Risk of chronic kidney disease in non-obese individuals with clustering of metabolic factors: a longitudinal study

The Effect of Metabolic Syndrome and Its Individual Components on Renal Function: A Meta-Analysis

BACKGROUND

Observational studies have reported inconsistent findings in the relationship between metabolic syndrome (MetS), its components, and loss of renal function, mainly including eGFR decline, new-onset CKD, and ESRD. This meta-analysis was performed to investigate their potential associations.

METHODS

PubMed and EMBASE were systematically searched from their inception to 21 July 2022. Observational cohort studies in English assessing the risk of renal dysfunction in individuals with MetS were identified. Risk estimates and their 95% confidence intervals (CIs) were extracted and pooled using the random-effects approach.

RESULTS

A total of 32 studies with 413,621 participants were included in the meta-analysis. MetS contributed to higher risks of renal dysfunction (RR = 1.50, 95% CI = 1.39-1.61) and, specifically, rapid decline in eGFR (RR 1.31, 95% CI 1.13-1.51), new-onset CKD (RR 1.47, 95% CI 1.37-1.58), as well as ESRD (RR 1.55, 95% CI 1.08-2.22). Moreover, all individual components of MetS were significantly associated with renal dysfunction, while elevated BP conveyed the highest risk (RR = 1.37, 95% CI = 1.29-1.46), impaired fasting glucose with the lowest and diabetic-dependent risk (RR = 1.20, 95% CI = 1.09-1.33).

CONCLUSIONS

Individuals with MetS and its components are at higher risk of renal dysfunction.

Metabolic Risk Factors Associated With Chronic Kidney Disease in a Middle-Aged and Elderly Taiwanese Population: A Cross-Sectional Study

Background: This study aimed to quantify the proportion of participants with chronic kidney disease (CKD) and associated metabolic risk factors in a middle-aged and elderly population in Guishan District, Taoyuan City, Taiwan.

Methods: This cross-sectional study enrolled residents aged 50–90 years living in one community. All participants received a standardized personal interview, including a structured questionnaire, anthropometric measurements, and blood samples collected for laboratory testing. CKD was defined as the presence of kidney damage (urine albumin-creatinine ratio ≥30 mg/g) or estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m². Multiple logistic regression models were used to evaluate the risk factors associated with CKD.

Results: A total of 400 participants were enrolled. The overall proportion of participants with CKD was 20.5% (95% confidence interval [CI]: 16.54–24.46%). The proportions of participants with CKD among those aged 50–64, 65–74, and 75 years and over were 17.7, 18.8, and 35.7%, respectively (p = 0.01). Multiple logistic regression model revealed that elevated blood pressure (odds ratio [OR] = 2.23, 95% CI: 1.16–4.30), hyperglycemia (OR = 2.87, 95% CI: 1.64–5.00), hyperuricemia (OR = 1.38, 95% CI: 1.14–1.69), and metabolic syndrome (OR = 2.30, 95% CI: 1.31–4.06) were significantly associated with CKD.

Conclusions: The prevalence of CKD in the study population was high. Hypertension, hyperglycemia, hyperuricemia, and metabolic syndrome are significantly associated with CKD in a middle-aged and elderly population in Taiwan.

Relationship between chronic kidney disease and sarcopenia

Few studies have investigated the relationship between sarcopenia and mild to moderate renal decline. This study aimed to investigate the relationship between chronic kidney disease (CKD) and sarcopenia. In total, 123 patients hospitalized with CKD and 57 healthy volunteers who underwent physical examination during the same period (control group) were analyzed. Body compositions were measured by dual-energy X-ray absorptiometry, and the relative appendicular skeletal muscle index (RASMI) was calculated. Muscular strength was evaluated using hydraulic hand dynamometer. Walking speed within 6 m was measured for muscular function assessment. Single-photon emission computed tomography was performed to measure the glomerular filtration rate of CKD patients, who were then divided into CKD1 (55 patients in CKD stages 1 and 2) and CKD2 (68 patients in CKD stages 3-5). RASMI showed a downward trend with CKD progression (P = 0.001). Multivariate logistic regression analysis showed that age and CKD progression were independent risk factors for sarcopenia. The morbidity of sarcopenia was significantly greater in CKD patients than in healthy volunteers, and the degree of muscle loss was closely related to CKD progression.

