Alcohol consumption and kidney function decline in the elderly: alcohol and kidney disease

Bidirectional negative relationship between thyrotropin and kidney function during alcohol intoxication in males

Introduction

Despite a well-established direct toxic effect of alcohol on renal cells, there is a salutary dose-dependent effect of alcohol consumption on common laboratory parameters related to kidney performance. Alcohol also impacts thyroid hormones, while thyroid status modulates kidney function. The modulation of kidney parameters with thyrotropin (TSH) and thyroid status indicates a possible interaction between alcohol, kidney, and thyroid functions. This retrospective study was conducted to test the hypothesis that the positive effect of alcohol use on the estimated glomerular filtration rate (eGFR) is mediated by alcohol's effect on thyroid hormones.

Methods

We reviewed the electronic medical records of 767 hospitalized adult patients free of thyroid disorders who received medical care in the Mayo Clinic Health System from June 2019 through June 2022 and had blood alcohol concentration (BAC), serum TSH, and serum creatinine measured during the hospitalization. We calculated the eGFR using both the re-expressed Modification of Diet in Renal Disease (MDRD II) study equation and the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) Creatinine equation.

Results

We found a significant relationship of BAC with eGFR (CKD-EPI) and TSH in males only. BAC had a positive association with eGFR (b = 0.24, p = 0.0001) and negative with TSH (b=-0.17, p = 0.006). The covariance between the two outcomes (eGFR and TSH) was negative (b = -0.12, p = 0.049). The path analyses using the eGFR MDRD II equation were not significant in males, whereas females had no significant path analyses with either of the eGFR equations.

Discussion

We observed that BAC influences both eGFR and TSH, whereas eGFR and TSH influence each other. After considering important covariates (e.g., age, body mass index, diabetes mellitus, cardiovascular disease, chronic kidney disease, and chronic liver disease) and the negative bidirectional effect of TSH and eGFR, a positive impact of BAC on eGFR was observed in males.

A Dose-Dependent Association between Alcohol Consumption and Incidence of Proteinuria and Low Glomerular Filtration Rate: A Systematic Review and Meta-Analysis of Cohort Studies

Previous cohort studies have reported conflicting associations between alcohol consumption and chronic kidney disease, characterized by proteinuria and low glomerular filtration rate (GFR). This systematic review, which included 14,634,940 participants from 11 cohort studies, assessed a dose-dependent association of alcohol consumption and incidence of proteinuria and low estimated GFR (eGFR) of <60 mL/min/1.73 m2. Compared with non-drinkers, the incidence of proteinuria was lower in drinkers with alcohol consumption of ≤12.0 g/day (relative risk 0.87 [95% confidence interval 0.83, 0.92]), but higher in drinkers with alcohol consumption of 36.1–60.0 g/day (1.09 [1.03, 1.15]), suggesting a J-shaped association between alcohol consumption and the incidence of proteinuria. Incidence of low eGFR was lower in drinkers with alcohol consumption of ≤12.0 and 12.1–36.0 than in non-drinkers (≤12.0, 12.1–36.0, and 36.1–60.0 g/day: 0.93 [0.90, 0.95], 0.82 [0.78, 0.86], and 0.89 [0.77, 1.03], respectively), suggesting that drinkers were at lower risk of low eGFR. In conclusion, compared with non-drinkers, mild drinkers were at lower risk of proteinuria and low eGFR, whereas heavy drinkers had a higher risk of proteinuria but a lower risk of low eGFR. The clinical impact of high alcohol consumption should be assessed in well-designed studies.

Alcohol consumption and its association with chronic kidney disease: Evidence from a 12-year China health and Nutrition Survey

BACKGROUND AND AIMS

Alcohol consumption is a major threat to global health. The aim of the present study was to explore the association between alcohol consumption and chronic kidney disease (CKD) in a Chinese population.

METHODS AND RESULTS

A total of 4664 participants, aged ≥18 years, who participated in a baseline alcohol survey in 1997 and were followed up in 2009 of the China Health and Nutrition Survey (CHNS), were recruited in the current study. Data on alcohol consumption was obtained using standardized questionnaires, with CKD (defined as eGFR <60 mL/min/1.73 m²) as the outcome. The results showed that 37.3% of the participants had consumed alcohol at the baseline. Current drinkers were mainly men, with at least senior high school education, and a history of smoking. In the 2009 survey, 14.5% of the participants had CKD. Association analyses revealed that alcohol drinkers had a lower likelihood of CKD than non-drinkers (11.0% vs. 16.6%, aOR: 0.76, 95%CI: 0.58-1.00), after adjusting potential covariates. Restricted cubic splines revealed that the relationship between alcohol consumption and CKD prevalence was U-shaped. The probability of CKD significantly increased when alcohol consumption exceeded 18 standard drinks per week (aOR: 1.66, 95%CI: 1.00-2.76). Approximately one-fourth of participants changed their drinking patterns during the 12-year follow-up, and male drinkers with persistent drinking patterns had the lowest prevalence of CKD (aOR: 0.48, 95% CI: 0.31-0.73).

CONCLUSION

Alcohol consumption showed a U-shaped association with CKD. Moderate drinkers exhibited a lower disease prevalence compared with non-drinkers and heavy drinkers. Further studies should be conducted to explore the mechanisms underlying this protective effect. However, non-drinkers should not start drinking alcohol even with this protective effect.

Pretransplant and Posttransplant Alcohol Consumption and Outcomes in Kidney Transplantation: A Prospective Multicenter Cohort Study

The impact of pretransplant and posttransplant alcohol consumption on outcomes in kidney transplant recipients (KTRs) is uncertain. Self-reported alcohol consumption was obtained at the time of transplant and 2 years after transplant in a prospective cohort study. Among 907 KTRs, 368 (40.6%) were drinkers at the time of transplant. Compared to non-drinkers, alcohol consumption did not affect the risk of death-censored graft failure (DCGF), biopsy-proven acute rejection (BPAR), cardiovascular events, or all-cause mortality. Compared to persistent non-drinkers, the development of DCGF, BPAR, cardiovascular events, all-cause mortality, or posttransplant diabetes mellitus was not affected by the alcohol consumption pattern (persistent, de novo, or stopped drinking) over time. However, de novo drinkers had a significantly higher total cholesterol (p < 0.001) and low-density lipoprotein cholesterol levels (p = 0.005) compared to persistent non-drinkers 5 years after transplant, and had significantly higher total cholesterol levels (p = 0.002) compared to the stopped drinking group 7 years after transplant, even after adjusting for the use of lipid-lowering agents, age, sex, and body mass index. Although pretransplant and posttransplant alcohol consumption were not associated with major outcomes in KTRs during the median follow-up of 6.0 years, a new start of alcohol use after KT results in a relatively poor lipid profile.

