High Salt Intake and Risk of Chronic Bronchitis: The Copenhagen Male Study—A 10-Year Followup

Objective . The role of salt intake as a risk factor for asthma, bronchial hyperresponsiveness, and other bronchial symptoms has been addressed in a number of studies. Collectively, these studies indicate an increased risk of bronchial symptoms with high consumption of salt, but the issue remains controversial. We tested prospectively the hypothesis that salt intake would be an independent risk factor for chronic bronchitis (CB). Design . A 10-year prospective study of 2,183 men aged 46 to 65 years without any relevant lung symptoms at baseline. Main Outcome . Chronic bronchitis. Results . During the 10-year followup, the overall incidence of CB was 7.1% among men without any relevant lung symptoms at baseline. In a multiple logistic regression analysis, controlling for age, smoking habits, occupational dust exposure, alcohol use, and social class, the odds ratio associated with self-assessed high salt preference (reported by 24%) was 1.6 (1.1–2.4). Interpretation . The results suggest that salt restriction may prevent chronic bronchitis.