Season affects body composition and estimation of fluid overload in haemodialysis patients: Variations in body composition; A survey from the European MONDO database

BackgroundSeasonal variations in blood pressure (BP) and inter-dialytic weight gain (IDWG) are well established in dialysis patients. However, no study has assessed changes in body composition (BC) in this population. MethodsIn this survey, seasonal variations in fat mass (FM), lean tissue mass (LTM), extracellular water (ECW) and fluid overload (FO) were assessed in 42 099 dialysis patients (mean age 61.2 years, 58% males) from the Fresenius Medical Care Europe database, as part of the MONitoring Dialysis Outcomes (MONDO) consortium, in relation to other nutritional parameters, IDWG and BP. BC was assessed by a body composition monitor (BCM®, Fresenius Medical Care, Bad Homburg, Germany). ResultsFM was highest in winter and lowest in summer (ΔFM -1.17 kg; P < 0.001), whereas LTM was lowest during winter and highest in summer (ΔLTM 0.86 kg; P < 0.0001). ECW and FO were lowest in winter, and highest in spring (ΔECW: 0.13 L; P < 0.0001, ΔFO: 0.31 L; P < 0.0001) and summer (ΔECW: 0.15 L; P < 0.0001 and ΔFO: 0.2 L; P < 0.0001), despite a higher systolic blood pressure (SBP; 136.7 ± 17.4 mmHg) and IDWG (3.0 ± 1.1 kg) during winter. C-reactive protein (CRP), serum sodium and haemoglobin levels were highest in winter, whereas serum albumin was lowest in fall. Normalized protein catabolic rate (nPCR) was lowest in winter and matched variations in BC only to a minor degree. ConclusionsBC and hydration state, assessed by bio-impedance spectroscopy, follows a seasonal pattern which may be of relevance for the estimation of target weight, and for the interpretation of longitudinal studies including estimates of BC. Whether these changes should lead to therapeutic interventions could be the focus of future studies.