Cigarette smoking and chronic kidney diseases

Cigarette smoking and progression of kidney dysfunction: a longitudinal cohort study

INTRODUCTION

Cigarette smoking is one of the most important life-modifiable risk factors for CVD events. The effect on CKD progression caused by smoking remained uncertain, while the effect on CVD had been established.

METHOD

The study population included participants from the specific health check and specific health guidance, an annual health check-up for all inhabitants of Japan who were aged between 40 and 74 years. 149,260 subjects (male, 37.1%; female, 62.9%) were included in this analysis.

RESULTS

The relationship between smoking status along with new-onset proteinuria and eGFR deterioration more than 15 mL/min/1.73 m2 was examined. Median observation periods were 1427 days [738, 1813] in males and 1437 days [729, 1816] in females. In male participants, the strongest factor upon kidney dysfunction was new-onset proteinuria (1.41 [1.31 1.51], P < 0.001). The second strongest factor on kidney deterioration was smoking (1.24 [1.16 1.31], P < 0.001). In female participants, strongest factor upon kidney dysfunction was smoking (1.27 [1.16-1.39], P < 0.001). The second strongest factor on kidney deterioration was new-onset proteinuria (1.26 [1.17 1.36], P < 0.001). To reveal the relationship of effects from new-onset proteinuria and smoking on the kidney function, the participants were divided into four groups with and without new-onset proteinuria and smoking. The group with both proteinuria and smoking had significantly worst renal prognosis (P for trend < 0.001).

CONCLUSION

Large longitudinal observation study revealed smoking has an evil effect on the progression of CKD. This evil effect could be observed in CKD patients with proteinuria as well as in general population without new-onset proteinuria.

Short-term inhalation exposure to cigarette smoke induces oxidative stress and inflammation in lungs without systemic oxidative stress in mice

Smoking is a well-established risk factor for various pathologies, including pulmonary diseases, cardiovascular disorders, and cancers. The toxic effects of cigarette smoke (CS) are mediated through multiple pathways and diverse mechanisms. A key pathogenic factor is oxidative stress, primarily induced by excessive formation of reactive oxygen species. However, it remains unclear whether smoking directly induces systemic oxidative stress or if such stress is a secondary consequence. This study aimed to determine whether short-term inhalation exposure to CS induces oxidative stress in extrapulmonary organs in addition to the lung in a murine model. In the experiment, 3R4F reference cigarettes were used to generate CS, and 8-week-old male BALB/c mice were exposed to CS at a total particulate matter concentration of either 0 or 800 µg/L for four consecutive days. CS exposure led to an increase in neutrophils, eosinophils, and total cell counts in bronchoalveolar lavage fluid. It also elevated levels of lactate dehydrogenase and malondialdehyde (MDA), markers indicative of tissue damage and oxidative stress, respectively. Conversely, no significant changes were observed in systemic oxidative stress markers such as total oxidant scavenging capacity, MDA, glutathione (GSH), and the GSH/GSSG ratio in blood samples. In line with these findings, CS exposure elevated NADPH oxidase (NOX)-dependent superoxide generation in the lung but not in other organs like the liver, kidney, heart, aorta, and brain. Collectively, our results indicate that short-term exposure to CS induces inflammation and oxidative stress in the lung without significantly affecting oxidative stress in extrapulmonary organs under the current experimental conditions. NOX may play a role in these pulmonary-specific events.

Prediction of immunotherapy response in idiopathic membranous nephropathy using deep learning-pathological and clinical factors

Background

Owing to individual heterogeneity, patients with idiopathic membranous nephropathy (IMN) exhibit varying sensitivities to immunotherapy. This study aimed to establish and validate a model incorporating pathological and clinical features using deep learning training to evaluate the response of patients with IMN to immunosuppressive therapy.

Methods

The 291 patients were randomly categorized into training (n = 219) and validation (n = 72) cohorts. Patch-level convolutional neural network training in a weakly supervised manner was utilized to analyze whole-slide histopathological features. We developed a machine-learning model to assess the predictive value of pathological signatures compared to clinical factors. The performance levels of the models were evaluated using the area under the receiver operating characteristic curve (AUC) on the training and validation tests, and the prediction accuracies of the models for immunotherapy response were compared.

Results

Multivariate analysis indicated that diabetes and smoking were independent risk factors affecting the response to immunotherapy in IMN patients. The model integrating pathologic features had a favorable predictive value for determining the response to immunotherapy in IMN patients, with AUCs of 0.85 and 0.77 when employed in the training and test cohorts, respectively. However, when incorporating clinical features into the model, the predictive efficacy diminishes, as evidenced by lower AUC values of 0.75 and 0.62 on the training and testing cohorts, respectively.

Conclusions

The model incorporating pathological signatures demonstrated a superior predictive ability for determining the response to immunosuppressive therapy in IMN patients compared to the integration of clinical factors.

Screening and Management of Coronary Artery Disease in Kidney Transplant Candidates

Cardiovascular disease (CVD) is a major cause of morbidity and mortality in patients with chronic kidney disease (CKD), especially in end-stage renal disease (ESRD) patients and during the first year after transplantation. For these reasons, and due to the shortage of organs available for transplant, it is of utmost importance to identify patients with a good life expectancy after transplant and minimize the transplant peri-operative risk. Various conditions, such as severe pulmonary diseases, recent myocardial infarction or stroke, and severe aorto-iliac atherosclerosis, need to be ruled out before adding a patient to the transplant waiting list. The effectiveness of systematic coronary artery disease (CAD) treatment before kidney transplant is still debated, and there is no universal screening protocol, not to mention that a nontailored screening could lead to unnecessary invasive procedures and delay or exclude some patients from transplantation. Despite the different clinical guidelines on CAD screening in kidney transplant candidates that exist, up to today, there is no worldwide universal protocol. This review summarizes the key points of cardiovascular risk assessment in renal transplant candidates and faces the role of noninvasive cardiovascular imaging tools and the impact of coronary revascularization versus best medical therapy before kidney transplant on a patient's cardiovascular outcome.

The toxic effects of electronic cigarette aerosol and cigarette smoke on cardiovascular, gastrointestinal and renal systems in mice

Electronic cigarette (EC) has been suggested to be less harmful than cigarette smoking, but the research on the full extent of their harm reduction potential is still lacking. This study aimed to evaluate the influence of EC aerosol and cigarette smoke (CS) on cardiovascular, gastrointestinal, and renal functions in mice after prolonged exposure. Forty-eight C57BL/6J male mice were randomly grouped and then exposed to fresh air (control), mung bean-flavored EC aerosol with low and high dose (EC1L, 6 mg/kg; EC1H, 12 mg/kg), watermelon-flavored EC aerosol with low and high dose (EC2L, 6 mg/kg; EC2H, 12 mg/kg), and finally a cigarette smoke (CS, 6 mg/kg), respectively. After 10 weeks of exposure, the heart rate increased for both the EC and CS groups, and the effect of CS on blood oxygen saturation was significantly higher than that of the EC group (P < 0.01). Proteomic analysis of the heart tissue showed that the overlapped differential expression protein from the EC and CS exposures was Crip2. For the gastrointestinal system, oral mucosa was significantly damaged in CS group. Compare with CS, EC had significantly fewer negative effects on most of the indictors which focused on in this study.

