Diet and sedentary behaviour in relation to mortality in US adults with a cardiovascular condition. Results from the National Health and Nutrition Examination Survey linked to the US mortality registry

Cardiovascular disease (CVD) is the most common chronic condition and the highest cause of mortality in the US. The aim of the present work was to investigate diet and sedentary behaviour in relation to mortality in US CVD survivors. The National Health and Nutrition Examination Surveys conducted between 1999 and 2014 linked to the US mortality registry updated to 2015 was investigated. Multivariate adjusted Cox regression was used to derive mortality hazards in relation to sedentary behaviour and nutrients intake. A multiplicative and additive interaction analysis was conducted to evaluate how sedentariness and diet influence mortality in US CVD survivors. A sample of 2,473 participants followed for a median period of 5.6 years resulted in 761 deaths, 199 deaths were due to CVD. A monotone increasing relation between time spent in sedentary activities and mortality risk were observed for all-cause and CVD mortality (HR = 1.20, 95% CI = 1.09, 1.31 and HR = 1.19, 95% CI = 1.00, 1.67, respectively). Inverse mortality risks in the range of 22 to 34% was observed when comparing the highest to the lowest tertile of dietary fiber, vitamin A, carotene, riboflavin, and vitamin C. Sedentariness below 360 minutes/day and dietary fiber and vitamin intake above the median interact on an additive scale influencing positively all-cause and CVD mortality risk. Reduced sedentariness in combination with a varied diet rich in dietary fiber and vitamins, appears to be a useful strategy to reduce all-cause and CVD mortality in US CVD survivors.