Marijuana Use and Estimated Glomerular Filtration Rate in Young Adults

Sex Differences in the Association Between Cumulative Use of Cannabis and Cognitive Function in Middle Age: The Coronary Artery Risk Development in Young Adults Study

Background: Cannabis use may impair cognitive function (CF) differently in men and women, due to sex-specific differences in neurobiological mechanisms and environmental risk factors. Objective: Assess sex differences in the association between cumulative exposure to cannabis and cognitive performance in middle age. Methods: We studied participants from the Coronary Artery Risk Development in Young Adults (CARDIA) Study, including Black and White men and women 18-30 years old at baseline followed over 30 years. Our cross-sectional analysis of CF scores at year 30 was stratified by sex. We computed categories of cumulative exposure in "cannabis-years" (1 cannabis-year=365 days of use) from self-reported use every 2 to 5 years over 30 years. At years 25 and 30, we assessed CF with the Rey Auditory Verbal Learning Test (verbal memory), the Digit Symbol Substitution Test (processing speed), and the Stroop Interference Test (executive function). At year 30, additional measures included Category and Letter Fluency Test (verbal ability) and the Montreal Cognitive Assessment (global cognition). We computed standardized scores for each cognitive test and applied multivariable adjusted linear regression models for self-reported cumulative cannabis use, excluding participants who used cannabis within 24 h. In a secondary analysis, we examined the association between changes in current cannabis use and changes in CF between years 25 and 30. Results: By year 30, 1,352 men and 1,793 women had measures of CF; 87% (N=1,171) men and 84% (N=1,502) women reported ever cannabis use. Men had a mean cumulative use of 2.57 cannabis-years and women 1.29 cannabis-years. Self-reported cumulative cannabis use was associated with worse verbal memory in men (e.g., -0.49 standardized units [SU] for ≥5 cannabis-years of exposure; 95% CI=-0.76 to -0.23), but not in women (SU=0.02; 95% CI=-0.26 to 0.29). Other measures of CF were not associated with cannabis. Changes in current cannabis use between years 25 and 30 were not associated with CF in men or women. Conclusions: Self-reported cumulative cannabis exposure was associated with worse verbal memory in men but not in women. Researchers should consider stratified analyses by sex when testing the association between cannabis and cognition.

Urine Epidermal Growth Factor and Kidney Function Decline in Middle-Aged Adults

Rationale & Objective

The diagnosis and prognostication of chronic kidney disease (CKD) largely rely on glomerular measures that may not reflect tubular damage. We investigated the associations of urine kidney tubule biomarkers with estimated glomerular filtration rate (eGFR) change among middle-aged adults, when chronic diseases typically emerge.

Study Design

An observational cohort study.

Setting & Participants

A total of 1,145 participants of the Coronary Artery Risk Development in Young Adults (CARDIA) study without CKD, hypertension, or cardiovascular disease at the year 20 visit.

Exposures

Seven different biomarkers of tubular health: urine epidermal growth factor (EGF), alpha-1-microglobulin (α1m), interleukin-18, kidney injury molecule-1, monocyte chemoattractant protein-1, uromodulin, and chitinase-3-like protein 1.

Outcomes

Ten-year eGFR change and incident reduced eGFR (new onset of eGFR < 60 mL/min/1.73 m2).

Analytical Approach

We examined associations of tubular health biomarkers with 10-year eGFR change and incident reduced eGFR with linear mixed models and interval-censored proportional hazards regression models, respectively. Both minimally and fully adjusted models were controlled for urine creatinine levels.

Results

The mean age of participants was 44.8 ± 3.7 years, with 39% African American and 56% female. The average 10-year change in eGFR was -18.6 mL/min/1.73 m2 (95% CI, -19.4 to -17.8). In contrast to the other tubular biomarkers, which showed conflicting results, EGF demonstrated strong, consistent associations with both kidney outcomes. Each 1-standard deviation (SD) higher EGF was associated with a 2.37 mL/min/1.73 m2 (95% CI, 0.64-4.10) smaller 10-year decrease in eGFR and a 42% (95% CI, 4%-64%) lower risk of incident reduced eGFR in the fully adjusted model.