The Association of Smoking and Hyperuricemia with Renal Arteriolosclerosis in IgA Nephropathy

The combination effects of smoking (SMK) and hyperuricemia (HU) on renal arteriolosclerosis in patients with IgA nephropathy remain unknown. We examined the cross-sectional association between smoking (current or former) and renal arteriolar hyalinosis and wall thickening with or without HU [uric acid (UA) level ≥ 7 and ≥5 mg/dL in men and women] in 87 patients with IgA nephropathy who underwent renal biopsy. Arteriolar hyalinosis and wall thickening were assessed by the semiquantitative grading of arterioles. The SMK/HU subgroup showed the highest indices for hyalinosis and wall thickening, followed by the non-SMK/HU, SMK/non-HU, and non-SMK/non-HU subgroups. Multiple logistic analysis showed that SMK/HU, but not SMK/non-HU, was significantly associated with an increased risk of higher-grade renal arteriolar wall thickening. However, this did not occur with hyalinosis compared to non-SMK/non-HU. The adjusted odds ratio (95% confidence interval, p value) for SMK/HU was 12.8 (1.36-119, p < 0.05) for wall thickening. An association between SMK and renal arteriolar wall thickening might be prevalent only among patients with HU and in patients with IgA nephropathy. Further prospective studies are needed to determine whether patients with HU and SMK history exhibit rapid eGFR deterioration.

A prediction model of CKD progression among individuals with type 2 diabetes in the United States

BACKGROUND

CKD progression among individuals with T2D is associated with poor health outcomes and high healthcare costs, which have not been fully studied. This study aimed to predict CKD progression among individuals with diabetes.

METHOD

Using ACCORD trial data, a time-varying Cox model was developed to predict the risk of CKD progression among patients with CKD and T2D. CKD progression was defined as a 50 % decline, or 25 mL/min/1.73 m² decline in eGFR from baseline, doubling of the serum creatinine, or onset of ESKD. A list of candidate variables included demographic characteristics, physical exam results, laboratory results, medical history, drug use, and healthcare utilization. A stepwise algorithm was used for variable selection. Model performance was evaluated by Brier score and C-statistics. Confidence intervals (CI) were calculated using a bootstrap method. Decomposition analysis was conducted to assess the predictor contribution. Generalizability was assessed on patient-level data of the Harmony Outcome trial and CRIC study.

RESULTS

A total of 6982 diabetes patients with CKD were used for model development, with a median follow-up of 4 years and 3346 events. The predictors for CKD progression included female sex, age at T2D diagnosis, smoking status, SBP, DBP, HR, HbA1c, alanine aminotransferase (ALT), eGFR, UACR, retinopathy event, hospitalization. The model demonstrated good discrimination (C-statistics 0.745 [95 % CI 0.723-0.763]) and calibration (Brier Score 0.0923 [95 % CI 0.0873-0.0965]) performance in the ACCORD data. The most contributing predictors for CKD progression were eGFR, HbA1c, and SBP. The model demonstrated acceptable discrimination and calibration performance in the two external data.

CONCLUSION

For high-risk patients with both diabetes and CKD, the tool as a dynamic risk prediction of CKD progression may help develop novel strategies to lower the risk of CKD progression.

Xenobiotics Delivered by Electronic Nicotine Delivery Systems: Potential Cellular and Molecular Mechanisms on the Pathogenesis of Chronic Kidney Disease

Chronic kidney disease (CKD) is characterized as sustained damage to the renal parenchyma, leading to impaired renal functions and gradually progressing to end-stage renal disease (ESRD). Diabetes mellitus (DM) and arterial hypertension (AH) are underlying diseases of CKD. Genetic background, lifestyle, and xenobiotic exposures can favor CKD onset and trigger its underlying diseases. Cigarette smoking (CS) is a known modified risk factor for CKD. Compounds from tobacco combustion act through multi-mediated mechanisms that impair renal function. Electronic nicotine delivery systems (ENDS) consumption, such as e-cigarettes and heated tobacco devices, is growing worldwide. ENDS release mainly nicotine, humectants, and flavorings, which generate several byproducts when heated, including volatile organic compounds and ultrafine particles. The toxicity assessment of these products is emerging in human and experimental studies, but data are yet incipient to achieve truthful conclusions about their safety. To build up the knowledge about the effect of currently employed ENDS on the pathogenesis of CKD, cellular and molecular mechanisms of ENDS xenobiotic on DM, AH, and kidney functions were reviewed. Unraveling the toxic mechanisms of action and endpoints of ENDS exposures will contribute to the risk assessment and implementation of proper health and regulatory interventions.

Effects of Smoking on Diabetic Nephropathy

Diabetes is a systemic metabolic disease with serious complications that cause significant stress on the healthcare system. Diabetic kidney disease is the primary cause of end stage renal disease globally and its progression is accelerated by various factors. Another major healthcare hazard is tobacco consumption and smoking has deleterious effects on renal physiology. Prominent factors are defined as sympathetic activity, atherosclerosis, oxidative stress and dyslipidemia. This review aims to enlighten the mechanism underlying the cumulative negative effect of simultaneous exposure to hyperglycemia and nicotine.

Title IgA Nephropathy and Oral Bacterial Species Related to Dental Caries and Periodontitis

A relationship between IgA nephropathy (IgAN) and bacterial infection has been suspected. As IgAN is a chronic disease, bacteria that could cause chronic infection in oral areas might be pathogenetic bacteria candidates. Oral bacterial species related to dental caries and periodontitis should be candidates because these bacteria are well known to be pathogenic in chronic dental disease. Recently, several reports have indicated that collagen-binding protein (cnm)-(+) Streptococcs mutans is relate to the incidence of IgAN and the progression of IgAN. Among periodontal bacteria, Treponema denticola, Porphyromonas gingivalis and Campylobacte rectus were found to be related to the incidence of IgAN. These bacteria can cause IgAN-like histological findings in animal models. While the connection between oral bacterial infection, such as infection with S. mutans and periodontal bacteria, and the incidence of IgAN remains unclear, these bacterial infections might cause aberrantly glycosylated IgA1 in nasopharynx-associated lymphoid tissue, which has been reported to cause IgA deposition in mesangial areas in glomeruli, probably through the alteration of microRNAs related to the expression of glycosylation enzymes. The roles of other factors related to the incidence and progression of IgA, such as genes and cigarette smoking, can also be explained from the perspective of the relationship between these factors and oral bacteria. This review summarizes the relationship between IgAN and oral bacteria, such as cnm-(+) S. mutans and periodontal bacteria.

Relationship between IgA Nephropathy and Porphyromonas gingivalis; Red Complex of Periodontopathic Bacterial Species

IgA nephropathy (IgAN) has been considered to have a relationship with infection in the tonsil, because IgAN patients often manifest macro hematuria just after tonsillitis. In terms of oral-area infection, the red complex of periodontal bacteria (Porphyromonas gingivalis (P. gingivalis), Treponema denticol (T. denticola) and Tannerella forsythia (T. forsythia)) is important, but the relationship between these bacteria and IgAN remains unknown. In this study, the prevalence of the red complex of periodontal bacteria in tonsil was compared between IgAN and tonsillitis patients. The pathogenicity of IgAN induced by P. gingivalis was confirmed by the mice model treated with this bacterium. The prevalence of P. gingivalis and T. forsythia in IgAN patients was significantly higher than that in tonsillitis patients (p < 0.001 and p < 0.05, respectively). A total of 92% of tonsillitis patients were free from red complex bacteria, while only 48% of IgAN patients had any of these bacteria. Nasal administration of P. gingivalis in mice caused mesangial proliferation (p < 0.05 at days 28a nd 42; p < 0.01 at days 14 and 56) and IgA deposition (p < 0.001 at day 42 and 56 after administration). Scanning-electron-microscopic observation revealed that a high-density Electron-Dense Deposit was widely distributed in the mesangial region in the mice kidneys treated with P. gingivalis. These findings suggest that P. gingivalis is involved in the pathogenesis of IgAN.

Cigarette smoking may accelerate the progression of IgA nephropathy

Background

Whether cigarette smoking is associated with the progression of immunoglobulin A nephropathy (IgAN) remains uncertain; therefore, we aimed to evaluate the effect of cigarette smoking on the prognosis of IgAN.

