Dietary salt intake and mortality in patients with type 2 diabetes

Diabetes Care. 2011 Mar;34(3):703-9. doi: 10.2337/dc10-1723. Epub 2011 Feb 2.


Objective: Many guidelines recommend that patients with type 2 diabetes should aim to reduce their intake of salt. However, the precise relationship between dietary salt intake and mortality in patients with type 2 diabetes has not been previously explored.

Research design and methods: Six hundred and thirty-eight patients attending a single diabetes clinic were followed in a prospective cohort study. Baseline sodium excretion was estimated from 24-h urinary collections (24hU(Na)). The predictors of all-cause and cardiovascular mortality were determined by Cox regression and competing risk modeling, respectively.

Results: The mean baseline 24hU(Na) was 184 ± 73 mmol/24 h, which remained consistent throughout the follow-up (intraindividual coefficient of variation [CV] 23 ± 11%). Over a median of 9.9 years, there were 175 deaths, 75 (43%) of which were secondary to cardiovascular events. All-cause mortality was inversely associated with 24hU(Na), after adjusting for other baseline risk factors (P < 0.001). For every 100 mmol rise in 24hU(Na), all-cause mortality was 28% lower (95% CI 6-45%, P = 0.02). After adjusting for the competing risk of noncardiovascular death and other predictors, 24hU(Na) was also significantly associated with cardiovascular mortality (sub-hazard ratio 0.65 [95% CI 0.44-0.95]; P = 0.03).

Conclusions: In patients with type 2 diabetes, lower 24-h urinary sodium excretion was paradoxically associated with increased all-cause and cardiovascular mortality. Interventional studies are necessary to determine if dietary salt has a causative role in determining adverse outcomes in patients with type 2 diabetes and the appropriateness of guidelines advocating salt restriction in this setting.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Diabetes Mellitus, Type 2 / mortality*
  • Diabetes Mellitus, Type 2 / urine
  • Female
  • Humans
  • Male
  • Middle Aged
  • Prospective Studies
  • Sodium / urine
  • Sodium Chloride, Dietary*


  • Sodium Chloride, Dietary
  • Sodium