Sensibilidade e especificidade do índice de massa corporal no diagnóstico de obesidade em pacientes renais crônicos não dialíticos: comparação com métodos padrão ouro e pontos de corte

Abstract

Introduction: Nutritional status is an important predictor of prognosis in chronic kidney disease (CKD), including pre-dialysis. Anthropometric measures universally used for the diagnosis of obesity in the general population may not present the same performance in individuals with CKD. Aim: To verify the sensitivity and specificity of the body mass index (BMI) in relation to the percentage of body fat (%BF) obtained by dual energy X-ray absorptiometry (DEXA) and air displacement plethysmography (PDA) for patients with nondialysis chronic kidney disease. Methods: The BMI was obtained. DEXA and ADP were used to determine %BF and they were considered gold standard methods. Results: A total of 78 patients were evaluated, a mean age of 54.4 ± 13.9 years old. There was a higher prevalence of overweight/obesity (55.2%), according to BMI, and high %BF, according to DEXA (69.2%) and ADP (53.8%). The BMI showed a statistically significant correlation with the %BF obtained by both methods and in both sexes (p <0.05). To detect high %BF, the BMI of 25 kg/m2 had better sensitivity and specificity values for DEXA (73.3% and 66.7%, respectively) and ADP (77.3% and 52.9%, respectively) ) in men, and for DEXA (79.9% and 46.7%, respectively) in women. However, the BMI of 26 kg/m2 for ADP in women would be more accurate (70.0% and 73.7%, respectively). Conclusion: The prevalence of patients with excess body fat was elevated. The cutoff points for BMI were not adequate in these patients and suggested that BMI = 25 kg / m2 for men and BMI = 26 kg / m2 for the best diagnostic conditions of obesity.