Does marijuana affect kidney function?
A new study found little evidence that marijuana use affects kidney function in healthy young adults. The analysis appears in an upcoming issue of the Clinical Journal of the American Society of Nephrology (CJASN).
Because marijuana is becoming increasingly accepted in the United States, there is a critical need for studies examining its risks and benefits. Regarding kidney health, animal studies suggest that marijuana might affect kidney function, but data in humans are limited.
In the first study of its kind, Julie Ishida, MD, MAS (University of California, San Francisco and San Francisco VA Medical Center) and her colleagues examined the potential links between marijuana use and kidney function in healthy young adults. Their analysis included data from the Coronary Artery Risk Development in Young Adults (CARDIA) study, which contained repeated assessments of marijuana use and kidney outcomes.
The team found that at the start of the study, individuals with higher marijuana use had lower kidney function. Upon follow-up, however, marijuana use was not associated with change in kidney function over time or the appearance of albumin in the urine, which is a sign of kidney damage.
“Results from our observational study in young adults with normal kidney function may not translate into a clinically meaningful difference and may be insufficient to inform decision-making concerning marijuana use; however, it is possible that the association between marijuana use and kidney function could be different in other populations such as older adults or patients with kidney disease, so additional research is needed,” said Dr. Ishida.
In a recent study of healthy young adults, marijuana use was not associated with change in kidney function over time or the appearance of albumin in the urine, which is a sign of kidney damage. Additional studies are needed to assess the effects of marijuana in older adults and patients with kidney disease.
Marijuana Use by CKD Patients May Hasten Renal Function Decline
|The following article is part of conference coverage from Kidney Week 2018 in San Diego hosted by the American Society of Nephrology. Renal & Urology News staff will be reporting live on medical studies conducted by nephrologists and other specialists who are tops in their field in acute kidney injury, chronic kidney disease, dialysis, transplantation, and more. Check back for the latest news from Kidney Week 2018.|
SAN DIEGO—Patients with chronic kidney disease (CKD) who use marijuana use may experience a more rapid decline in renal function than non-users, according to study findings presented at the American Society of Nephrology’s Kidney Week 2018 meeting. Marijuana use was not associated with renal function decline among individuals without CKD.
The findings are from a post-hoc analysis of data from the ASSESS-AKI (Assessment Serial Evaluation, and Subsequent Sequelae of Acute Kidney Injury) matched cohort study. Investigators defined CKD as an estimated glomerular filtration rate (eGFR) below 60 mL/min/1.73 m 2 . Of the 1599 participants in the study, 113 (7%) used marijuana. Marijuana users were significantly younger than non-users (mean 54 vs 65 years).
Among patients with CKD at baseline, the mean annual rate of decline in eGFR was 3.22 mL/min/1.73 m 2 among marijuana users compared with 1.42 mL/min/1.73 m 2 among non-users, a significant difference between the groups, a team led by Joshua L. Rein, DO, of the Icahn School of Medicine at Mount Sinai in New York, reported.
Among individuals without CKD at baseline, the mean annual rate of decline in eGFR was 1.74 and 1.63 mL/min/1.73 m 2 for marijuana users and non-users, respectively, a non-significant difference. In this group, marijuana use was not associated with development of CKD.
Marijuana use was not associated with changes in albuminuria over time in patients with or without CKD.
The investigators observed a strong but non-significant trend toward CKD progression—defined as a greater than 50% decrease in eGFR from baseline—among marijuana users with CKD at baseline.
“Marijuana is the most commonly used recreational drug and legal recreational and medicinal use is increasing worldwide,” Dr Rein told Renal & Urology News. “With increasing use and availability of marijuana, we felt it was important to understand the impact of marijuana use on the risk of CKD.”
Patients with advanced CKD and end-stage renal disease experience substantial symptom burden that is frequently undertreated due to adverse medication side effects, he stated. “Medical marijuana may be effective at treating chronic pain and nausea, among other symptoms common to this patient population,” Dr Rein said. “However, the effects of smoked marijuana in those with significant kidney disease are unknown.”
Marijuana use is increasing among adults, most rapidly among middle aged and elderly individuals, populations with a substantial CKD burden. “Recreationally, marijuana is most often smoked, and just like for tobacco, patients with CKD should not smoke marijuana,” Dr Rein said. “Medical marijuana is more commonly vaporized or consumed as a capsule or in food, which remove the cardiopulmonary side effects, but the renal effects remain unknown. Renal function in marijuana users with CKD should be closely monitored.”
With growing acceptance of both medical and recreational marijuana use, future research is needed to investigate the renal endocannabinoid system and the impact of marijuana use on kidney disease outcomes, he said.
Dr Rein acknowledged that his team was unable to assess the motivations or reasons for marijuana use and whether participants were using marijuana recreationally or medically.
|Visit Renal & Urology News’ conference section for continuous coverage from Kidney Week 2018.|
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Rein JL, Texter LJ, Wurfel MM, et al. Marijuana use and kidney outcomes in the ASSESS-AKI Cohort. Data presented at the American Society of Nephrology’s 2018 Kidney Week conference in San Diego, Oct. 23-28. Abstract FR-PO233
Marijuana users with chronic kidney disease experienced a significantly greater annual decline in estimated glomerular filtration rate than non-users, study finds.