NDT Advance Access originally published online on September 21, 2007
Nephrology Dialysis Transplantation 2008 23(2):687-692; doi:10.1093/ndt/gfm618
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Seasonal variations in serum sodium levels and other biochemical parameters among peritoneal dialysis patients
1Division of Nephrology, Department of Internal Medicine, Taipei Veterans General Hospital, 2Division of Nephrology 3Division of General Medicine, Department of Internal Medicine, Taipei Veterans General Hospital and School of Medicine, National Yang-Ming University and 4Division of Nephrology, Department of Internal Medicine, Taipei Medical University and Hospital, Taipei, Taiwan
Correspondence to: Tzen-Wen Chen, MD, PhD, Division of Nephrology, Department of Medicine, Taipei Medical University and Hospital, No. 252, Wu Hsing St., Sinyi District, Taipei 110, Taiwan. Email: twchen{at}tmu.edu.tw
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Abstract |
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Background. Although modest seasonal variations in blood biochemical composition have been reported in end-stage renal disease patients treated with haemodialysis, there have been no adequate explanations. The current study aimed to explore whether these phenomena are present in peritoneal dialysis patients and to discuss these variations.
Methods. This was a retrospective study with an enrollment of 44 anuric PD patients. Serum biochemical parameters, peritoneal function, dialysis adequacy, peritoneal ultrafiltration volume and body weight were analysed in relation to climate variables for a study period of 2 years.
Results. PD patients exhibited cyclic variations in blood biochemical concentrations. Monthly mean outdoor temperature was inversely correlated with serum concentrations of sodium (r = –0.712, P < 0.001), potassium (r = –0.697, P < 0.001), bicarbonate (r = –0.642, P < 0.001), BUN (r = –0.654, P < 0.001), albumin (r = –0.496, P = 0.012), peritoneal ultrafiltration volume (r = –0.723, P = 0.001) and body weight (r = –0.623, P < 0.001). Serum chloride and creatinine concentrations were not correlated with temperature or other climate variables.
Conclusions. PD patients showed seasonal variations in serum electrolyte concentration and peritoneal ultrafiltration volume. Monthly outdoor mean temperature was inversely correlated with serum electrolytes and ultrafiltration volume. A likely explanation is loss of these electrolytes through perspiration. Neglect of this annual cycle in PD patients may lead to biases in interpretation of clinical study and individual laboratory data.
Keywords: electrolyte; end-stage renal disease; peritoneal dialysis; perspiration; seasonal variation; ultrafiltration
Received for publication: 23. 2.07
Accepted in revised form: 14. 8.07