Smoking and the kidney

The Indian Chronic Kidney Disease (ICKD) study: baseline characteristics

Background

Chronic kidney disease (CKD) is an important cause of morbidity and mortality worldwide. There is a lack of information on epidemiology and progression of CKD in low–middle income countries. The Indian Chronic Kidney Disease (ICKD) study aims to identify factors that associate with CKD progression, and development of kidney failure and cardiovascular disease (CVD) in Indian patients with CKD.

Methods

ICKD study is prospective, multicentric cohort study enrolling patients with estimated glomerular filtration rate (eGFR) 15–60 mL/min/1.73 m², or >60 mL/min/1.73 m² with proteinuria. Clinical details and biological samples are collected at annual visits. We analysed the baseline characteristics including socio-demographic details, risk factors, disease characteristics and laboratory measurements. In addition, we compared characteristics between urban and rural participants.

Results

A total of 4056 patients have been enrolled up to 31 March 2020. The mean ± SD age was 50.3 ± 11.8 years, 67.2% were males, two-thirds of patients lived in rural areas and the median eGFR was 40 mL/min/1.73 m². About 87% were hypertensive, 37% had diabetes, 22% had CVD, 6.7% had past history of acute kidney injury and 23% reported prior use of alternative drugs. Diabetic kidney disease, chronic interstitial nephritis (CIN) and CKD-cause unknown (CKDu) were the leading causes. Rural participants had more occupational exposure and tobacco use but lower educational status and income. CIN and unknown categories were leading causes in rural participants.

Conclusions

The ICKD study is the only large cohort study of patients with mild-to-moderate CKD in a lower middle income country. Baseline characteristics of study population reveal differences as compared with other cohorts from high-income countries.

Comprehensive lifestyle modification as complementary therapy to prevent and manage post-transplant diabetes mellitus*

Post-transplant diabetes mellitus (PTDM) is one from the most common metabolic complications after kidney transplantation. PTDM develops in the early period after transplantation. The risk factors of PTDM are carbohydrate imbalances occurring in the patient prior to transplantation, surgery and the inclusion of immunosuppressive treatment. Kidney transplant patients tend to gain weight, which is associated with an increased risk of post-transplant diabetes, cardiovascular diseases and abnormal transplanted kidney function. Patients after kidney transplantation should be advised to adopt a lifestyle based on a proper diet, exercise, weight control and smoking cessation. The strategy to reduce the risk factors for PTDM development should start before transplantation and continue after kidney transplantation. A targeted, non-pharmacological approach to patients already during the dialysis period may have a significant impact on reducing post-transplantation diabetes. Lifestyle interventions can effectively reduce the risk of development and inhibit the progression of post-transplantation diabetes. The article describes elements of comprehensive non-pharmacological management based on available knowledge of rehabilitation, dietetics and psychology.

Renal risk profiling in newly diagnosed hypertensives in an urban population in Nigeria

Introduction

Hypertension is a cause and consequence of chronic kidney disease globally. The other factors that work in concert with hypertension to cause CKD are yet to be clearly elucidated. Studies have identified proteinuria, dyslipidemia, obesity, smoking and family history of CKD as renal risk factors. Due to the high morbidity and mortality associated with occurrence of CKD including the enormous financial burden involved in its management, the knowledge of prevention and understanding of the risk factors for development of CKD is highly essential. Therefore, Identifying well defined risk factors that display strong graded association with the occurrence and progression of CKD can help in elucidating potential targets for disease modification.

Objective

The aim of this study was to determine the prevalence of renal risk factors and their impact on kidney function in newly diagnosed hypertensive Nigerians.

Methods

This was a case control study of two hundred and fifty newly diagnosed hypertensive Nigerians recruited from two contiguous hospitals in an urban setting in south western Nigeria. Another group of two hundred and fifty apparently healthy age and sex matched normotensive Nigerians in the same community were recruited as controls.