Association between metabolic syndrome and incident chronic kidney disease among Chinese: A nation-wide cohort study and updated meta-analysis

AIMS

We prospectively examined the relationship between metabolic syndrome (MetS) and incident chronic kidney disease (CKD) among middle-aged and elderly Chinese, and conducted a systematic review and meta-analysis of all cohort studies on this topic.

MATERIALS AND METHODS

Our research data were derived from the China Health and Retirement Longitudinal Study. Participants (n=5752, age ≥45 years) without CKD (defined as estimated glomerular filtration rate <60 ml/min/1.73m² ) at baseline were followed up for 4 years. We applied logistic regressions to examine the association of MetS with incident CKD. In addition, we pooled our effect estimates and those from previous cohort studies in the meta-analysis.

RESULTS

In a 4-years follow-up, 61 (4.27%) developed CKD in participants with MetS versus 102 (2.36%) in participants without MetS. After adjustment for potential confounders, odds ratio for incident CKD was 1.82 [95% confidence interval (95% CI): 1.19-2.78] comparing participants with MetS with those without MetS. There was a linear positive association between the number of MetS components and incident CKD (p for trend <0.001). In the updated meta-analysis of 25 studies among 350,655 participants with 29,368 incident cases of CKD, the pooled relative risk of developing CKD in participants with MetS was 1.34 (95% CI: 1.28-1.39), compared with those without MetS.

CONCLUSIONS

Individuals with MetS had higher risk of incident CKD in middle-aged and elderly Chinese adults, which was supported by a comprehensive review of cohort studies from multiple populations. It may be advisable to routinely monitor renal functions among individuals with MetS.

The Association between Anthropometric Indices of Obesity and Chronic Kidney Disease in Middle-aged Japanese Men and Women: A Cohort Study

Objective This study investigated associations between three indices of obesity-the body mass index (BMI), waist circumference (WC), and waist-to-height ratio (WHtR)-and the incidence of chronic kidney disease (CKD). Methods The employees of a company in Japan (1,725 men, 1,186 women; aged 35-55 years) had BMI, WC, and WHtR measured in health examinations. The incidence of CKD was determined at annual medical examinations over a six-year period. The hazard ratios for CKD were calculated using proportional hazard models, and the χ² statistic was used to compare the strengths of the associations. Results The mean BMI (kg/m²), WC (cm), and WHtR were 23.6, 84.3, and 0.49 for men and 22.3, 79.7, and 0.50 for women, respectively. The incidence of CKD (/1,000 person-years) was 18.1 for men and 8.4 for women. In men, positive linear associations were observed between the BMI, WC, and WHtR and the risk of CKD, even after adjusting for the presence of metabolic abnormalities (p for trend <0.001, 0.012, and 0.023, respectively). In women, a linear association was observed only between the WHtR and CKD, not the BMI or WC (p for trend =0.042, 0.057, and 0.186). The χ² statistics were the highest for the BMI in both men and women. Conclusion The BMI, WC, and WHtR were linearly associated with the risk of CKD independently of metabolic abnormalities in men, while the associations were weaker or not significant in women. The BMI was the most strongly associated with the incidence of CKD in both men and women.

Sodium Pentaborate Pentahydrate ameliorates lipid accumulation and pathological damage caused by high fat diet induced obesity in BALB/c mice

BACKGROUND

Obesity is one of the most popular topic in the field of research. In order to defeat this highly widespread disease, the mechanism of fat accumulation at the molecular level and its elimination are crucial. The use of boron has been showing promising results during the recent years.

METHODS

In this study, anti-obesity potential of Sodium Pentaborate Pentahydrate (SPP) used as a dietary supplement on BALB/c mice fed with a high-fat diet was evaluated. Mice were divided into four groups with different diets, consisting of a normal diet, a high-fat diet (HFD) (containing 60 % fat), a HFD-supplemented with 0.5 mg/g body weight (BW) of SPP and a HFD-supplemented with 1.5 mg/g body weight (BW) of SPP. The animals were then observed for 10 weeks and physically monitored, and were sacrificed at the end of the experiment for physical and physicochemical evaluation.

RESULTS

According to the physical parameters measured -body weight, food and water intake ratios-, the results indicate that SPP decreased weight gain in a dose dependent manner. Measurement of the hormone levels in the blood and fat accumulation in organs of mice also supported the anti-obesity effects of SPP. Expressions of adipogenesis related genes were also negatively regulated by SPP administration in white adipose tissue (WAT) tissue.