Limitations

Observational design, measurements of eGFR were done only at 5-year intervals during follow-up.

Conclusions

In middle-aged, community-dwelling adults without hypertension, cardiovascular disease or CKD, higher urine EGF concentrations are associated with slower eGFR decline, whereas other kidney tubule biomarkers lacked a consistent association with kidney function decline.

A Retrospective Cohort Study That Examined the Impact of Cannabis Consumption on Long-Term Kidney Outcomes

Background: Cannabis consumption for recreational and medical use is increasing worldwide. However, the long-term effects on kidney health and disease are largely unknown. Materials and Methods: Post hoc analysis of cannabis use as a risk factor for kidney disease was performed using data from the Assessment, Serial Evaluation, and Subsequent Sequelae of Acute Kidney Injury (ASSESS-AKI) study that enrolled hospitalized adults with and without acute kidney injury from four U.S. centers during 2009-2015. Associations between self-reported cannabis consumption and the categorical and continuous outcomes were determined using multivariable Cox regression and linear mixed models, respectively. Results: Over a mean follow-up of 4.5±1.8 years, 94 participants without chronic kidney disease (CKD) (estimated glomerular filtration rate [eGFR] >60 mL/min/1.73 m2) who consumed cannabis had similar rates of annual eGFR decline versus 889 nonconsumers (mean difference=-0.02 mL/min/1.73 m2/year, p=0.9) and incident CKD (≥25% reduction in eGFR compared with the 3-month post-hospitalization measured eGFR and achieving CKD stage 3 or higher) (adjusted hazard ratio [aHR]=1.2; 95% confidence interval [CI]=0.7-2.0). Nineteen participants with CKD (eGFR <60 mL/min/1.73 m2) who consumed cannabis had more rapid eGFR decline versus 597 nonconsumers (mean difference=-1.3 mL/min/1.73 m2/year; p=0.02) that was not independently associated with an increased risk of CKD progression (≥50% reduction in eGFR compared with the 3-month post-hospitalization eGFR, reaching CKD stage 5, or receiving kidney replacement therapy) (aHR=1.6; 95% CI=0.7-3.5). Cannabis consumption was not associated with the rate of change in urine albumin to creatinine ratio (UACR) over time among those with (p=0.7) or without CKD (p=0.4). Conclusions: Cannabis consumption did not adversely affect the kidney function of participants without CKD but was associated with a faster annual eGFR decline among participants with CKD. Cannabis consumption was not associated with changes in UACR over time, incident CKD, or progressive CKD regardless of baseline kidney function. Additional research is needed to investigate the kidney endocannabinoid system and the impact of cannabis use on kidney disease outcomes.

Association of marijuana, tobacco and alcohol use with estimated glomerular filtration rate in women living with HIV and women without HIV

OBJECTIVE

Marijuana, tobacco and alcohol use are prevalent among people with HIV and may adversely affect kidney function in this population. We determined the association of use of these substances with estimated glomerular filtration rate (eGFR) among women with HIV (WWH) and women without HIV.

DESIGN

We undertook a repeated measures study of 1043 WWH and 469 women without HIV within the United States Women's Interagency HIV Study, a multicenter, prospective cohort of HIV-seropositive and HIV-seronegative women.

METHODS

We quantified substance exposures using semi-annual questionnaires. Using pooled eGFR data from 2009 to 2019, we used linear regression models with multivariable generalized estimating equations to ascertain associations between current and cumulative substance use exposures with eGFR, adjusting for sociodemographics, chronic kidney disease risk factors and HIV-related factors.

RESULTS

Marijuana use of 1-14 days/month versus 0 days/month was associated with 3.34 ml/min per 1.73 m 2 [95% confidence interval (CI) -6.63, -0.06] lower eGFR and marijuana use of >0.02-1.6 marijuana-years versus 0-0.2 marijuana-years was associated with 3.61 ml/min per 1.73 m 2 (95% CI -5.97, -1.24) lower eGFR. Tobacco use was not independently associated with eGFR. Alcohol use of seven or more drinks/week versus no drinks/week was associated with 5.41 ml/min per 1.73 m 2 (95% CI 2.34, 8.48) higher eGFR and alcohol use of >0.7-4.27 drink-years and >4.27 drink-years versus 0-0.7 drink-years were associated with 2.85 ml/min per 1.73 m 2 (95% CI 0.55, 5.15) and 2.26 ml/min per 1.73 m 2 (95% CI 0.33, 4.20) higher eGFR, respectively.

