Smoking in dialysis patients: a systematic review and meta-analysis of mortality and cardiovascular morbidity

Epidemiology of tobacco use in dialysis patients in France and survey of nephrologists' involvement in counseling on tobacco discontinuation

BACKGROUND

Tobacco smoking is an independent risk factor for chronic kidney disease (CKD) and increases morbidity and mortality in CKD patients. The primary objective of the study was to investigate the epidemiology of smoking in patients undergoing maintenance dialysis in France. A second objective was to assess the involvement of nephrologists in supporting patients for smoking cessation.

METHODS

Data on the smoking history of prevalent patients on maintenance dialysis in France between 2010 and 2020 were obtained from the REIN database (Renal Epidemiology and Information Network), updated by all French nephrology and dialysis centers. As for the support to smoking discontinuation, a questionnaire on smoking cessation assistance was sent to all members of the French Society of Nephrology, Dialysis and Transplantation (SFNDT).

RESULTS

The proportion of current smokers among patients on maintenance dialysis was 10.4% in 2010, 11.2% in 2015 and 11.6% in 2020. A total of 228 nephrologists among the 790 members of the SFNDT participated in the survey (28.9%). Most respondents were women (57.3%), worked at a public hospital (61.1%), were under 40 years of age (51.3%) and had no history of smoking (60.8%). The majority reported asking patients about their smoking status and offering brief advice. Among respondents, 72.8% offered help with smoking cessation, 46.3% referred their smoking patients to a tobacco specialist, 51.8% reported prescribing drugs to quit tobacco, and 81.6% requested further training in how to support patients for smoking cessation.

CONCLUSION

Smoking cessation training for nephrologists and dedicated programs for patients in nephrology units could improve our practices and decrease the high prevalence of smoking in patients with ESKD.

Pathophysiological concepts and screening of cardiovascular disease in dialysis patients

Dialysis patients experience 10-20 times higher cardiovascular mortality than the general population. The high burden of both conventional and nontraditional risk factors attributable to loss of renal function can explain higher rates of cardiovascular disease (CVD) morbidity and death among dialysis patients. As renal function declines, uremic toxins accumulate in the blood and disrupt cell function, causing cardiovascular damage. Hemodialysis patients have many cardiovascular complications, including sudden cardiac death. Peritoneal dialysis puts dialysis patients with end-stage renal disease at increased risk of CVD complications and emergency hospitalization. The current standard of care in this population is based on observational data, which has a high potential for bias due to the paucity of dedicated randomized clinical trials. Furthermore, guidelines lack specific guidelines for these patients, often inferring them from non-dialysis patient trials. A crucial step in the prevention and treatment of CVD would be to gain better knowledge of the influence of these predisposing risk factors. This review highlights the current evidence regarding the influence of advanced chronic disease on the cardiovascular system in patients undergoing renal dialysis.

Cutaneous squamous cell carcinoma and mortality in end-stage renal disease

BACKGROUND

In the general population, cutaneous squamous cell carcinoma (cSCC) is associated with increased all-cause mortality. Transplant patients have been shown to have an increased risk of developing cSCC, and their cSCC is associated with an increased risk for mortality. In end-stage renal disease (ESRD) patients, there is extensive mortality and immune dysfunction. Because of this immune system dysfunction, we examined whether cSCC is associated with increased risk of all-cause mortality among ESRD patients, as well as the risk factors for cSCC.

METHODS

We analyzed ESRD patients in the United States Renal Data System from 2004-2014, excluding organ transplant recipients. We assessed mortality using a Cox Proportional Hazards (CPH) model to control for various demographic and clinical parameters, identified using international classification of diseases (ICD)-9 codes.

RESULTS

Of the 1,035,193 patients included, 624 (0.1%) were diagnosed with cSCC. The median survival time for those with cSCC was 3.91 years [95% confidence interval (CI) = 3.67-4.15], versus 2.92 years [95%CI = 2.92-2.93] for patients without cSCC. ESRD patients with cSCC were at lower risk of death [adjusted hazard ratio = 0.75; 95%CI = 0.69-0.82] compared to those without. Decreased risk of death was also associated with parameters such as black race, Hispanic ethnicity, tobacco dependence and actinic keratosis. Increased mortality risk was associated with increasing age, male sex, hemodialysis (versus peritoneal dialysis) and alcohol dependence.

CONCLUSIONS

Contrary to expectations, ESRD patients with a cSCC diagnosis showed reduced all-cause mortality risk relative to those without. The reason for this discrepancy remains unclear, suggesting the need for further study.

Smoking is a Risk Factor for Endogenous Peritonitis in Patients Undergoing Peritoneal Dialysis

BACKGROUND

Peritonitis is one of the most common complications in patients undergoing peritoneal dialysis, (PD) but it is difficult to predict or prevent. In this study, we analyzed the risk of endogenous peritonitis in patients receiving PD.

