Cigarette smoking and renal function impairment

Association between remnant cholesterol and chronic kidney disease in Chinese hypertensive patients

Background

Remnant cholesterol (RC) and chronic kidney disease (CKD) have not been definitively linked in individuals with different characteristics. This study aims to investigate the relationship between serum RC level and CKD and examine possible effect modifiers in Chinese patients with hypertension.

Methods

Our study is based on the Chinese H-type Hypertension Project, which is an observational registry study conducted in real-world settings. The outcome was CKD, defined as an estimated glomerular filtration rate of less than 60 ml/min·1.73 m2. Multivariate logistic regression and smooth curve fitting were used to analyze the association between RC and CKD. Subgroup analyses were subsequently conducted to examine the effects of other variables.

Results

The mean age of the 13,024 patients with hypertension at baseline was 63.8 ± 9.4 years, and 46.8% were male. A conspicuous linear positive association was observed between RC level and CKD (per SD increment; odds ratio [OR], 1.15; 95% confidence interval [CI], 1.08-1.23). Compared with the lowest quartile group of RC, the risk of CKD was 53% higher (OR, 1.53; 95% CI, 1.26-1.86) in the highest quartile group. Furthermore, a stronger positive association between RC level and CKD was found among participants with a higher body mass index (BMI <24 vs. ≥24 kg/m2; P-interaction = 0.034) or current non-smokers (smoker vs. non-smoker; P-interaction = 0.024).

Conclusions

Among Chinese adults with hypertension, RC level was positively associated with CKD, particularly in those with a BMI of ≥24 kg/m2 and current non-smokers. These findings may help improve lipid management regimens in patients with hypertension.

Determinants of the Evolution of Kidney Function With Age

Introduction

Kidney function declines with age, but its determinants in the general population remain incompletely understood. We investigated the rate and determinants of kidney function decline in the general population.

Methods

Participants with information on kidney function were selected from a population-based cohort study. Joint models were used to investigate the evolution of the estimated glomerular filtration rate (eGFR, expressed in ml/min per 1.73 m² per year) and the urine albumin-to-creatinine ratio (ACR, expressed in mg/g per year) with age. We stratified for 8 potential determinants of kidney function decline, including sex, cardiovascular risk factors, and cardiovascular disease.

Results

We included 12,062 participants with 85,922 eGFR assessments (mean age 67.0 years, 58.7% women) and 3522 participants with 5995 ACR measurements. The annual eGFR decline was 0.82 and the ACR increase was 0.05. All determinants appeared detrimental for eGFR and ACR, except for prediabetes and higher body mass index which proved only detrimental for ACR. In participants without the determinants, eGFR decline was 0.75 and ACR increase was 0.002. Higher baseline eGFR but faster eGFR decline with age was detected in men (0.92 vs. 0.75), smokers (0.90 vs. 0.75), and participants with diabetes (1.07 vs. 0.78).

Conclusion

We identify prediabetes, smoking, and blood pressure as modifiable risk factors for kidney function decline. As with diabetes, hyperfiltration seems important in accelerated kidney function decline in men and smokers. The interpretation of kidney function decline may require adjustment for age and sex to prevent overdiagnosis of chronic kidney disease in aging populations.

Impact of recipient and donor smoking in living-donor kidney transplantation: a prospective multicenter cohort study

The smoking status of kidney transplant recipients and living donors has not been explored concurrently in a prospective study, and the synergistic adverse impact on outcomes remains uncertain. The self-reported smoking status and frequency were obtained from recipients and donors at the time of kidney transplantation in a prospective multicenter longitudinal cohort study (NCT02042963). Smoking status was categorized as "ever smoker" (current and former smokers collectively) or "never smoker." Among 858 eligible kidney transplant recipients and the 858 living donors, 389 (45.3%) and 241 (28.1%) recipients were considered ever smokers at the time of transplant. During the median follow-up period of 6 years, the rate of death-censored graft failure was significantly higher in ever-smoker recipients than in never-smoker recipients (adjusted HR, 2.82; 95% CI 1.01-7.87; P = 0.048). A smoking history of >20 pack-years was associated with a significantly higher rate of death-censored graft failure than a history of ≤20 pack-years (adjusted HR, 2.83; 95% CI 1.19-6.78; P = 0.019). No donor smoking effect was found in terms of graft survival. The smoking status of the recipients and donors or both did not affect the rate of biopsy-proven acute rejection, major adverse cardiac events, all-cause mortality, or post-transplant diabetes mellitus. Taken together, the recipient's smoking status before kidney transplantation is dose-dependently associated with impaired survival.

