Low-Carbohydrate Diet Score and Coronary Artery Calcium Progression: Results From the CARDIA Study.

OBJECTIVE

To investigate whether low-carbohydrate diets (LCDs) were associated with coronary artery calcium (CAC) progression. Approach and

Results

We included the participants who completed computed tomography assessment of baseline CAC in 2000 to 2001 (year 15) and follow-up (year 20 or 25) and food frequency questionnaire (years 0, 7, and 20) in the CARDIA study (Coronary Artery Risk Development in Young Adults). CAC progression was defined as CAC >0 at follow-up among participants with baseline CAC of 0 and an annualized change of 10 or percent change of ≥10% for those with 0<baseline CAC<100 or baseline CAC≥100, respectively. Among 2226 included participants (age, 40.4±3.5 years; 45.4% men), the carbohydrate intake accounted for 47.8±6.5% of total energy, and 204 (9.2%) had CAC at baseline (year 15). Over a mean follow-up of 8.3 years, 591 (26.5%) participants had CAC progression. After adjustment for traditional cardiovascular risk factors and other dietary factors, carbohydrate intake as a percentage of total energy was inversely associated with the risk of CAC progression (hazard ratio, 0.731 [95% CI, 0.552-0.968]; P=0.029). Furthermore, the animal-based but not plant-based LCD score was significantly associated with a higher risk of CAC progression (animal-based LCD score: hazard ratio, 1.456 [95% CI, 1.015-2.089]; P=0.041; plant-based LCD score: hazard ratio, 1.016 [95% CI, 0.821-1.257]; P=0.884; both comparing extreme groups).

CONCLUSIONS

LCDs starting at a young age are associated with an increased risk of subsequent CAC progression, particularly when animal protein or fat are chosen to replace carbohydrates. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT00005130.