METHODS

We included all patients who underwent PD at our hospital from April 2015 to March 2020. There were 22 cases of peritonitis, including 18 cases of endogenous peritonitis without evidence of exit-site infection or technical failure. We evaluated older age, female sex, obesity, diabetes, diverticulosis, and constipation as potential important risk factors for endogenous peritonitis and included these as confounding factors, along with a current or previous history of smoking, in univariate logistic regression models.

RESULTS

A previous or current history of smoking (p = 0.0065) was the most significant risk factor for endogenous peritonitis in the univariate logistic regression model. In addition, smoking was the most significant independent risk factor for endogenous peritonitis (p = 0.0034) in multivariate logistic regression models. Diabetes was also significant in univariate and multivariate logistic regression analysis.

CONCLUSIONS

Smoking is a significant independent risk factor for endogenous peritonitis in patients undergoing PD. Cessation of smoking may lower the risk of endogenous peritonitis in this patient group.

Smoking and risk of fractures requiring hospitalization in hemodialysis patients: a nationwide cohort study in Japan

BACKGROUND

Smoking is a well-established lifestyle risk factor for fractures in the general population, but evidence specific to hemodialysis populations is lacking. This nationwide cohort study used data from the Japanese Society for Dialysis Therapy Renal Data Registry to examine the association between smoking status and fractures.

METHODS

A total of 154,077 patients (64.2% men; mean age, 68 years) aged ≥20 years undergoing maintenance hemodialysis thrice a week at the end of 2016 were followed for 1 year. Among these, 19,004 (12.3%) patients were current smokers. Standardized incidence rate ratios of hospitalization due to any fracture were calculated and analyzed by multivariable logistic regression analysis, controlling for potential confounders. Propensity score matching and subgroup analyses were also performed as sensitivity analyses.

RESULTS

During the 1-year follow-up period, 3,337 fractures requiring hospitalization (1,201 hip, 479 vertebral, and 1,657 other fractures) occurred in 3,291 patients. The age- and sex-standardized incidence ratio for current smokers was 1.24 (95% confidence interval, 1.12-1.39) relative to non-smokers. Standardized incidence ratios were similar after stratification by age group and sex. Multivariable logistic regression analysis revealed a 1.25-fold higher risk of any fracture requiring hospitalization (95% confidence interval, 1.10-1.42) in current smokers relative to non-smokers in a fully adjusted model. Propensity score matching showed similar results (odds ratio, 1.25; 95% confidence interval, 1.05-1.48). Subgroup analyses for baseline covariates revealed no significant interactions.

CONCLUSIONS

Smoking is a significant risk factor for any fracture requiring hospitalization in hemodialysis patients.

Cancer Screening in End-Stage Kidney Disease

The incidence of cancer is higher in patients with end-stage kidney disease (ESKD) than among the general population. Despite this, screening for cancer is generally not cost-effective and may worsen quality of life in these patients. This is due to high mortality rates (patients are not living long enough to reap the benefits of screening), the inaccuracy of cancer screening tests, and the increased risks associated with therapy in patients with ESKD. Specific groups of patients with ESKD who have a longer-than-expected life expectancy or higher-than-expected cancer risk may benefit from screening. These groups include patients on peritoneal dialysis, patients on home hemodialysis, Black and Asian-American patients, transplant-eligible patients, and those at higher risk of cancer including patients with acquired cystic kidney disease, those who have been previously exposed to cytotoxic agents or aristolochic acid, and patients with a genetic predisposition to cancer. In this narrative review, we will examine the prevalence of and risk factors for cancer in patients with ESKD and the effectiveness of cancer screening, and discuss specific situations in which cancer screening may be effective.

Quantifying Regional and Health Care Variations to Identify Ways to Improve Hemodialysis Service Quality and Survival Outcomes

The authors examined variations in hemodialysis care and quantified the effect of these variations on all-cause mortality. Insurance claims data from April 1, 2017 to March 30, 2018 were reviewed. In total, 2895 hospital patients were identified, among whom 398 died from various causes. Controlling effects of the facility and secondary medical care areas, all-cause mortality was associated with older age, heart failure, malignancy, cerebral stroke, severe comorbidity, and the first and ninth centile of physician density. Multilevel analyses indicated a significant variation at facility level (σ22 0.27, 95% confidence interval: 0.09-0.49). Inclusion of all covariates in the final model significantly reduced facility-level variance. Physician density emerged as an important factor affecting survival outcome; thus, a review of workforce and resource allocation policies is needed. Better clinical management and standardized work processes are necessary to attenuate differences in hospital practice patterns.

Smoking Cessation and Coronary Artery Calcification in CKD

BACKGROUND AND OBJECTIVES

Smoking is associated with vascular calcification and a higher risk of cardiovascular disease. In this study, we investigated the association of smoking dose and cessation with coronary artery calcification (CAC) in patients with CKD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

From a nationwide, prospective cohort of Korean patients with CKD, 1914 participants were included. Prevalent CAC was defined as an Agatston score >0, using computed tomography. CAC progression was defined as ≥30%/yr increase in Agatston score at the 4-year follow-up examination in patients with baseline CAC.