Results

Seventy (28%) of the newly diagnosed hypertensives had estimated glomerular filtration rate of less than 60ml/min, while 42.4% and 18.8% of the subjects and the controls had microalbuminuria respectively. The newly diagnosed hypertensives had significantly higher prevalence of analgesic use (86.4% versus 41.6%, p < 0.001), alcohol consumption (20.8% versus 12%, p = 0.008), use of canned salted food (18.8% versus 8.4%, p= 0.001) and central obesity (36.1% versus 26.8%, p= 0.025) compared to controls.

Conclusion

There is a significant occurrence of modifiable renal risk factors in newly diagnosed hypertensives and this offers a platform for instituting preventive strategies in the community.

Associations between Water Quality Measures and Chronic Kidney Disease Prevalence in Taiwan

To determine the relationships between exposure to environmental contaminants in water and chronic kidney disease (CKD), we investigated the associations of 61 water attributes with the prevalence of CKD and End-Stage Renal Disease (ESRD) using data from 2005 to 2011 from all 22 counties and cities in the main island of Taiwan. We acquired patient information from the Taiwan Longitudinal Health Insurance Database to calculate the age-standardized CKD and ESRD prevalence rates and linked the patients’ residences to the water quality monitoring data, which were sampled periodically for a total of over 45,000 observations obtained from the Taiwan Environmental Water Quality Information Database. The association analysis adjusting for gender, age, and annual effects showed that the zinc (Zn), ammonia, chemical oxygen demand (COD), and dissolved oxygen in rivers were weakly correlated with CKD (τ = 0.268/0.250/0.238/−0.267, p = 6.01×10⁻⁶/2.52×10⁻⁵/6.05×10⁻⁵/3.30×10⁻⁵, respectively), but none for ESRD. The importances of Zn and COD in rivers were also demonstrated in a CKD regression model. Moreover, an unusually high CKD prevalence was related to arsenic contamination in groundwater. A further prospective cohort study would improve our understanding of what level of environmental water with risky properties could affect the development of CKD.

Deceased-Donor Smoking History Is Associated With Increased Recipient Mortality After Kidney Transplant: A Population-Cohort Study

OBJECTIVES

Historical data have suggested that donor smoking is associated with detrimental clinical outcomes for recipients of kidneys from deceased donors. However, the effects of smoking status of a kidney donor on the outcomes of the recipient in a contemporary setting of immunosuppression and transplant practice have not yet been ascertained.

MATERIALS AND METHODS

This retrospective, population-cohort study analyzed data of all deceased-donor kidney-alone transplant procedures performed in the United Kingdom between April 2001 and April 2013. Our study included 11?199 deceased-donor kidney allograft recipients, with median follow-up of 46 months posttransplant.

RESULTS

In our cohort, 5280 deceased donors (47.1%) had a documented history of smoking. Deceased donors with versus those without smoking history were more likely to be younger (mean age of 48 vs 50 years; P < .001), be of white ethnicity (96.6% vs 95.3%; P < .001), and have brain death before donation (77.1% vs 74.9%; P = .006). On unadjusted survival analyses, overall patient survival was significantly shorter in patients who received kidney allografts from deceased donors with smoking history (hazard ratio of 1.12, 95% confidence interval, 1.00-1.25; P = .044). No significant association was seen for death-censored or overall graft survival. Our multivariate survival analyses showed that, after accounting for confounding factors, the effects of donor smoking status remained significant for patient survival (hazard ratio of 1.16, 95% CI, 1.03-1.29; P =.011) but not graft survival.

CONCLUSIONS

This population-cohort study suggests that deceased-donor kidneys from smokers contribute to an increased risk of death for kidney allograft recipients. These study findings imply donor smoking history should be factored into the risk stratification decision for recipient selection to optimize decision making; however, further clarification and validation of these data are warranted.

Sub-acute administration of lower doses of nicotine caused sex-dependent improvement of renal function in Wistar rats

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Exposure to nicotine is associated with sex-dependent variation in electrolyte disturbances.

