The obesity paradox: A further consideration in dialysis patients

Abstract

Several epidemiological cohorts have demonstrated that higher body mass index (BMI) is associated with lower mortality risk among patients receiving hemodialysis. However, BMI may be an inaccurate indicator of nutritional status among dialysis patients because it does not differentiate between muscle and fat mass or provide information about body fat distribution. More sophisticated methods of body composition analysis are therefore required to address the question of which component is associated with greater survival. Recent evidence has also shown that changes in body weight and body composition are more strongly associated with mortality in dialysis patients than measurement of BMI at a single time point. Given that obesity is common among the dialysis population, weight loss interventions are encouraged for obese dialysis patients who are on a transplant waiting list in order to increase the access for transplantation.

Association of Body Mass Index and Waist Circumference with All-Cause Mortality in Hemodialysis Patients

“…Recent studies have suggested that metabolically unhealthy obesity and a visceral pattern of body fat deposition [3,29] are more important contributors to a risk assessment of mortality than the overall "body volume" as measured by the BMI. The WC, a representative marker of visceral body fat, was found to correlate with inflammation, whereas subcutaneous body fat may be an indicator of the nutritional status [30].…”

Underweight and low waist circumference prior to percutaneous coronary intervention increase the risk for end-stage renal disease: A Nationwide Population Based-cohort Study

“…Recently, measures of central or abdominal obesity, de ned by the WC and waist-hip ratio, have been used as more important predictors to assess the mortality risk than BMI [29,30]. WC, a representative marker of visceral body fat, was found to correlate with in ammation, whereas subcutaneous body fat may be an indicator of the nutritional status [31].…”

Obesity in work-up of kidney transplant candidates – review of clinical practice guidelines.

“…Interestingly, an obesity paradox was described in dialyzed patients [47][48]. It is associated with better survival of obese patients who were transplanted than all patients who stay on transplant waiting list.…”

“…It is associated with better survival of obese patients who were transplanted than all patients who stay on transplant waiting list. Howver these results may be confounded by worse outcome of malnourished ESKD patients [47,[49][50]. Moreover, obesity reduces the likelihood of being enrolled to the waiting list, but not the transplantation once enrolled, especially among women [17].…”