Clinical Trial Registration:clinicaltrials.gov, identifier NCT02042963.

Association of alcohol consumption with the incidence of proteinuria and chronic kidney disease: a retrospective cohort study in Japan

BACKGROUND

The difference in the clinical impact of alcohol consumption on kidney function based on sex remains to be elucidated. This study aimed to assess the association between the dose of alcohol consumption and the incidence of proteinuria and chronic kidney disease stratified by sex.

METHODS

This retrospective cohort study included 26,788 workers (19,702 men and 7086 women) with normal renal function (estimated glomerular filtration rate ≥ 60 mL/min/1.73 m²) at annual health examinations between January 2010 and March 2015 in Japan. The main exposure was alcohol consumption. The primary outcomes were the incidence of proteinuria (dipstick urinary protein ≥ 1) and incidence of low estimated glomerular filtration rate (eGFR; rate < 60 mL/min per 1.73 m²; decreased from the baseline eGFR by 25%).

RESULTS

During a median observational period of 4 years (interquartile range: 2-6), 1993 (10.1%) men and 462 (6.5%) women developed proteinuria, whereas 667 (3.4%) men and 255 (3.6%) women developed low eGFR. After adjustment for clinically relevant factors using a Cox proportional hazards model, alcohol consumption of ≥ 46 g/day in females was significantly associated with the incidence of proteinuria (hazard ratio, 1.57; 95% confidence interval, 1.10-2.26) and low eGFR (hazard ratio, 1.62; 95% confidence interval, 1.04-2.53). However, no significant association between alcohol consumption and primary outcomes was observed in men.

CONCLUSIONS

In conclusion, daily higher alcohol consumption was significantly associated with a higher incidence of proteinuria and low eGFR among women. Women might be prone to high alcohol consumption with kidney dysfunction.

Impact of Chronic Alcohol Use on Fluid Resuscitation in Burn Patients

Acute alcohol intoxication in burn patients has been associated with increased mortality, renal dysfunction, and difficulty with adequate fluid resuscitation. It is less clear how chronic alcohol use, regardless of intoxication status on admission, impacts patient outcomes. In this study, we examine varying levels of alcohol use in burn patients and its impact on both short- and long-term outcomes.

Modifiable Lifestyle Behaviors and CKD Progression: A Narrative Review

Living a healthy lifestyle is one of the safest and most cost-effective ways to improve one's quality of life and prevent and/or manage chronic disease. As such, current CKD management guidelines recommend that patients adhere to a healthy diet, perform ≥150 minutes per week of physical activity, manage their body weight, abstain from tobacco use, and limit alcohol. However, there are limited studies that investigate the relationship between these lifestyle factors and the progression of CKD among people with established CKD. In this narrative review, we examine the reported frequencies of health lifestyle behavior engagement among individuals with non-dialysis-dependent CKD and the existing literature that examines the influences of diet, physical activity, weight management, alcohol consumption, and tobacco use on the progression of CKD, as measured by decline in GFR, incident ESKD, or elevated proteinuria or albuminuria in individuals with CKD. Many of the available studies are limited by length of follow-up and small sample sizes, and meta-analyses were limited because the studies were sparse and had heterogeneous classifications of behaviors and/or referent groups and of CKD progression. Further research should be done to determine optimal methods to assess behaviors to better understand the levels at which healthy lifestyle behaviors are needed to slow CKD progression, to investigate the effect of combining multiple lifestyle behaviors on important clinical outcomes in CKD, and to develop effective techniques for behavior change. Despite the lack of evidence of efficacy from large trials on the ability of lifestyle behaviors to slow CKD progression, maintaining a healthy lifestyle remains a cornerstone of CKD management given the undisputed benefits of healthy lifestyle behaviors on cardiovascular health, BP control, and survival.

Relation of Alcohol Intake to Kidney Function and Mortality Observational, Population-Based, Cohort Study

Data are conflicting about the effects of alcohol intake on kidney function. This population-based study investigated associations of alcohol intake with kidney function and mortality. The study cohort included adult participants in Exam-1, Exam-2 (6-year follow-up), and Exam-3 (20-year follow-up) of the Gubbio study. Kidney function was evaluated as estimated glomerular filtration rate (eGFR, CKD-Epi equation, mL/min × 1.73 m2). Daily habitual alcohol intake was assessed by questionnaires. Wine intake accounted for >94% of total alcohol intake at all exams. Alcohol intake significantly tracked over time (R > 0.66, p < 0.001). Alcohol intake distribution was skewed at all exams (skewness > 2) and was divided into four strata for analyses (g/day = 0, 1−24, 25−48, and >48). Strata of alcohol intake differed substantially for lab markers of alcohol intake (p < 0.001). In multivariable regression, strata of alcohol intake related cross-sectionally to eGFR at all exams (Exam-1: B = 1.70, p < 0.001; Exam-2: B = 1.03, p < 0.001; Exam-3: B = 0.55, p = 0.010) and related longitudinally to less negative eGFR change from Exam-1 to Exam-2 (B = 0.133, p = 0.002) and from Exam-2 to Exam-3 (B = 0.065, p = 0.004). In multivariable Cox models, compared to no intake, intakes > 24 g/day were not associated with different mortality while an intake of 1−24 g/day was associated with lower mortality in the whole cohort (HR = 0.77, p = 0.003) and in the subgroup with eGFR < 60 mL/min × 1.73 m2 (HR = 0.69, p = 0.033). These data indicate a positive independent association of alcohol intake with kidney function not due to a mortality-related selection.

Alcohol intake and the risk of chronic kidney disease: results from a systematic review and dose-response meta-analysis

Many prospective cohort studies have investigated the association between the consumption of alcohol and CKD risk and have revealed inconsistent results. In the present study, we aimed to perform a meta-analysis of these studies to assess this association.We searched the PubMed and Embase databases up to 2020 and reviewed the reference lists of relevant articles to identify appropriate studies. We calculated the pooled relative risks with 95% CIs using random effects models, and then performed subgroup and meta-regression analyses. Dose-response meta-analyses were performed by sex separately. We identified 25 eligible prospective cohort studies, including 514,148 participants and 35,585 incident CKD cases. Compared with the category of minimal alcohol intake, light (RR = 0.90, I2 = 49%), moderate (RR = 0.86, I2 = 40%), and heavy (RR = 0.85, I2 = 51%) alcohol intake were associated with a lower risk of CKD. Subgroup meta-analysis by sex indicated that light (RR = 0.92, I2 = 0%), moderate (RR = 0.83, I2 = 39%) and heavy (RR = 0.76, I2 = 40%), alcohol consumption were inversely associated with CKD risk in male. Dose-response meta-analyses detected a nonlinear inverse association between alcohol consumption and the risk of CKD in all participants and linear inverse association in female participants. This meta-analysis shows that light (<12 g/day), moderate (12-24 g/day), and heavy (>24 g/day) alcohol consumption are protective against chronic kidney disease in adult participants especially in males.