Proteinuria and its relation to cardiovascular disease

Chronic kidney disease (CKD) and its associated morbidity pose a worldwide health problem. As well as risk of endstage renal disease requiring renal replacement therapy, cardiovascular disease is the leading cause of premature death among the CKD population. Proteinuria is a marker of renal injury that can often be detected earlier than any tangible decline in glomerular filtration rate. As well as being a risk marker for decline in renal function, proteinuria is now widely accepted as an independent risk factor for cardiovascular morbidity and mortality. This review will address the prognostic implications of proteinuria in the general population as well as other specific disease states including diabetes, hypertension and heart failure. A variety of pathophysiological mechanisms that may underlie the relationship between renal and cardiovascular disease have been proposed, including insulin resistance, inflammation, and endothelial dysfunction. As proteinuria has evolved into a therapeutic target for cardiovascular risk reduction in the clinical setting we will also review therapeutic strategies that should be considered for patients with persistent proteinuria.

Health behaviors and risk factors associated with chronic kidney disease in Korean patients with diabetes: the Fourth Korean National Health and Nutritional Examination Survey

PURPOSE

The purpose of this study was to identify health behavior and risk factors for chronic kidney disease (CKD) in Korean patients with diabetes.

METHODS

This study was a secondary analysis of the Fourth Korean National Health and Nutritional Examination Survey (2007-2009). Of the 24,871 participants, 1,239 aged over 19 years with diagnosis of diabetes were included. Stratified and cluster variables in the analysis-plan file for a weighted, complex sample were analyzed. CKD was confirmed by the estimated glomerular filtration rate level of 15.0-59.9 mL/min/1.732 m(2). Odds ratios between the variables and CKD were calculated using logistic regression analysis with adjustment for gender, age, educational background, income, and duration of diagnosis.

RESULTS

The results showed that 14.7% of participants with diabetes were accompanied with CKD. The risk of developing CKD in those who made efforts to take proper nutrition but failed was 1.76 times higher than those taking nutrition properly. In those who used to smoke compared to their nonsmoking counterparts, the risk was 2.06 times higher; in those who did not do vigorous exercise compared to those who did, the risk was 2.12 times higher; in those with hypertension than those without, the risk was 2.4 times higher; and in those with anemia compared to those without, the risk was 2.32 times higher. Only 19% of the participants received health education for diabetes, which did not affect the incidence of CKD.

CONCLUSION

Since renal functions are affected by lifestyle factors, it is critical for healthcare professionals to provide diabetic patients with health education focused on changing their behavior so that it is conducive to health. It is also necessary to consider that diabetes education should be made more available and provided more effectively to these patients.

Nodular Glomerulosclerosis: Renal Lesions in Chronic Smokers Mimic Chronic Thrombotic Microangiopathy and Hypertensive Lesions

Cigarette smoking is associated with vascular lesions and chronic renal failure. In this report, we describe clinical and kidney biopsy findings for a 66-year-old woman with a history of long-term heavy cigarette smoking who developed proteinuria and decreasing renal function. This study also describes clinical and kidney biopsy findings for 9 patients with a history of smoking. None of these patients had hypertension, diabetes mellitus, or other risk factors that might result in vascular injury. Renal biopsy specimens showed a range of long-term changes with varying degrees of focal segmental or focal global glomerulosclerosis, nodular glomerulosclerosis, ischemic glomeruli, interstitial fibrosis and tubular atrophy, and mild to moderate arterial sclerosis and arteriolar hyalinosis. Electron microscopy often showed glomerular capillary wall thickening caused by subendothelial expansion by cellular elements and new basement formation resulting in segments of double contours. These changes indicate endothelial injury and glomerular capillary wall remodeling; the lesions mimic those seen in patients with chronic hypertension and chronic or healed thrombotic microangiopathies.

