Seasonal variation in hemodialysis initiation: A single-center retrospective analysis

The number of new dialysis patients has been increasing worldwide, particularly among elderly individuals. However, information on seasonal variation in hemodialysis initiation in recent decades is lacking, and the seasonal distribution of patients' conditions immediately prior to starting dialysis remains unclear. Having this information could help in developing a modifiable approach to improving pre-dialysis care. We retrospectively investigated the records of 297 patients who initiated hemodialysis at Hiroshima Prefectural Hospital from January 1st, 2009 to December 31st, 2013. Seasonal differences were assessed by χ2 or Kruskal-Wallis tests. Multiple comparison analysis was performed with the Steel test. The overall number of patients starting dialysis was greatest in winter (n = 85, 28.6%), followed by spring (n = 74, 24.9%), summer (n = 70, 23.6%), and autumn (n = 68, 22.9%), though the differences were not significant. However, there was a significant winter peak in dialysis　initiation among patients aged ≥65 years, but not in those aged <65 years. Fluid overload　assessed by clinicians was the most common uremic symptom among all patients, but a　winter peak was only detected in patients aged ≥65 years. The body weight gain ratio　showed a similar trend to fluid overload assessed by clinicians. Pulmonary edema was most　pronounced in winter among patients aged ≥65 years compared with other seasons. The　incidences of infection were modestly increased in summer and winter, but not statistically　significant. Cardiac complications were similar in all seasons. This study demonstrated　the existence of seasonal variation in dialysis initiation, with a winter peak among patients　aged ≥65 years. The winter increment in dialysis initiation was mainly attributable to　increased fluid overload. These findings suggest that elderly individuals should be monitored　particularly closely during the winter

Linagliptin Ameliorates Methylglyoxal-Induced Peritoneal Fibrosis in Mice

Recent studies have reported increases of methylglyoxal (MGO) in peritoneal dialysis patients, and that MGO-mediated inflammation plays an important role in the development of peritoneal fibrosis through production of transforming growth factor-β1 (TGF-β1). Linagliptin, a dipeptidyl peptidase-4 inhibitor, exerts anti-inflammatory effects independent of blood glucose levels. In this study, we examined whether linagliptin suppresses MGOinduced peritoneal fibrosis in mice. Male C57/BL6 mice were divided into three groups: control, MGO injection plus saline, and MGO injection plus linagliptin (n = 6 per group). Peritoneal fibrosis was induced by daily intraperitoneal injection of saline containing 40 mmol/L MGO for 21 days. Saline was administered intraperitoneally to the control group. Linagliptin (10 mg/kg) or saline were administrated by once-daily oral gavage from 3 weeks before starting MGO injections. Immunohistochemical staining revealed that linagliptin suppressed expression of α-smooth muscle actin and fibroblast-specific protein-1, deposition of type I and III collagen, and macrophage (F4/80) infiltration. Peritoneal equilibration testing showed improved peritoneal functions in mice treated with linagliptin. Peritoneal injection of MGO increased plasma levels of glucagon-like peptide-1 (GLP-1) in mice, and a further increase was observed in linagliptin-treated mice. Although MGO increased plasma glucose levels, linagliptin did not decrease plasma glucose levels. Moreover, linagliptin reduced the TGF-β1 concentration in the peritoneal fluid of MGO-treated mice. GLP-1 receptor (GLP-1R) was expressed in monocytes/macrophages and linagliptin suppressed GLP-1R expression in MGO-injected mice. These results suggest that oral administration of linagliptin ameliorates MGO-induced peritoneal fibrosis.This work was supported by a grant from Ryokufukai and the Japanese Association of Dialysis Physicians

Monthly air temperature in Hiroshima, Japan from January 2009 to December 2013.

<p>Mean monthly air temperature (closed circles), maximum air temperature (closed squares), and minimum air temperature (open squares) in South Ward of Hiroshima City. Data obtained from the Japan Meteorological Agency.</p

Seasonal variation in number of patients according to main symptoms at dialysis initiation.

<p>Number of patients with fluid overload, general malaise, nausea or appetite loss, hyperkalemia, other uremic symptoms, and no symptom at dialysis initiation among Groups A and B.</p

Seasonal variation in the number of patients initiating dialysis.

<p>(A) Number of all patients initiating dialysis. (B) Number initiating dialysis according to age. (C) Number initiating dialysis among patients aged <65 years (Group A) (left) and ≥65 years (Group B) (right).</p

Clinical characteristics.

<p>Clinical characteristics.</p

Seasonal variations in conditions at dialysis initiation.

<p>Seasonal variations in conditions at dialysis initiation.</p