Impact of Cigarette Smoking on Living Kidney Donors

Impact of donor smoking history on kidney transplant recipient outcomes: A systematic review and meta-analysis

BACKGROUND

Impact of donor smoking history on kidney transplant recipient outcomes is undefined.

METHODS

We systematically searched, critically appraised, and summarized associations between donor smoking and primary outcomes of death-censored and all-cause graft failure (DCGF, ACGF), and secondary outcomes of allograft histology, delayed graft function, serum creatinine, estimated glomerular filtration rate, and mortality. We searched MEDLINE, Embase, and Cochrane Databases from 2000 to 2023. Risk of bias was assessed using Risk of Bias in Non-randomized Studies - of Exposure tool. Quality of evidence was assessed by Grading of Recommendations Assessment, Development and Evaluation Working Group recommendations. We pooled results using inverse variance, random-effects model and reported hazard ratios for time-to-event outcomes or binomial proportions. Statistical heterogeneity was assessed with I2 statistic.

RESULTS

From 1785 citations, we included 17 studies. Donor smoking was associated with modestly increased DCGF (HR 1.05 (95% CI: 1.01, 1.09); I2 = 0%; low quality of evidence), predominantly in deceased donors, and ACGF in adjusted analyses (HR 1.12 (95% CI: 1.06, 1.19); I2 = 20%; very low quality of evidence). Other outcomes could not be pooled meaningfully.

CONCLUSIONS

Kidney donor smoking history was associated with modestly increased risk of death-censored graft failure and all-cause graft failure. This review emphasizes the need for further research, standardized reporting, and thoughtful consideration of donor factors like smoking in clinical decision-making on kidney utilization and allocation.

Cannabis and Cigarette Use Before and After Living Kidney Donation

Background:

It is unclear whether kidney donation leads to lifestyle changes in terms of cannabis and cigarette use.

Objective:

To describe cigarette and cannabis use before and after kidney donation and to determine their associations with lifestyle and clinical factors.

Design:

Retrospective cohort study.

Setting:

The Living Kidney Donor program in the Champlain Local Health Integration Network at The Ottawa Hospital in Ottawa, Canada.

Patients:

The study included 178 living kidney donors who donated between January 2009 and December 2018.

Measurements:

Donors were screened for cannabis and cigarette use by telephone interview. Their clinical characteristics and changes in kidney function before and after donation were recorded.

Methods:

Cannabis and cigarette use before and after kidney donation were compared using chi-square test. Risk factors associated with their use was examined by univariate and multivariate logistic regression. Wilcoxon rank sum test was used to examine the association of cannabis and Chronic Kidney Disease Epidemiology Collaboration equation (CKD-EPI) estimated glomerular filtration rate (eGFR) at donation and at last follow-up. T-test was used to examine the association of cigarette smoking and CKD-EPI eGFR at donation and at last follow-up.

Results:

Among 305 donors, 262 met inclusion criteria and 178 participated (mean of 4.7 ± 2.9 years from kidney donation). Cannabis and cigarette use were reported by 5% (9 of 178) and 13% (23 of 178) at donation. After donation, 8% (14 of 178) and 5% (9 of 178) started cannabis and cigarettes, respectively; 74% (17 of 23) of smokers remained smokers after donation and 88% (53 of 60) who quit smoking before donation did not restart after donation. In multivariate analysis, non-married/common-in-law status was associated with cannabis use (odds ratio, 2.73; 95% confidence interval, 1.05-7.11; P = .04). There was no difference in eGFR pre- or post-donation among cannabis or cigarette users.

Limitations:

The single-center study design limits generalizability. Social desirability bias may have affected survey responses and cigarette smoking was not quantified.

Conclusions:

Cannabis and cigarette use was uncommon in the studied population and was not associated with remaining kidney function. Cannabis use increased post-donation. Most smokers remained smokers after donation and most donors who quit smoking before donation did not restart after donation. This warrants education and support for potential donors who smoke, to quit smoking prior to donation to reduce risks of cardiovascular and end-stage kidney disease.

Trial Registration:

Not applicable as this is not a clinical trial.

Long-Term Outcome of Live Kidney Donation in South Korea

Background

Kidney donors may be at increased risk for end-stage renal disease (ESRD) as well as cardiovascular and all-cause mortality. In particular, data on long-term safety after kidney donation in Asian populations are lacking. We aimed to assess the safety of live kidney donation in Korean donors by using a matched control group.

Material/Methods

We conducted a retrospective cohort study using a hospital-based database (Asan Medical Center, Seoul, Korea) and a control group from the national health insurance claims database in South Korea. We analyzed the health status of 1608 kidney donors who underwent donation between September 1990 and December 2015, and we compared their characteristics with those of matched 6426 non-donors (1: 4 ratio). We also measured the glomerular filtration rate (GFR) with ⁵¹Cr EDTA and urinary albumin excretion and assessed the prevalence of hypertension, diabetes, and general health status in 200 volunteer donors.

Results

Mortality was significantly lower in kidney donors compared with the matched controls (130.2 vs. 185.4 per 100,000 person-years, P=0.02). There was no significant difference in mortality if a donor had hypertension or was a current smoker at the time of donation. There was also no significant difference in ESRD (43.1 vs. 35.2 per 100,000 person-years, P=0.07) between the 2 groups regardless of hypertension and smoking status. Among the 200 donors with measured GFR, 11.5% had GFR values <60 ml/min/1.73 m² at 9.4±5.3 years after donation. Older age (P=0.001) and female sex (P=0.021) were significantly associated with GFR values <60 mL/min/1.73 m².

Conclusions

Mortality and ESRD were uncommon in carefully selected kidney donors. However, donors with pre-existing risk factors should be followed up more closely to ensure long-term safety.