A higher coffee intake appears linked to a lower risk of acute kidney injury offering the potential for cardio-renal protection through diet
A higher intake of coffee could represent a dietary intervention to protect against the development of incident acute kidney injury (AKI) according to the findings of a prospective cohort study by US researchers.
Coffee is a widely consumed drink and in a 2017 umbrella review of health benefits, it was concluded that there was a large reduction in risk for several health conditions after consumption of three to four cups a day. Furthermore, a 2019 study, found that a higher coffee intake (> 3 cups/day) was associated with a 21% lower risk of hospitalisation for liver-related hospitalisations.
A higher coffee intake has been shown to be associated with a lower risk of type 2 diabetes which is an important precursor to chronic kidney disease. In fact, a higher intake of coffee has actually been found to be associated with a reduced risk of incident chronic kidney disease which suggests that the drink might reduce the risk of progression of kidney disease.
Nevertheless, whether or not consumption of coffee is associated with a reduced risk of incident acute kidney injury is currently uncertain and was the subject of the present study.
The US team used data collected as part of the Atherosclerosis Risk in Communities (ARIC) study, which is designed to investigate the aetiology of atherosclerosis and its clinical sequelae and variation in cardiovascular risk factors, medical care, and disease by race, sex, place and time.
The study includes over 14,000 participants aged 45 to 64 years and as part of the study, consumption of coffee was self-reported and categorised as never; almost never (< 1 cup/day), 1 cup/day, 2 to 3 cups/day and > 3 cups/day. Incident cases of acute kidney injury (AKI) were defined as requiring hospitalisation during the follow-up period.
Other participant data collected included demographics, co-morbidities including diabetes, alcohol intake and smoking status. Hazard ratios were calculated based on a comparison with those who reported never consumed coffee and models fully adjusted for covariates such as co-morbidities, age, gender etc.
Higher coffee intake and acute kidney injury
A total of 14,207 individuals with a mean age of 54.2 years (54.9% female) were included in the analysis. Overall, 27% reported never drinking coffee, 23% drank 2 to 3 cups/day and 17% reported drinking more than 3 cups/day.
During a median follow-up period of 24 years, there were 1694 incident cases of AKI and in the fully-adjusted model, comparison of never to any level of coffee intake was associated with an 11% lower risk of AKI (hazard ratio, HR = 0.89, 95% CI 0.80 – 0.99, p = 0.03).
When the researchers compared the level of coffee drunk, compared to those who never drank the beverage, consuming 2 – 3 cups/day was associated with a 17% lower risk of developing AKI (HR = 0.83, 95% CI 0.72 – 0.95) and a 12% reduced risk for those drinking more than 3 cups/day (HR = 0.88).
The authors concluded that a higher coffee intake was associated with a lower risk of incident AKI and called for larger studies to investigate the effects of coffee consumption on kidney perfusion in those with impaired kidney function at high risk for AKI.
Tommerdahl KL et al. Coffee Consumption May Mitigate the Risk for Acute Kidney Injury: Results From the Atherosclerosis Risk in Communities Study Kidney Int Rep 2022