CONCLUSION

Among a large cohort of WWH and women without HIV, marijuana use was associated with a lower eGFR while alcohol use was associated with a higher eGFR.

Cannabis Use and Risk of Acute Kidney Injury in Patients with Advanced Chronic Kidney Disease Transitioning to Dialysis

Background: The current social and legal landscape is likely to foster the medicinal and recreational use of cannabis. Synthetic cannabinoid use is associated with acute kidney injury (AKI) in case reports; however, the association between natural cannabis use and AKI risk in patients with advanced chronic kidney disease (CKD) is unknown. Materials and Methods: From a nationally representative cohort of 102,477 U.S. veterans transitioning to dialysis between 2007 and 2015, we identified 2215 patients with advanced CKD who had undergone urine toxicology (UTOX) tests within a year before dialysis initiation and had inpatient serial serum creatinine levels measured within 7 days after their UTOX test. The exposure of interest was cannabis use compared with no use as ascertained by the UTOX test. We examined the association of this exposure with AKI using logistic regression and inverse probability of treatment weighting with extensive adjustment for potential confounders. Results: The mean age of the overall cohort was 61 years; 97% were males, 51% were African Americans, 97% had hypertension, 76% had hyperlipidemia, and 75% were diabetic. AKI occurred in 56% of the cohort, and in multivariable-adjusted analysis, cannabis use (when compared with no substance use) was not associated with significantly higher odds of AKI (odds ratio 0.85, 95% confidence interval 0.38-1.87; p=0.7). These results were robust to various sensitivity analyses. Conclusions: In this observational study examining patients with advanced CKD, cannabis use was not associated with AKI risk. Additional studies are needed to characterize the impact of cannabis use on risk of kidney disease and injury.

Cannabis Use and CKD: Epidemiological Associations and Mendelian Randomization

Rationale & Objective

The association between cannabis use and chronic kidney disease (CKD) is controversial. We aimed to assess association of CKD with cannabis use in a large cohort study and then assess causality using Mendelian randomization with a genome-wide association study (GWAS).

Study Design

Retrospective cohort study and genome-wide association study.

Setting & Participants

The retrospective study was conducted on the All of Us cohort (N=223,354). Genetic instruments for cannabis use disorder were identified from 3 GWAS: the Psychiatric Genomics Consortium Substance Use Disorders, iPSYCH, and deCODE (N=384,032). Association between genetic instruments and CKD was investigated in the CKDGen GWAS (N > 1.2 million).

Exposure

Cannabis consumption.

Outcomes

CKD outcomes included: cystatin-C and creatinine-based kidney function, proteinuria, and blood urea nitrogen.

Analytical Approach

We conducted association analyses to test for frequency of cannabis use and CKD. To evaluate causality, we performed a 2-sample Mendelian randomization.

Results

In the retrospective study, compared to former users, less than monthly (OR, 1.01; 95% CI, 0.87-1.18; P = 0.87) and monthly cannabis users (OR, 1.15; 95% CI, 0.86-1.52; P = 0.33) did not have higher CKD odds. Conversely, weekly (OR, 1.28; 95% CI, 1.01-1.60; P = 0.04) and daily use (OR, 1.25; 95% CI, 1.04-1.50; P = 0.02) was significantly associated with CKD, adjusted for multiple confounders. In Mendelian randomization, genetic liability to cannabis use disorder was not associated with increased odds for CKD (OR, 1.00; 95% CI, 0.99-1.01; P = 0.96). These results were robust across different Mendelian randomization techniques and multiple kidney traits.

Limitations

Likely underreporting of cannabis use. In Mendelian randomization, genetic instruments were identified in the GWAS that included individuals primarily of European ancestry.