Modifiable Lifestyle Factors for Primary Prevention of CKD: A Systematic Review and Meta-Analysis

BACKGROUND

Despite increasing incidence of CKD, no evidence-based lifestyle recommendations for CKD primary prevention apparently exist.

METHODS

To evaluate the consistency of evidence associating modifiable lifestyle factors and CKD incidence, we searched MEDLINE, Embase, CINAHL, and references from eligible studies from database inception through June 2019. We included cohort studies of adults without CKD at baseline that reported lifestyle exposures (diet, physical activity, alcohol consumption, and tobacco smoking). The primary outcome was incident CKD (eGFR<60 ml/min per 1.73 m²). Secondary outcomes included other CKD surrogate measures (RRT, GFR decline, and albuminuria).

RESULTS

We identified 104 studies of 2,755,719 participants with generally a low risk of bias. Higher dietary potassium intake associated with significantly decreased odds of CKD (odds ratio [OR], 0.78; 95% confidence interval [95% CI], 0.65 to 0.94), as did higher vegetable intake (OR, 0.79; 95% CI, 0.70 to 0.90); higher salt intake associated with significantly increased odds of CKD (OR, 1.21; 95% CI, 1.06 to 1.38). Being physically active versus sedentary associated with lower odds of CKD (OR, 0.82; 95% CI, 0.69 to 0.98). Current and former smokers had significantly increased odds of CKD compared with never smokers (OR, 1.18; 95% CI, 1.10 to 1.27). Compared with no consumption, moderate consumption of alcohol associated with reduced risk of CKD (relative risk, 0.86; 95% CI, 0.79 to 0.93). These associations were consistent, but evidence was predominantly of low to very low certainty. Results for secondary outcomes were consistent with the primary finding.

CONCLUSIONS

These findings identify modifiable lifestyle factors that consistently predict the incidence of CKD in the community and may inform both public health recommendations and clinical practice.

Association of self-reported moderate vegetable juice intake with small decline in kidney function in a five-year prospective study

OBJECTIVES

Although consumption of vegetable and 100% fruit juices are an acceptable alternative for vegetable and fruit intake, information about their actual effects on kidney function is sparse. The aim of this study was to determine the association between the consumption of vegetable and fruit juices and changes in kidney function in a Japanese population over a 5-y period.

METHODS

In this prospective study, we analyzed 2755 Japanese (742 men and 2013 women) individuals who participated in both the baseline and follow-up surveys in the Daiko study (a study within the Japan Multi-Institutional Collaborative Cohort study). Estimated glomerular filtration rate (eGFR) was calculated by age, sex, and serum creatinine level. For each beverage, we categorized all participants into four groups-rare (rarely consumed), low (≤2 cups/wk), moderate (3-4 cups/wk), or frequent (≥5 cups/wk) consumers of the beverage-based on a food frequency questionnaire.

RESULTS

The mean baseline and follow-up eGFR (SD) were 82.4 (14.6) and 72.2 (12.6), respectively. In fully adjusted regression analyses, moderate consumption of vegetable juice was associated a lower decline in eGFR compared with the rare consumption group (β = -1.30; P = 0.01). Moreover, stratified analyses revealed that this significant association remained in those who were young, female, non-obese, normotensive, smoked cigarettes, consumed alcohol, or exercised. However, no significant association was found in analyses for fruit juices.

CONCLUSIONS

This 5-y prospective study suggested an association between self-reported moderate consumption of vegetable juice and changes (possibly smaller decline) in kidney function in a relatively healthy Japanese population.

The impact of diabetes on the association between alcohol intake and the risk of end-stage kidney disease in the Singapore Chinese Health Study

BACKGROUND

The relationship between alcohol intake and end-stage kidney disease (ESKD) risk is controversial. Moreover, while evidence has shown that the relationship between alcohol and atherosclerosis may be modified by diabetes, whether this applies to ESKD is unknown.

METHODS

We examined these associations in the Singapore Chinese Health Study, a prospective cohort of 63 257 adults aged 45 to 74 years. Information on alcohol intake, diet, lifestyle factors, and medical history was collected at recruitment. We identified 1217 ESKD cases via linkage with the Singapore Renal Registry after a mean follow-up of 17.5 years. Cox regression models were used to estimate hazard ratios (HRs) and 95% CI of ESKD.

RESULTS

Among the participants without diabetes at baseline, monthly to weekly drinking was associated with a decreased risk of ESKD (HR 0.69; 95% CI, 0.54-0.87) compared to nondrinkers. In contrast, this association was attenuated and not significant among those with diabetes (HR 0.82; 95% CI, 0.58-1.16; P_interaction = .19). Comparatively, alcohol intake of ≥2 drinks per day was significantly associated with an increased risk of ESKD compared to nondrinkers among those with diabetes (HR 2.00; 95% CI, 1.14-3.53) but not among those without diabetes (HR 0.91; 95% CI, 0.53-1.56; P_interaction = .01). The risk of ESKD among those with diabetes and who also consumed ≥2 drinks per day was increased by nearly 12-fold compared to nondrinkers without diabetes (HR 11.6; 95% CI, 6.73-19.9).

CONCLUSION

Low-dose drinking is associated with a reduced risk of ESKD among individuals without diabetes. However, joint exposure to heavy drinking and diabetes is associated with a substantially higher risk of ESKD.

Serum Gamma-Glutamyltransferase, Daily Alcohol Consumption, and the Risk of Chronic Kidney Disease: The Kansai Healthcare Study

BACKGROUND

Serum gamma-glutamyltransferase has been recognized as the risk factor of cardiovascular and metabolic diseases. However, the association between serum gamma-glutamyltransferase and the risk of chronic kidney disease is not well known, and no prospective studies have examined separately the relationship of serum gamma-glutamyltransferase with the risk of proteinuria versus that of low estimated glomerular filtration rate (eGFR).

METHODS

We prospectively followed 9,341 Japanese men who did not have low eGFR, proteinuria, or diabetes, and did not take antihypertensive medications at entry for the analysis of proteinuria, and we followed 9,299 men for the analysis of low eGFR. We defined "persistent proteinuria" as proteinuria detected two or more times consecutively and persistently as ≥1+ on urine dipstick at the annual check-up until the end of follow-up. Low eGFR was defined as eGFR <60 mL/min/1.73 m².