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Lower doses of sub-acute nicotine administration enhanced renal function.

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Nicotine-enhanced renal function is more pronounced in female than in male Wistar rats.

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Nicotine-enhanced renal function may be mediated through α7-nAchR.

The adverse and beneficial health effects of nicotine (NIC), the major alkaloid found in cigarettes and tobacco, are controversial. Most studies on NIC have focused on its effects on cardiovascular and nervous functions. This study aimed at determining dose- and sex-specific effects of sub-acute (28 days) NIC administration on some indices of kidney function in Wistar rats. Forty rats (20 males and 20 females), 8–9 weeks old (each housed in separate metabolic cage), were used for this study such that graded doses of NIC (1, 2 and 4 mg/kg i.p. for 28 days) were administered to both sexes while each control received distilled water at 0.2 mL/100 g i.p. Blood was collected under ketamine anesthesia (10 mg/kg i.m) for analyses and results obtained were compared at p < 0.05. The result showed beneficial alterations in plasma and urine level of creatinine, urea and uric acid (p < 0.05) as well as plasma and urine electrolyte level (Na⁺ and K⁺) in both sexes (p < 0.05). Also, there was significant improvement in creatinine clearance (p < 0.05) with no appreciable difference in their histological examination. Although these beneficial effects were more pronounced in the female than in the male (p < 0.05), administration at the highest dose showed potentially deleterious alterations from normal beneficial trend (p < 0.05) in both sexes. It was concluded that sub-acute administration of lower doses of NIC improves kidney function of Wistar rats; an effect that was more pronounced in the females than their male counterparts.

Smoking History Is Associated With Adverse Outcomes for Kidney Allograft Recipients

OBJECTIVES

Donor kidney measurements may affect outcomes of transplanted allografts. We tested allograft and recipient measurements on kidney allograft outcomes. In this study, we compared the effects of kidney allograft volumes, which were measured using computed tomographic angiography before transplant, and allograft weight, which was measured during surgery, in relation to the recipient's body weight and body mass index on kidney function at 6 and 12 months after transplant.

MATERIAL AND METHODS

We included 74 patients (40 female and 34 male patients, mean age of 50.42 ±; 9.75 y) in this study.

RESULTS

Intraoperative allograft weight was 182.68 ± 40.33 g (range, 104-266 g). The allograft volume measured using computed tomographic angiography scanning was 123.34 ± 24.26 mL (range, 78-181 mL). The estimated glomerular filtration rates of the recipients at 6 and 12 months after transplant correlated negatively with age and recipient body mass index but correlated positively with allograft volume/recipient body weight, allograft volume/recipient body mass index, allograft weight, allograft weight/recipient body weight, and allograft weight/recipient body mass index values, as concluded by univariate analyses. From multivariate analyses, we found variables of interest presumed to significantly affect the 12-month estimated glomerular filtration rates, including recipient age, allograft volume/recipient body weight, allograft volume/recipient body mass index, allograft weight, allograft weight/recipient body weight, and allograft weight/recipient body mass index.

CONCLUSIONS

Transplanted allograft and recipient body values may be used as predictors of estimated glomerular filtration rates 6 and 12 months after transplant.

Smoking in Renal Transplantation; Facts Beyond Myth

Smoking is one of the preventable leading causes of death worldwide. Most of the studies focused on the association between smoking and cardiovascular disease, pulmonary diseases, malignancy and death. However, the direct effect of smoking on the renal system was undermind. There are emerging evidence correlating tobacco use with pathological changes in the normal kidneys. The effect is more obvious on the renal allograft most probably due to the chronic immune suppression status and the metabolic effect of the drugs. Several studies have documented a deleterious effect of smoking on the renal transplant recipients. Smoking was associated with lowering patient and graft survival. Smoking cessation proved to improve graft survival and to a lesser extent recipient survival. Even receiving a renal transplant from a smoker donor increases the risk of death for the recipient and carries a poorer graft survival compared to non-smoking donors. Most of the studies investigating the effect of smoking were based on self-reporting questioners, which may be misleading due to poor recall or the desire to give socially acceptable answers. This made the need of a reliable biomarker of ultimate importance. Cotinine was proposed as a promising biomarker that may help to provide objective evidence regarding the status of smoking and the dose of nicotine exposure, yet there are still some limitations of its use. The aim of this work is to review the current evidence to improve our understanding of this critical topic. Indeed, this will help to guide better-designed studies in the future.