Conclusions

Despite the epidemiological association between cannabis use and CKD, there was no evidence of a causal effect, indicating confounding in observational studies.

Marijuana use and DNA methylation-based biological age in young adults

BACKGROUND

Marijuana is the third most commonly used drug in the USA and efforts to legalize it for medical and recreational use are growing. Despite the increase in use, marijuana's effect on aging remains understudied and understanding the effects of marijuana on molecular aging may provide novel insights into the role of marijuana in the aging process. We therefore sought to investigate the association between cumulative and recent use of marijuana with epigenetic age acceleration (EAA) as estimated from blood DNA methylation.

RESULTS

A random subset of participants from The Coronary Artery Risk Development in Young Adults (CARDIA) Study with available whole blood at examination years (Y) 15 and Y20 underwent epigenomic profiling. Four EAA estimates (intrinsic epigenetic age acceleration, extrinsic epigenetic age acceleration, PhenoAge acceleration, and GrimAge acceleration) were calculated from DNA methylation levels measured at Y15 and Y20. Ever use and cumulative marijuana-years were calculated from the baseline visit to Y15 and Y20, and recent marijuana use (both any and number of days of use in the last 30 days) were calculated at Y15 and Y20. Ever use of marijuana and each additional marijuana-year were associated with a 6-month (P < 0.001) and a 2.5-month (P < 0.001) higher average in GrimAge acceleration (GAA) using generalized estimating equations, respectively. Recent use and each additional day of recent use were associated with a 20-month (P < 0.001) and a 1-month (P < 0.001) higher GAA, respectively. A statistical interaction between marijuana-years and alcohol consumption on GAA was observed (P = 0.011), with nondrinkers exhibiting a higher GAA (β = 0.21 [95% CI 0.05, 0.36], P = 0.008) compared to heavy drinkers (β = 0.05 [95% CI - 0.09, 0.18], P = 0.500) per each additional marijuana-year. No associations were observed for the remaining EAA estimates.

CONCLUSIONS

These findings suggest cumulative and recent marijuana use are associated with age-related epigenetic changes that are related to lifespan. These observed associations may be modified by alcohol consumption. Given the increase in use and legalization, these findings provide novel insight on the effect of marijuana use on the aging process as captured through blood DNA methylation.

Patient views regarding cannabis use in chronic kidney disease and kidney failure: a survey study

BACKGROUND

Cannabis is frequently used recreationally and medicinally including for symptom management in patients with kidney disease.

METHODS

We elicited the views of Canadian adults with kidney disease regarding their cannabis use. Participants were asked whether they would try cannabis for anxiety, depression, restless legs, itchiness, fatigue, chronic pain, decreased appetite, nausea/vomiting, sleep, cramps and other symptoms. The degree to which respondents considered cannabis for each symptom was assessed with a modified Likert scale ranging from 1-5 (anchored at 1 'definitely would not' and 5 being 'definitely would'). Multilevel multivariable linear regression was used to identify respondent characteristics associated with considering cannabis for symptom control.

RESULTS

Of 320 respondents, 290 (90.6%) were from in-person recruitment (27.3% response rate) and 30 (9.4%) responses were from online recruitment. 160/320 respondents (50.2%) had previously used cannabis including smoking (140, 87.5%), oils (69, 43.1%) and edibles (92, 57.5%). The most common reasons for previous cannabis use were recreation (84/160, 52.5%), pain alleviation (63/160, 39.4%) and sleep enhancement (56/160, 35.0%). Only 33.8% of previous cannabis users thought their physicians were aware of their cannabis use. >50% of respondents probably would or definitely would try cannabis for symptom control for all 10 symptoms. Characteristics independently associated with interest in trying cannabis for symptom control included symptom type (pain, sleep, restless legs), online respondent (ß 0.7, 95% CI 0.1-1.4) and previous cannabis use (ß 1.2, 95% CI 0.9, 1.5).

CONCLUSIONS

Many patients with kidney disease use cannabis and there is interest in trying cannabis for symptom control.

