Healthy diet and high cardiorespiratory fitness both needed to protect against CAC progressionGripeteg L, Arvidsson D, Johannesson E, et al. - Am J Cardiol 2018; published online ahead of print
Introduction and methods
Cardiorespiratory fitness (CRF) is one of the strongest predictors of CV disease and mortality, and in combination with a healthy diet, it may improve vascular health . Total coronary artery calcium (CAC) is an established measure of the extent of coronary arteriosclerosis . Studies investigating the associations between CRF, healthy diet and CAC, have yielded conflicting findings .
In this analysis of the Swedish CArdioPulmonary BioImage Study (SCAPIS), the concomitant association of CAC with a compound measure of a healthy food intake (HFI) and with CRF was investigated. SCAPIS is a national, prospective, observational study including 30,000 individuals aged 50-64 years .
A sample of 1,111 SCAPIS participants was randomly selected, and underwent extensive imaging, functional studies of the heart, lungs and metabolism. Participants also completed a questionnaire to collect information on lifestyle, living conditions, health, socioeconomic status, and performed a CRF test. In total, 706 participants had complete data for this analysis. Food intake was assessed with the web-based interactive food frequency questionnaire MiniMeal-Q . A submaximal exercise test was performed to assess CRF. CAC was assessed based on international standards . A large proportion of participants had a CAC score of zero (58%).
- There was a positive association between HFI and the odds of having no CAC (standardized regression coefficient β = 0.18; P <0.001), whereas the relationship between HFI and CAC score among individuals with CAC was non-significant (β = -0.09; P=0.34).
- CRF showed no significant association with having no CAC (β = -0.08; P=0.12), nor with the level of CAC score (β = -0.04; P = 0.64).
- In the extended regression analysis the level of CRF affected the relationship between HFI and the continuous CAC score (P-interaction HFI x CRF : 0.02).
- There was a borderline significant positive relationship between HFI and level of CAC score in participants with the lowest CRF level (β = 0.42; P=0.052), but for each increasing level of CRF, the relationship between HFI and the level of CAC score changed, up to a significant negative association for the highest CRF level (β = -0.48; P=0.045).
Healthy food intake was associated with having no CAC, and in combination with higher CRF, HFI was also associated with lower CAC levels. These results support the importance of concomitant maintenance of healthy diet and CRF in middle-aged men and women to counteract the development of CAC. These findings also suggest the importance of the healthy habits to different phases of CAC development; healthy food intake may protect from the development of CAC, while higher CRF may be required for protecting from further progression of CAC.