CONCLUSION

These findings promise a treatment approach and drug development that can be used against obesity when SPP is used in the right doses. As a future aspect, clinical studies with SPP will reveal the effect of boron derivatives on obesity.

Metabolic abnormalities, but not obesity per se, associated with chronic kidney disease in a Taiwanese population

BACKGROUND AND AIMS

It is inconclusive whether obesity itself or metabolic abnormalities are linked to chronic kidney disease (CKD). The aim of this study was to examine the association between different subtypes of obesity and metabolic abnormalities with CKD in adults.

METHODS AND RESULTS

This study enrolled 14,983 eligible subjects stratified into metabolically healthy normal weight (MHNW), metabolically healthy overweight (MHOW), metabolically healthy obesity (MHO), metabolically unhealthy normal weight (MUNW), metabolically unhealthy overweight (MUOW), and metabolically unhealthy obesity (MUO) according to body mass index and metabolic syndrome status (ATP-III criteria). The metabolic healthy phenotype was defined as the absence of both metabolic syndrome and any known diabetes, coronary artery disease, stroke, hypertension or dyslipidemia. Early and advanced CKD were defined as eGFR<60, proteinuria, or structural abnormalities as detected by renal sonography. The prevalence of CKD was 2.5, 3.0, 4.0, 10.6, 9.5, and 10.5% in subjects with MHNW, MHOW, MHO, MUNW, MUOW, and MUO, respectively. In the multivariate analysis, the MUNW (OR:2.22, P < 0.001), MUOW (OR:2.22, P < 0.001), and MUO (OR:2.45, P < 0.001) groups were associated with early CKD. For advanced CKD, the OR was 2.56 (P < 0.001), 2.31 (P < 0.001), and 3.49 (P < 0.001) in the MUNW, MUOW, and MUO groups, respectively. The associated risks of early and advanced CKD were not significant in the MHOW and MHO group. MUOW and MUO were associated with higher risk of CKD compared with MHOW and MHO after adjusting other variables.

CONCLUSIONS

Metabolic abnormalities, but neither overweight nor obesity, were associated with a higher risk of CKD in adults.

Combined Associations of Body Mass Index and Metabolic Health Status on Medical and Dental Care Days and Costs in Japanese Male Employees: A 4-Year Follow-Up Study

BACKGROUND

The combined associations of body mass index (BMI) levels and metabolic dysfunction with medical and dental care utilizations is unclear.

METHODS

A 4-year follow-up study was performed in 16,386 Japanese male employees (mean age 48.2 [standard deviation, 11.0] years) without a history of cardiovascular disease (CVD), cancer, or renal failure. They were classified into eight phenotypes based on four BMI levels (underweight, <18.5; normal weight, 18.5-24.9; overweight, 25.0-29.9; and obese, ≥30.0 kg/m²) and the presence or absence of ≥2 of 4 metabolic abnormalities: high blood pressure, high triglycerides, low high-density-lipoprotein cholesterol, and high blood sugar. Based on their health insurance claims data, we compared medical and dental care days and costs among the eight different BMI/metabolic phenotypes during 2010-2013.

RESULTS

The combinations of BMI levels and metabolic status were significantly associated with the adjusted mean and median medical outpatient days and costs and the median dental outpatient days and costs. The obese/unhealthy subjects had the highest medical outpatient days and costs, and the underweight/unhealthy subjects had the highest dental outpatient days and costs. The underweight/unhealthy subjects also had the highest medical inpatient days and hospitalization rates of CVD, and had higher medical costs compared with the obese/healthy subjects. The differences in median medical costs between healthy and unhealthy phenotypes were larger year by year across all BMI levels.

CONCLUSIONS

Identification of obesity phenotypes using both BMI levels (including the underweight level) and metabolic status may more precisely predict healthcare days and costs compared with either BMI or metabolic status alone.

Metabolic syndrome and its components are related to a higher risk for albuminuria and proteinuria: Evidence from a meta-analysis on 10,603,067 subjects from 57 studies

BACKGROUND & AIM

Previous studies have explored the relation of metabolic syndrome (MetS), its components and the risk of albuminuria/proteinuria but their results are inconsistent. Then, we aimed to conduct a meta-analysis in order to resolve these controversies.