Self-reported marijuana use and its effects on overall approval in potential living kidney donors

BACKGROUND

Past and present substance use is an important part of the psychosocial evaluation of potential living kidney donors (LKDs). Increasing state legalizations and social acceptance of marijuana (MJ) use can create challenges for transplant centers.

METHODS

We investigated the frequency of reporting MJ use, and its effect on the LKD evaluation. A retrospective chart review was performed on all living donor candidates from December 2016 to December 2019 for reports of MJ use, both on an electronic intake form and during clinic evaluation with a licensed social worker (SW).Active MJ use was defined as current use or use within one year of evaluation. Baseline characteristics between MJ users and non-users were compared at each step of donor evaluation. We explored variables associated with MJ use including additional consults and testing during the donor evaluation. Overall approval and donation rates for living donors with active MJ use were compared to non-users. Additionally, 1-year donor follow up was compared between the two groups. Results Of 1,818 living donor candidates who completed the intake form, 132 admitted to active MJ use. Compared to non-users, MJ users were more likely to be younger, male, single, renting a home, and with a lower level of education. 33 of 338 candidates who completed a social work evaluation reported MJ use. Compared to non-users, MJ users were more frequently classified as moderate or high risk on SW evaluation, and often required a toxicology screen or psychiatry visit for clearance to donate. 24.2% of MJ users vs 9.5% of non-users discontinued their evaluation (P<0.01). 42.4% of MJ users vs 56.1% of non-users donated their kidney (P = 0.13). For those who donated, MJ users were less likely than non-users to follow up at 1 year (57.1% vs 83.0, p-value 0.02).

CONCLUSION

MJ users were often asked to complete additional steps in their evaluation before an approval decision was made, which may have led to the higher rate of donor drop out observed in this group. Further research is needed to assess the effects of MJ use on living donor candidacy, as well as any effects of MJ use on long-term donor outcomes. This article is protected by copyright. All rights reserved.

Substance use among adolescents and young adults with chronic kidney disease or kidney failure

Substance use, a significant public health issue, is well described in the adult chronic kidney disease (CKD) population. Knowledge about substance use in the adolescent and young adult (AYA) CKD population such as prevalence, impact on kidney function, medication adherence, and psychosocial well-being remain largely unknown. Awareness of and inquiring about substance use is paramount to providing evidence-based care and preparation to transition to adult-focused health services. The authors in this review identify commonly used substances (alcohol, tobacco, marijuana, etc.) and how they impact kidney function and care of the AYA with CKD or kidney failure. Recommendations for screening and intervention strategies are provided.

Marijuana Use and In-Hospital Outcomes After Percutaneous Coronary Intervention in Michigan, United States

OBJECTIVES

The aim of this study was to evaluate the association between reported marijuana use and post-percutaneous coronary intervention (PCI) in-hospital outcomes.

BACKGROUND

Marijuana use is increasing as more states in the United States legalize its use for recreational and medicinal purposes. Little is known about the frequency of use and relative safety of marijuana among patients presenting for PCI.

METHODS

The authors analyzed Blue Cross Blue Shield of Michigan Cardiovascular Consortium PCI registry data between January 1, 2013, and September 30, 2016. One-to-one propensity matching and multivariable logistic regression were used to adjust for differences between patients with or without reported marijuana use, and rates of post-PCI complications were compared.

RESULTS

Among 113,477 patients, 3,970 reported marijuana use. Compared with those without reported marijuana use, patients with reported marijuana use were likely to be younger (53.9 years vs 65.8 years), to use tobacco (73.0% vs 26.8%), to present with ST-segment elevation myocardial infarction (27.3% vs 15.9%), and to have fewer cardiovascular comorbidities. After matching, compared with patients without reported marijuana use, those with reported marijuana use experienced significantly higher risks for bleeding (adjusted odds ratio [aOR]: 1.54; 95% confidence interval [CI]: 1.20-1.97; P < 0.001) and cerebrovascular accident (aOR: 11.01; 95% CI: 1.32-91.67; P = 0.026) and a lower risk for acute kidney injury (aOR: 0.61; 95% CI: 0.42-0.87; P = 0.007). There were no significant differences in risks for transfusion and death.