RESULTS

Prevalent CAC was observed in 952 (50%) patients. Compared with never smokers, former smokers had a similar prevalence ratio for CAC, but current smokers had a 1.25-fold higher prevalence ratio (95% confidence interval [95% CI], 1.10 to 1.42). Among former smokers, a lower smoking load of <10 pack-years (prevalence ratio, 0.77; 95% CI, 0.65 to 0.90) and longer duration of smoking cessation (prevalence ratio for 10 to <20 years, 0.85; 95% CI, 0.73 to 0.98: prevalence ratio for ≥20 years, 0.83; 95% CI, 0.73 to 0.96) were associated with lower risk of prevalent CAC compared with current smoking. The prevalence ratios did not differ between never smoking and long-term cessation. However, short-term cessation with heavy smoking load was associated with a higher risk of prevalent CAC (prevalence ratio, 1.21; 95% CI, 1.03 to 1.40) compared with never smoking. CAC progression was observed in 111 (33%) patients with baseline CAC. Compared with never smokers, former smokers showed a similar risk of CAC progression, but current smokers had a higher risk (relative risk, 1.92; 95% CI, 1.30 to 2.86).

CONCLUSIONS

In CKD, former smoking with a lower smoking load and long-term cessation were associated with a lower risk of prevalent CAC than current smoking. CAC progression was more pronounced in current smokers.

Survival Percentile and Predictors of Difference in Survival among Hemodialysis Patients and Their Additive Interaction Using Laplace Regression

Background: Identifying survival modifiable factors and additive interaction between them could help in prioritizing the clinical care of Hemodialysis (HD) patients. We aimed to examine the survival rate and its predictors in HD patients; and explore the additive interaction between survival modifiable factors.

Study design: A retrospective cohort study.

Methods: The present study was performed on 1142 HD patients in Hamadan Province, western Iran from 2007 to 2017. Data were collected through a researcher-made checklist on hospital records. Laplace regression was used to evaluate differences in 40^th survival percentiles in different levels of predictors as well as exploring the pairwise additive interactions between variables.

Results: We observed significantly higher survival in nonsmoker patients (40^th percentile difference = 5.34 months, 95% CI: 2.06, 8.61). Survival was shorter by more than 3 years in CRP positive patients (40^th percentile difference=36.9 months, 95% CI: 32.37, 41.42). Patients with normal albumin (40^th percentile difference =24.92, 95% CI: 18.04, 31.80) and hemoglobin (40^th percentile difference = 18.65, 95% CI: 12.43, 24.86) had significantly higher survival (P<0.001). There was super-additive interaction between being CRP negative and nonsmoker (β₃ = 9.42 months, 95% CI: 3.35, 15.49 (P=0.002)).

Conclusion: High CRP and low serum albumin and hemoglobin were associated with the increased risk of death in HD patients. The results of this study support the presence of super-additive interaction between CRP status with serum hemoglobin and also CRP status with smoking, resulting in excess survival in HD patients.

Dialysis patients who smoke are more hypertensive, more fluid overloaded and take more antihypertensive medications than nonsmokers

Background

Smoking remains a powerful risk factor for death in end-stage renal disease (ESRD) and so is the presence of fluid overload. The relationship between smoking, blood pressure (BP) control and volume overload is insufficiently explored in patients on maintenance dialysis.

Methods

This is a retrospective cross-sectional cohort study, utilizing existing patients’ data generated during routine ESRD care, including bimonthly protocol bioimpedance fluid assessment of the volume status.

Results

We analyzed the data of 63 prevalent patients receiving thrice weekly maintenance hemodiafiltration treatments at one rural dialysis unit in Hungary. The cohort’s mean ± SD age was 61.5 ± 15.3 years; 65% male, 38% diabetic, with a mean arterial blood pressure (MAP) 99.5 ± 16.8 mmHg and Charlson score 3.79 ± 2.04. Of these, 38 patients were nonsmokers and 25 smokers. The nonsmokers’ MAP was 94.3 ± 14.0 versus smokers’ 105.9 ± 18.9 mmHg (p: .002); nonsmokers took an average 0.73 ± 0.92 antihypertensive medications vs. 1.73 ± 1.21 for smokers (p: .0001). The distribution of taking more antihypertensive medications is skewed toward a higher number among the smokers (2x5 chi square p: .004). By bioimpedance spectroscopy, nonsmokers had an average 10.93 ± 7.65 percent overhydration (OH) over the extracellular space compared to 17.63 ± 8.98 in smokers (p: .005).

Conclusions

Smoking may be a significant mediator of not only BP but also of chronic fluid overload in ESRD patents. Additional, larger studies are needed to explore the mechanistic link between smoking and volume overload.

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.

