High prevalence of overweight in a stable Spanish hemodialysis population: a cross sectional study

In the general population, the prevalence of overweight is high and is considered a mortality risk factor. In maintenance hemodialysis (MHD) patients reports regarding overweight and its predictors are scarce. Our aim was to evaluate the prevalence and predictors of overweight in MHD patients, supplemented with additional follow-up data on mortality.

Retrospective, observational, cross-sectional study of 190 white, noncomplicated patients on MHD recruited from 5 Spanish dialysis centers. Three anthropometric indexes were scored (relative body weight, skinfold thickness, and midarm muscle circumference), and body mass index (BMI) and dietary intake during a 5-day period were recorded. Patient survival was evaluated during a mean follow-up period of 25 +/- 20 months.

Undernutrition (score < 7) was detected in only 15% of patients, and no patient had severe malnutrition (score < 4). The percentage of patients scored below 7, was similar in nondiabetics and type 2 diabetic patients, whereas it was significantly higher in type 1 diabetics (P =.002). Notably, 38% of patients (38% of nondiabetics, 50% of type 2 diabetics, and none of the type 1 diabetics) were overweight (BMI > or = 25 kg/m(2)). To evaluate the predictors of overweight, a stepwise logistic regression analysis was performed entering age, sex, time on dialysis, caloric intake normalized for ideal energy requirements, and protein intake. Overweight was independently influenced only by ageing (odds ratio [OR], 1.04; confidence interval [CI], 1.02-1.07; P =.0007) and female gender (OR, 2.05; CI, 1.09-3.86; P <.0001). By Cox proportional multivariate analysis, survival was positively influenced by BMI (RR, 0.88, CI, 0.79-0.97; P <.01). As expected, albumin also had a positive influence whereas age and diabetes had a negative influence on survival. This preliminary result suggests that a higher BMI may exert a protective role on survival.

Overweight represents the predominant nutritional abnormality in our MHD population, especially in the elderly, women, and type 2 diabetics.