Methods

We divided 1239 IgAN patients from West China Hospital of Sichuan University who met the inclusion criteria into smoker (current or former) and non-smoker groups. The endpoint was end-stage renal disease (ESRD: eGFR < 15 mL/min/1.73 m² or undergoing renal replacement treatment) and/or eGFR decreased by > 50%. Kaplan–Meier, correlation, logistic regression and Cox proportional hazards analyses were performed. The association between cigarette smoking and IgAN was further verified by propensity-score-matched cohort analysis.

Results

During the mean follow-up period of 61 months, 19% (40/209) of the smoker group and 11% (110/1030) of the non-smoker group reached the study endpoint (p < 0.001). Multivariate Cox regression analysis revealed that cigarette smoking (hazard ratio (HR) = 1.58; p = 0.043) was an independent risk factor predicting poor renal progression in IgAN, and that IgAN patients with chronic kidney disease (CKD) stage 3–4 were more susceptible to cigarette smoking (p < 0.001). After propensity score matching (PSM), a significant correlation between cigarette smoking and renal outcomes in IgAN patients was seen. Furthermore, Spearman’s correlation test revealed that smoking dose was negatively correlated with eGFR (r = 0.141; p < 0.001) and positively related with proteinuria (r = 0.096; p = 0.001).

Conclusions

Cigarette smoking is an independent risk factor for IgAN progression, especially for advanced patients.

Impact of educational level on incident chronic kidney disease during 13 years of follow-up: a prospective cohort study

OBJECTIVES

To examine the association between educational level and chronic kidney disease (CKD) among the Iranian population.

STUDY DESIGN

This is a prospective cohort study conducted in the framework of the Tehran Lipid and Glucose Study.

METHODS

A total of 8173 Iranians (men = 3659) aged ≥20 years were included in the study. CKD was defined as estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m². The association between educational status and CKD was explored using multivariate Cox proportional regression analyses, adjusted for age, gender, current smoking, marital status, body mass index, waist circumference, baseline eGFR, diabetes, hypertension, physical activity, history of cardiovascular diseases and dyslipidaemia.

RESULTS

During a median follow-up of 13.14 years, 2609 cases of incident CKD were identified; the corresponding incidence rate was 26.35 (range 25.39-27.34) per 1000 person-years. Compared to low educational level, middle and high educational levels showed lower risks for incident CKD in the crude model [hazard ratio (HR) 0.37 (95% confidence interval {CI} 0.34-0.40) and HR 0.40 (95% CI 0.35-0.45), respectively]; however, these HRs changed direction after further adjustment for age and gender [HR 1.26 (95% CI 1.14-1.39) and HR 1.40 (95% CI 1.22-1.61), respectively]. The increased risk of incident CKD for those at higher educational levels remained significant in the fully adjusted model. In addition, results from the gender stratified analyses were in the same direction as those found among the whole study population (P-value for interaction of gender and education >0.8).

CONCLUSIONS

Higher educational levels were associated with incident CKD during more than a decade of follow-up; this finding may be attributed to unhealthy lifestyle behaviours among this population group.

Gender-biased kidney damage in mice following exposure to tobacco cigarette smoke: More protection in premenopausal females

Multiple clinical studies documented renal damage in chronic cigarette smokers (CS) irrespective of their age and gender. Premenopausal female smokers are known to exert a certain cardiovascular and renal protection with undefined mechanisms. Given the multiple demographic variables within clinical studies, this experimental study was designed to be the first to assess whether gender‐biased CS‐induced kidney damage truly exists between premenopausal female and age‐matched C57Bl6J male mice when compared to their relative control groups. Following 6 weeks of CS exposure, cardiac function, inflammatory marker production, fibrosis formation, total and glomerular ROS levels, and glomerulotubular homeostasis were assessed in both genders. Although both CS‐exposed male and female mice exhibited comparable ROS fold change relative to their respective control groups, CS‐exposed male mice showed a more pronounced fibrotic deposition, inflammation, and glomerulotubular damage profile. However, the protection observed in CS‐exposed female group was not absolute. CS‐exposed female mice exhibited a significant increase in fibrosis, ROS production, and glomerulotubular alteration but with a pronounced anti‐inflammatory profile when compared to their relative control groups. Although both CS‐exposed genders presented with altered glomerulotubular homeostasis, the alteration phenotype between genders was different. CS‐exposed males showed a significant decrease in Bowman's space along with reduced tubular diameter consistent with an endocrinization pattern of chronic tubular atrophy, suggestive of an advanced stage of glomerulotubular damage. CS‐exposed female group, on the other hand, displayed glomerular hypertrophy with a mild tubular dilatation profile suggestive of an early stage of glomerulotubular damage that generally precedes collapse. In conclusion, both genders are prone to CS‐induced kidney damage with pronounced female protection due to a milder damage slope.

Efficacy of corticosteroid therapy for IgA nephropathy patients stratified by kidney function and proteinuria

BACKGROUND

Steroid therapy is one of the important therapies for IgA nephropathy (IgAN), but the features of the IgAN patients who have the benefit from this therapy remained unclear.

METHODS

This retrospective observational study, using data of 874 patients with IgAN analyzed the proteinuria and kidney function of IgAN patients who had beneficial effect by steroid therapy. Two advantages of the present study were a large cohort and a long observational period.

RESULTS

Corticosteroid therapy had ameliorated the kidney prognosis [incident rate ratio (IRR) 0.57 (95%CI 0.34-0.92), P = 0.029]. Because of interaction between kidney function and use of corticosteroid (P = 0.047), stratification analysis by kidney function revealed that prognosis of kidney function in IgAN patients whose eGFR was less than 60 ml/min/1.73m² was ameliorated by corticosteroid therapy [IRR 0.50 (95%CI 0.26-0.97), P = 0.015); while, there was no change of kidney prognosis in IgAN patients whose eGFR was above 60 ml/min/1.73 m². To make the target of corticosteroid therapy for IgAN patients more clear, IgAN patients, whose eGFR were less than 60 ml/min/1.73 m², were stratified by proteinuria (1 g/day). In IgAN patients whose eGFR were under 60 ml/min/1.73 m² and whose proteinuria were over 1.0 g/day, corticosteroid therapy seemed to ameliorate kidney function [IRR 0.39 (95%CI 0.19-0.86), P < 0.05]; while, there was obviously no change by corticosteroid therapy in IgAN patients whose eGFR were less than 60 ml/min/1.73 m² and whose proteinuria were less than 1.0 g/day.

CONCLUSION

Our results suggested that steroid therapy was especially effective for IgAN patients whose eGFR was less than 60 ml/min/1.73 m² and whose proteinuria was more than 1.0 g/day.

Risk of Kidney Dysfunction from Polypharmacy among Older Patients: A Nested Case-Control Study of the South Korean Senior Cohort

Polypharmacy, the concurrent use of multiple medicines, could increase the risk of kidney dysfunction among older adults because it likely burdens the aging kidneys to excrete multiple pharmaceutical ingredients and their metabolites. This study aimed to examine the relation between polypharmacy and kidney dysfunction among older patients. A nested case-control study was conducted using the National Health Insurance Service - Senior Cohort (NHIS-SC, 2009-2013), representative of the Korean senior population. It consisted of all health insurance claims linked to records of mandatory health examination. Kidney dysfunction was defined as having an eGFR lower than 60, with a decline rate of 10% or more compared to the baseline eGFR. Polypharmacy was defined based on daily counts of pharmaceutical ingredients during one year prior to the case's event date. It was classified into polypharmacy (five to 10 ingredients) and excessive polypharmacy (10 or more ingredients). After matching case and control groups based on a range of potential confounders, conditional logistic regression was performed incorporating adjustments on disease-specific, medication-specific, and lifestyle-related risk factors. The matching resulted in 14,577 pairs of cases and controls. Exposure to polypharmacy was significantly associated with increase in the risk of kidney dysfunction; i.e., crude model (polypharmacy: OR = 1.572, 95% CI = 1.492-1.656; excessive polypharmacy: OR = 2.069, 95% CI = 1.876-2.283) and risk adjustment model (polypharmacy: OR = 1.213, 95% CI = 1.139-1.292; excessive polypharmacy: OR = 1.461, 95% CI = 1.303-1.639). The significant associations were robust across different definitions of kidney dysfunction. These findings inform healthcare providers and policy makers of the importance of polypharmacy prevention to protect older adults from kidney dysfunction.