Active Smoking is Associated with Lower Dialysis Adequacy in Prevalent Dialysis Patients

BACKGROUND:

Dialysis adequacy measured by single pool Kt/V (spKt/V) lower than 1.2 or urea reduction rate (URR) lower than 65% is associated with a significant increase in patient mortality rate. Patients’ adherence to the medical treatment is crucial to achieve recommended targets for spKt/V. Smoking is a recognized factor of non-adherence.

AIM:

In this study we sought to assess the association of active smoking and dialysis adequacy.

METHODS:

A total of 134 prevalent dialysis patients from one dialysis center were included in an observational cross-sectional study. Clinical, laboratory and dialysis data were obtained from medical charts in previous 6 months. The number of missed, on purpose interrupted or prematurely terminated dialysis sessions was obtained. Dialysis adequacy was calculated as spKt/V and URR. Patients were questioned about current active smoking status. T-test and Chi-Square test were used for comparative analysis of dialysis adequacy with regard to smoking status.

RESULTS:

The majority of patients declared a non-smoking status (100 (75%)) and 34 (25%) were active smokers. Male gender, younger age and shorter dialysis vintage were significantly more often present in the active smokers ((9 (26%) vs 25 (73%), p = 0.028; 57.26 ± 12.59 vs 50.15 ± 14.10, p = 0.012; 118.59 ± 76.25 vs 88.82 ± 57.63, p = 0.030)), respectively. spKt/V and URR were significantly lower and Kt/V target was less frequently achieved in smokers ((1.46 ± 0.19 vs. 1.30 ± 0.021, p = 0.019; 67.14 ± 5.86 vs. 63.64 ± 8.30, p = 0.002; 14 (14%) vs. 11 (32%), p = 0.023), respectively. Shorter dialysis sessions, larger ultra filtrations and higher percentage of missed/interrupted dialysis session on patients’ demand were observed in smokers (4.15 ± 0.30 vs. 4.05 ± 0.17, p = 0.019; 3.10 ± 0.78 vs. 3.54 ± 0.92, p = 0.017; 25 (0.3%) vs. 48 (1.8%), p = 0.031), respectively.

CONCLUSION:

Active smokers, especially younger men, achieve lower than the recommended levels for dialysis adequacy. Non-adherence to treatment prescription in smokers is a problem to be solved. Novel studies are recommended in patients on dialysis, to further elucidate the association of dialysis adequacy with the active smoking status.

Insulin Resistance and Cardiovascular Risks in Different Groups of Hemodialysis Patients: A Multicenter Study

BACKGROUND

To investigate the association between insulin resistance (IR) and cardiovascular disease (CVD) risks among hemodialysis patients.

METHODS

We conducted a cross-sectional study between 2013 and 2017, on 384 hemodialysis patients from seven hospital-based-dialysis centers. HOMA-IR is classified according to median value. The CVD risks were defined by the K/DOQI Guidelines. Logistic regression analysis was used.

RESULTS

Patients' age was 60.9 ± 11.8, 58.1% men, and 40.3% overweight/obese. The median of HOMA-IR was 5.4, 82.8% high systolic blood pressure, and 85.7% hyperhomocysteinemia. In multivariate analysis, IR was significantly associated with higher odds of low high-density lipoprotein cholesterol, high triglyceride, and impaired fasting glucose in groups of normal weight, overweight/obese, nondiabetes, diabetes, and overall sample. IR linked with elevated high-sensitive C-reactive protein in normal weight patients (odd ratio, OR=2.21, 95% confidence interval, 1.16-4.22, p < .05), with hypoalbuminemia in normal weight patients (OR=8.31, 95% CI, 2.35-29.37, p < .01), in nondiabetes patients (OR=6.59, 95% CI, 1.81-23.95, p < .01), and overall sample (OR=3.07, 1.51-6.23, p < .01).

CONCLUSIONS

The level of IR and prevalence of CVD risks were high in hemodialysis patients. IR was independently associated with CVD risks.

Clinical Studies of Interventions to Mitigate Cardiovascular Risk in Peritoneal Dialysis Patients

Cardiovascular disease (CVD) is highly prevalent in the peritoneal dialysis (PD) population, affecting up to 60% of cohorts. CVD is the primary cause of death in up to 40% of PD patients in Australia, New Zealand, and the United States. Cardiovascular mortality rates are reported to be approximately 14 per 100 patient-years, which are 10- to 20-fold greater than those of age- and sex-matched controls. The excess risk of CVD is related to a combination of traditional risk factors (such as hypertension, dyslipidemia, obesity, smoking, sedentary lifestyle, and insulin resistance), nontraditional (kidney disease-related) risk factors (such as anemia, chronic volume overload, inflammation, malnutrition, hyperuricemia, and mineral and bone disorder), and PD-specific risk factors (such as dialysis solutions, glycation end products, hypokalemia, residual kidney function, and ultrafiltration failure). Interventions targeting these factors may mitigate cardiovascular risk, although high-level clinical evidence is lacking. This review summarizes the evidence relating to cardiovascular interventions targeting modifiable CVD risk factors in PD patients, as well as highlighting the key recommendations of the International Society for Peritoneal Dialysis Cardiovascular and Metabolic Guidelines.

