title: Season affects body composition and estimation of fluid overload in haemodialysis patients: variations in body composition; a survey from the European MONDO database.
abstract: BACKGROUND
  Seasonal 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.
  
  
  METHODS
  In 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).
  
  
  RESULTS
  FM was highest in winter and lowest in summer (▵FM -1.17 kg; P < 0.001), whereas LTM was lowest during winter and highest in summer (▵LTM 0.86 kg; P < 0.0001). ECW and FO were lowest in winter, and highest in spring (▵ECW: 0.13 L; P < 0.0001, ▵FO: 0.31 L; P < 0.0001) and summer (▵ECW: 0.15 L; P < 0.0001 and ▵FO: 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.
  
  
  CONCLUSIONS
  BC 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.
authors.affiliation: Department of Internal Medicine, Division of Nephrology, Maastricht University Medical Centre, Maastricht, The Netherlands.
authors.forename: Natascha J H
authors.initials: NJ
authors.lastname: Broers
authors.affiliation: Fresenius Medical Care North America, Waltham, MA, USA.
authors.forename: Len A
authors.initials: LA
authors.lastname: Usvyat
authors.affiliation: Fresenius Medical Care, Bad Homburg, Germany.
authors.forename: Daniele
authors.initials: D
authors.lastname: Marcelli
authors.affiliation: Fresenius Medical Care, Bad Homburg, Germany.
authors.forename: Inga
authors.initials: I
authors.lastname: Bayh
authors.affiliation: Fresenius Medical Care, Bad Homburg, Germany.
authors.forename: Laura
authors.initials: L
authors.lastname: Scatizzi
authors.affiliation: Fresenius Medical Care, Bad Homburg, Germany.
authors.forename: Bernard
authors.initials: B
authors.lastname: Canaud
authors.affiliation: Department of Internal Medicine, Division of Nephrology, Maastricht University Medical Centre, Maastricht, The Netherlands.
authors.forename: Frank M
authors.initials: FM
authors.lastname: van der Sande
authors.affiliation: Renal Research Institute, New York, NY, USA.
authors.forename: Peter
authors.initials: P
authors.lastname: Kotanko
authors.affiliation: Fresenius Medical Care, Bad Homburg, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Moissl
authors.affiliation: Department of Internal Medicine, Division of Nephrology, Maastricht University Medical Centre, Maastricht, The Netherlands.
authors.forename: Jeroen P
authors.initials: JP
authors.lastname: Kooman
mesh_terms: D001794:Blood Pressure / Q000502:physiology; D001823:Body Composition; D002097:C-Reactive Protein / Q000378:metabolism; D016208:Databases, Factual; D005060:Europe; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis; D012621:Seasons; D012709:Serum Albumin / Q000032:analysis; D014883:Water-Electrolyte Imbalance / Q000503:physiopathology*; D015430:Weight Gain
chemical_list: D012709:Serum Albumin; D002097:C-Reactive Protein
keywords: bio-impedance spectroscopy; body composition; body composition monitor; fluid status