An Analysis of Anthropometric Indicators and Modifiable Lifestyle Parameters Associated with Hypertensive Nephropathy

The surge in prevalence of chronic noncommunicable diseases like hypertension and chronic kidney disease has been linked with modifiable lifestyle practices and increased body fat. This study sought to compare the association between different modifiable lifestyle practices, adiposity indices, renal function parameters, and hypertension as well as the predictive implications for levels of these parameters in target cardiac organ damage among an urban Ghanaian hypertensive population. Using a hospital-based case-control study design, 241 Ghanaian indigenes from the Kumasi metropolis were recruited for this study. The case group was made up of 180 hypertensives and 61 normotensives served as controls. In addition to sociodemographic data, standard haemodynamic, anthropometric, renal function, and cardiac organ damage assessments were done. The prevalence of chronic kidney disease (CKD) ranged from 13.3% to 16.6% depending on the equation used in estimating the glomerular filtration rate (eGFR). Percentage cluster distribution by chronic kidney disease was observed to be significantly tilted toward the upper quartiles (3rd and 4th) of the haemodynamic parameters measured. Chronic kidney disease was significantly higher among self-reported smokers and alcoholic hypertensives. In this urban population, adiposity was associated with hypertension and renal insufficiency. Chronic kidney disease was associated with hypertension and cardiac abnormalities.

Exposure to waterpipe smoke induces renal functional and oxidative biomarkers variations in mice

CONTEXT

Waterpipe smoking (WPS) has been known for over 400 years. It has been spread widely especially between youth because of the addition of pleasant flavor and because it was misconsidered to be less harmful than cigarette.

OBJECTIVE

In this study, we investigated the effect of waterpipe smoking on renal oxidative and functional parameters and compared that at acute and chronic exposure time in mice.

MATERIALS AND METHODS

Mice were divided into three groups, namely acute, chronic and fresh air control. Acute group was exposed to waterpipe smoke for one hour daily for six days using whole-body exposure system, while chronic group was exposed to waterpipe smoke for one hour daily for 30 days using whole-body exposure system.

RESULT

Exposure to waterpipe smoke has shown significant changes on the mice kidney functional parameters such as creatinine and blood urea nitrogen. Both exposures (acute and chronic) has shown a significant reduction in superoxide dismutase (SOD) activity (p < 0.05), whereas the activity of other antioxidant enzymes (catalase and GPx) reduced only with chronic exposure to waterpipe smoke (p < 0.05). Additionally, the level of thiobarbituric acid reactive substances (TBARS) in mice kidney homogenates has shown a significant elevation following chronic exposure to waterpipe smoke (p < 0.05).

DISCUSSION AND CONCLUSION

In conclusion, chronic waterpipe smoke affects the kidney parameter and antioxidant markers, therefore affecting its functionality of detoxifying and removal of poisonous material from the body.

Estimating the glomerular filtration rate in the Spanish working population: chronic kidney disease prevalence and its association with risk factors

OBJECTIVE

This study aims to investigate the influence of estimated glomerular filtration rate (eGFR) with two equations (and by one or two separate measurements), on the prevalence of chronic kidney disease (CKD) and its association with blood pressure, and cardiovascular and metabolic risk factors.