Clinical spectrum of chronic renal failure in the elderly: a hospital based study from eastern India

The aim of this study was to describe the clinical spectrum of chronic renal failure (CRF) in the elderly. The diagnosis of CRF was made using standard clinical criteria. The elderly was defined as person with over 60 years of age. In total, 200 elderly patients with CRF were evaluated between July 2002 and February 2004. Their age (male: 146; female: 54) ranged between 60 and 90 (mean 64.31+/-4.18) years. Diabetic nephropathy was the most common (46%) cause of CRF. Hypertensive nephrosclerosis, chronic interstitial nephritis and obstructive uropathy were responsible for CRF in 18%, 14% and 13% of patients, respectively. We observed chronic glomerulonephritis in 7% of elderly CRF. Urinary tract infection (55.5%), hypovolemia (22.2%), accelerated hypertension (11.1%) and sepsis (11.1%) were responsible for acute exacerbation of renal failure in 36 (18%) patients. Associated co-morbid conditions were noted in 93 (46.5%) patients. They included; coronary artery disease 46 (49.46%), cerebrovascular disease 20 (21.50%), osteoarthritis 13 (13.97%), chronic obstructive pulmonary disease 6 (6.45%), dilated cardiomyopathy 5 (5.37%), and malignancy in 3 (3.22%) patients. Acute dialytic support was required in 164 (82%) cases and remaining 36 (18%) patients received conservative management. Mortality was noted in 25 (12.5%) cases. The coronary artery disease (48%), acute pulmonary edema (20%) and hyperkalemia (12%) were the main causes of death. Subsequent evaluation revealed that 102 (51%) patients had ESRD of which only 3 (2.94%) patients could afford CAPD. A total of 11 (10.7%) patients underwent chronic maintenance hemodialysis for 3-4 months and then discontinue dialysis mainly because of financial constraints. Remaining 88 (86.27 %) patients with ESRD were discharged from hospital after symptomatic improvement with acute dialysis. Thus, diabetic nephropathy related to type-2 diabetes was the commonest cause of CRF in our elderly patients. Chronic renal failure in elderly was associated with a number of co-morbid conditions, which contributed significantly to morbidity and mortality. Acute on chronic renal failure with severe uremic complications were an important cause of hospitalization. The financial constraint was the major limiting factor for the management of elderly ESRD patients.

Histopathological evaluation of renal vascular changes in rats exposed to passive smoking

Cigarette smoking is an important risk factor for renal damage due to its effects on small interlobular arteries. We investigated the effects of long-term passive smoking on renal vascular structures in healthy rats exposed to smoke soon after birth. Forty-two Sprague-Dawley rats (21 males and 21 females) exposed to passive smoking comprised the experimental group and 33 non-exposed rats (17 males and 16 females) comprised the control group. The number of renal vessels, as well as the level of glomerular capillary sclerosis, hyalinosis of arterioles, and myointimal hyperplasia of arteries was assessed in renal biopsy specimens. The mean number of renal vessels in male and female rats exposed to passive smoke (21.71 and 13.81, respectively) did not significantly differ from the mean number of renal vessels in male and female control rats (22.47 and 13.06, respectively) (p>0.05). Levels of glomerulosclerosis, hyalinosis, and myointimal hyperplasia also did not differ between the experimental and control groups (p>0.05). Histopathologic evidence of renal vascular damage was not found in young rats exposed to passive smoke for 4 months. A longer or higher degree of exposure to cigarette smoke components may be required before such changes manifest, and aging and primary renal disease may play a role.

Effects of long-term passive smoking on the diameter of glomeruli in rats: Histopathological evaluation

BACKGROUND AND AIMS

Long-term smoking increases the risk of renal diseases and it also causes the progression of the diseases. The aim of this study was to evaluate the effects of smoking on glomeruli in healthy rats exposed to long-term passive smoking for a short period of time after birth.