CONCLUSIONS

A modest fraction of patients undergoing PCI used marijuana. Reported marijuana use was associated with higher risks for cerebrovascular accident and bleeding and a lower risk for acute kidney injury after PCI. Clinicians and patients should be aware of the higher risk for post-PCI complications in these patients.

Cannabis Dependence or Abuse in Kidney Transplantation: Implications for Posttransplant Outcomes

BACKGROUND

Cannabis is categorized as an illicit drug in most US states, but legalization for medical indications is increasing. Policies and guidance on cannabis use in transplant patients remain controversial.

METHODS

We examined a database linking national kidney transplant records (n = 52 689) with Medicare claims to identify diagnoses of cannabis dependence or abuse (CDOA) and associations [adjusted hazard ratio (aHR) with 95% upper and lower confidence limits (CLs)] with graft, patient, and other clinical outcomes.

RESULTS

CDOA was diagnosed in only 0.5% (n = 254) and 0.3% (n = 163) of kidney transplant recipients in the years before and after transplant, respectively. Patients with pretransplant CDOA were more likely to be 19 to 30 years of age and of black race, and less likely to be obese, college-educated, and employed. After multivariate and propensity adjustment, CDOA in the year before transplant was not associated with death or graft failure in the year after transplant, but was associated with posttransplant psychosocial problems such as alcohol abuse, other drug abuse, noncompliance, schizophrenia, and depression. Furthermore, CDOA in the first year posttransplant was associated with an approximately 2-fold increased risk of death-censored graft failure (aHR, 2.29; 95% CL, 1.59-3.32), all-cause graft loss (aHR, 2.09; 95% CL, 1.50-2.91), and death (aHR, 1.79; 95% CL, 1.06-3.04) in the subsequent 2 years. Posttransplant CDOA was also associated with cardiovascular, pulmonary, and psychosocial problems, and with events such as accidents and fractures.

CONCLUSIONS

Although associations likely, in part, reflect associated conditions or behaviors, clinical diagnosis of CDOA in the year after transplant appears to have prognostic implications for allograft and patient outcomes. Recipients with posttransplant CDOA warrant focused monitoring and support.

The nephrologist's guide to cannabis and cannabinoids

PURPOSE OF REVIEW

Cannabis (marijuana, weed, pot, ganja, Mary Jane) is the most commonly used federally illicit drug in the United States. The present review provides an overview of cannabis and cannabinoids with relevance to the practice of nephrology so that clinicians can best take care of patients.

RECENT FINDINGS

Cannabis may have medicinal benefits for treating symptoms of advanced chronic kidney disease (CKD) and end-stage renal disease including as a pain adjuvant potentially reducing the need for opioids. Cannabis does not seem to affect kidney function in healthy individuals. However, renal function should be closely monitored in those with CKD, the lowest effective dose should be used, and smoking should be avoided. Cannabis use may delay transplant candidate listing or contribute to ineligibility. Cannabidiol (CBD) has recently exploded in popularity. Although generally well tolerated, safe without significant side effects, and effective for a variety of neurological and psychiatric conditions, consumers have easy access to a wide range of unregulated CBD products, some with inaccurate labeling and false health claims. Importantly, CBD may raise tacrolimus levels.

SUMMARY

Patients and healthcare professionals have little guidance or evidence regarding the impact of cannabis use on people with kidney disease. This knowledge gap will remain as long as federal regulations remain prohibitively restrictive towards prospective research.

Should donors who have used marijuana be considered candidates for living kidney donation?

BACKGROUND

The use of marijuana in the USA has been steadily increasing over the last 10 years. This study is the first to investigate the effect of marijuana use by live kidney donors upon outcomes in both donors and recipients.

METHODS

Living kidney donor transplants performed between January 2000 and May 2016 in a single academic institution were retrospectively reviewed. Donor and recipient groups were each divided into two groups by donor marijuana usage. Outcomes in donor and recipient groups were compared using t-test, Chi-square and mixed linear analysis (P < 0.05 considered significant).