RESULTS

During the 11-year observation period, 151 men developed persistent proteinuria and 1,276 men developed low eGFR. In multivariate models, the highest quartile (≥71 IU/L) of serum gamma-glutamyltransferase was independently related to the development of persistent proteinuria (hazard ratio 3.39; 95% confidence interval, 1.92-5.97) compared with the lowest quartile (≤25 IU/L). In joint analysis of alcohol consumption and serum gamma-glutamyltransferase, non-drinkers in the highest tertile (≥58 IU/L) of serum gamma-glutamyltransferase had the highest risk of persistent proteinuria. However, there was no association between serum gamma-glutamyltransferase and low eGFR.

CONCLUSION

In middle-aged Japanese men, elevated serum gamma-glutamyltransferase was independently associated with future persistent proteinuria, but not with low eGFR.

Alcohol Consumption and Progression of Chronic Kidney Disease: Results From the Korean Cohort Study for Outcome in Patients with Chronic Kidney Disease

OBJECTIVE

To assess the association of alcohol consumption with chronic kidney disease (CKD) progression in patients with CKD.

PATIENTS AND METHODS

The KoreaN cohort study for Outcome in patients with CKD (KNOW-CKD) is a prospective observational study that included detailed questionnaires regarding alcohol consumption. The 1883 individuals with CKD were enrolled from April 1, 2011, through February 28, 2016, and followed until May 31, 2017. Using a questionnaire, alcohol consumption pattern was classified according to the amount of alcohol per occasion (none, moderate, or binge) or drinking frequency (none, occasional, or regular). The primary endpoint was a composite of 50% or greater decline in estimated glomerular filtration rate (eGFR) from the baseline level or end-stage renal disease.

RESULTS

During a follow-up of 5555 person-years (median, 2.95 years), the primary outcome occurred in 419 patients. Unadjusted cause-specific hazards model showed that the risk of the primary outcome was lower in drinkers than in non-drinkers. However, a fully adjusted model including eGFR and proteinuria yielded a reverse association. Compared with non-drinking, regular and occasional binge drinking were associated with a 2.2-fold (95% CI, 1.38-3.46) and a 2.0-fold (95% CI, 1.33-2.98) higher risk of CKD progression, respectively. This association was particularly evident in patients who had decreased kidney function and proteinuria. There was a significant interaction between alcohol consumption and eGFR for CKD progression. The slopes of eGFR decline were steeper in binge drinkers among patients with eGFR less than 60 mL/min/1.73 m².

CONCLUSIONS

Heavy alcohol consumption was associated with faster progression of CKD.

Alcohol Consumption and Incident Kidney Disease: Results From the Atherosclerosis Risk in Communities Study

OBJECTIVE(S)

Moderate alcohol consumption has been found to be associated with lower risk of coronary heart disease and myocardial infarction, which share similar risk factors and pathophysiology with chronic kidney disease (CKD). However, there is inconsistent evidence on the association between alcohol consumption and CKD.

DESIGN AND METHODS

We conducted a prospective analysis of 12,692 participants aged 45-64 years from the Atherosclerosis Risk in Communities (ARIC) study. We categorized participants into 6 alcohol consumption categories: never drinkers, former drinkers, ≤1 drink per week, 2 to 7 drinks per week, 8 to 14 drinks per week, and ≥15 drinks per week based on food frequency questionnaire responses at visit 1 (1987-1989). Incident CKD was defined as estimated glomerular filtration rate <60 mL/minute/1.73 m2 accompanied by ≥25% estimated glomerular filtration rate decline, a kidney disease-related hospitalization or death or end-stage renal disease.

RESULTS

During a median follow-up of 24 years, there were 3,664 cases of incident CKD. Current drinkers were more likely to be men, whites, and to have a higher income level and education level. After adjusting for total energy intake, age, sex, race-center, income, education level, health insurance, smoking, and physical activity, there was no significant association between being a former drinker and risk of incident CKD. Participants who drank ≤1 drink per week, 2 to 7 drinks per week, 8 to 14 drinks per week, and ≥15 drinks per week had, respectively, a 12% (hazard ratio [HR]: 0.88, 95% confidence interval [CI]: 0.79-0.97), 20% (HR: 0.80, 95% CI: 0.72-0.89), 29% (HR: 0.71, 95% CI: 0.62-0.83), and 23% (HR: 0.77, 95% CI: 0.65-0.91) lower risk of CKD compared with never drinkers.

CONCLUSION(S)

Consuming a low or moderate amount of alcohol may lower the risk of developing CKD. Therefore, moderate consumption of alcohol may not likely be harmful to the kidneys.

Socioeconomic Determinants of Knowledge of Kidney Disease Among Residents in Nigerian Communities in Lagos State, Nigeria

Objectives

We sought to estimate the knowledge, sociodemographic determinants, and risk-inducing lifestyles of kidney disease (KD) among Nigerians living in Lagos State.

Methods

We conducted a cross-sectional descriptive study to assess the level of knowledge of KD and its associated sociodemographic factors of individuals living in urban and semi-urban communities of Lagos State, Nigeria. It is hoped that the results of this study will help to inform preventive modalities. We used a pretested, structured questionnaire to draw information from 1171 Nigerians aged ≥ 15 years.

Results

The mean age of respondents was 33.5±11.1 years. In our cohort, 72.4% of respondents were knowledgeable of KD, with media as their major source of information (41.6%). Knowledge of KD was significantly associated with age (p = 0.044), education (p < 0.001), marital status (p < 0.001), and place of residence (p = 0.048). The established KD risk-inducing lifestyle factors were habitual use of herbal supplements, significant alcohol consumption, and diabetes (p < 0.050). Significant predictors of knowledge of KD included primary education (Odds ratio (OR) = 0.367, 95% confidence interval (CI): 0.11–1.22; p =0.102), secondary education (OR = 0.296, 95% CI: 0.17–0.51; p < 0.001), Igbo ethnic group (OR = 1.471, 95% CI: 0.99–2.17; p = 0.047), and place of residence (OR = 1.332, 95% CI: 1.00–1.77; p = 0.048). Age 30–39 years (OR = 0.749, 95% CI: 0.48–1.18; p = 0.214), 40–49 years (OR = 1.083, 95% CI: 0.69–1.69; p = 0.727), and not working (OR = 1.178, 95% CI: 0.88–1.57; p < 0.269) were non-significant predictors of knowledge of KD.

Conclusions

Our cohort had inadequate knowledge of linking risk-inducing lifestyles to KD development. Effective measures and efforts should be made to create awareness and educate the general population on KD and prevention measures related to risk-inducing lifestyles to reduce the burden of KD among Nigerians.

