Adding salt to foods and hazards of microvascular, cerebrovascular and cardiovascular diseases

Background We aimed to examine the association of the frequency of adding salt to foods and the hazards of the incidence and mortality risks for a range of vascular outcomes, including microvascular, cerebrovascular, and cardiovascular diseases. Methods 438,307 participants from the UK Biobank who completed the questionnaire on the frequency of adding salt to foods and were free of vascular disease at baseline were enrolled. Information on the frequency of adding salt to foods (do not include salt used in cooking) was collected at baseline through a touch-screen questionnaire. The primary outcomes included incident microvascular diseases, cerebrovascular diseases, and cardiovascular diseases, respectively. The secondary outcomes included: (1) each component of these vascular diseases (10 components in total), (2) first occurrence of fatal and non-fatal vascular diseases. Results During a median follow-up of 12.1 years, a total of 17,169 (3.9%), 10,437 (2.4%), and 48,203 (11.0%) participants developed microvascular, cerebrovascular and cardiovascular diseases, respectively. Overall, the hazards of incident microvascular, cerebrovascular and cardiovascular diseases increased with the increasing frequency of adding salt to foods (all P for trend <0.001). Similar trends were found for the secondary outcomes. Moreover, the positive association of always adding salt to foods with hazard of cardiovascular diseases was stronger among current-smokers ( P -interaction = 0.010), younger participants ( P -interaction <0.001), and those with lower body mass index levels ( P -interaction = 0.003). Conclusions Higher frequency of adding salt to foods was associated with higher hazards of non-fatal and fatal microvascular, cerebrovascular and cardiovascular diseases, and each component of these vascular diseases.