Salt Preference and the Incidence of Cardiovascular Disease in a Japanese General Population: The Jichi Medical School Cohort Study

Abstract

Dietary salt intake has been reported to be associated with cardiovascular disease (CVD). However, there were few studies that assessed the relationship of salt preference with CVD. We examined the association between salt preference and the incidence of CVD and its subtypes in a Japanese general population. Based on the prospective Jichi Medical School Cohort Study, data were analyzed from 11,394 eligible participants. A baseline survey of the preference for salt was obtained by questionnaire and health examinations from April 1992 through July 1995 in 12 communities in Japan. The participants were followed up until December 2005 (mean follow-up period, 10.7 ± 2.4 years). Subjects were divided into three categories according to their preference for salt: favor, so-so, and disfavor. A Cox proportional hazards model was used to calculate hazard ratios (HRs) of the incidence of CVD according to the preference categories. We observed 485 cardiovascular events (258 in men and 227 in women). Among the men, the multivariable adjusted HRs for incidence of myocardial infarction and subarachnoid hemorrhage for favor versus so-so salt preference were 0.34 (95% confidence interval, 0.17 - 0.71) and 7.10 (0.88 - 56.84), respectively. Among the women, age-adjusted HRs for the incidence of CVD, total stroke, cerebral hemorrhage, and cerebral infarction for the favor preference were 1.41 (1.02 - 1.95), 1.36 (0.97 - 1.91), 1.79 (0.87 - 3.71), and 1.40 (0.89 - 2.19), respectively. The data indicated that preference for salt may be associated with an increase in the incidence of CVD in women.