METHODS

Between January 2010 and October 2011, the Ibermutuamur CArdiovascular RIsk Assessment project included 128 588 workers (77.2% men, mean age 39.3 years, range 16-75), who underwent two consecutive yearly medical check-ups and had information for eGFR according to the MDRD-IDMS and CKD-EPI equations (serum creatinine was measured by a isotope-dilution mass spectrometry traceable method in a single central laboratory). CKD was defined by an eGFR less than 60 ml/min per 1.73 m. Subclinical (occult) renal disease was defined as an eGFR less than 60 ml/min per 1.73 m in patients with serum creatinine below 1.3 mg/dl and below 1.2 mg/dl in men and women, respectively.

RESULTS

In this working population, prevalence of CKD was very low, but two to six times lower when two separate eGFRs below 60 ml/min per 1.73 m were used. The prevalence of CKD was significantly lower with the CKD-EPI compared to the MDRD-IDMS equation. The same applies to occult CKD. In male workers, occult CKD was practically nonexistent.Multivariate analyses show that blood pressure, total serum cholesterol, and serum glucose (positively), and high-density lipoprotein and low-density lipoprotein (negatively) were associated with CKD, with both equations. Another metabolic factor (waist circumference) was only associated (positively) with CKD defined by the CKD-EPI equation, which appears to be associated with most components of the metabolic syndrome.

CONCLUSIONS

The CKD-EPI formula, calculated on the basis of two reported blood samples, may provide the most specific definition of CKD.

Clinical challenges in diagnosis and management of diabetic kidney disease

Diabetic kidney disease (DKD) is a major and increasing worldwide public health issue. There is a great need for implementing treatments that either prevent or significantly slow the progression of DKD. Although there have been significant improvements in management, the increasing numbers of patients with DKD illustrate that current management is not wholly adequate. The reasons for suboptimal management include the lack of early diagnosis, lack of aggressive interventions, and lack of understanding about which interventions are most successful. There are a number of challenges and controversies regarding the current management of patients with DKD. Understanding of these issues is needed in order to provide the best care to patients with DKD. This article describes some of the clinically important challenges associated with DKD: the current epidemiology and cost burden and the role of biopsy in the diagnosis of DKD. Treatment controversies regarding current pharmacologic and nonpharmacologic approaches are reviewed and recommendations based on the published literature are made.

Associations of smoking with alterations in renal hemodynamics may depend on sex--investigations in potential kidney donors

BACKGROUND/AIMS

Cigarette smoking is a risk factor for renal damage, but little is known about subclinical effects of smoking on renal hemodynamics and parameters of renal function in humans. We examined the associations of smoking with systemic and renal hemodynamics and renal function parameters in healthy individuals.

METHODS

Data from 196 potential living kidney donors were analysed retrospectively. Mean arterial blood pressure (MAP), effective renal plasma flow (ERPF) and creatinine clearance had been measured. We additionally calculated parameters of renal hemodynamics. Data were analyzed for the effects of smoking and sex dependent on age and MAP.

RESULTS

Systemic and renal hemodynamic parameters did not differ between smokers and non-smokers. In non-smokers of both sexes MAP was negatively correlated with ERPF, and higher MAP was associated with increased renal vascular resistance and with afferent arteriolar resistance, with glomerular pressure (PG) remaining constant. However, in male, but not in female smokers, ERPF and PG increased with MAP. A correlation of age with a steeper decline in ERPF in male smokers was lost in multiple regression analysis.

CONCLUSIONS

As compared to women, smoking men may exhibit an increased glomerular hydrostatic pressure, which is a known promoter of kidney damage.