Chronic kidney disease patients who smoke have higher serum phosphorus

Introduction:

Mineral and bone metabolism disorders in chronic kidney disease (CKD-MBD) constitute a syndrome defined by changes in calcium, phosphorus (P), vitamin D and parathormone, fibroblast growth factor 23 (FGF-23) and its specific cofactor, Klotho. CKD-MBD, as well as smoking, are associated with an increased risk of cardiovascular disease. However, it is not known whether or not smoking impacts the cardiovascular risk in CKD- MBD.

Objective:

To analyze the relationship between smoking and CKD-MBD markers.

Methods:

We evaluated 92 patients divided into: 1) Control Group: non-smokers without CKD; 2) CKD group in stages III and IV under conservative treatment (20 non-smokers and 17 smokers); 3) CKD group on dialysis (21 non-smokers and 19 smokers). Clinical, demographic, and biochemical markers were compared between the groups.

Results:

FGF-23 and Klotho levels were not different between smokers and non-smokers. Patients in the CKD group on conservative treatment had higher serum P than non-smokers (p = 0.026) even after adjusted for renal function (p = 0.079), gender (p = 0.145) and age (p = 0.986).

Conclusion:

Smoking confers a higher cardiovascular risk to CKD patients under conservative treatment as it is associated with higher levels of P. Further studies are needed to confirm and better elucidate this finding.

Chronic Nicotine Exposure Reduces Antioxidant Function of Simvastatin in Renal Proximal Tubule Cells

BACKGROUND/AIM

We have previously reported that simvastatin exhibits antioxidant properties via extracellular signal-regulated kinase (ERK)/cAMP-response element binding (CREB) protein-dependent induction of heme oxygenase-1 (HO1) and chronic nicotine exposure inhibits ERK/CREB signaling in renal proximal tubule cells (through p66shc). Herein, whether nicotine dampens simvastatin-dependent HO1 induction was determined.

MATERIALS AND METHODS

Renal proximal tubule (NRK52E) cells were pre-treated with 200 μM nicotine for 24 h followed by 10 μM simvastatin. Promoter activity of HO1 and manganese superoxide dismutase (MnSOD) and activation of CREB and ERK (via ELK1) were determined in luciferase reporter assays. CREB and p66shc were modulated via genetic means.

RESULTS

Nicotine suppressed simvastatin-dependent activation of HO1 and MnSOD promoters and activity of CREB and ELK1 via p66shc. Overexpression of CREB or knockdown of p66shc restored simvastatin-dependent induction of HO1 and MnSOD in the presence of nicotine.

CONCLUSION

Antioxidant efficiency of simvastatin might be significantly lessened in smokers/E-cigarette users.

The joint impact of habitual exercise and glycemic control on the incidence of chronic kidney disease (CKD) in middle-aged and older males

Background

This retrospective study evaluated the influence of the joint impact of habitual exercise and glycemic control on the incidence of chronic kidney disease (CKD) during a 6-year follow-up period in middle-aged and older males.

Methods

The study population included 303 males without a history of cardiovascular disease, stroke, renal dysfunction, or dialysis treatment. Their lifestyle behaviors regarding exercise and physical activity were evaluated using a standardized self-administered questionnaire. The participants were divided into four categories according to the performance or non-performance of habitual exercise and the presence or absence of hyperglycemia.

Results

After 6 years, 32 subjects (10.6%) developed CKD (estimated glomerular filtration rate < 60 ml/min/1.73 m² and/or proteinuria). The cumulative incidence of CKD was significantly higher among subjects who did not perform habitual exercise and hyperglycemic subjects (log-rank test: p < 0.05, respectively). According to a Cox proportional hazards model, the hazard ratio (HR) for the incidence of CKD in subjects with a normal glucose tolerance (NGT) who did not perform habitual exercise (HR = 2.82, 95% confidence of interval (CI) = 1.07–7.36, p = 0.034) and that in hyperglycemic subjects who did not perform habitual exercise (HR = 5.89, 95% CI = 1.87–16.63, p = 0.003) were significantly higher in comparison to the subjects with a NGT who performed habitual exercise.

Conclusions

These results suggest that the habitual exercise and good glycemic control and their combination were associated with the incidence of CKD.

Sequential determination of nickel and cadmium in tobacco, molasses and refill solutions for e-cigarettes samples by molecular fluorescence

In this work, a new procedure was developed for separation and preconcentration of nickel(II) and cadmium(II) in several and varied tobacco samples. Tobacco samples were selected considering the main products consumed by segments of the population, in particular the age (youth) and lifestyle of the consumer. To guarantee representative samples, a randomized strategy of sampling was used. In the first step, a chemofiltration on nylon membrane is carried out employing eosin (Eo) and carbon nanotubes dispersed in sodium dodecylsulfate (SDS) solution (phosphate buffer pH 7). In this condition, Ni(II) was selectively retained on the solid support. After that, the filtrate liquid with Cd(II) was re-conditioned with acetic acid /acetate buffer solution (pH 5) and followed by detection. A spectrofluorimetric determination of both metals was carried out, on the solid support and the filtered aqueous solution, for Ni(II) and Cd(II), respectively. The solid surface fluorescence (SSF) determination was performed at λem = 545nm (λex = 515nm) for Ni(II)-Eo complex and the fluorescence of Cd(II)-Eo was quantified in aqueous solution using λem = 565nm (λex = 540nm). The calibration graphs resulted linear in a range of 0.058-29.35μgL-1 for Ni(II) and 0.124-56.20μgL-1 for Cd(II), with detection limits of 0.019 and 0.041μgL-1 (S/N = 3). The developed methodology shows good sensitivity and adequate selectivity, and it was successfully applied to the determination of trace amounts of nickel and cadmium present in tobacco samples (refill solutions for e-cigarettes, snuff used in narguille (molasses) and traditional tobacco) with satisfactory results. The new methodology was validated by ICP-MS with adequate agreement. The proposed methodology represents a novel fluorescence application to Ni(II) and Cd(II) quantification with sensitivity and accuracy similar to atomic spectroscopies, introducing for the first time the quenching effect on SSF.

The association between changes in lifestyle behaviors and the incidence of chronic kidney disease (CKD) in middle-aged and older men

Background

This study was designed to evaluate whether changes in lifestyle behaviors are correlated with the incidence of chronic kidney disease (CKD).

Methods

The subjects consisted of 316 men without a history of cardiovascular disease, stroke, or renal dysfunction or dialysis treatment. The following lifestyle behaviors were evaluated using a standardized self-administered questionnaire: habitual moderate exercise, daily physical activity, walking speed, eating speed, late-night dinner, bedtime snacking, skipping breakfast, and drinking and smoking habits. The subjects were divided into four categories according to the change in each lifestyle behavior from baseline to the end of follow-up (healthy–healthy, unhealthy–healthy, healthy–unhealthy and unhealthy–unhealthy).

Results

A multivariate analysis showed that, with respect to habitual moderate exercise and late-night dinner, maintaining an unhealthy lifestyle resulted in a significantly higher odds ratio (OR) for the incidence of CKD than maintaining a lifestyle (OR 8.94; 95% confidence interval [CI], 1.10–15.40 for habitual moderate exercise and OR 4.00; 95% CI, 1.38–11.57 for late-night dinner). In addition, with respect to bedtime snacking, the change from a healthy to an unhealthy lifestyle and maintaining an unhealthy lifestyle resulted in significantly higher OR for incidence of CKD than maintaining a healthy lifestyle (OR 4.44; 95% CI, 1.05–13.93 for healthy–unhealthy group and OR 11.02; 95% CI, 2.83–26.69 for unhealthy–unhealthy group).