Alcohol Consumption Can be a "Double-Edged Sword" for Chronic Kidney Disease Patients

Excessive drinking of alcohol is becoming a worldwide problem, and people have recognized that there exists a close relationship between chronic kidney disease (CKD) and alcohol consumption. However, there are many inconsistencies between experimental and clinical studies on alcohol consumption and kidney damage. The possible reason for this contradictory conclusion is the complex drinking pattern of humans and some bioactivators in wine. In addition, the design itself of the clinical studies can also produce conflicting interpretations of the results. Considering the benefits of light-to-moderate alcohol consumption, we recommend that CKD patients continue light-to-moderate drinking, which is beneficial to them. Because alcohol consumption can lead to adverse events, we do not advise non-drinkers to start to drink. Although light-to-moderate alcohol consumption may not pose a risk to patients with CKD, the patients’ condition needs to be considered. Consumption of even small amounts of alcohol can be associated with increased death risk. Additional clinical and experimental studies are needed to clarify the effect of alcohol on the kidneys and alcohol consumption on CKD patients.

Alcohol Consumption and Risk of Chronic Kidney Disease: A Nationwide Observational Cohort Study

Alcohol consumption is a significant public health issue worldwide. The rat model and epidemiological studies have both reported conflicting results about the effects of alcohol on the kidneys. We aimed to explore the relationships between alcohol consumption and chronic kidney disease. Data from the National Health Interview Survey, the National Health Insurance research database, and the National Deaths Dataset were used. Standardized in-person interviews were executed in 2001, 2005, and 2009 to obtain the demographic characteristics of study population. The participants were followed up until 2013. The primary outcome was new-onset chronic kidney disease. We analyzed 45,200 adults older than 18 years (50.8% men and 49.2% women), and the overall mean (SD) age was 42.73 (16.64) years. During the 8.5 (3.5) years of follow-up, new-onset chronic kidney disease was recognized in 1535 (5.5%), 292 (2.7%), and 317 (4.9%) non-drinking, social-drinking, and regular-drinking participants, respectively. The participants who were social and regular drinkers had a significantly decreased risk of chronic kidney disease incidence (social drinking: adjusted hazard ratio (HR), 0.85; 95% confidence interval (CI), 0.74-0.97; p = 0.018; regular-drinking: AHR, 0.85; 95% CI, 0.74-0.98; p = 0.024), with baseline demographics and comorbidities adjusted. In conclusion, social and regular drinkers had decreased risk of chronic kidney disease when compared with non-drinkers.

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.

Alcohol Drinking and the Risk of Chronic Kidney Damage: A Meta-Analysis of 15 Prospective Cohort Studies

The relationship between alcohol drinking and chronic kidney damage, mainly including declined glomerular filtration rate (GFR), proteinuria, and end-stage renal disease, was conflicting. Thus, a meta-analysis was conducted to investigate their potential associations. PubMed and Web of Science were searched to identify prospective studies assessing the associations between alcohol drinking and chronic kidney damage published up to March 2019. Random-effects model was employed to pool the relative risks (RR) with 95% confidence intervals (CIs). Subgroup meta-analyses stratified by the basic characteristics of subjects were performed. A total of 15 cohort studies were included in the present study, with 268,723 participants and 31,766 incident cases. Participants with low (<13 g/d), moderate (13 to 26 g/d), and high (26 to 60 g/d) dose of alcohol drinking had 12% (RR: 0.88, 95% CI: 0.83 to 0.93), 24% (RR: 0.76, 95% CI: 0.70 to 0.83), and 21% (RR: 0.79, 95% CI: 0.71 to 0.88) lower risk of chronic kidney damage compared with the reference group (non- or occasional drinkers), respectively. The lower risk for chronic kidney damage remained significant for the declined GFR, or in men, or for participants aged less than 55 yrs, or studies with longer than 8 yrs of follow-up, while severe alcohol drinking (≥60 g/d) insignificantly increased 7% risk of chronic kidney damage (RR: 1.07, 95% CI: 0.53 to 2.15). No obvious heterogeneity and no publication bias were observed. Based on our meta-analysis, participants with alcohol drinking less than 60 g/d were at lower risk of declined GFR, especially in men or participants aged less than 55 yrs. Much more prospective cohort studies are required to confirm our present findings.

Alcohol use disorder tied to development of chronic kidney disease: A nationwide database analysis

INTRODUCTION

Alcohol use disorder (AUD) is a spectrum of high risk behaviors including alcohol abuse and dependence. Chronic kidney disease (CKD) is progressive loss of renal function for more or equal to 3 months or presence of any irreversible kidney damage. Common risk factors of CKD have been identified, but the impact of alcohol consumption on kidney function is controversial. The study aims to investigate the relationship between alcohol use disorder and CKD on a national scale.

METHODS

This retrospective cohort study was conducted using Taiwan's National Health Insurance research database. Patients aged 20 years or older, without CKD and with the diagnosis of AUD (ICD-9-CM codes 303.X; 305.0, V113) from years 2000 to 2013 were enrolled. Control cohort was selected to match the demographics of the target population. Patients were followed until the end of 2013 or earlier if they developed CKD, died, or lost follow up. Baseline characteristics and comorbidities were identified for risk stratification.

RESULTS

We identified 11639 patients in the AUD cohort and 46556 patients in the control cohort. Compared to patients in the control cohort, those in the AUD group were more likely to have multiple comorbidities (p < 0.001 for all comorbidities). After adjustment of age, gender, baseline comorbidities, and nonsteroidal anti-inflammatory drug use, the diagnosis of AUD was associated with an increased risk of CKD development (aHR = 1.62, 95% CI, 1.46-1.81). During the mean follow up periods of 6.47 (standard deviation (SD) = 3.80) years for the AUD cohort and 7.23 (SD = 3.75) years for the control cohort, the overall incidence density of CKD was significantly higher in patients with AUD than those in the control cohort (3.48 vs 6.51 per 1000 person-years, aHR = 1.68, 95% CI, 1.50-1.87). Kaplan-Meier analysis showed that the AUD cohort had a higher cumulative incidence of CKD than the control cohort (log-rank test, p value < 0.001). Patients with AUD had higher risks of CKD in all the stratified groups, except for the subgroup with age over 65 years old.

CONCLUSION

Our study suggested that AUD was associated with an increased incidence of newly diagnosed CKD by nearly two folds. Young age, in particular, had a higher association between AUD and CKD. Considering the preventable nature of AUD, establishing effective health policies is imperative to reduce high-risk alcohol behaviors and thereby prevent alcohol-related kidney disease. Further prospective studies are warranted to further elucidate the causation of AUD on kidney function.

Alcohol consumption and incidence of proteinuria: a retrospective cohort study

BACKGROUND

Previous studies report conflicting results of a dose-dependent association between alcohol consumption and incidence of chronic kidney disease. Only a few studies have assessed the clinical impact of > 45-65 g/day of critically high alcohol consumption.

