Coffee and caffeinated drinks are among the most popular beverages in the world. About seven of every eight people in the US ingest caffeine daily, at 135 mg/day.
The highest concentration of caffeine is in coffee, however, among commonly consumed drinks, which has become a research focus among scientists looking at how coffee consumption impacts the rates of several diseases.
A new study published in Nutrition, Metabolism and Cardiovascular Diseases explores how coffee consumption affects the incidence of abdominal aortic calcification (AAC), comparing adults with hypertension, diabetes, and cardiovascular disease (CVD) and those without.
Study: Coffee consumption and abdominal aortic calcification among adults with and without hypertension, diabetes, and cardiovascular diseases. Image Credit: NOBUHIROASADA/Shutterstock.com
Moderate coffee consumption is associated with a lower risk of several diseases, called metabolic syndrome, Parkinson’s Disease (PD), type 2 diabetes, and some cancers. Notably, a single cup of coffee daily was associated with decreased mortality risk.
Conversely, the acute rise in blood pressure following coffee consumption may underlie the association of high coffee consumption with CVD risk in those with severe hypertension.
Coffee also induces insulin insensitivity, and increased consumption may raise the risk of mortality from any cause, as well as from CVD, particularly among CVD patients.
This data indicates differential benefits from coffee, depending on the prior presence of hypertension, hyperglycemia, and CVD.
Calcification of the coronary arteries is linked to lower coffee consumption. In the current study, abdominal arterial calcification was used as an early marker of atherosclerosis, preceding the actual development of clinical disease.
The aim was to see if coffee modified the AAC profile in these two groups of adults.
The investigators used data from the National Health and Nutrition Examination Survey (NHANES) 2013–2014, including over 2,500 participants. They assessed AAC severity using dual-energy X-ray absorptiometry (DXA).
Three groups were categorized: no, low and high total coffee intake, the cut-off being 390 g/day or more. The same categories were formed for caffeinated coffee drinkers as well. Decaffeinated coffee drinkers were few, so only two groups were formed in this respect, namely, those who drank decaf coffee and others.
AAC was scored by the Kauppila system based on a visual assessment of the severity of calcification in the aortic wall in each of eight segments, four posterior and four anterior, obtained by lateral spine DXA imaging. The scores are finally added up. A score >6 is considered indicative of severe AAC.
Smoking, dietary patterns, kidney disease, plasma lipids, and other metabolites of value were considered while analyzing the risk factors to mitigate possible confounding effects.
What did the study show?
Most coffee drinkers were older, White, and current smokers, but fewer were diabetic. They also had higher mean vitamin D levels and incomes but lower kidney function and poorer diet quality.
No significant associations were observed between coffee consumption and AAC scores overall. However, in the presence of any of these risk factors – hypertension, diabetes, and CVD – individuals with a mean coffee consumption of 390 g/d or more (high consumption) had higher AAC scores.
In the hypertensive group, the AAC score was 0.72 higher, with high consumption vs. none. This difference was not seen in non-hypertensive patients.
For diabetes, the difference was 1.2 units, while with CVD, the AAC scores were two units higher with high coffee consumption. This was not observable in adults without these diseases.
These associations were mirrored when decaf and caffeinated coffee drinkers were compared. Those who drank decaffeinated coffee were not at risk for higher AAC scores. Still, caffeinated coffee drinkers showed an increased risk, provided they had any of the three risk factors listed above.
Severe AAC risk was increased by 50% in those with high consumption. The risk was increased to 70% when hypertension was present as well. The odds for severe AAC were increased with diabetes or CVD in conjunction with excessive coffee drinking, though the difference from those without these conditions was insignificant.
What are the implications?
This pioneering study shows that...
...patients with hypertension, diabetes, and CVD should focus on coffee consumption, especially caffeinated coffee, to reduce the burden of AAC.”
Coffee produces an acute rise in blood pressure, reduced endothelial function, poorer responses to glucose absorption, increased sympathetic arousal, and disrupted sleep patterns. It may potentially worsen cholesterol metabolism.
These are typically counteracted by the benefits of caffeine on the metabolism but could lead to harmful effects in the presence of AAC risk factors in certain subgroups. This is corroborated by some studies showing a risk of death from CVD in hypertensive individuals or those with CVD who drank excessive coffee.
Coffee drinking also increases the odds of sudden cardiac death among those with coronary artery disease. These findings are inconclusive, however, since other research shows contradictory results.
Further study will be required to examine whether these differences are due to variations in the type of coffee, ethnicity, or duration of follow-up.
Overall, it is essential to note that earlier findings demonstrating a benefit from coffee consumption on coronary artery calcification cannot be extrapolated to other arteries, particularly the abdominal aorta.