Membrane transport status does not predict peritonitis risk in patients on peritoneal dialysis

AIM

The aim of this study is to determine whether peritoneal membrane transport status (MTS) is associated with peritonitis or poor peritoneal dialysis-related outcomes.

METHODS

This retrospective cohort study analysed data of incident adult patients on peritoneal dialysis in Western Sydney between 1 October 2003 and 31 December 2012. Only patients who underwent peritoneal equilibration and adequacy tests within 6 months of commencement were included. Kaplan-Meier survival curves for time until first peritonitis and time until composite endpoint of peritonitis, death or technique failure, censored for transplant, were constructed.

RESULTS

About 397 patients, mean age 58.8(+/-2SD29) years, body mass index (BMI) 26.6(+/-5) kg/m² and serum albumin 35.4(+/-5) g/L were included. About 59.2% had high/high-average peritoneal MTS; 45.8% were past and current smokers; 51.9% developed at least one episode of peritonitis; 7.6% changed to haemodialysis; 6.3% underwent transplantation; 8.8% died; and 25.4% remained free of the aforementioned events over a mean follow-up period of 22.5 months (range 0-115 months). Peritoneal MTS was not associated with time to first peritonitis (p = 0.67) or composite endpoint of peritonitis, death or technique failure (p = 0.12). Smoking and hypoalbuminaemia independently predicted time to first peritonitis. Past and current smokers had a hazard ratio of 1.38 (95% CI 1.03-1.86) for shorter time to first peritonitis, significant after adjustment for serum albumin (p = 0.033). Serum albumin <32 g/L had a hazard ratio of 1.74 (95% CI 1.13-2.67) for shorter time to first peritonitis, significant after adjusting for smoking (p = 0.012).

CONCLUSION

Smoking and hypoalbuminaemia, but not MTS, were associated with shorter time to first peritonitis and composite endpoint of peritonitis, death and technique failure.

Management of Traditional Cardiovascular Risk Factors in CKD: What Are the Data?

Patients with non-dialysis-dependent chronic kidney disease (NDD-CKD) are 10 times more likely to die of cardiovascular (CV) diseases than the general population, and dialysis-dependent patients are at even higher risk. Although traditional CV risk factors are highly prevalent in individuals with CKD, these patients were often excluded from studies targeting modification of these risks. Although treatment of hypertension is beneficial in CKD, the best target blood pressure has not been established. Trial data showed that renin-angiotensin-aldosterone blockade may prevent CV events in patients with CKD. The risks of aspirin may equal the benefits in NDD-CKD samples, and there are no trials testing aspirin in dialysis-dependent patients. Lipid-lowering therapy improves CV outcomes in NDD-CKD, but not in dialysis-dependent patients. Strict glycemic control prevents CV events in nonalbuminuric individuals, but showed no benefit in those with baseline albuminuria with albumin excretion > 300mg/g, and there are no data in dialysis-dependent patients. Data for lifestyle modifications, such as weight loss, physical activity, and smoking cessation, are mostly observational and extrapolated from non-CKD samples. This comprehensive review summarizes the best existing evidence and current clinical guidelines for modification of traditional risk factors for the prevention of CV events in patients with CKD and identifies knowledge gaps.

Trends in Rates of Lower Extremity Amputation Among Patients With End-stage Renal Disease Who Receive Dialysis

IMPORTANCE

Patients with end-stage renal disease (ESRD) who receive dialysis are at high risk of lower extremity amputation. Recent studies indicate decreasing rates of lower extremity amputation in non-ESRD populations, but contemporary data for patients with ESRD who receive dialysis are lacking.

OBJECTIVES

To assess rates of lower extremity amputation among patients with ESRD who receive dialysis during a recent 15-year period; to analyze whether those rates differed by age, sex, diabetes, or geographic region; and to determine 1-year mortality rates in this population after lower extremity amputation.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective study of 3 700 902 records obtained from a US national registry of patients with ESRD who receive dialysis assessed cross-sectional cohorts for each calendar year from 2000 through 2014. Adult patients with prevalent ESRD treated with hemodialysis or peritoneal dialysis covered by Medicare Part A and B on January 1 of each cohort year were included. Data analysis was conducted from August 2017 to April 2018.

EXPOSURES

Age, sex, diabetes, and hospital referral region.

MAIN OUTCOMES AND MEASURES

Annual rates per 100 person-years of nontraumatic major (above- or below-knee) and minor (below-ankle) amputations.