METHODS

Sixty-five rats were randomly assigned into four groups. Groups 1 (18 males) and 2 (18 females) were exposed to smoke, whereas groups 3 (15 males) and 4 (14 females) were not exposed to smoke. Overall, 130 renal units were evaluated, and diameters of 10 different glomeruli were measured. The renal and bodyweights of the rats were measured.

RESULTS

The diameter of the glomeruli was 95.51 +/- 9.25 and 100.91 +/- 4.06 microm in groups 1 and 3, respectively (P < 0.05). It was 97.32 +/- 4.06 and 98.86 +/- 6.25 microm in groups 2 and 4, respectively (P > 0.05). Irrespective of the sex, the diameter of the glomeruli was 96.42 +/- 7.15 microm in smokers and 99.92 +/- 5.56 microm in non-smokers (P < 0.05). The renal weights of the male rats affected by smoke were significantly lower than that of those that were not affected by smoke (P < 0.05). Bodyweights of male rats affected by smoke were significantly lower that of those not affected (P < 0.05). There was a weak correlation between the diameter of the glomeruli and the bodyweights of male rats affected by smoke (r = 0.474, P < 0.05).

CONCLUSION

We conclude that passive smoking might have a negative affect on renal morphometry and body growth.

Proteinuria: an underappreciated risk factor in cardiovascular disease

Changes in renal function produced by hypertension appear to be associated with higher cardiovascular morbidity and mortality. Indices of altered renal function (eg, microalbuminuria, increased serum creatinine concentrations, decrease in estimated creatinine clearance, or overt proteinuria) are independent predictors of cardiovascular morbidity and mortality. The Framingham Heart Study documented the relevance of proteinuria for cardiovascular prognosis in the community. The International Nifedipine GITS study: Intervention as a goal in Hypertension Treatment (INSIGHT) study assessed the role of proteinuria as a very powerful risk factor. Several studies demonstrated that microalbuminuria is a predictor of cardiovascular disease. It has been shown that the presence of microalbuminuria in primary hypertension carries an elevated cardiovascular risk. Furthermore, recent data indicate that even minor derangements of renal function are associated with an increase in cardiovascular risk factors, and promote progression of atherosclerosis. All these parameters should routinely be evaluated in clinical practice, and in the future must be considered in any stratification of cardiovascular risk in hypertensive patients.

The kidney as a sensor of cardiovascular risk in essential hypertension

Renal damage as a consequence of uncontrolled arterial hypertension is well recognized. Antihypertensive therapy has come to very significantly decrease the vascular damage in the kidneys of hypertensive patients. However, prevalence of mild renal insufficiency remains present in a significant proportion of the hypertensive population. This is accompanied by a marked increase in cardiovascular risk, as a consequence of the clustering of other cardiovascular risk factors and of insufficiently controlled BP. Prevention and protection of renal and cardiovascular damage in these patients will be one of the most relevant tasks in the future.

Halting the progression of chronic nephropathy

The incidence of end-stage renal disease (ESRD) is increasing worldwide. In the United States alone, there were 372,000 patients requiring renal replacement therapy in the year 2000 and is expected to rise to 650,000 by the year 2010. The trends in Europe and Japan are forecasted to follow a similar path. These increases represent a significant burden to countries worldwide; not only due to the financial costs of providing ESRD care, but also because of lost productivity and significant morbidity and mortality for the affected patients. There is clearly a pressing need for the aggressive identification and early treatment of patients with nephropathy to prevent progression to ESRD. Research in the last 25 yr has made great advances in the understanding of the progression of chronic renal disease in diabetic and nondiabetic proteinuric nephropathy. There are now effective treatment options that can slow the progression of chronic nephropathies in many individuals, and ongoing research has raised the tantalizing prospect of the reversal of renal disease progression.

Renal protection by antihypertensive therapy

The attainment of adequate renal protection requires strict blood pressure control and a diminution of proteinuria or microalbuminuria to values as near from normalcy as possible. It has been considered that by getting the first, the second could be attained at the same price. Recent data have confirmed that renal protection in hypertensive patients, diabetics or not, requires combination therapy that has to include an angiotensin converting enzyme inhibitor or an angiotensin receptor blocker. A calcium channel blocker can be added to this without renal compromise. A diuretic will also be needed in most cases. Proteinuria will diminish with this combination in particular if up-titration of the drug blocking the effects of angiotensin II is performed. The control of other associated risk factors is also required, in particular smoking and lipids.

