Early and long term body composition evolution post kidney transplantation influenced by the pre transplant nutritional characteristics: results of the CORPOS study

Abstract

Many previous studies of renal transplant recipients have demonstrated that weight gain post kidney transplantation (KT) is frequent and may predispose to co morbidity. The aim of this prospective study was to evaluate changes in body composition (BC) during the first two years post KT and to determine predictors of these changes, with a special focus on pre KT parameters. When listed for a KT, 41 patients (14 women - 27 men) were included between 2007 and 2008 in a longitudinal study of evaluation of BC. Fat Free Mass (FFM) and Fat Mass (FM) were estimated by Dual-energy X- ray absorptiometry. At the same time, Extra Cellular Water (ECW) was measured by bio impedance spectroscopy. Cellular Active Mass (CAM) was defined as FFM – ECW. Energy and protein intake (EI –PI), physical activity (PA), biochemical and nutritional parameters were also recorded. Patients were evaluated every 6 months before KT, and 15 days, 1, 3, 6, 12 and 24 months after KT. During the first 2 years post KT, FM increase 0.09 kg/month (p=0.007), FFM by 0.06kg/month (p=0.0556) and MCA by 0.04kg/month (p=0.04). Univariate analysis showed that during the first 30 days post KT, FFM is strongly influenced by male gender, higher BMI, higher PIbefore KT, higher PA before KT and lower CRP post KT. During the first 2 years, FFM evolution is associated with male gender, higher EI and PI post KT. Early post KT evolution of FM is related to high BMI and high cumulative dose of corticosteroids. Long term evolution is associated with EI and use of corticosteroids. Pre KT EI and PI, as well as male gender and BMI influenced significantly the early evolution of MCA. In adjusted analyses, BMI and gender remained independently associated with FM, FFM and CAM. Furthermore, higher FFM level was associated with higher EI. We confirm that successful KT is associated with BC modifications; which can be detected very early post KT. These very early changes are strongly associated with energy, protein intake and physical activity level pre KT. Management of post KT weight gain should be anticipated with a special care on nutritional intake and physical activity in patients waiting kidney transplantation.