Abstract: 【Abstract】Objectives To observe the seasonal variation of serum albumin in peritoneal dialysis patients, and to analyze its related factors including dietary protein intake and protein loss. Methods We enrolled 41 clinically stable patients on peritoneal dialysis in our Peritoneal Dialysis Center between Sep. 2006 and Aug. 2007. Serum albumin, dietary protein intake and protein loss through urine and dialysate were recorded every one to two months, and the average values in the four seasons were calculated. Results Forty-one patients with the age of 59.69±14.23 yrs and with the dialysis duration of 35.85 months (6-104 month) were enrolled. The seasonal variation of serum albumin was obtained after adjusted for age, sex, dialysis duration, protein intake and total protein loss, with the nadir value in summer (35.45±0.38g/l) and peak value in winter (37.19±0.39g/l; P＜0.001, compared with the value in summer). There were no significant differences in the changes of dietary protein intake and total protein loss throughout the year. Next, we divided patients into two groups according to the median of age. The seasonal variation of serum albumin was more obvious in lower age group (age ≤ 62 years) than in elder age group (P＜0.05), and the differences in serum albumin in cold and warm season were 2.35g/l and 1.20g/l, respectively. Conclusions The seasonal variation of serum albumin in peritoneal dialysis can not be explained by the changes of dietary protein intake and protein loss. The extent of seasonal variation in serum albumin was more obvious in patients less than 62 yrs. The mechanism underlying these phenomena remains to be further explored.

Key words: Peritoneal dialysis, Albumin, Seasonal variation