Body mass index, comorbid conditions and quality of life in hemodialysis patients.

INTRODUCTION: Few studies have evaluated the prevalence of comorbid conditions, as well as the health-related quality of life (HRQL), in hemodialysis (HD) patients stratified according to body mass index (BMI), and these have led to conflicting results. We compared the prevalence of comorbidities and HRQL in HD patients stratified according to BMI.
METHODS: One hundred and twelve HD patients were stratified into 4 groups according to the BMI: underweight (<18.5), normal-weight (18.5-24.9), overweight (25.0-29.9) and obese (>or=30). Medical conditions enabling computation of the Charlson Comorbidity Index and HRQL were assessed through the SF-36 questionnaire.
RESULTS: There were 3 underweight (excluded from the analysis), 58 normal weight, 33 overweight and 18 obese patients. There were 68 males and 41 females. In obese patients, compared with overweight and normal-weight patients, there were significantly higher prevalences of hypertension (88.8% vs. 66.6% vs. 31%; p<0.001), diabetes (33.3% vs. 9.1% vs. 3.4%; p=0.001), coronary disease (61.1% vs. 36.3% vs. 31%; p=0.001) and cerebrovascular disease (50% vs. 21.2% vs. 22.4%; p=0.04). The prevalences of other comorbidities were similar in the 3 groups. Similarly, the Charlson Comorbidity Index was significantly higher in obese than in overweight and normal-weight patients (p=0.02). In the SF-36, there was a trend for the obese subjects to score lower than normal-weight patients on the bodily pain and role emotional scales. With regard to the physical functioning scale and the physical component summary score, the difference was statistically significant. Obese HD patients did not score significantly lower on the scale related to mental health.
CONCLUSIONS: The present study showed that obese patients have a higher prevalence of some comorbidities and score lower on physical functioning scale and on the physical component summary of the SF-36 instrument.