RESULTS

For each annual cohort, there were fewer women (47.5% in 2000, 46.2% in 2005, 44.9% in 2010, and 44.0% in 2014) than men, more than half the patients were white individuals (58.1% in 2000, 56.9% in 2005, 56.9% in 2010, and 56.7% in 2014), and a small proportion were employed (13.9% in 2000, 15.1% in 2005, 16.1% in 2010, and 16.5% in 2014). The rate of lower extremity amputations for patients with ESRD who receive dialysis decreased by 51.0% from 2000 to 2014, driven primarily by a decrease in the rate of major amputations (5.42 [95% CI, 5.28-5.56] in 2000 vs 2.66 [95% CI, 2.59-2.72] per 100 person-years in 2014). Patients with diabetes had amputation rates more than 5 times as high as patients without diabetes. Patients younger than 65 years had higher adjusted amputation rates than older patients, and men had consistently higher adjusted amputation rates than women. Adjusted 1-year mortality rates after lower extremity amputation for patients with ESRD who receive dialysis decreased from 52.2% (95% CI, 50.9%-53.4%) in 2000 to 43.6% (95% CI, 42.5%-44.8%) in 2013. In general, amputation rates decreased among all regions from 2000 to 2014, but regional variability persisted across time despite adjustment for differences in patient demographics and comorbid conditions.

CONCLUSIONS AND RELEVANCE

Although rates of lower extremity amputations among US patients with ESRD who receive dialysis decreased by 51% during a recent 15-year period, mortality rates remained high, with nearly half of patients dying within a year after lower extremity amputation. Our results highlight the need for more research on ways to prevent lower extremity amputation in this extremely high-risk population.

Is the management of diabetes different in dialysis patients?

Diabetes is highly and increasingly prevalent in the dialysis population and negatively impacts both quality and quantity of life. Nevertheless, the best approach to these patients is still debatable. The question of whether the management of diabetes should be different in dialysis patients does not have a clear yes or no answer but is divided into too many sub-issues that should be carefully considered. In this review, lifestyle, cardiovascular risk, and hyperglycemia management are explored, emphasizing the possible pros and cons of a similar approach to diabetes in dialysis patients compared to the general population.

Smoking has no impact on survival and it is not associated with ACE gene I/D polymorphism in hemodialysis patients

INTRODUCTION

The relationship between smoking and mortality in patients on hemodialysis is controversial. Earlier studies showed that the insertion/deletion (I/D) polymorphism of the ACE gene might have an effect on mortality. The aim of this study was to test the impact of smoking on survival and whether this association was influenced by ACE gene I/D polymorphism in patients on maintenance hemodialysis.

PARTICIPANTS AND METHODS

In this prospective, multicenter cohort study we analyzed 709 prevalent patients on maintenance hemodialysis. Patients were allocated into groups based on their smoking habit. Outcome data were collected during the 144-month follow-up period. Outcomes of current smokers and lifelong non-smokers were compared. In order to control for interactions between predictor variables, we also identified 160 matched pairs for further sub-analysis.

RESULTS

The vast majority of patients (67%) were non-smokers, followed by current smokers (22.2%) and ex-smokers (9.8%). Smoking had no impact on survival in the matched pair analysis ( p = 0.99). After adjustment for ACE I/D polymorphism and other co-variates, smoking had no effect on survival.

CONCLUSION

Our data suggest that smoking has no impact on survival; neither is it associated with ACE gene I/D polymorphism in hemodialysis patients.

Differential impact of smoking on mortality and kidney transplantation among adult Men and Women undergoing dialysis

BACKGROUND

The extent to which smoking contributes to adverse outcomes among men and women of all ages undergoing dialysis is uncertain. The objective of this study was to determine the differential impact of smoking on risks of mortality and kidney transplantation by age and by sex at dialysis initiation.

METHODS

We conducted a population-based cohort of incident U.S dialysis patients (n = 1, 220, 000) from 1995-2010. Age- and sex-specific mortality and kidney transplantation rates were determined for patients with and without a history of cardiovascular disease. Multivariable Cox regression evaluated relative hazard ratios (HR) for death and kidney transplantation at 2 years stratified by atherosclerotic condition, smoking status and age. Analyses were adjusted for demographic characteristics, non-cardiovascular conditions, laboratory variables, socioeconomic and lifestyle factors.

RESULTS

The average age was 62.8 (±15) years old, 54 % were male, and the majority was white. During 2-year follow-up, 40.5 % died and 5.7 % were transplanted. Age- and sex-specific mortality rates were significantly higher while transplantation rates were significantly lower for smokers with atherosclerotic conditions than non-smokers (P < 0.01). The adjusted mortality hazards were significantly higher for smokers with pre-existing coronary disease (HR 1.15, 95 % CI (1.11-1.18), stroke (HR 1.21, 1.16-1.27) and peripheral vascular disease (HR = 1.21, 1.17-1.25) compared to non-smokers without these conditions (HR 1.00, referent group). The magnitude of effect was greatest for younger patients than older patients. Contrastingly, the adjusted risks of kidney transplantation were significantly lower for smokers with coronary disease: (HR 0.60, 0.52-0.69), stroke; (HR 0.47, 0.37-0.60), and peripheral arterial disease (HR 0.55, 0.46-0.66) respectively compared to non-smokers without these conditions.

