Female patients with end-stage renal failure treated by hemodialysis had a low mortality rate and small patient number compared to male patients: 5-year follow-up study in Japan

Background: This study aimed to evaluate gender differences in patient characteristics in maintenance hemodialysis in Takagi Hospital and, in particular, to evaluate gender differences in adverse events, gastrointestinal bleeding, and bone fractures during longitudinal follow-up period. Methods: This study included 151 patients undergoing maintenance hemodialysis for end-stage renal failure at Takagi Hospital, a regional core hospital in Japan, in December 2017. All the patients were followed up for five years or until mortality with monitoring in outpatient care. All patients were divided into a female group of 61 and a male group of 90. Patient characteristics and events were evaluated in the electronic medical record including gastrointestinal bleeding and bone fractures diagnosed and treated in Takagi Hospital. Gastrointestinal bleeding was diagnosed by endoscopy. Upper bone fractures included humeral fractures and radius fractures, and lower bone fractures were femoral neck fractures and vertebral compression fractures. Results: The patient number was small in females, which was due to the origin of renal failure with less frequency of diabetes mellitus ( P < 0.02). Mortality rate was significantly less in females ( P < 0.03) of younger generations less than 75 years old ( P < 0.014). Multivariate analysis indicated a decrease in diabetes mellitus (odd ratio: 2.3, 95% confidence interval: 1.1-4.8, P = 0.03) and less mortality in those younger than 75 years old (odd ratio: 0.2, 95% confidence interval: 0.1-0.8, P = 0.02) were independent characterized factors in females. Regarding adverse severe events during five years, gastrointestinal bleeding and mortality due to bleeding were not different between females and males. Bone fractures were high in females (females: 34.4% vs. males: 18.9%; P < 0.03), whereas the mortality rate of bone fractured patients was markedly high in males (females: 28.6% vs males: 76.5%; P = 0.003). The increase in mortality rate in males was in patients with lower body bone fractures ( P = 0.006). Conclusions: Diabetes mellitus-induced end-stage renal failure was less common in females. The mortality rate during hemodialysis was lower in females, especially in patients less than 75 years old. Lower body bone fractures exacerbated mortality more frequently in males compared to females.