RESULTS

This was 294 living renal donor medical records were reviewed including 31 marijuana-using donors (MUD) and 263 non-MUDs (NMUD). It was 230 living kidney recipient records were reviewed including 27 marijuana kidney recipients (MKRs) and 203 non-MKRs (NMKR). There was no difference in donor or recipient perioperative characteristics or postoperative outcomes based upon donor marijuana use (P > 0.05 for all comparisons). There was no difference in renal function between NMUD and MUD groups and no long-term difference in kidney allograft function between NMKR and MKR groups.

CONCLUSIONS

Considering individuals with a history of marijuana use for living kidney donation could increase the donor pool and yield acceptable outcomes.

Accuracy of Medical Marijuana Claims Made by Popular Websites

BACKGROUND

With increasing popularity of marijuana, consumers are likely turning to the internet for information regarding medical marijuana. Accuracy of medical marijuana claims is a significant concern because consumers change their medication management based on information from a single website.

OBJECTIVE

The purpose of this study was to evaluate the accuracy and quality of medical marijuana claims on popular websites. Methods : Commonly used websites containing claims regarding medical marijuana were selected by utilizing three online marketing tools that rank websites based on number of views, number of visitors, and visitor engagement. Once the top ten most popular websites were selected, medical claims regarding marijuana were reviewed for accuracy and quality using evidence-based tools.

RESULTS

Seventy-six percent of claims made by websites were inaccurate and were based on low-quality evidence. Of the medical marijuana claims reviewed, 10% of websites made appropriate cause and effect conclusions. Furthermore, approximately 3% of the medical marijuana claims were written by a healthcare professional.

CONCLUSION

The findings show there is misleading and inaccurate information readily available to consumers online.

Self-Reported Tobacco, Alcohol, and Illicit Drug Use and Progression of Chronic Kidney Disease

BACKGROUND AND OBJECTIVES

Previous studies suggest that tobacco, alcohol, and illicit drug use is associated with CKD. We examined the associations of substance use with CKD progression and all-cause mortality among patients with CKD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The Chronic Renal Insufficiency Cohort Study is a prospective, longitudinal cohort study among 3939 participants with CKD in the United States. Self-reported tobacco smoking, alcohol drinking, marijuana use, and hard illicit drug (cocaine, heroin, or methamphetamine) use were obtained at baseline and annual follow-up visits. CKD progression was defined as incident ESKD or halving of eGFR. Substance use was modeled as the cumulative average exposure to capture both recent and long-term use in multivariable time-dependent Cox regression.

RESULTS

Over a median 5.5-year follow-up, 1287 participants developed CKD progression, and 1001 died. Baseline proportions of tobacco smoking, alcohol drinking, marijuana use, and hard illicit drug use were 13%, 20%, 33%, and 12%, respectively. Compared with nonsmoking throughout follow-up, multivariable-adjusted hazard ratios for persistent tobacco smoking were 1.02 (95% confidence interval, 0.86 to 1.21) for CKD progression and 1.86 (95% confidence interval, 1.54 to 2.24) for all-cause mortality. Compared with nondrinking throughout follow-up, multivariable-adjusted hazard ratios for persistent alcohol drinking were 1.06 (95% confidence interval, 0.88 to 1.29) for CKD progression and 0.73 (95% confidence interval, 0.58 to 0.91) for all-cause mortality. Compared with nonuse throughout follow-up, multivariable-adjusted hazard ratios for persistent marijuana use were 0.94 (95% confidence interval, 0.82 to 1.07) for CKD progression and 1.11 (95% confidence interval, 0.96 to 1.30) for all-cause mortality. Compared with nonuse throughout follow-up, multivariable-adjusted hazard ratios for persistent hard illicit drug use were 1.25 (95% confidence interval, 1.00 to 1.55) for CKD progression and 1.41 (95% confidence interval, 1.10 to 1.81) for all-cause mortality.

CONCLUSIONS

Hard illicit drug use is associated with higher risk of CKD progression and all-cause mortality, tobacco smoking is associated with higher risk of all-cause mortality, and alcohol drinking is associated with lower risk of all-cause mortality among patients with CKD.