METHOD

PubMed and Scopus were systematically searched from their inception to 1 march 2018. Risk estimates and their 95% confidence intervals were extracted and pooled using the random-effects approach.

RESULT

A total of 57 studies, 44 studies on albuminuria and 13 studies on proteinuria, with a total sample size of 10,603,067 participants, were included in this meta-analysis. Overall, MetS was contributed to higher risks of proteinuria (OR = 2.08, 95%CI = 1.85-2.34) and albuminuria (OR = 1.92, 95%CI = 1.71-2.15), independent of diabetes status; although, this relationship was more noticeable in studies that used the WHO definition of MetS and in non-East Asian populations. Also, the relationship between MetS and proteinuria was sex independent, while, for albuminuria was significant only in men. MetS components such as obesity, impaired fasting glucose, elevated blood pressure and hypertriglyceridemia were associated with significant increases in proteinuria and albuminuria risk, while lower HDL-Cholesterol was only linked to greater risk of proteinuria. Moreover, the total impact of MetS on proteinuria was more remarkable than each component of the syndrome and an escalating dose-response association was found between the number of MetS components and albuminuria risk.

CONCLUSION

MetS and its components are potential risk factors for albuminuria and proteinuria.

Adipokines demonstrate the interacting influence of central obesity with other cardiometabolic risk factors of metabolic syndrome in Hong Kong Chinese adults

OBJECTIVE

Metabolic syndrome (MetS) or prediabetes is a complex disorder that is defined by a clustering of cardiometabolic risk factors, including obesity, hypertriglyceridemia, reduced high-density lipoprotein (HDL) cholesterol, hypertension, and insulin resistance. Among cardiometabolic risk factors, central obesity plays a key role in the development of MetS through alterations in the secretion of adipokines and interacts with other MetS risk factors to unfavorably influence overall cardiometabolic risk. Obesity has grasped epidemic proportions in Asia, which has the highest number of people with diabetes in the world. But, the importance of central obesity in the clustering of all four MetS risk factors or vice versa in predicting severity of MetS has not yet been investigated in Asian population. Therefore, the present study examined the influence of central obesity on circulating levels of adipokines through its interaction with the clustering of cardiometabolic risk factors of MetS including hyperglycemia, hypertriglyceridemia, dyslipidemia and hypertension in Hong Kong Chinese adults.

SUBJECTS

Blood samples from 83 Hong Kong Chinese adults, who were previously screened for MetS according to the guideline of the United States National Cholesterol Education Program Expert Panel Adult Treatment Panel III criteria were selected. Insulin and adipokines, including visfatin, chemerin, plasminogen activator inhibitor-1 (PAI-1), resistin, C-C motif chemokine ligand 2 (CCL-2), interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-10 (IL-10), tumour necrosis factor-α (TNF-α), leptin and adiponectin were assessed.

RESULTS

The interacting effect of central obesity with all of the other four MetS risk factors increased the proinflammatory status of adipokines (TNF-α, leptin) and decreased the anti-inflammatory status of adipokine (adiponectin).

CONCLUSION

Our results indicate that the inflammatory status of MetS may be more severe in the presence of central obesity. Adipokines, as biomarkers for pathophysiological changes, may help to improve early patient identification and to predict MetS-associated morbidity and mortality.

Metabolic syndrome and its components are associated with increased chronic kidney disease risk: Evidence from a meta-analysis on 11 109 003 participants from 66 studies

BACKGROUND & AIMS

Observational studies examining the relationship between metabolic syndrome and the risk of chronic kidney disease (CKD) have reported inconclusive results. This meta-analysis was performed to resolve these controversies.

METHODS

The MEDLINE, EMBASE, and PubMed databases were systematically searched from their inception until March 2016 to identify all relevant studies. Risk estimates and their corresponding 95% confidence intervals (CIs) for the associations of MetS and its components with CKD risk were extracted and pooled using a random-effects model.

