Low salt intake is associated with all-cause and cardiovascular mortality among Japanese hemodialysis (HD) patients, according to a new report.
In a retrospective cohort study that included 88,115 HD patients, a salt intake of less than 2.00, 2.00–3.99, and 4.00–5.99 g/day was associated with significant 2.0-, 1.6-, and 1.4-fold higher odds of all-cause mortality, respectively, and 2.4-, 1.7-, and 1.4-fold higher odds of cardiovascular death, respectively, compared with a salt intake of 6.00–7.99 g/day (reference). Salt intake higher the reference range was not significantly associated with the odds of either outcome.
For the study, which was published in the American Journal of Nephrology, Tatsuyoshi Ikenoue, MD, of Kyoto University Graduate School of Medicine and Public Health in Kyoto, Japan, and colleagues calculated salt intake from intra-dialytic weight loss and pre- and post-dialysis serum sodium levels. At baseline, the median salt intake was 6.4 g/day. At 1 year, 1845 patients (2.1%) died, 807 from cardiovascular causes.
The authors stated that the guidelines have recommended restriction of salt intake to a low level for patients on HD. The guidelines recommend restricting salt intake to less than 5–6 g/day. “We found that there is an unsafe lower limit for salt intake and, therefore, do not affirm these recommendations,” Dr Ikenoue and colleagues wrote. “We did not observe an increased risk for death among high salt intake patients.”
The investigators concluded that their study findings suggest a lower limit of salt intake be included in clinical guidelines for HD patients.
Ikenoue T, Koike K, Fukuma S, et al. Salt intake and all-cause mortality in hemodialysis patients. Am J Nephrol. 2018;48:87-95.