CONCLUSIONS

We provide compelling evidence that smoking is associated with adverse clinical outcomes and reduced lifespans among dialysis patients of all ages and sexes. The adverse impact is greatest for younger men and women.

Smoking and renal function in people living with human immunodeficiency virus: a Danish nationwide cohort study

INTRODUCTION

Smoking is a main risk factor for morbidity and mortality in people living with human immunodeficiency virus (PLHIV), but its potential association with renal impairment remains to be established.

METHODS

We did a nationwide population-based cohort study in Danish PLHIV to evaluate the association between smoking status and 1) overall renal function and risk of chronic kidney disease (CKD), 2) risk of any renal replacement therapy (aRRT), and 3) mortality following aRRT. We calculated estimated creatinine clearance using the Cockcroft-Gault equation (CG-CrCl), and evaluated renal function graphically. We calculated cumulative incidence of CKD (defined as two consecutive CG-CrCls of ≤60 mL/min, ≥3 months apart) and aRRT and used Cox regression models to calculate incidence rate ratios (IRRs) for risk of CKD, aRRT, and mortality rate ratios (MRRs) following aRRT.

RESULTS

From the Danish HIV Cohort Study, we identified 1,475 never smokers, 768 previous smokers, and 2,272 current smokers. During study period, we observed no association of smoking status with overall renal function. Previous and current smoking was not associated with increased risk of CKD (adjusted IRR: 1.1, 95% confidence interval [CI]: 0.7-1.7; adjusted IRR: 1.3, 95% CI: 0.9-1.8) or aRRT (adjusted IRR: 0.8, 95% CI: 0.4-1.7; adjusted IRR: 0.9, 95% CI: 0.5-1.7). Mortality following aRRT was high in PLHIV and increased in smokers vs never smokers (adjusted MRR: 3.8, 95% CI: 1.3-11.2).

CONCLUSION

In Danish PLHIV, we observed no strong association between smoking status and renal function, risk of CKD, or risk of aRRT, but mortality was increased in smokers following aRRT.

Treg/Th17 imbalance is associated with cardiovascular complications in uremic patients undergoing maintenance hemodialysis

Investigations of Treg/Th17 imbalance associated with cardiovascular complications in hemodialysis are limited. The aim of this study was to examine the association between Treg/Th17 balance and cardiovascular comorbidity in maintenance hemodialysis (MHD). Uremic patients included in the present study were divided into three groups: the WHD group comprising 30 patients with no cardiovascular complications or maintenance hemodialysis (MHD), the MHD1 group comprising 36 patients presenting with cardiovascular complications during MHD, and the MHD2 group comprising 30 patients with a lack of cardiovascular complications during MHD. The control group comprised 20 healthy volunteers. Th17 and Treg cells were measured by fluorescence-activated cell scanning (FACS). IL-6 and IL-10 levels were determined by enzyme-linked immunosorbent assay (ELISA). Monocyte surface expression of the costimulatory molecules CD80 and CD86 was assessed by FACS after the monocytes were cocultured with Th17 or Treg cells in the presence or absence of IL-17. Results revealed that the percentage of Th17 of total CD4(+) cells was significantly higher in the MHD1 (36.27±9.62% in) and WHD (35.98±8.85%) groups compared with the MHD2 (19.64±5.97%) and healthy (1.12±1.52%) groups. Elevated IL-6 levels were obtained in Th17 cells for the MHD1 and WHD groups, whereas a marked decrease was evident when IL-17 was blocked. However, no significant differences or cardiovascular complications were detected in the expression of CD80 and CD86 in the MHD group, whereas the expression of the uremic subgroups was statistically higher compared with the healthy controls. To the best of our knowledge, this is the first study to demonstrate that the Treg/Th17 imbalance may be associated with the pathogenesis of cardiovascular complications in uremic patients undergoing hemodialysis through the B7-independent upregulation of IL-6 induced by IL-17.

[Kidney and smoking: literature review and focus]

Smoking remains a major public health problem. It is associated with a considerable number of deaths in the world's population. Smoking is just like high blood pressure, an independent predictor of progression to any primary renal disease and renal transplant patients. It seems that smoking cessation slows the progression of kidney disease in smokers. The literature data are sometimes contradictory about it because of some methodological weaknesses. However, experimental models highlight the harmful effects of tobacco by hemodynamic and non-hemodynamic factors. The conclusion is that a major effort should be further produced by the nephrology community to motivate our patients to stop smoking.

The impact of chronic obstructive pulmonary disease and smoking on mortality and kidney transplantation in end-stage kidney disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) and tobacco use are leading causes of morbidity and mortality. The prevalence and clinical impact of COPD on mortality and kidney transplantation among patients who begin dialysis therapy is unclear.