RESULTS

A total of 66 studies, including 18 prospective cohorts and 48 cross-sectional studies, with 699 065 CKD patients and 11 109 003 participants were included in the meta-analysis. When all definitions were pooled, the presence of MetS was associated with a significant 50% increase of CKD risk (OR = 1.50, 95% CI = 1.43-1.56), with evidence of moderate heterogeneity (I2  = 72.3%, P < .001). The risk of CKD associated with MetS was higher in studies using the American Heart Association/National Heart, Lung, and Blood Institute criteria (OR = 1.68, 95% CI = 1.25-2.10) compared with those using the Adult Treatment Panel III (OR = 1.49, 95% CI = 1.42-1.56) and the International Diabetes Federation (OR = 1.32, 95% CI = 1.22-1.41) definitions. This relationship was independent of diabetes status. Moreover, all individual components of the MetS were significantly associated with CKD, and their coexistence resulted in an escalating dose-response relationship. The sensitivity and subgroup analyses established the stability of the findings.

CONCLUSIONS

This meta-analysis strongly suggests that the metabolic syndrome and its components are independently associated with the increased risk of CKD.

Combined effect of body mass index and metabolic status on the risk of prevalent and incident chronic kidney disease: a systematic review and meta-analysis

OBJECTIVE

The risk of chronic kidney disease (CKD) differs in the normal weight, overweight, and obese individuals owing to metabolic abnormality. We aimed to determine the combined effects of body mass index (BMI) and metabolic status on the risk of the prevalence and incidence of CKD.

METHODS

Pubmed, Scopus, Web of science, and abstracts from recently relevant meetings prior to April 2016 were searched to identify eligible studies. Pooled relative risks (RR) and 95% confidence intervals (CI) were calculated using a random effects model.

RESULTS

Eight cross-sectional studies and four longitudinal follow-up studies with a total of 14787 and 166718 participants were separately included in present study. Compared with metabolically healthy normal weight individuals, metabolically healthy obese individuals showed increased risk for CKD, with RR of 1.235 (95%CI: 1.027 to 1.484), while metabolically health overweight individuals still presented in a healthy pattern, RR=1.094(95%CI: 0.774 to 1.547). In addition, metabolically abnormal groups had much higher risk for CKD, with RR of 1.572 (95%CI: 1.373 to 1.801), 1.652(95%CI: 1.139 to 2.397) and 1.898(95%CI: 1.505 to 2.395) across metabolically unhealthy normal weight, overweight and obese individuals respectively.

CONCLUSION

Individuals with abnormal metabolic status are at a significantly elevated risk for CKD, regardless of BMI. For metabolically healthy individuals, CKD risk increases with the growth of BMI, and obese persons eventually have a higher risk.

Validity of a Risk Prediction Equation for CKD After 10 Years of Follow-up in a Japanese Population: The Ibaraki Prefectural Health Study

BACKGROUND

Chronic kidney disease (CKD) is an important health problem for which risk equations have been developed for Western populations. This study aimed to develop and validate a risk prediction equation for CKD in a Japanese population.

STUDY DESIGN

Observational cohort study.

SETTING & PARTICIPANTS

The study included 135,007 participants who completed an annual health checkup in 1993 to 1996 in the Ibaraki Prefecture in Japan. Participants were initially free of CKD (defined as stage 3, 4, or 5 CKD or proteinuria [2+ or 3+] by dipstick). Follow-up information was available from health checkups 10 years after the initial evaluation. We used data from 40,963 women and 17,892 men in the northern region of the prefecture for the development of risk prediction equations and 53,042 women and 23,110 men in the southern region for external validation.

PREDICTORS

Age, estimated glomerular filtration rate (eGFR), body mass index, proteinuria, hematuria, hypertension, diabetes mellitus, smoking, and drinking.

OUTCOME

Occurrence of CKD (defined as eGFR<60mL/min/1.73m² and/or proteinuria [2+ or 3+] by dipstick).

ANALYTICAL APPROACH

Logistic regression analysis to estimate risk for CKD stratified by sex.

RESULTS

During follow-up, 7,500 cases of CKD developed in the northern region and 8,964, in the southern region. Older age, proteinuria (1+), higher systolic blood pressure, medication for hypertension, and current smoking were associated with increased risk for CKD in both sexes, whereas higher eGFR and daily alcohol intake were associated with lower risk. C statistics of risk estimation equations for CKD at 10 years were >0.8 for both the development and external validation populations, and discrimination of the risk estimation was fairly good in women and men.

LIMITATIONS

Fluctuations in variables were not evaluated because the study used annual health checkups. This study excluded a large number of people for whom a 10-year health checkup was not available.