METHODS

This retrospective cohort study included 88,647 males and 88,925 females with dipstick urinary protein ≤ ± and estimated glomerular filtration rate ≥ 60 mL/min/1.73 m² at their first annual health examinations between April 2008 and March 2010 in Japan. The exposure was the self-reported alcohol consumption. The outcome was proteinuria defined as dipstick urinary protein ≥ 1 + or ≥ 2 +.

RESULTS

During median 1.8 years (interquartile range 1.0-2.1) of the observational period, 5416 (6.1%) males and 3262 (3.7%) females developed proteinuria defined as dipstick urinary protein ≥ 1 +. In males, a U-shape association between alcohol consumption and proteinuria was observed in a multivariable-adjusted Poisson regression model [incidence rate ratio (95% confidence interval) of rare, occasional, and daily drinkers with ≤ 19, 20-39, 40-59, and ≥ 60 g/day: 1.00 (reference), 0.86 (0.79-0.94), 0.70 (0.64-0.78), 0.82 (0.75-0.90), 1.00 (0.90-1.11), and 1.00 (0.85-1.17), respectively], whereas a J-shape association was observed in females [1.00 (reference), 0.81 (0.75-0.87), 0.74 (0.64-0.85), 0.93 (0.78-1.11), 1.09 (0.83-1.44), and 1.45 (1.02-2.08), respectively]. Similar associations with dipstick urinary protein ≥ 2 + were shown in males and females.

CONCLUSIONS

Moderate alcohol consumption was associated with lower risk of proteinuria in both males and females. Females with ≥ 60 g/day of high alcohol consumption were at higher risk of proteinuria, whereas males were not. Females were more vulnerable to high alcohol consumption, than males.

Investigation of Metabolic Factors Associated with eGFR Decline Over 1 Year in a Japanese Population without CKD

Aim: Early intervention before the progression of chronic kidney disease (CKD) is essential to prevent end-stage renal disease (ESRD) and cardiovascular complications. This study evaluated the correlation between metabolic and lifestyle-related factors and the decline of estimated glomerular filtration rate (eGFR) over 1 year in a Japanese population without CKD.

Methods: Subjects who received two consecutive annual health checkups from 2013 to 2015 were involved. Factors associated with eGFR decline were identified using multiple regression models.

Results: A total of 2531 subjects aged 58.9 ± 11.7 years old were included in this study. Baseline levels of HDL-C and ApoA1 correlated with the eGFR decline over 1 year defined as eGFR reduction rate of 15% or more and/or eGFR at the next year < 60 ml/min/m² (odds ratio (OR) 0.87 (per 10 mg/dl); 95% CI, 0.80–0.94; p = 0.0012, 0.90 (per 10 mg/dl); 0.86–0.96; p = 0.0004, respectively). A U-shaped relationship between the eGFR decline and HDL-C or ApoA1 levels was not observed in non-CKD population of this study. Metabolic syndrome was significantly associated with eGFR decline (OR 1.32; 1.04–1.67; p = 0.0205), although obesity-related factors did not show a significant correlation with eGFR decline over 1 year.

Conclusion: Low HDL-C and ApoA1 levels significantly correlated with eGFR decline in a short period of 1 year. Metabolic syndrome also showed a significant association with eGFR decline. This study suggests the importance of hypertension and low HDL-C in the metabolic syndrome effect on eGFR decline rather than obesity in non-CKD population.

Positive linear dose-response relationships, but no J-shaped relationship, between drinking habits and estimated glomerular filtration rate in middle-aged Japanese men

The relationship between drinking frequency and amount of alcohol consumption (i.e., drinking habits) and the risk of chronic kidney disease (CKD) remains unclear. We aimed to clarify either a linear or J-shaped dose-response relationship between drinking habits and estimated glomerular filtration rate (eGFR) as a biomarker for identifying individuals at high risk of CKD. In a large-scale cross-sectional study, 403 men and 121 women with an eGFR of 30-60 mL/min per 1.73 m(2) were defined as cases, and 1209 men and 363 women with ≥60 mL/min/1.73 m(2) were randomly extracted as controls (one case subject was matched with three control subjects, matched according to age and season of data collection). We calculated multivariate-adjusted CKD risk and the corresponding mean eGFR according to drinking habits. In men, negative and positive linear relationships with drinking habits were found for CKD risk and mean eGFR (p < 0.001 for all linear terms), respectively, but there were no corresponding J-shaped relationships (not significant for all quadratic terms). In regard to the mean eGFR, however, positive linear relationships were only shown in men in the highest eGFR quartile (p < 0.05 and p < 0.01 for drinking frequency and amount of alcohol consumption, respectively). In women, no association was found. Regarding each drinking habit, we found a positive linear dose-response relationship to eGFR in middle-aged men with an eGFR ≥30 mL/min/1.73 m(2).

Alcohol and Exercise Affect Declining Kidney Function in Healthy Males Regardless of Obesity: A Prospective Cohort Study

Background

Although lifestyle is associated with metabolic syndrome and cardiovascular diseases, there has been no sufficient evidence of lifestyles on incident chronic kidney disease (CKD). The purpose of this prospective cohort study is to investigate the effects of lifestyles on kidney function in healthy people.

Methods

A total of 7473 healthy people were enrolled in this Saitama Cardiometabolic Disease and Organ Impairment Study, Japan. Data on alcohol consumption, exercise frequency, and sleep duration were collected. The outcome event was incident CKD or decrease in estimated glomerular filtration rate (eGFR) by >25% in 3 years.

Results

Subjects were classified into four groups according to body mass index and gender. Mean ± standard deviation of age was 38.8±10.5 years; eGFR, 78.1±15.2 ml/min/1.73m². In the male groups, multivariate logistic regression models showed that the outcome events were associated with a small amount of alcohol consumed (20 to 140g of alcohol/week) (ref. more than 140g of alcohol/week); non-obese male, adjusted odds ratio 1.366 (95% confidence interval, 1.086, 1.718); obese male (body mass index ≥25), 1.634 (1.160, 2.302); and with frequent exercise (twice a week or more) (ref. no exercise); non-obese male, 1.417 (1.144, 1.754); obese male, 1.842 (1.317, 2.577). Sleep duration was not associated with the outcome events.

Conclusion

These findings suggest that, regardless of obesity, a small amount of alcohol consumed and high exercise frequency were associated with the increased risk of loss of kidney function in the male groups.

High alcohol consumption and the risk of renal damage: a systematic review and meta-analysis

BACKGROUND

The risk of renal damage in patients with high alcohol consumption is controversial. The objective of this meta-analysis was to evaluate the associations between high alcohol consumption and progression of kidney damage including chronic kidney disease (CKD), end-stage renal disease (ESRD) and proteinuria.