Conclusions

The results of the present study suggest that the lack of habitual moderate exercise, late-night dinner, and bedtime snacking may increase the risk of CKD.

•

The lack of exercise habit is associated with the incidence of CKD.

•

Late-night dinner and bedtime snacking increase the risk of CKD.

•

Early lifestyle intervention is necessary to prevent CKD incidence.

Total shoulder arthroplasty: risk factors for intraoperative and postoperative complications in patients with primary arthritis

BACKGROUND

This study evaluated and identified risk factors for the development of intraoperative and postoperative surgical complications in total shoulder arthroplasty in patients with primary osteoarthritis.

METHODS

We evaluated patient-specific factors, including age, sex, body mass index, prior nonarthroplasty surgery, smoking, alcohol consumption, and the American Society of Anesthesiologists (ASA) Physical Status Classification System in 275 patients (76 men, 199 women) with an average age of 68 years (range, 51-85 years). We categorized the number and severity of all complications and correlated these results with the patient-specific factors RESULTS: Twenty-seven complications (9.8%) in 275 shoulder arthroplasties were recorded. We identified 22 patients (8%) with category I complications and 5 (2.8%) with category II complications. Patients with an ASA score of 3 showed an increased likelihood of having a surgical complication compared with the control group with ASA scores of 1 and 2 (odds ratio, 4.28; 95% confidence interval, 1.79-10.20; P < .01). Smokers were more prone to surgical complications than nonsmokers (odds ratio, 5.08; 95% confidence interval, 1.96-13.11; P = .02).

CONCLUSION

Surgical complication rates after anatomic total shoulder arthroplasty in patients with primary osteoarthritis correlate with the patient's overall health status and nicotine consumption. This may be useful for predicting the likelihood of surgical complications and may thus prove important for clinicians to better assess and explain possible risks before surgery.

Maternal Smoking during Pregnancy, Household Smoking after the Child's Birth, and Childhood Proteinuria at Age 3 Years

BACKGROUND AND OBJECTIVES

Smoking is a well known risk factor of proteinuria in adults; however, clinical studies in children are limited. The purpose of this study is to clarify the associations of maternal smoking during pregnancy and household smoking after the child's birth with the risk of proteinuria at age 3 years old.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We performed a population-based retrospective cohort study on 44,595 children using data on prenatal health checkups, home visit neonatal health checkups, and health checkups at 4, 9, and 18 months and 3 years of age in Kobe City, Japan. Maternal smoking status (nonsmoker, past smoker, or current smoker) was collected with standardized questionnaires. The outcome of interest was the presence of proteinuria at 3 years of age defined as urinary protein ≥1+. To evaluate the association between child proteinuria and smoking status, we performed multivariate logistic regression model analyses adjusted for confounding factors.

RESULTS

The prevalence rates of children in the maternal smoking groups (none, past, and current) were 78.9%, 4.4%, and 16.7%, respectively. The frequencies of child proteinuria defined as ≥1+ urinary protein were 1.7% in the current smoking group, 1.6% in the past smoking group, and 1.3% in the nonsmoking group. Maternal smoking during pregnancy was associated with child proteinuria (odds ratio, 1.24; 95% confidence interval, 1.00 to 1.52; P=0.05) in the multiple logistic regression model, although nonmaternal family smoking during pregnancy was not significantly associated with child proteinuria (odds ratio, 0.97; 95% confidence interval, 0.79 to 1.19; P=0.77). We also found a similar association with household smoking after the child's birth (odds ratio, 1.23; 95% confidence interval, 0.99 to 1.54; P=0.06), although this observation was not significant.

CONCLUSIONS

Maternal smoking during pregnancy was one of the risk factors of childhood proteinuria. We also found a similar association with household smoking after the child's birth, although this observation was not significant.

Serum Uric Acid Level Predicts Progression of IgA Nephropathy in Females but Not in Males

Background

Immunoglobulin A nephropathy (IgAN) is one of most common forms of glomerulonephritis. At this point, the clinical impact of hyperuricemia on IgAN is not clear. The aim of the present study was to explore the clinical impact of hyperuricemia on the progression of IgAN.

Study Design

Multicenter retrospective cohort study.

Setting & Participants

935 IgAN patients who were diagnosed by kidney biopsy at Osaka University Hospital, Osaka General Hospital, and Osaka Rosai Hospital. were included in this study.

Predictor

Uric acid levels at renal biopsy.

Outcomes

The outcome of interest was the time from the kidney biopsy to the time when a 50% increase in the baseline serum creatinine level was observed, which was defined as "progression".

Measurements

The baseline characteristics according to the kidney biopsy at the time of diagnosis were collected from the medical records, and included age, gender, body mass index, hypertension, diabetes (use of antidiabetic drugs), serum levels of creatinine, urinary protein, smoking status, RAAS blockers and steroid therapy.

Results

An elevated serum uric acid level was an independent risk factor for progression in female patients (per 1.0 mg/dL, multivariate-adjusted incident rate ratio 1.33 [95% confidence interval 1.07, 1.64], P = 0.008) but not in male patients (1.02 [0.81, 1.29], P = 0.855). To control a confounding effect of renal function on an association between serum uric acid level and progression in female patients, age- and serum creatinine-matched and propensity score-matched analyses were performed, and these results also supported the effect by uric acid on kidney disease progression independent of basal kidney function.

Limitations

A cohort analyzed retorospectively.

Conclusions

This study revealed that an elevated uric acid level was an independent risk factor for ESKD in female IgAN patients. Therefore, uric acid might be a treatable target in female IgAN patients.

Effects of smoking and its cessation on creatinine- and cystatin C-based estimated glomerular filtration rates and albuminuria in male patients with type 2 diabetes mellitus: the Fukuoka Diabetes Registry

Cigarette smoking is an important modifiable risk factor for lifestyle diseases. The smoking rate remains high, and the prevalence of diabetes mellitus is increasing in Asian countries; however, few studies have examined the effects of smoking on chronic kidney disease (CKD) in Asian diabetic patients. The aim of the present study was to investigate the association between smoking and its cessation with CKD and its components in patients with type 2 diabetes. A total of 2770 Japanese male patients with type 2 diabetes aged ⩾20 years were divided according to the amount of cigarette smoking and the years since cessation. The associations with CKD, the urinary albumin-creatinine ratio (UACR) and the estimated glomerular filtration rate (eGFR) were cross-sectionally examined. The proportions of CKD and the mean UACR dose-dependently increased with increases in both the number of cigarettes per day and the Brinkman index compared with the never smokers. The creatinine-based eGFR also increased with increases in the amount of smoking, whereas the cystatin C-based eGFR decreased, and their average did not significantly change. These parameters exhibited inverse associations with the years after smoking cessation compared with the association with the amount of smoking. A dose-dependent association of active smoking and a graded inverse association of the years since quitting with CKD enhance the merit of smoking cessation in patients with type 2 diabetes.

The Association Between Unhealthy Lifestyle Behaviors and the Prevalence of Chronic Kidney Disease (CKD) in Middle-Aged and Older Men

Background

This cross-sectional study evaluated the association between unhealthy lifestyle behaviors and the prevalence of chronic kidney disease (CKD) in middle-aged and older men.

Methods

The subjects included 445 men without a history of cardiovascular disease, stroke, or dialysis treatment, who were not taking medications. Unhealthy lifestyle behaviors were evaluated using a standardized self-administered questionnaire and were defined as follows: 1) lack of habitual moderate exercise, 2) lack of daily physical activity, 3) slow walking speed, 4) fast eating speed, 5) late-night dinner, 6) bedtime snacking, and 7) skipping breakfast. The participants were divided into four categories, which were classified into quartile distributions based on the number of unhealthy lifestyle behaviors (0–1, 2, 3, and ≥4 unhealthy behaviors).

