1. The association between coffee consumption and coronary artery calcium (CAC) levels was U shaped, with patients drinking between 3-5 cups of coffee least likely to have increased CAC levels.
2. As compared to non-coffee drinkers, coffee drinkers were older, men, and current smokers.
Evidence Rating Level: 3 (Average)
Study Rundown: Consumption of coffee has been associated with many health benefits including decreased risk of type 2 diabetes and decreased LDL oxidation. However, studies have shown that coffee consumption may be linked to increased cholesterol levels. Coronary artery calcium (CAC) is the buildup of calcium in the walls of coronary arteries and serves as a marker of subclinical atherosclerotic disease that can help predict future cardiovascular disease. The purpose of this study was to assess the relationship between coffee consumption and the development of CAC, measured by cardiac CT scanning, in otherwise asymptomatic individuals in a Korean cohort. Coffee consumption was measured as non-drinkers, <1, 1-<3, 3-<5, and 5 cups or greater per day. It was found that CAC levels had a quadratic, U-shaped, relationship with coffee consumption with levels being lowest in participants who drank 3-5 cups/day. A vast majority of the participants were male, and it was noted that participants with higher coffee consumption had higher fasting glucose, HBA1c, total cholesterol, triglycerides, LDL-C and lower HDL-C as compared to non coffee drinkers.
While this study presents compelling evidence supporting the cardiac benefits to moderate coffee consumption, its design as a cross-sectional study precludes declaration of a causal relationship. Additionally, this study population was entirely Korean and a large portion of the participants were males, which could affect the generalizability of the study. Further, a biochemical mechanism describing the relationship between coffee and cardiovascular disease still needs to defined. Despite these limitations, the findings support evidence from recent studies which also found that coffee consumption was associated with the reduction of cardiovascular events and warrant a more thorough prospective analysis.
In-Depth [cross-sectional study]: The purpose of this study was to asses the relationship between coffee consumption and CAC levels in participants who were asymptomatic for cardiovascular disease. This study included 25,138 men and women who had participated in the Kangbuk Samsung Health Study, a South Korean cohort in which participants had completed a food questionnaire and had a cardiac CT, who did not have any evidence of cardiovascular disease. The average age of participants was 41.3 years± SD 7.5 years and 83.7% of participants were male. They were categorized as non-coffee drinkers, >1 cup/day, 1->3 cups/day, 3-<5 cups/day and 5 cups or greater per day. Multivariate-adjusted CAC ratios, controlling for smoking, HbA1c, schooling, alcohol use, physical activity, diet, blood pressure among other confounding factors, comparing coffee drinkers to non-coffee drinkers were found as the following in <1 cup/day 0.77(CI95% 0.49 to 1.19), 1-<3 cups/day 0.66(CI95% 0.43 to 1.02), 3-<5 cups/day 0.59 (CI95% 0.38 to 0.93), and 5 cups or greater per day 0.81 (CI95% 0.46 to 1.43). The odds ratios were significant for a quadratic relationship (p<0.02)
©2015 2 Minute Medicine, Inc. All rights reserved. No works may be reproduced without expressed written consent from 2 Minute Medicine, Inc. Inquire about licensing here. No article should be construed as medical advice and is not intended as such by the authors or by 2 Minute Medicine, Inc.