METHODS

A literature search was performed using MEDLINE, EMBASE and Cochrane Databases from inception through August 2014 to identify studies investigating the association between high alcohol consumption and CKD, ESRD or proteinuria. Studies that reported odds ratios, relative risks or hazard ratios comparing the risk of CKD, ESRD or proteinuria in patients consuming high amount of alcohol versus those who did not consume alcohol were included. Pooled risk ratios (RRs) and 95% confidence interval (CI) were calculated using a random-effect, generic inverse variance method.

RESULTS

Twenty studies with 292 431 patients were included in our analysis to assess the associations between high alcohol consumption and progression of kidney damage. The pooled RRs of CKD, proteinuria and ESRD in patients with high alcohol consumption were 0.83 (95% CI: 0.71-0.98), 0.85 (95% CI: 0.62-1.17) and 1.00 (95% CI: 0.55-1.82), respectively. Post hoc analysis assessing the sex-specific association between high alcohol consumption and CKD demonstrated pooled RRs of 0.72 (95% CI: 0.57-0.90) in males and 0.78 (95% CI: 0.58-1.03) in females.

CONCLUSIONS

Our study demonstrates an inverse association between high alcohol consumption and risk for developing CKD in males. There is no significant association between high alcohol consumption and the risk for developing proteinuria or ESRD.

Lifestyle factors and indices of kidney function in the Framingham Heart Study

BACKGROUND AND OBJECTIVES

Lifestyle characteristics are modifiable factors that could be targeted as part of chronic kidney disease (CKD) prevention. We sought to determine the association of lifestyle characteristics with incident estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m(2) and rapid eGFR decline in older adults in the United States.

METHODS

Prospective cohort study of Framingham Offspring participants with baseline eGFR <60 ml/min/1.73 m(2) (n = 1,802) who attended the seventh (1998-2001; baseline) and eighth (2005-2008; follow-up) examinations (mean age = 59 years, 54.8% women). Predictors included measures of diet quality, physical activity, alcohol intake, and current smoking status assessed during baseline. Outcomes were based on creatinine-based eGFR at baseline and follow-up and included incident eGFR <60 ml/min/1.73 m(2) (at follow-up) and rapid eGFR decline (annual eGFR decrease ≥3 ml/min/1.73 m(2)).

RESULTS

Over an average follow-up of 6.6 years, 9.5% (n = 171) of participants developed incident eGFR <60. A trend was observed across quartiles of diet quality, with higher levels of diet quality associated with a decreased odds ratio (OR) of incident eGFR <60 (p trend = 0.045). Higher diet quality was associated with decreased odds of rapid eGFR decline (p trend = 0.03) and was attenuated with additional adjustment (p trend = 0.07). In sensitivity analysis for rapid eGFR decline using a secondary definition (annual eGFR decrease ≥3 and incident eGFR <60), diet associations remained significant with additional adjustment (p trend = 0.04). No associations were observed with physical activity, smoking status, or alcohol intake with incident eGFR <60 or rapid eGFR decline (all p > 0.19).

CONCLUSIONS

Higher diet quality may be associated with a decreased risk of incident eGFR <60 ml/min/1.73 m(2), and rapid eGFR decline. Whether adherence to a healthy diet can prevent reduction in kidney function warrants further study.

Is it time to tip your glass to prevent CKD?

Chronic kidney disease (CKD) is a major global medical and public health challenge. On the basis primarily of a modest number of prospective epidemiological studies, it appears that alcohol consumption reduces the risk of CKD in the general population. Our understanding of the potential benefits of alcohol consumption with regard to CKD is likely to evolve in the future and will be informed primarily by observational epidemiological studies.

Drinking pattern and risk of chronic kidney disease: the kansai healthcare study

BACKGROUND/AIMS

The association between alcohol consumption and the risk of chronic kidney disease (CKD) has been reported. What is not known is whether drinking pattern combined with the weekly frequency of alcohol consumption and the quantity per drinking day is associated with the risk of CKD.

METHODS

We enrolled 9,112 Japanese nondiabetic men aged 40 to 55 years with absence of proteinuria, an estimated glomerular filtration rate (eGFR) of 60 ml/min/1.73 m(2) or higher, and not on antihypertensive medications at baseline. CKD was defined if eGFR was <60 ml/min/1.73 m(2). The weekly frequency classification was nondrinkers, 1-3 drinking days/week, or 4-7 drinking days/week. The quantity consumed per drinking day was classified as 0.1-23.0 g ethanol/drinking day, 23.1-46.0 g ethanol/drinking day, 46.1-69.0 g ethanol/drinking day, and ≥69.1 g ethanol/drinking day.

RESULTS

During the 79,099 person-years, 1,253 subjects developed CKD. Compared to nondrinkers, those who consumed 23.1-46.0 or 46.1-69.0 g ethanol/drinking day on 4-7 drinking days/week had a decreased risk of CKD (multiple-adjusted hazard ratio (HR) 0.62 (0.52-0.74) and 0.76 (0.59-0.97), respectively). The association between the quantity per drinking day and the incidence of CKD was U-shaped among each category of the weekly frequency. HRs within similar categories of quantity per drinking day were lower in the 4-7 drinking days/week group than in the 1-3 drinking days/week group.

CONCLUSION

Among middle-aged Japanese men, the people who drank middle-range quantity, specifically who drank 4-7 days/week, had lower risk of CKD than nondrinkers.

Analysis of risk factors associated with renal function trajectory over time: a comparison of different statistical approaches

BACKGROUND

The most commonly used methods to investigate risk factors associated with renal function trajectory over time include linear regression on individual glomerular filtration rate (GFR) slopes, linear mixed models and generalized estimating equations (GEEs). The objective of this study was to explain the principles of these three methods and to discuss their advantages and limitations in particular when renal function trajectories are not completely observable due to dropout.

METHODS

We generated data from a hypothetical cohort of 200 patients with chronic kidney disease at inclusion and seven subsequent annual measurements of GFR. The data were generated such that both baseline level and slope of GFR over time were associated with baseline albuminuria status. In a second version of the dataset, we assumed that patients systematically dropped out after a GFR measurement of <15 mL/min/1.73 m(2). Each dataset was analysed with the three methods.

RESULTS

The estimated effects of baseline albuminuria status on GFR slope were similar among the three methods when no patient dropped out. When 32.7% dropped out, standard GEE provided biased estimates of the mean GFR slope in normo-, micro- and macroalbuminuric patients. Linear regression on individual slopes and linear mixed models provided slope estimates of the same magnitude, likely because most patients had at least three GFR measurements. However, the linear mixed model was the only method to provide effect estimates on both slope and baseline level of GFR unaffected by dropout.