Results

According to a multivariate analysis, the odds ratio (OR) for CKD (defined as estimated glomerular filtration rate [eGFR] <60 mL/min/1.73 m² and/or proteinuria) was found to be significantly higher in the ≥4 group than in the 0–1 group (OR 4.67; 95% confidence interval [CI], 1.51–14.40). Moreover, subjects’ lack of habitual moderate exercise (OR 3.06; 95% CI, 1.13–8.32) and presence of late-night dinner (OR 2.84; 95% CI, 1.40–5.75) and bedtime snacking behaviors (OR 2.87; 95% CI, 1.27–6.45) were found to be significantly associated with the prevalence of CKD.

Conclusions

These results suggest that an accumulation of unhealthy lifestyle behaviors, especially those related to lack of habitual moderate exercise and presence of late-night dinner and bedtime snacking may be associated with the prevalence of CKD.

The accumulation of healthy lifestyle behaviors prevents the incidence of chronic kidney disease (CKD) in middle-aged and older males

AIM

This study was retrospectively designed to evaluate the influence of healthy lifestyle behaviors on the incidence of chronic kidney disease (CKD) during a 5-year follow-up period in middle-aged and older males.

METHODS

The subjects included 252 males without a history of cardiovascular disease, stroke, renal dysfunction and/or dialysis treatment who were not taking any medications. Their lifestyle behaviors were evaluated using a standardized self-administered questionnaire and defined as follows: (1) habitual moderate exercise, (2) daily physical activity, (3) fast walking speed, (4) slow eating speed, (5) no late-night dinner, (6) no bedtime snacking and (7) no skipping breakfast. The participants were divided into four categories, which were classified into quartile distributions according to the number of healthy lifestyle behaviors (7-6, 5, 4 and ≤3 groups).

RESULTS

After 5 years, the incidence of CKD [estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m(2) and/or proteinuria] was observed in 23 subjects (9.1%). The Kaplan-Meier survival curves showed that the cumulative incidence of CKD significantly decreased according to an increase in the number of healthy lifestyle behaviors (log-rank test: p = 0.003). According to a multivariate analysis, habitual moderate exercise [hazard ratio (HR) 0.20, 95% confidence of interval (CI) 0.06-0.69, p = 0.011] and no bedtime snacking (HR 0.19, 95 % CI 0.08-0.48, p = 0.004) were significantly associated with the incidence of CKD.

CONCLUSIONS

These results suggest that the accumulation of healthy lifestyle behaviors, especially those related to habitual moderate exercise and no bedtime snacking, is considered to be important to reduce the risk of CKD.

Body Mass Index Modifies an Association between Self-Reported Regular Exercise and Proteinuria

AIM

Regular exercise habits are well-known to exert a favorable effect on the metabolic syndrome, which may cause proteinuria and chronic kidney disease (CKD). However, it remains unknown if exercise exerts a favorable effect on proteinuria and kidney dysfunction. The aim of this study was to reveal the association between exercise and the prevalence of proteinuria and kidney dysfunction and the attenuation by obesity.

METHODS

This study was a cross-sectional cohort study that included 292,013 participants who underwent the Specific Health Check and Guidance in Japan. The exercise score (range 0-3) was based on the number of positive answers to three questions regarding exercise habits. The outcome was defined as urinary protein detected by a dipstick test and kidney dysfunction [estimated glomerular filtration rate (GFR) less than 45 ml/min/1.73 m(2)].

RESULTS

The exercise score was significantly associated with the prevalence of proteinuria in both males [vs. exercise score 0; exercise score 1, multivariate-adjusted odds ratio 0.86 (95% confidence interval 0.81-0.92), P<0.001; exercise score 2, 0.84 (0.79-0.90), P<0.001; exercise score 3, 0.77 (0.72-0.82), P<0.001] and females (same as in males). After the male subjects were divided into quintiles according to body mass index (BMI) in more than three groups (22.9<BMI<24.1), there was no significant association between the exercise score and the prevalence of proteinuria. In females, a higher exercise score was associated with a lower prevalence of proteinuria, regardless of BMI. The association between the exercise score and kidney dysfunction was as similar as that between the exercise score and proteinuria, except the attenuation of BMI.

CONCLUSION

Exercise may associate with a lower prevalence of proteinuria and kidney dysfunction, and a high BMI may attenuate this association between exercise and proteinuria in male subjects.

Human adipose-derived stem cells ameliorate cigarette smoke-induced murine myelosuppression via secretion of TSG-6

OBJECTIVE

Bone marrow-derived hematopoietic stem and progenitor cells (HSC/HPC) are critical to homeostasis and tissue repair. The aims of this study were to delineate the myelotoxicity of cigarette smoking (CS) in a murine model, to explore human adipose-derived stem cells (hASC) as a novel approach to mitigate this toxicity, and to identify key mediating factors for ASC activities.

METHODS

C57BL/6 mice were exposed to CS with or without i.v. injection of regular or siRNA-transfected hASC. For in vitro experiments, cigarette smoke extract was used to mimic the toxicity of CS exposure. Analysis of bone marrow HPC was performed both by flow cytometry and colony-forming unit assays.

RESULTS

In this study, we demonstrate that as few as 3 days of CS exposure results in marked cycling arrest and diminished clonogenic capacity of HPC, followed by depletion of phenotypically defined HSC/HPC. Intravenous injection of hASC substantially ameliorated both acute and chronic CS-induced myelosuppression. This effect was specifically dependent on the anti-inflammatory factor TSG-6, which is induced from xenografted hASC, primarily located in the lung and capable of responding to host inflammatory signals. Gene expression analysis within bone marrow HSC/HPC revealed several specific signaling molecules altered by CS and normalized by hASC.

CONCLUSION

Our results suggest that systemic administration of hASC or TSG-6 may be novel approaches to reverse CS-induced myelosuppression.

Single-nucleotide polymorphism of the UMOD promoter is associated with the outcome of chronic kidney disease patients

Uromodulin (UMOD) is the most abundant protein secreted in urine and the mutated form of the UMOD gene is associated with UMOD-associated kidney disease (UAKD). Although UMOD accumulates in the kidney of UAKD patients, it is unclear whether this also occurred in the chronic kidney disease (CKD) patients. Therefore, the association of single-nucleotide polymorphisms (SNPs) in the promoter region of UMOD gene with the kidney survival time of CKD was investigated. The promoter region of the UMOD gene was sequenced for 111 CKD patients. The Kaplan-Meier method was used to identify the disease outcome associated with SNPs in the promoter region of the UMOD gene in CKD patients. The Cox proportional hazard model was used to identify risk factors for the kidney survival time of CKD. SNPs in reference to GenBank accession NG-000016 were detected at 23 sites of the 481-bp in the UMOD promoter region from the CKD patients and the healthy controls. The 6 SNPs with minor allele frequency >5% in the CKD patients or controls were used for disease risk and outcome analysis. The frequent allele rs13333226AA was associated with a shorter period of kidney survival time in CKD patients (P=0.005). The length of kidney survival time in CKD patients with the rs13333226AA genotype was significantly shorter than that of patients with the frequent allele rs13333226AG+GG (relative risk, 0.361; 95% confidence interval, 0.171-0.761; P=0.007). In conclusion, analysis of genetic polymorphisms in UMOD may help to identify the CKD patient subgroups at a high risk for a disease outcome, thereby helping to refine therapeutic decisions in CKD patients.

