients scored less on CCI, had better postdialysis BP, and had fewer hospital admissions in the previous 12 months compared to the other BMI groups. These findings distinctly contrast with what is seen among obese persons in the general population.