Contribution of glomerular filtration rate to 10-year cardiovascular and mortality risk among hypertensive adults: Tehran lipid and glucose study

The authors tested the hypotheses that (1) estimated glomerular filtration rate (eGFR) predicts cardiovascular disease (CVD) or mortality risk among hypertensive patients, (2) associations are curvilinear, and (3) diabetes modifies these associations. Data from a 10-year follow-up of 3179 hypertensive patients 18 years and older were analyzed. Measurements included eGFR and CVD risk factors, and outcomes were CVD and mortality. Cox models were developed to estimate the hazard ratios (HRs) for different endpoints for a 1-standard deviation (SD) increment in eGFR. The nonlinearity in associations was examined by cubic spline method. Mean (SD) age of the participants (59.0% women) was 56.3 (12.3) years. During follow-up (10-year), 629 incident cases of CVD (296 women) and 320 deaths (130 women) were documented. The incidence rate of different outcomes decreased across increasing eGFR quintiles. Among men, irrespective of their diabetes status, eGFR was inversely associated with risk of mortality. Among women, irrespective of their diabetes status, eGFR did not predict mortality. Neither among men nor among women did eGFR predict CVD or coronary heart disease. No evidence was found for nonlinearity in these associations. eGFR was independently associated with mortality among hypertensive men with or without diabetes. When information on traditional CVD risk factors was available, eGFR provided no additional predictive value for CVD.

The effects of continuing and discontinuing smoking on the development of chronic kidney disease (CKD) in the healthy middle-aged working population in Japan

OBJECTIVES

The strength of the association between smoking and the development of chronic kidney disease (CKD) in the healthy middle-aged working age population has not been established.

METHODS

This was a retrospective 6-year observational study involving 4,121 male and 2,877 female workers who were free of primary kidney disease, diabetes mellitus, severe hypertension, and the signs and symptoms of CKD. Proteinuria was detected by a dipstick method, and glomerular filtration rate (GFR) was estimated by the equation of the Japan Society of Nephrology.

RESULTS

Sixty men (1.5 %) and 21 women (0.7 %) developed proteinuria over the 6 years of the study. Irrespective of sex, in comparison with non-smokers, those who continued smoking showed an odds ratio (OR) of 2.52 with a 95 % confidence interval (CI) of 1.50-4.25 for developing proteinuria while those who quit smoking showed an OR of 1.29 (95 % CI 0.48-3.42), following adjustment for confounders. Among the study population, 443 men (10.7 %) and 356 women (12.4 %) developed a GFR of <60 mL/min/1.73 m(2), corresponding to stage III CKD. Continuing smokers had a low OR (0.74, 95 % CI 0.60-0.90) for developing a low GFR, as well as a higher mean GFR than non-smokers. The reduction in GFR during the 6-year study period was not different between smokers and non-smokers, but it was larger in those who developed proteinuria than in those who did not, irrespective of smoking.

CONCLUSIONS

Continuing smokers showed a twofold or more higher risk of developing proteinuria. Discontinuation of smoking substantially reduced the risk. A longer observational period may be required to detect the smoking-induced risk of developing stage III CKD in the middle-aged working population.

Smoking in diabetic nephropathy: sparks in the fuel tank?

Diabetic nephropathy is associated with high morbidity and mortality and the prevalence of this disease is continuously increasing worldwide. Long-term diabetes increases the likelihood of developing secondary complications like nephropathy, the most common cause of end stage renal disease. Usually, other factors like hypertension, alcoholism and smoking also partly contribute to the progression of diabetic nephropathy. Among this, cigarette smoking in diabetes has been repeatedly confirmed as an independent risk factor for the onset and progression of diabetic nephropathy. Various studies suggest that smoking is a major fuel in the development of high oxidative stress and subsequently hyperlipidemia, accumulation of advanced glycation end products, activation of the renin angiotensin system and Rho-kinase, which are observed to play a pathogenic role in the progression of diabetic nephropathy. Furthermore, cigarette smoking in diabetic patients with vascular complications produces a variety of pathological changes in the kidney, such as thickening of the glomerular basement membrane and mesangial expansion with progression in glomerulosclerosis and interstitial fibrosis, which ultimately results in end stage renal failure. Strong associations are consistently found between chronic cigarette smoking and diabetic microvascular complications. A diverse group of studies unveil potential mechanisms that may explain the role of cigarette smoking in the progression of diabetic nephropathy. Tremendous efforts are being made to control smoking mediated progression of diabetic nephropathy, but no promising therapy is yet available. The present review critically discusses the possible detrimental role of chronic cigarette smoking in the progression of diabetic nephropathy and various possible pharmacological interventions to attenuate the exacerbation of diabetic nephropathy.