Single nucleotide polymorphisms in the D-loop region of mitochondrial DNA is associated with the kidney survival time in chronic kidney disease patients

BACKGROUND

The mitochondrial displacement loop (D-loop) is known to accumulate mutations and SNPs at a higher frequency than other regions of mitochondrial DNA (mtDNA). We had identified chronic kidney disease (CKD) risk-associated SNPs in the D-loop of CKD patients previously. In this study, we investigated the association of SNPs in the D-loop of mtDNA with the kidney survival of CKD.

METHODS

The D-loop region of mtDNA was sequenced for 119 CKD patients from the inpatient of the Fourth Hospital of Hebei Medical University. The Kaplan-Meier method was used to identify disease outcome-associated SNPs in the D-loop of CKD patients. The Cox proportional hazards model was used to identify risk factors for the kidney survival of CKD.

RESULTS

In the present study, we identified 20 SNPs with a frequency higher than 5% and assessed the relationship of these SNPs with kidney survival time in CKD patients, a SNP of 146 was identified by log-rank test for statistically significant prediction of the kidney survival time. In an overall multivariate analysis, allele 146 was identified as an independent predictor of kidney survival time in CKD patients. The survival time of kidney in the CKD patients with 146C was significantly shorter than that of kidney in CKD patients with 146T (relative risk, 2.336; 95% CI, 1.319-3.923; p = 0.001).

CONCLUSION

SNPs in the D-loop can predict the kidney survival of CKD patients. Analysis of genetic polymorphisms in the mitochondrial D-loop can help to identify CKD patient subgroup at high risk of a poor disease outcome.

Slight increase in urinary albumin excretion within the normal range predicts incident hypertension in a community-based Japanese population: the Takahata study

Recent studies have suggested that urine albumin excretion in the high normal range predicts hypertension. However, the relationship between urinary albumin excretion in spot urine and incident hypertension remains unclear in the general Japanese population. To clarify this relationship, we conducted a cohort study in a community-based population of 412 normotensive individuals without diabetes and renal insufficiency and examined the incidence of hypertension using the urinary albumin-to-creatinine ratio (UACR) at baseline. Incident hypertension was defined as new-onset systolic blood pressure ⩾ 140 mm Hg and/or diastolic blood pressure ⩾ 90 mm Hg and/or the use of anti-hypertensive drugs. During the follow-up period (median, 6.7 years), 133 subjects (32.3%) newly developed hypertension. The incidence of hypertension increased with an increase in baseline UACR (20.4% for UACR <5 mg g(-1), 34.0% for 5-9.9 mg g(-1) UACR and 40.4% for 10-29.9 mg g(-1), P=0.002). Multivariate logistic regression analysis, after adjustment for possible confounders, showed that UACR 5-9.9 mg g(-1) and 10-29.9 mg g(-1) were independent risks for incident hypertension compared with UACR <5 mg g(-1) (odds ratio (OR) 2.15, 95% confidence interval (CI) 1.16-4.10 and OR 2.67, 95% CI 1.36-5.38, respectively). Subgroup analysis revealed that subjects with increased UACR (⩾ 5 mg g(-1)) had a higher risk of incident hypertension than did those with low UACR (<5 mg g(-1)), irrespective of their backgrounds (age, sex, smoking, alcohol consumption, obesity and urinary sodium excretion). In conclusion, this study showed that a slight increase in urinary albumin excretion might predict incident hypertension in a community-based Japanese population.

Nodular glomerulosclerosis with anti-glomerular basement membrane-like glomerulonephritis; a distinct pattern of kidney injury observed in smokers

Background

Cigarette smoking has recently been recognized as a risk factor for developing nodular glomerulosclerosis and has also been frequently encountered in patients with anti-glomerular basement membrane (anti-GBM) disease. However, the concurrent presence of both patterns of glomerular injury has not been previously reported.

Material and methods

In this article, we describe three patients with non-diabetic nodular glomerulosclerosis, anti-GBM-like glomerulonephritis (GN) and a history of heavy smoking.

Results

Our cohort included three patients, of which two were men (53 and 77 years old) and one a 28-year-old woman. None of the patients had a history of diabetes mellitus but all of them were heavy smokers who presented with renal insufficiency and proteinuria. Nodular glomerulosclerosis and occasional small, non-circumferential crescents in different stages of development were found on kidney biopsy. Immunofluorescence microscopy studies showed intense linear IgG staining along the glomerular basement membranes in the absence of granular immune-type deposits. Electron microscopy evaluation revealed prominent endothelial cell injury without detectable electron-dense deposits. One patient was dialysis-dependent a few months post-biopsy while the other two patients maintained their kidney function 18 and 24 months post-biopsy but without a significant improvement of serum creatinine.

Conclusions

The combination of nodular glomerulosclerosis and anti-GBM-like GN appears to be a distinct pattern of injury observed in a small subset of heavy smokers. Although this pattern of glomerular injury might be less aggressive than the typical anti-GBM GN, it does not appear to carry a favorable prognosis.

Smoking is a risk factor for the progression of idiopathic membranous nephropathy

Background

Multiple studies have shown cigarette smoking to be a risk factor for chronic kidney disease. However, it is unknown whether smoking similarly increases the risk for progression of membranous nephropathy.

Methods

This study used the Nagoya Nephrotic Syndrome Cohort Study (N-NSCS), including 171 patients with idiopathic membranous nephropathy (IMN) from 10 nephrology centers in Japan. The dose-response relationships between cigarette smoking and the outcomes were assessed by using multivariate Cox proportional hazards models adjusted for clinically relevant factors. The primary outcome was a 30% decline in the estimated glomerular filtration rate (eGFR). The secondary outcome was first complete remission (CR) of proteinuria.

Results

During the observation period (median, 37 months; interquartile range, 16–71 months), 37 (21.6%) patients developed a 30% decline in eGFR and 2 (1.2%) progressed to ESRD. CR occurred in 103 (60.2%) patients. Multivariate Cox proportional hazards models revealed current smoking (adjusted hazard ratio [HR], 7.81 [95% confidence interval (CI), 3.17–19.7]), female sex (adjusted HR, 3.58 [95% CI, 1.87–8.00]), older age (adjusted HR, 1.71 [95% CI, 1.13–2.62] per 10 years), the number of cigarettes smoked daily (adjusted HR, 1.61 [95% CI, 1.23–2.09] per 10 cigarettes daily), and cumulative smoking of ≥40 pack-years (adjusted HR, 5.56 [95% CI, 2.17–14.6]) to be associated with a 30% decline in eGFR. However, smoking was not associated with CR.

Conclusion

Smoking is a significant and dose-dependent risk factor for IMN progression. All patients with IMN who smoke should be encouraged to quit.

An association between serum γ-glutamyltransferase and proteinuria in drinkers and non-drinkers: a Japanese nationwide cross-sectional survey

BACKGROUND

The association between alcohol consumption and chronic kidney disease (CKD), characterized by reduced glomerular filtration rate and proteinuria, is controversial. Recent studies suggest that serum γ-glutamyltransferase (GGT) level, a conventional marker of excessive alcohol consumption, predicts the CKD incidence. Little information is available on the difference in the clinical impact of alcohol consumption and GGT on proteinuria.

METHODS

The present cross-sectional survey included 332,296 Japanese people aged ≥40 years in 2008. To examine the associations of GGT and alcohol consumption with proteinuria, 134,600 men and 197,696 women were classified into 20 categories based on GGT quartiles and alcohol consumption categories, and their prevalence rate ratios (PRR) of proteinuria defined as ≥1+ of dipstick urinary protein were calculated after adjusting for clinically relevant factors.

RESULTS

Prevalence of proteinuria was 7.5 and 3.7 % in men and women, respectively. In both gender an association between alcohol consumption and proteinuria was in a J-shaped fashion with the lowest PRR of mild drinkers with ≤19 g/day of ethanol consumption, whereas an association between serum GGT level and proteinuria was linear. Compared with rare drinkers in the lowest GGT quartile, the subjects in higher GGT quartiles had a higher probability of proteinuria, irrespective of alcohol consumption. An optimal cutoff level of serum GGT was 43.6 and 23.2 IU/L in men and women, respectively.