CONCLUSIONS

Estimations of risk for CKD after 10 years of follow-up in a general Japanese population can be achieved with a high level of validity.

Association between Sarcopenia and Dipstick Proteinuria in the Elderly Population: The Korea National Health and Nutrition Examination Surveys 2009-2011

Background

Sarcopenia and proteinuria are significant health difficulties in the elderly; however, few studies have investigated their relationship. In this study, we investigated the association between sarcopenia and proteinuria in Korean subjects over 60 years old.

Methods

We included data from the Korean National Health and Nutrition Examination Survey, a cross-sectional, nationally representative survey conducted from 2009 to 2011 (n=4,008). Sarcopenia was defined using appendicular skeletal muscle mass as a percentage of body weight. Proteinuria was defined by a urine dipstick test result above trace levels.

Results

The overall proteinuria prevalence was 7.2%. The incidence of sarcopenia was significantly higher in subjects with proteinuria. The prevalence of proteinuria was significantly higher in the sarcopenic group (5.5% vs. 14.5% in the non-chronic kidney disease (CKD) group; 17.2% vs. 23.2% in the CKD group) than in the non-sarcopenic group. Furthermore, sarcopenic participants had worse metabolic parameters, such as higher body mass indexes, waist circumferences, and fasting glucose levels, and lower high-density lipoprotein cholesterol levels than those in the non-CKD group. After adjustment for confounders, the odds ratios (95% confidence interval) for proteinuria were 2.84 (1.92–4.18) in the sarcopenic non-CKD group, 3.70 (2.59–5.30) in the non-sarcopenic CKD group, and 5.19 (2.64–10.18) in the sarcopenic CKD group, compared to the non-sarcopenic, non-CKD group. Sarcopenia increased the proteinuria risk in elderly participants without CKD, even after adjustment for obesity, hypertension, diabetes, and metabolic syndrome.

Conclusion

These findings showed that sarcopenia was associated with dipstick proteinuria, especially in elderly participants without CKD, regardless of comorbidities.

Prevention of renal apoB retention is protective against diabetic nephropathy: role of TGF-β inhibition

Animal studies demonstrate that hyperlipidemia and renal lipid accumulation contribute to the pathogenesis of diabetic nephropathy (DN). We previously demonstrated that renal lipoproteins colocalize with biglycan, a renal proteoglycan. The purpose of this study was to determine whether prevention of renal lipid (apoB) accumulation attenuates DN. Biglycan-deficient and biglycan wild-type Ldlr^-/- mice were made diabetic via streptozotocin and fed a high cholesterol diet. As biglycan deficiency is associated with elevated transforming growth factor-β (TGF-β), in some experiments mice were injected with either the TGF-β-neutralizing antibody, 1D11, or with 13C4, an irrelevant control antibody. Biglycan deficiency had no significant effect on renal apoB accumulation, but led to modest attenuation of DN with ∼30% reduction in albuminuria; however, biglycan deficiency caused a striking elevation in TGF-β. Use of 1D11 led to sustained suppression of TGF-β for approximately 8 weeks at a time. The 1D11 treatment caused decreased renal apoB accumulation, decreased albuminuria, decreased renal hypertrophy, and improved survival, compared with the 13C4 treatment. Thus, prevention of renal apoB accumulation is protective against development of DN. Furthermore, this study demonstrates that prevention of renal apoB accumulation is a mechanism by which TGF-β inhibition is nephroprotective.

A systematic review and meta-analysis suggests obesity predicts onset of chronic kidney disease in the general population