Cocaine use, hypertension, and end-stage renal disease

Cocaine use has been associated with both acute renal failure and hypertension (HTN), but only recently have data suggested it may lead to a chronic insidious form of renal failure. We designed a cross-sectional study to compare the association of cocaine use in hemodialysis patients with and without a diagnosis of HTN-related end-stage renal disease (HTN-ESRD). Two hundred one black patients from two outpatient hemodialysis units in an urban community were evaluated. There were 193 eligible patients, 106 men and 87 women, aged 49.28 +/- 14.4 years. A history of significant cocaine use before dialysis was reported by 55 of 193 subjects (28.5%). A diagnosis of HTN-ESRD was reported in 49 of 55 cocaine users (89.1%) compared with 64 of 138 nonusers (46.38%; odds ratio, 9.44; 95% confidence interval, 3.79 to 23.49; P < 0.0005). Of the 113 subjects with HTN-ESRD, 49 subjects (43.4%) had a history of cocaine abuse, either alone or in combination with other drugs. Subjects with HTN-ESRD with cocaine use were younger than those without cocaine use (40.7 +/- 9.0 versus 53.8 +/-15.3 years; P < 0.0005) and had a shorter reported duration of HTN (5.3 +/- 5.4 versus 12.7 +/- 9.8 years; P < 0.0005, adjusted for age and sex). In our urban dialysis population, a clinical diagnosis of HTN-ESRD was strongly associated with a history of cocaine use and earlier onset of ESRD. Cocaine should be considered as a cause of ESRD in patients without a clear cause of renal failure.

Excess risk of renal allograft loss associated with cigarette smoking

BACKGROUND

Cigarette smoking contributes to a number of health-related problems, but its impact on renal transplant survival beyond accelerated patient death is unclear.

METHODS

We performed a cohort study of 645 adult renal allograft recipients from 1985 to 1995 to evaluate the relationship between smoking and graft outcome.

RESULTS

Twenty-four percent of recipients (156/645) were smokers at the time of transplant evaluation. Of these, 90% continued to smoke after transplantation. Pretransplant smoking was significantly associated with reduced overall graft and death-censored graft survival. Patients who were smokers at the time of pretransplant evaluation had kidney graft survival of 84%, 65%, and 48% at 1, 5, and 10 years, respectively, compared with graft survival in nonsmokers of 88%, 78%, and 62% (P=0.007). Pretransplant smoking adversely affected death-censored graft survival in recipients of cadaveric (P=0.02) and of living donor kidneys (P=0.02). Reduced graft survival in pretransplant smokers could not be accounted for by differences in rejection (64% vs. 61%, P=0.35). In a multivariate analysis, pretransplant smoking was associated with a relative risk of 2.3 for graft loss. Among patients with a smoking history before transplantation, death-censored graft survival was significantly higher for those who quit smoking before transplant evaluation.

CONCLUSIONS

Cigarette smoking before kidney transplantation contributes significantly to allograft loss. The effect of smoking on graft outcome is not explained by increases in rejection or patient death. Smoking cessation before renal transplantation has beneficial effects on graft survival. These effects should be emphasized to patients with end-stage renal disease who are considering renal transplantation.

Progression, remission, regression of chronic renal diseases

The prevalence of chronic renal disease is increasing worldwide. Most chronic nephropathies lack a specific treatment and progress relentlessly to end-stage renal disease. However, research in animals and people has helped our understanding of the mechanisms of this progression and has indicated possible preventive methods. The notion of renoprotection is developing into a combined approach to renal diseases, the main measures being pharmacological control of blood pressure and reduction of proteinuria. Lowering of blood lipids, smoking cessation, and tight glucose control for diabetes also form part of the multimodal protocol for management of renal patients. With available treatments, dialysis can be postponed for many patients with chronic nephropathies, but the real goal has to be less dialysis-in other words remission of disease and regression of structural damage to the kidney. Experimental and clinical data lend support to the notion that less dialysis (and maybe none for some patients) is at least possible.