CONCLUSIONS

The subjects with higher serum GGT level had a higher probability of proteinuria, regardless of alcohol consumption, suggesting that GGT has a clinically greater impact on CKD than alcohol consumption.

Periodontal disease bacteria specific to tonsil in IgA nephropathy patients predicts the remission by the treatment

Background

Immunoglobulin (Ig)A nephropathy (IgAN) is the most common form of primary glomerulonephritis in the world. Some bacteria were reported to be the candidate of the antigen or the pathogenesis of IgAN, but systematic analysis of bacterial flora in tonsil with IgAN has not been reported. Moreover, these bacteria specific to IgAN might be candidate for the indicator which can predict the remission of IgAN treated by the combination of tonsillectomy and steroid pulse.

Methods and Findings

We made a comprehensive analysis of tonsil flora in 68 IgAN patients and 28 control patients using Denaturing gradient gel electrophoresis methods. We also analyzed the relationship between several bacteria specific to the IgAN and the prognosis of the IgAN. Treponema sp. were identified in 24% IgAN patients, while in 7% control patients (P = 0.062). Haemophilus segnis were detected in 53% IgAN patients, while in 25% control patients (P = 0.012). Campylobacter rectus were identified in 49% IgAN patients, while in 14% control patients (P = 0.002). Multiple Cox proportional-hazards model revealed that Treponema sp. or Campylobactor rectus are significant for the remission of proteinuria (Hazard ratio 2.35, p = 0.019). There was significant difference in remission rates between IgAN patients with Treponema sp. and those without the bacterium (p = 0.046), and in remission rates between IgAN patients with Campylobacter rectus and those without the bacterium (p = 0.037) by Kaplan-Meier analysis. Those bacteria are well known to be related with the periodontal disease. Periodontal bacteria has known to cause immune reaction and many diseases, and also might cause IgA nephropathy.

Conclusion

This insight into IgAN might be useful for diagnosis of the IgAN patients and the decision of treatment of IgAN.

Effect of tobacco smoking and smoking cessation on plasma lipoproteins and associated major cardiovascular risk factors: a narrative review

Cigarette smoking, active or passive, kills about 6 million people each year worldwide. Cardiovascular disease (CVD) is responsible for 40% of all smoking-related deaths, lung cancer accounts for 20% of all smoking-related deaths, and chronic obstructive pulmonary disease is related to another 20% of deaths. In this narrative review we consider the relationship between cigarette smoking and CVD. We discuss disease states and/or CVD risk factors related to smoking, such as dyslipidaemia, vascular inflammation, endothelial dysfunction, arterial stiffness, insulin resistance, type 2 diabetes mellitus (T2DM), chronic kidney disease (CKD), and non-alcoholic fatty liver disease (NAFLD) as well as their complex interrelations. Smoking cessation can correct abnormalities related to smoking; however, success rates are relatively low. In cases of inability to quit, measures to minimize the adverse effects of smoking specifically related to CVD should be taken. Smokers should receive best practice treatment, according to guidelines, as for non-smokers.

Kidney function and tobacco smoke exposure in US adolescents

BACKGROUND AND OBJECTIVE

Active smoking and secondhand smoke (SHS) are known risk factors for kidney disease in adults. We evaluated the association between exposure to active smoking or SHS and kidney function in US adolescents.

METHODS

This is a cross-sectional study in 7516 adolescents aged 12-17 who participated in NHANES 1999-2010 and had serum creatinine and cotinine measures. Active smoking was defined as self-reported smoking or serum cotinine concentrations >10 ng/mL. SHS was defined as nonactive smokers who self-reported living with ≥1 smokers or serum cotinine concentrations ≥ 0.05 ng/mL. Kidney function was determined by using the chronic kidney disease in children estimated glomerular filtration rate (eGFR) equation.

RESULTS

Median (interquartile range) eGFR and serum cotinine concentrations were 96.8 (85.4-109.0) mL/minute per 1.73 m(2) and 0.07 (0.03-0.59) ng/mL, respectively. After multivariable adjustment, eGFR decreased 1.1 mL/minute per 1.73 m(2) (95% confidence interval [CI]: -1.8 to -0.3) per interquartile range increase in serum cotinine concentrations. The mean (95%CI) difference in eGFR for serum cotinine tertiles 1, 2, and 3 among children exposed to SHS compared to unexposed were -0.4 (-1.9 to 1.2), -0.9 (-2.7 to 0.9), and -2.2 (-4.0 to -0.4) mL/minute per 1.73 m(2), respectively (P = .03). The corresponding values among tertiles of active smokers compared to unexposed were 0.2 (-2.2 to 2.6), -1.9 (-3.8 to 0.0), and -2.6 (-4.6 to -0.6) mL/minute per 1.73 m(2) (P = .01).

CONCLUSIONS

Tobacco smoke exposure was associated with decreased eGFR in US adolescents, supporting the possibility that tobacco smoke effects on kidney function begin in childhood.

A combination of healthy lifestyle factors is associated with a decreased incidence of chronic kidney disease: a population-based cohort study

A combination of healthy lifestyle factors is associated with lower risks of coronary heart disease, diabetes and stroke, but little is known about its association with chronic kidney disease (CKD). This study analyzed the effect of a combination of healthy lifestyle factors on the incidence of proteinuria among participants without CKD. Of the 7565 persons aged 40-79 years who participated in the Specific Health Checkups and Guidance System in Sado Island, Japan in 2008, 4902 participants (2015 males) without CKD were included. The healthy lifestyle score was calculated by summing the total number of lifestyle factors for which the participants were at low risk. Low risk was defined as (1) nonsmoker, (2) body mass index (BMI) <25 kg m(-2), (3) moderate or less alcohol consumption, (4) regular exercise and (5) better eating patterns. Logistic analysis was used to examine the relationship between the baseline score in 2008 and the development of proteinuria in 2009. Proteinuria developed in 2.2% of participants (males, 3.2; females, 1.5%). Compared with participants with a healthy lifestyle score of 0 to 2, participants with a score of 5 had a lower risk (odds ratio: 0.39, 95% confidence interval: 0.16-0.94), independently of having diabetes, hypertension and hypercholesterolemia. Overall, 47% of the cases in this cohort could be attributed to lack of adherence to this low-risk pattern. These findings underscore the importance of a healthier lifestyle in preventing CKD.

Impact of visit-to-visit variability of blood pressure on deterioration of renal function in patients with non-diabetic chronic kidney disease

An association between visit-to-visit variability (VVV) of blood pressure (BP) and renal damage was recently reported in a cross-sectional study. We aimed to clarify the longitudinal effect of VVV of BP on deterioration of renal function in patients with non-diabetic chronic kidney disease (CKD). We retrospectively studied 56 patients with non-diabetic CKD (stage 3 or 4) who visited our nephrology clinic between September 1994 and May 2011. VVV of BP was defined as the standard deviation and coefficient of variation (CV) of office BP measured at 12 consecutive visits. Main outcomes were the annual decline in the estimated glomerular filtration rate (eGFR) and the composite renal end point defined as a doubling of serum creatinine or the need for dialysis. The median observation period was 83 months. Standard deviation and CV of office systolic BP (SBP) were significantly associated with the slope of the eGFR after adjustments for confounders. The adjusted risk for composite renal end points more than doubled for each increment of 1-standard deviation of the standard deviation of office SBP (hazard ratio (HR) 2.20, P=0.001), and for each increment of 1-standard deviation of the CV of office SBP (HR 2.12, P=0.002). The present study demonstrated that the visit-to-visit variability of BP is an independent determinant of deterioration of renal function in patients with non-diabetic CKD.