Obesity and chronic kidney disease (CKD) are public health priorities that share core pathophysiological mechanisms. However, whether high body mass index (BMI) increases risk of CKD de novo remains ill-defined. To evaluate the role of BMI in predicting CKD onset in the general adult population, we performed a systematic review and meta-analysis of PubMed and ISI Web of Science databases articles published between January 2000 and August 2016 without language restriction. We selected studies in adult individuals from a general population with normal renal function at baseline that reported the risk of low estimated glomerular filtration (eGFR) (under 60 mL/min/1.73m²) and/or albuminuria (1+ at dipstick or an albumin creatinine ratio of 3.4 mg/mmol or more) as hazard ratio, odds ratio or relative risk related to obesity, overweight, or BMI as continuous value. A total of 39 cohorts covering 630, 677 participants with a mean follow-up of 6.8 years were selected. Obesity increased the relative risk, 95% confidence interval and heterogeneity (I²) of developing low eGFR (1.28, 1.07-1.54, [I²: 95.0%]) and albuminuria (1.51, 1.36-1.67, [I²: 62.7%]). Increase of BMI unit was also associated with higher risk of low eGFR (1.02, 1.01-1.03, [I²: 24.3%]) and albuminuria (1.02, 1.00-1.04, [I²: 0%]). Conversely, overweight did not predict onset of either low eGFR (1.06, 0.94-1.21, [I²: 50.0%]) or albuminuria (1.24, 0.98-1.58, [I²: 49.4%]). Thus, a high BMI predicts onset of albuminuria without kidney failure (CKD stages 1-2) as well as CKD stages 3 and higher, the effect being significant only in obese individuals. Hence, our findings may have implications to improve risk stratification and recommendations on body weight control in the general population.

Influence of chronic kidney disease on hospitalization, chronic dialysis, and mortality in Japanese men: a longitudinal analysis

BACKGROUND

Little is known concerning the risk of hospitalization and the risk of death before receiving dialysis by the stage of chronic kidney disease (CKD) in Japan.

METHODS

The subjects comprised a total of 13,911 Japanese men (mean age 49.2 ± 9.9 years). Based on the results of a health checkup performed in 2006, they were divided into 5 groups according to their estimated glomerular filtration rate (GFR) levels and dialysis status: GFR ≥60, 45-59, 30-44, <30 mL/min/1.73 m², and undergoing dialysis. From 2006 through to 2013, we investigated their hospitalization, dialysis initiation, and cause-specific death. The adjusted hazard ratios (HRs) for each end point were calculated compared with the GFR ≥60 mL/min/1.73 m² group using a Cox proportional hazard model.

RESULTS

A lower GFR was independently associated with higher risks of overall hospitalization, dialysis initiation, and all-cause death. In particular, the HRs for long-term hospitalization (≥1 month a year), dialysis, and cardiovascular disease (CVD) death markedly increased along with a decreased GFR. The rate ratios of dialysis to all-cause death (calculated based on the incidences of dialysis and death per 1000 person-years) were 0.03 (0.11 vs. 3.19), 0.08 (0.29 vs. 3.62), 0.51 (12.5 vs. 24.7), and 4.50 (179.8 vs. 40.0) for GFR ≥60, 45-59, 30-44, and <30 mL/min/1.73 m², respectively.

CONCLUSION

In Japanese men, although the risk of CVD death before dialysis initiation can never be ignored, CKD patients aged <60 years with a GFR of <30 mL/min/1.73 m² are more likely to undergo dialysis prior to death.

Sex Differences in Associations Among Obesity, Metabolic Abnormalities, and Chronic Kidney Disease in Japanese Men and Women

Aims

The present study aimed to investigate relationships among abdominal obesity, metabolic abnormalities, and the prevalence of chronic kidney disease (CKD) in relatively lean Japanese men and women.

Participants and methods

The participants included 8133 men and 15 934 women between 40 and 75 years of age recruited from the government health check-up center in Kanazawa City, Japan. The prevalence of abdominal obesity, high blood pressure, dyslipidemia, and high fasting plasma glucose levels were assessed according to the Japanese criteria for metabolic syndrome. The estimated glomerular filtration rate (eGFR) was calculated using the modified Modification of Diet in Renal Disease equation for the Japanese population, and participants with an eGFR <60 mL/min/1.73 m² and/or proteinuria were diagnosed with CKD.

Results

Overall, 23% of males and 14% of females met criteria for CKD. Having more numerous complicated metabolic abnormalities was significantly associated with a higher odds ratio (OR) of CKD for men and women, irrespective of abdominal obesity. However, there was a sex difference in the OR of CKD for obese participants without metabolic abnormalities, such that abdominal obesity without metabolic abnormalities was significantly associated with a higher OR for men (multivariate-adjusted OR 1.63; 95% confidence interval [CI], 1.16–2.28) but not for women (OR 1.01; 95% CI, 0.71–1.44).

Conclusions

The present findings demonstrated that obesity without metabolic abnormalities was associated with a higher risk of CKD in men but not women in a relatively lean Japanese population.