Adverse effects of smoking in the renal patient

Smoking is a known risk factor for cardiovascular diseases, cancer, and several other health problems. It is the number one preventable cause of death in modern countries. The first evidence that smoking may be a renal risk factor was published in 1978. Since then, several studies documented that smoking is nephrotoxic in patients with diabetic and non-diabetic renal disease. Data from the Multiple Risk Factor Intervention Trial indicate that smoking even increases the renal risk in the general male population: an increased relative risk for end-stage renal failure (ESRF) was found for smokers as compared to non-smokers (up to 1.69 for heavy smokers). Several potential mechanisms of smoking-induced renal damage have been discussed, e.g. increase in blood pressure, alteration of intrarenal hemodynamics, as well as activation of the sympathetic nerve, the reninangiotensin and the endothelin systems. The pathomechanisms are, however, only partly understood. Once ESRF has become established, the failure to discontinue smoking adversely affects the prognosis of patients on renal replacement therapy, mainly by increasing the risk of cardiovascular complications. Discontinuation of smoking has been shown to improve both renal and cardiovascular prognosis in the renal patient and is probably the single most effective measure to retard progression of renal failure.

Effects of current smoking and smoking discontinuation on renal function and proteinuria in the general population

BACKGROUND

Smoking may adversely affect the progression of renal diseases. However, it is unknown whether smoking affects renal function in subjects without nephropathy.

METHODS

In 1998, 28,409 volunteers from the general population were examined at the Institut Régional pour la Santé (IRSA). Renal function was estimated with creatinine clearance using the Cockcroft formula. Dipstick proteinuria was assessed on an overnight urine sample by a trained technician.

RESULTS

Adjusted creatinine clearance was higher in current smokers than in former smokers and never smokers (100.6 +/- 13.6 vs. 98.8 +/- 13.9 mL/min/1.73 m2, P < 0.0001, and vs. 98.5 +/- 14.0 mL/min/1. 73 m2, P < 0.0001, respectively). This difference was predominant in men and weak in women, and was associated with the number of cigarettes smoked daily. The slope of the projected age-related decline in the creatinine clearance accelerated with age, but it was similar in current smokers, former smokers, and never smokers. Creatinine clearance was associated with a relative risk of proteinuria [for each mL/min/1.73 m2, the relative risk was 1.007 (95% CI, 1.000 to 1.015), P = 0.056, for 1+ or higher proteinuria; and 1.018 (1.004 to 1.030), P = 0.0078, for 2+ or higher proteinuria]. Current and former smokers had a marked risk of 2 or higher proteinuria [adjusted RR (95% CI), 3.26 (1.66 to 6.80), P = 0. 0009, and 2.69 (1.24 to 5.99), respectively, P = 0.013, vs. never smoking], which was independent of the daily or cumulative cigarette consumption.

CONCLUSIONS

In the general population, smokers do not exhibit lower creatinine clearance than never smokers. In fact, creatinine clearance is slightly higher in current smokers at least in men, even when normotensive and hypertensive subjects are analyzed separately, but the difference is small, especially in women. This effect seems reversible upon smoking discontinuation. Chronic smoking results in a marked risk of irreversible proteinuria that may occur despite moderate smoking.

Cocaine and the kidney: a synthesis of pathophysiologic and clinical perspectives

Cocaine abuse has reached epidemic proportions in the United States, and several forms of renal disease have been associated with this widespread use. The hemodynamic actions of cocaine, as well as its effects on matrix synthesis, glomerular inflammation, and glomerulosclerosis, may contribute to renal injury. Cocaine abuse has been associated with various forms of acute renal failure and acid-base and/or electrolyte disorders and may also have a role in the progression of chronic renal failure to end-stage renal disease. In utero exposure to cocaine has been associated with urogenital tract anomalies. Medical management of a hypertensive emergency caused by acute cocaine toxicity requires a multisystem approach, with close monitoring of cardiac, neurological, and renal functions.