CONCLUSION

This study illustrates that the linear mixed model is the preferred method to investigate risk factors associated with renal function trajectories in studies, where patients may dropout during the study period because of initiation of renal replacement therapy.

Is alcohol drinking associated with renal impairment in the general population of South Korea?

BACKGROUND/AIMS

We examined relationships between the average amount of daily alcohol intake, drinking patterns, and renal dysfunction among South Korean adultsaged ≥ 20 years.

METHODS

The analysis used data from the Korean National Health and Nutrition Examination Survey (KNHANES), a cross-sectional survey of Korean civilians, conducted from January to December 2011. In this study, a sample of 5,251 participants was analysed.

RESULTS

Compared with abstinence, the odds ratio for a decrease in estimated glomerular filtration rate (eGFR) was 0.14 (95% CI: 0.01-0.91) among heavy drinkers, and 0.42 (95% CI: 0.17-0.98) among binge drinkers and the association between the amount of mean daily alcohol intake, binge-drinking status and a likelihood of reduced eGFR value showed significant trends (p = 0.041 and p = 0.038, respectively), after adjusting for age, smoking status, amount of physical activity, morbid hypertension, diabetes, dyslipidaemia, anaemia and body mass index. There was no significant association between alcohol consumption and the urine albumin to creatinine ratio in men, or between alcohol consumption and renal dysfunction in women.

CONCLUSIONS

Alcohol consumption was inversely associated with a reduction in eGFR in Korean men. However, these findings should be interpreted cautiously, given the other harmful effects related to alcohol consumption, especially heavy and binge drinking.

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.

Alcohol effects on cognitive change in middle-aged and older adults

OBJECTIVES

This study examines cognitive outcomes for alcohol drinking status over time, across cognitive ability and age groups.

METHODS

Data (1998-2005) from n = 571 Seattle Longitudinal Study participants aged 45+years (middle-aged: 45-64, young-old: 65-75, old-old: 75+) were analyzed to examine the alcohol drinking status effect (e.g., abstinent, moderate (less than seven drinks/week), at-risk (more than eight drinks/week)) on cognitive ability (e.g., memory, reasoning, spatial, verbal number, speed abilities).

RESULTS

Findings indicated that alcohol drinking status was associated with change in verbal ability, spatial ability, and perceptual speed. Decline in verbal ability was seen among alcohol abstainers and moderate alcohol consumers, but at-risk drinkers displayed relative stability. At-risk old-old adults and middle-aged adults (regardless of drinking status), displayed relative stability in spatial ability. Decline in spatial ability was however present among young-old adults across drinking status, and among abstaining and moderate drinking old-old adults. At-risk drinkers showed the most positive spatial ability trajectory. A gender effect in perceptual speed was detected, with women who abstained from drinking displaying the most decline in perceptual speed compared with women that regularly consumed alcohol, and men displaying decline in perceptual speed across drinking status.

DISCUSSION

In this study, consuming alcohol is indicative of cognitive stability. This conclusion should be considered cautiously, due to study bias created from survivor effects, analyzing two time points, health/medication change status, and overrepresentation of higher socioeconomic status and white populations in this study. Future research needs to design studies that can make concrete recommendations about the relationship between drinking status and cognition.

Renal impairment and moderate alcohol consumption in the elderly. Results from the Italian Longitudinal Study on Aging (ILSA)

OBJECTIVE

The influence of moderate alcohol consumption on renal function is not clear in elderly people. The aim of the present study was to investigate the relationship between alcohol consumption and renal function, expressed as serum creatinine levels and glomerular filtration rates (GFR), in an elderly population.

DESIGN

Perspective cohort study.

SETTING

Population-based study on an elderly Italian population.

SUBJECTS

A sample of 3404 Italian people (1619 women and 1785 men), aged 65-84 years, from the Italian Longitudinal Study on Aging (ILSA).

RESULTS

Prevalence and cumulative risk of impaired renal function (defined as GFR ≤ 60 ml/min) were estimated by sex and alcohol consumption groups. Logistic regression analysis adjusting for confounders (age, education, smoking, BMI and medications) and intermediate factors (blood cholesterol and fibrinogen, systolic hypertension and diabetes) showed that alcohol consumption level was not significantly related to the prevalence of mild renal impairment in elderly women. In men, both prevalence and incidence results seemed to suggest an inverse linear relationship between moderate alcohol consumption and the risk of mild renal impairment. A U-shaped association was shown for women at the incidence phase, suggesting a higher risk of developing renal impairment for women who drink more than 24 g alcohol/d.

CONCLUSIONS

Our results suggest that, in accordance with the recommendations on alcohol consumption in the elderly, moderate quantities of alcohol are not injurious to renal function in elderly men.

Nocturnal hypoxia and loss of kidney function

Background

Although obstructive sleep apnea (OSA) is more common in patients with kidney disease, whether nocturnal hypoxia affects kidney function is unknown.

Methods

We studied all adult subjects referred for diagnostic testing of sleep apnea between July 2005 and December 31 2007 who had serial measurement of their kidney function. Nocturnal hypoxia was defined as oxygen saturation (SaO2) below 90% for ≥12% of the nocturnal monitoring time. The primary outcome, accelerated loss of kidney function, was defined as a decline in estimated glomerular filtration rate (eGFR) ≥4 ml/min/1.73 m² per year.

Results

858 participants were included and followed for a mean study period of 2.1 years. Overall 374 (44%) had nocturnal hypoxia, and 49 (5.7%) had accelerated loss of kidney function. Compared to controls without hypoxia, patients with nocturnal hypoxia had a significant increase in the adjusted risk of accelerated kidney function loss (odds ratio (OR) 2.89, 95% confidence interval [CI] 1.25, 6.67).

Conclusion

Nocturnal hypoxia was independently associated with an increased risk of accelerated kidney function loss. Further studies are required to determine whether treatment and correction of nocturnal hypoxia reduces loss of kidney function.

The impact of demographic characteristics and lifestyle in the distribution of cystatin C values in a healthy greek adult population

Background. The aim of the present study was to examine sources of variation for serum cystatin C in a healthy Greek population. Methods. Cystatin C together with basic clinical chemistry tests was measured in a total of 490 adults (46 ± 16 yrs, 40% males) who underwent an annual health check. Demographic, anthropometric, and lifestyle characteristics were recorded. Results. Higher values of cystatin C were observed among males (P = .04), participants aged over 65 years (P < .001), current smokers (P = .001) and overweight/obese participants (P = .03). On the contrary, alcohol consumption and physical activity seemed to have no influence on cystatin C levels (P = .61; P = .95, resp.). Conclusions. In interpreting serum cystatin C values in a healthy adult population, age, gender, Body Mass Index, and cigarette smoking need to be considered, and determination of reference ranges among distinct subpopulations seem to be prudent.