METHODS

We explored the clinical impact of COPD and continued tobacco use on overall mortality and kidney transplantation in a national cohort study of US dialysis patients. National data on all dialysis patients (n = 769,984), incident between May 1995 and December 2004 and followed until October 31, 2006, were analyzed from the United States Renal Data System. Prevalence and period trends were determined while multivariable Cox regression evaluated relative hazard ratios (RR) for death and kidney transplantation.

RESULTS

The prevalence of COPD was 7.5% overall and increased from 6.7 to 8.1% from 1995-2004. COPD correlated significantly with older age, cardiovascular conditions, cancer, malnutrition, poor functional status, and tobacco use. Adjusted mortality risks were significantly higher for patients with COPD (RR = 1.20, 95% CI 1.18-1.21), especially among current smokers (RR = 1.28, 95% CI 1.25-1.32), and varied inversely with advancing age. In contrast, the adjusted risks of kidney transplantation were significantly lower for patients with COPD (RR = 0.47, 95% CI 0.41-0.54, for smokers and RR = 0.54, 95% CI 0.50-0.58, for non-smokers) than without COPD [RR = 0.72, 95% CI 0.70-0.75, for smokers and RR = 1.00 for non-smokers (referent category)].

CONCLUSIONS

Patients with COPD who begin dialysis therapy in the US experience higher mortality and lower rates of kidney transplantation, outcomes that are far worse among current smokers.

Predictive Factors for Coronary Artery Disease among Peritoneal Dialysis Patients without Diabetic Nephropathy

OBJECTIVES

Scientific literature indicates that the risk of coronary heart disease morbidity and death among peritoneal dialysis patients exceeds risk observed in non-renal patients. The aims of this study were to establish the independent predictors associated with increased risk of coronary heart disease in peritoneal dialysis patients without diabetic nephropathy.

MATERIALS AND METHODS

A number of 116 end-stage renal disease patients without diabetic nephropathy undergoing peritoneal dialysis were evaluated for coronary heart disease and predictive risk factors were investigated and identified. Also intima-media thickness measurements, as an early sign of atherosclerosis, were analyzed in a subset of patients in correlation with a number of traditional and non-traditional cardiovascular risk factors.

RESULTS

The study sample was found to be characterized by a high prevalence of traditional risk factors: hypertension (95.7%), dyslipidemia (93.1%) and metabolic syndrome (58.6%), but also of dialysis-related risk factors: inflammation (82.8%) and anemia (55.2%). Independent variables found to be associated in regression analysis with coronary heart disease were: age, smoking status, nephroangiosclerosis, albumin, C-reactive protein and iPTH levels. Intima-media thickness was significantly higher in patients with coronary heart disease, values greater than 0.89 mm being associated with increased risks for coronary heart disease, acute coronary syndrome and cardiovascular death.

CONCLUSIONS

The prevalence of traditional cardiovascular risk factors in these peritoneal dialysis patients is extremely high, but there are also some other factors involved, especially malnutrition and inflammation. Age higher than 55 years, smoking, albumin less than 3.5 g/dl, iPTH less than 150 pg/ml and nephroangiosclerosis were associated with highest odds ratio for coronary heart disease. An increasing CRP levels was associated with an increasing gradient for coronary heart disease risk.

Association of smoking with cardiovascular and infection-related morbidity and mortality in chronic hemodialysis

BACKGROUND AND OBJECTIVES

Smoking is common in the hemodialysis population and is associated with increased all-cause mortality and development of cardiovascular disease. Cause-specific outcomes have not yet been examined in detail. This study investigated the association of baseline smoking status with all-cause, cardiovascular, and infection-related morbidity and mortality in patients undergoing long-term hemodialysis.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Post hoc analysis of the HEMO Study in patients with available comorbidity, clinical, and nutritional data. Cox proportional hazards regression models were fit to estimate the association of smoking status with mortality. Poisson and negative binomial regression models were fit to estimate the association of smoking status with hospitalization rate.

RESULTS

Complete data were available for 1842 individuals (44% male, 63% black, 45% diabetic). Mean age was 58 ± 14 years. At baseline, 17% were current smokers and 32% were former smokers. After case-mix adjustment, compared with never smoking, current smoking was associated with greater infection-related mortality (hazard ratio [HR], 2.04; 95% confidence interval [CI], 1.32-3.10) and all-cause mortality (HR, 1.44; 95% CI, 1.16-1.79) and greater cardiovascular (incidence rate ratio [IRR], 1.49; 95% CI, 1.22-1.82), infection-related (IRR, 1.35; 95% CI, 1.11-1.64) and all-cause (IRR, 1.43; 95% CI, 1.24-1.65) hospitalization rates. The population attributable fraction (i.e., fraction of observed deaths that may have been avoided) was 5.3% for current smokers versus never-smokers and 2.1% for current versus former smokers.

CONCLUSIONS

Active smoking is prevalent in the chronic hemodialysis population and is associated with greater all-cause, cardiovascular, and infection-related morbidity and mortality.