Association between occupational heat stress and kidney disease among 37,816 workers in the Thai Cohort Study (TCS)

Background

We examined the relationship between self-reported occupational heat stress and incidence of self-reported doctor-diagnosed kidney disease in Thai workers.

Methods

Data were derived from baseline (2005) and follow-up (2009) self-report questionnaires from a large national Thai Cohort Study (TCS). Analysis was restricted to full-time workers (n = 17 402 men and 20 414 women) without known kidney disease at baseline. We used logistic regression models to examine the association of incident kidney disease with heat stress at work, after adjustment for smoking, alcohol drinking, body mass index, and a large number of socioeconomic and demographic characteristics.

Results

Exposure to heat stress was more common in men than in women (22% vs 15%). A significant association between heat stress and incident kidney disease was observed in men (adjusted odds ratio [OR] = 1.48, 95% CI: 1.01–2.16). The risk of kidney disease was higher among workers reporting workplace heat stress in both 2005 and 2009. Among men exposed to prolonged heat stress, the odds of developing kidney disease was 2.22 times that of men without such exposure (95% CI 1.48–3.35, P-trend <0.001). The incidence of kidney disease was even higher among men aged 35 years or older in a physical job: 2.2% exposed to prolonged heat stress developed kidney disease compared with 0.4% with no heat exposure (adjusted OR = 5.30, 95% CI 1.17–24.13).

Conclusions

There is an association between self-reported occupational heat stress and self-reported doctor-diagnosed kidney disease in Thailand. The results indicate a need for occupational health interventions for heat stress among workers in tropical climates.

Combined liver-kidney transplantation in patients infected with human immunodeficiency virus

Although human immunodeficiency virus (HIV) infection has been a major global health problem for almost 3 decades, with the introduction of highly active antiretroviral therapy in 1996 and effective prophylaxis and management of opportunistic infections, mortality from acquired immunodeficiency syndrome has decreased markedly. In developed countries, this condition is now being treated as a chronic condition. As a result, rates of morbidity and mortality from other medical conditions leading to end-stage liver, kidney, and heart disease are steadily increasing in individuals with HIV. Because the definitive treatment for end-stage organ failure is transplantation, the demand for it has increased among HIV-infected patients. For these reasons, many transplant centers have eliminated HIV infection as a contraindication to transplantation, as a result of better patient management and demand.

Protective effects of pentoxifylline on cigarette smoking-induced renal tissue damage in rats

In this study, we investigated the protective effect of pentoxifilline (PTX) on smoking-induced damage in rat kidney tissues. Twenty-seven male Wistar rats were used in the study. Animals were divided into three equal groups as follows: Group 1: control group with only normal saline (NS; 0.9% NaCl) injection for 8 weeks; Group 2: cigarette smoking and NS injection for 8 weeks; and Group 3: cigarette smoking and PTX injection for 8 weeks. The rats were sacrificed after 8 weeks and their kidneys were excised for histopathological analysis. Serial paraffin sections (5 µm) of the kidneys were cut and stained with hematoxylin and eosin (H&E) and periodic acid-Schiff (PAS). The terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) method was used to assess apoptosis. Glomerular diameters, glomerular cell number and proximal tubule cell numbers were compared between the groups. Our results showed that PTX treatment prevented negative effects of smoking in rat kidneys. There was a statistically significant difference in all assessed parameters between Group 2 and other groups (p < 0.05). In conclusion, our study shows that PTX treatment is effective in preventing the negative effects of cigarette smoking on kidneys by inhibiting cell damage with its antioxidant properties.

