Tatsuyoshi Ikenoue1,2,3, Kiyomi Koike4, Shingo Fukuma1,3, Satoshi Ogata5, Kunitoshi Iseki6, Shunichi Fukuhara1. 1. Department of Healthcare Epidemiology, Kyoto University Graduate School of Medicine and Public Health, Yoshida Konoe-cho, Kyoto, Japan. 2. Fujiidera Keijinkai Clinic, Fujiidera, Japan. 3. Human Health Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan. 4. Division of Nephrology, Department of Medicine, Kurume University School of Medicine, Kurume, Japan. 5. Committee of the Renal Data Registry, The Japanese Society for Dialysis Therapy, Tokyo, Japan. 6. Clinical Research Support Center, Tomishiro Central Hospital, Tomigusuku, Japan.
Abstract
BACKGROUND: Although some clinical practice guidelines regarding hemodialysis recommend salt restriction, few studies have examined the association between salt intake and clinical outcomes in hemodialysis patients. This study aimed to clarify the association between salt intake and mortality in hemodialysis patients. METHODS: This retrospective cohort study was based on the Japanese Society for Dialysis Therapy renal data registry database (2008) and included 88,115 adult patients who had received hemodialysis for at least 2 years. Estimated salt intake was the main predictor and was calculated from intra-dialytic weight loss and pre- and post-dialysis serum sodium levels. Nonlinear logistic regression was used to determine the association between salt intake and mortality, adjusting for potential confounders. The outcomes considered were all-cause mortality and cardiovascular death at 1 year. RESULTS: The median (25-75th percentile) salt intake at baseline was 6.4 (4.6-8.3) g/day. At 1 year, all-cause mortality occurred in 1,845 (2.1%) patients, including 807 cardiovascular deaths. The low salt intake group (< 6 g/day) demonstrated the highest all-cause mortality and cardiovascular deaths. No association was observed between high salt intake, all-cause mortality and cardiovascular deaths. The lowest risk for all-cause mortality and cardiovascular death occurred among patients with an estimated salt intake of 9 g/day. CONCLUSION: Low salt intake, but not high salt intake, was associated with all-cause and cardiovascular mortality in Japanese hemodialysis patients. Further studies to justify including a lower limit of salt intake for hemodialysis patients are suggested.
BACKGROUND: Although some clinical practice guidelines regarding hemodialysis recommend salt restriction, few studies have examined the association between salt intake and clinical outcomes in hemodialysis patients. This study aimed to clarify the association between salt intake and mortality in hemodialysis patients. METHODS: This retrospective cohort study was based on the Japanese Society for Dialysis Therapy renal data registry database (2008) and included 88,115 adult patients who had received hemodialysis for at least 2 years. Estimated salt intake was the main predictor and was calculated from intra-dialytic weight loss and pre- and post-dialysis serum sodium levels. Nonlinear logistic regression was used to determine the association between salt intake and mortality, adjusting for potential confounders. The outcomes considered were all-cause mortality and cardiovascular death at 1 year. RESULTS: The median (25-75th percentile) salt intake at baseline was 6.4 (4.6-8.3) g/day. At 1 year, all-cause mortality occurred in 1,845 (2.1%) patients, including 807 cardiovascular deaths. The low salt intake group (< 6 g/day) demonstrated the highest all-cause mortality and cardiovascular deaths. No association was observed between high salt intake, all-cause mortality and cardiovascular deaths. The lowest risk for all-cause mortality and cardiovascular death occurred among patients with an estimated salt intake of 9 g/day. CONCLUSION: Low salt intake, but not high salt intake, was associated with all-cause and cardiovascular mortality in Japanese hemodialysis patients. Further studies to justify including a lower limit of salt intake for hemodialysis patients are suggested.