MILAN – Recently published findings suggest coffee consumption may provide a beneficial effect on kidney function, thereby reducing the risk for developing chronic kidney disease, according to Healio.com.
“With no cure for CKD, the recent focus has been on the detection of mild/moderate CKD and prevention of progression to kidney failure, along with strategies to prevent and improve management of hypertension and diabetes,” Oliver J. Kennedy, BM BS, PhD, of the University of Southampton, United Kingdom, and colleagues wrote. “However, there is currently a lack of effective population-level strategies for
Although several epidemiologic studies have found regular coffee drinkers have lower risks for reduced eGFR and CKD, Kennedy and colleagues wrote that “those studies are at high risk for confounding because people with CKD risk factors, including high body mass index, hypertension and smoking, tend to drink more coffee.”
To combat these limitations, researchers used Mendelian randomization which, they wrote, “exploits genetic variations that affect modifiable risk factor exposure to estimate a causal association between exposure and outcome.”
Obtaining samples for genetic analysis from 227,666 participants in the U.K. Biobank (which was designed to investigate genetic predisposition and environmental exposure to disease development), researchers identified 2,126 single-nucleotide polymorphisms (SNPs) associated with coffee consumption and measured the impact of consumption on kidney outcomes. Primary outcomes considered were eGFR, incidence of CKD GFR stages G3 to G5 and albuminuria.
Investigators found that drinking an extra cup of coffee per day was associated with a protective effect against CKD G3-G5 (OR = 0.84) and albuminuria (OR = 0.81). Furthermore, an extra cup of coffee was associated with higher eGFR.
Researchers noted the active ingredient in coffee that may provide these effects remains undetermined and suggested non-caffeine chemical constituents (eg, chlorogenic acid and diterpenes) may play a role as these reduce inflammation and oxidative stress, which contribute to CKD onset and progression. In addition, they argued that as caffeine is a nonselective antagonist of A1 adenosine receptors, it may prevent reduction in eGFR.
“This [Mendelian randomization] MR analysis suggests a protective role of drinking coffee in maintaining kidney health among regular coffee drinkers,” they wrote. “The importance of these findings is underlined by modeling predictions of growing CKD prevalence in the United States in the next decade, which are most sensitive to assumptions in rates of eGFR decline. This is in the context of a lack of effective interventions to prevent declines in eGFRs among populations with and without CKD.”
In a related press release, Kennedy reasoned that “so many people drink coffee worldwide that even a small effect on the risk of developing chronic kidney disease would have large implications.”
Melissa J. Webb
