Response to Should sleeve gastrectomy be a preoperative standard in kidney transplant waitlisted patients with a BMI of 35 kg/m2

Abstract

ResponseWe thank the Polish colleagues for their thoughtful letter and their contribution to the discussion of our publication. We absolutely agree that the body mass index (BMI) is an imperfect method of measuring the severity of obesity in patients with chronic kidney disease. First, it is less accurate than abdominal adiposity, waist circumference, and waist-tohip ratio measurements for assessing obesity-related diseases and complications [1,2]. Second, obesity assessment using the BMI neglects the patient's body composition and the proportion between (abdominal) fat, fluid, and muscle tissue. While the former is associated with the metabolic syndrome, the latter seems to have a protective effect in dialysis patients and might contribute to the so-called obesity paradox in these patients [3,4]. However, it is important to note that the data supporting the effects of the obesity paradox are mainly based on BMI measurements. Publications that are more recent question the existence obesity paradox and rather suggest that the hypothesized effects are biased by the imperfection of BMI measurement itself [5,6]. On the other hand, BMI is a quick and simple tool and can be easily performed by any medical or non-medical personnel. Therefore, there is still a raison d'être for the BMI as a screening tool to identify patients at risk. However, patient identification should be followed by more elaborate obesity measures to qualify patients for further obesity treatment. The development of chronic kidney disease is a lengthy process: years pass between the onset of kidney disease, the need for dialysis, and kidney transplantation. Therefore, it is particularly