Patient Characteristics in Hemodialysis Mortality: A Comparison of Cerebro-Cardiovascular and Renal Failure Deaths in a Regional Core Hospital in Japan.

Patients with renal failure undergoing hemodialysis have a reduced survival rate. Patients with hemodialysis are well known to frequently experience complications such as infections, cerebro-cardiovascular disorders, and gastrointestinal bleeding. At the central hospital where we work in a rural area of Japan, we treat patients with hemodialysis until death, including cases with sudden changes in condition, and all clinical data leading to death are collected. Additionally, compared to previous reports on patients with hemodialysis, our hospital has a higher proportion of elderly patients, and deaths due to cerebro-cardiovascular diseases are also not uncommon. Overseas reports on whether there are differences in the underlying factors between deaths due to cerebro-cardiovascular disease and those due to renal failure in patients with hemodialysis have shown that obesity has a protective effect against deaths due to cerebro-cardiovascular disease, but the protective effect of obesity is limited in deaths due to renal failure. However, there are no reports on this point in Japan. To address this knowledge gap, the primary objective of this study was to compare patient characteristics between groups of patients with hemodialysis at our regional core hospital who died from cerebro-cardiovascular disease and those who died from renal failure. Continuous variables were assessed for normality using the Shapiro-Wilk test and visual inspection of histograms and Q-Q plots. Normally distributed continuous variables were compared using Student's t-test for two groups or one-way analysis of variance for multiple groups. Non-normally distributed continuous variables were analyzed using the Mann-Whitney U test for two groups or the Kruskal-Wallis test for multiple groups. Categorical variables were compared using the Chi-square test or Fisher's exact test. A total of 151 patients diagnosed with end-stage renal disease who were undergoing hemodialysis at the dialysis center of the nephrology department of our hospital as of December 2017 and had no history of cerebro-cardiovascular disease were enrolled in the study. All patients were followed up for five years or until death, whichever occurred first, until December 2022, and continuous monitoring of all diseases was conducted. The annual mortality rate among patients receiving dialysis was relatively high at 7.3%. Compared with the survival group, the mortality group had a higher proportion of males, older age, and bone fractures, as well as lower serum iron levels. Patients who died from cerebro-cardiovascular disease were significantly younger and had higher systolic blood pressure and higher body mass index (BMI) than those who died from renal failure. Additionally, among patients with a BMI of 22 or higher, deaths from cerebro-cardiovascular disease were significantly more common than those from renal failure. In conclusion, among patients with hemodialysis at regional core hospitals in Japan, those who died from cerebro-cardiovascular disease were significantly younger and had higher systolic blood pressure and BMI compared to those who died from renal failure. Although this finding differs from previous reports, it suggests that in the management of patients with hemodialysis at rural core hospitals in Japan, where the elderly population is high, it may be necessary to actively manage blood pressure and atherosclerosis while maintaining a BMI below 22 in younger patients.