Renal disease in patients with HIV infection: epidemiology, pathogenesis and management

With the introduction of highly active antiretroviral therapy, we have witnessed prolonged survival with the potential for normal life expectancy in HIV-infected individuals. With improved survival and increasing age, HIV-infected patients are increasingly likely to experience co-morbidities that affect the general population, including kidney disease. Although HIV-associated nephropathy, the most ominous kidney disease related to the direct effects of HIV, may be prevented and treated with antiretrovirals, kidney disease remains an important issue in this population. In addition to the common risk factors for kidney disease of diabetes mellitus and hypertension, HIV-infected individuals have a high prevalence of other risk factors, including hepatitis C, cigarette smoking and injection drug use. Furthermore, they have exposures unique to this population, including antiretrovirals and other medications. Therefore, the differential diagnosis is vast. Early identification (through efficient screening) and definitive diagnosis (by kidney biopsy when indicated) of kidney disease in HIV-infected individuals are critical to optimal management. Earlier interventions with disease-specific therapy, often with the help of a nephrologist, are likely to lead to better outcomes. In those with chronic kidney disease, interventions, such as aggressive blood pressure control with the use of ACE inhibitors or angiotensin receptor antagonists where tolerated, tight blood glucose control in those with diabetes, and avoidance of potentially nephrotoxic medications, can slow progression and prevent end-stage renal disease. Only with greater awareness of kidney-disease manifestations and their implications in this particularly vulnerable population will we be able to achieve success in confronting this growing problem.

Hypertension and the kidney

The kidney could be the cause of essential hypertension which can also cause renal disease. High blood pressure is also very common in chronic kidney disease, and is moreover a well-known risk factor for a faster progression of kidney failure. Hypertension and kidneys are thus closely linked. Hypertension must be aggressively treated in patients suffering from chronic kidney disease, with a blood pressure goal of less than 130/80 mmHg, even lower than 125/75 mmHg when proteinuria is over 1g/day, using optimal and effective antihypertensive drugs. Among them, the blockers of the renin-angiotensin axis offer nephroprotective but also cardioprotective properties beyond their effect on blood pressure.

C-reactive protein is associated with renal function abnormalities in a non-diabetic population

BACKGROUND

C-reactive protein (CRP) has recently been introduced in cardiovascular medicine as a predictor of myocardial infarction, stroke and peripheral artery disease in different populations. We hypothesized that elevated CRP levels are associated with renal function abnormalities.

METHODS

To test this hypothesis, we studied the relationship between CRP levels and renal function loss measured as diminished creatinine clearance in a large non-diabetic population (7317 subjects). In addition, the associations and confounding effects of established renal risk factors that could explain the association between CRP and diminished renal filtration were studied. Also, the association of CRP with early alterations in renal function, such as those evidenced by a relatively high glomerular filtration ("hyperfiltration"), was examined. CRP levels were divided in quartiles. Subjects with CRP levels within the first quartile were defined as the reference group. Diminished renal filtration and hyperfiltration were defined as a creatinine clearance below or exceeding two times the prediction interval of the age- and sex-related reference group.

RESULTS

Elevated CRP levels were positively associated with cardiovascular and renal risk factors: age, body mass index, blood pressure, serum cholesterol level, smoking, plasma glucose level and elevated urinary albumin excretion. Elevated CRP was positively associated with diminished filtration (OR 1.8; 95% CI 1.2 to 2.6). In multivariate analyses, CRP was independently associated with a diminished filtration (OR 1.9; 95% CI 1.3 to 2.9). Interestingly, CRP also was associated with hyperfiltration (highest quartile, OR 1.7; 95% CI 1.2 to 2.5). However, body mass index accounted for most of the relationship between CRP and hyperfiltration.

CONCLUSIONS

As in cardiovascular disease, CRP appears to be a risk marker for renal function loss. The mechanism of this relationship remains to be clarified. However, the association between CRP, body weight, and a relatively elevated creatinine clearance is a hypothesis-generating finding, suggesting that early inflammatory processes related to high body fat may predispose the kidney to glomerular hyperfiltration-related renal function loss.

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.