Metabolic Syndrome and Risk of Developing Chronic Kidney Disease in Japanese Adults

Metabolic syndrome as a risk factor for the development of kidney dysfunction: a meta-analysis of observational cohort studies

Background

Chronic kidney disease (CKD) is a major global health concern with increasing prevalence and associated complications. Metabolic syndrome (MetS) has been linked to CKD, but the evidence remains inconsistent. We conducted a systematic review and meta-analysis to investigate the association between MetS and kidney dysfunction.

Method

We conducted a comprehensive search of databases until December 2022 for cohort studies assessing the association between MetS and incident kidney dysfunction. Meta-analysis was performed using fixed and random effects models. Subgroup analyses were conducted to explore heterogeneity. Publication bias was assessed using Egger's and Begg's tests.

Result

A total of 24 eligible studies, involving 6,573,911 participants, were included in this meta-analysis. MetS was significantly associated with an increased risk of developing CKD (OR, 1.42; 95% CI, 1.28, 1.57), albuminuria or proteinuria (OR, 1.43; 95% CI, 1.10, 1.86), and rapid decline in kidney function (OR, 1.25; 95% CI, 1.07, 1.47). Subgroup analyses showed a stronger association as the number of MetS components increased. However, gender-specific subgroups demonstrated varying associations.

Conclusion

Metabolic syndrome is a significant risk factor for kidney dysfunction, requiring close renal monitoring. Lifestyle changes and targeted interventions may help reduce CKD burden. Further research is needed to understand the connection fully and assess intervention efficacy.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-023-01348-5.

Analyzing Longitudinal Health Screening Data with Feature Ensemble and Machine Learning Techniques: Investigating Diagnostic Risk Factors of Metabolic Syndrome for Chronic Kidney Disease Stages 3a to 3b

Longitudinal data, while often limited, contain valuable insights into features impacting clinical outcomes. To predict the progression of chronic kidney disease (CKD) in patients with metabolic syndrome, particularly those transitioning from stage 3a to 3b, where data are scarce, utilizing feature ensemble techniques can be advantageous. It can effectively identify crucial risk factors, influencing CKD progression, thereby enhancing model performance. Machine learning (ML) methods have gained popularity due to their ability to perform feature selection and handle complex feature interactions more effectively than traditional approaches. However, different ML methods yield varying feature importance information. This study proposes a multiphase hybrid risk factor evaluation scheme to consider the diverse feature information generated by ML methods. The scheme incorporates variable ensemble rules (VERs) to combine feature importance information, thereby aiding in the identification of important features influencing CKD progression and supporting clinical decision making. In the proposed scheme, we employ six ML models-Lasso, RF, MARS, LightGBM, XGBoost, and CatBoost-each renowned for its distinct feature selection mechanisms and widespread usage in clinical studies. By implementing our proposed scheme, thirteen features affecting CKD progression are identified, and a promising AUC score of 0.883 can be achieved when constructing a model with them.

New-onset metabolic syndrome is associated with accelerated renal function decline partially through elevated uric acid: an epidemiological cohort study

Background

The burden of metabolic syndrome (MetS) continues to rise globally and is associated with complications of multiple organ systems. We aimed to identify the association between changes in MetS status and accelerated renal function progression through a regional epidemiological survey in China, thus discovering influence factors with treatable potential.

Methods

This study was a population-based survey conducted in 2008 and 2014, assessing a representative sample of 5,225 individuals from rural areas of China. They were divided into four subgroups according to their MetS status in 2008 and 2014 (Never, Previously abnormal, New-onset, and Consistent). Multivariate logistic regression and stratification analysis evaluated the relationship between clinical factors and renal function decline under different MetS statuses. Smooth curve fitting further addressed the role of serum uric acid, illustrating the vital turning point of uric acid levels in the background of renal function deterioration.

Results

Of all groups of MetS states, the new-onset MetS showed the most significant eGFR decline, with a 6.66 ± 8.21 mL/min/1.73 m2 decrease over 6 years. The population with newly-onset MetS showed a considerable risk increase in delta eGFR with a beta coefficient of 1.66 (95%CI=1.09-2.23) after necessary correction. In searching for the drivers, the strength of the association was significantly reduced after additional adjustment for uric acid levels (β=0.91, 95%CI=0.35-1.45). Regarding the turning point, uric acid levels exceeding 426 μmol/L were more significantly associated with the stepped-up deterioration of kidney function for those with new-onset MetS.

Conclusion

Metabolic syndrome demonstrated a solid correlation with the progression of renal function, particularly in those with newly-onset MetS status. In addition to the diagnostic components of MetS, hyperuricemia could be used as a marker to identify the high risk of accelerating eGFR decline early. Furthermore, we suggested a potential renal benefit for the newly-onset MetS population when maintaining their serum uric acid level below the criteria for asymptomatic hyperuricemia.

Analysis of the association between glomerular filtration rate, proteinuria and metabolic syndrome in chronic kidney patients based on longitudinal data

Chronic kidney disease (CKD) is a group of chronic diseases caused by kidney damage from multiple causes. Metabolic syndrome (MS) manifests as dysfunction of endothelial cells and chronic functional inflammatory states, and may be involved in pathological changes related to renal impairment. Based on longitudinal data analysis of the association between estimated glomerular filtration rate (eGFR), proteinuria and MS in patients with CKD, this study aims to provide new ideas for the pathophysiological mechanism of CKD and a theoretical basis for the early prevention and effective intervention of MS-related kidney damage. A total of 126 patients with CKD were divided into non-MS group and MS group. According to the eGFR level, 126 patients with CKD were divided into G1 group, G2 group, G3a group, G3b group, G4 group and G5 group. Serum markers such as eGFR, urine protein, and triglycerides (TG) were collected. The correlation between eGFR, urine protein and MS-related indexes was analysed, and the risk factors affecting CKD complicated by MS were analysed. In patients with CKD, the levels of urine protein, abdominal circumference, TG, systolic blood pressure (SBP), diastolic blood pressure (DBP), and fasting blood glucose (FPG) were increased with the course of the disease, but the levels of eGFR and high density lipoprotein (HDL-C) were decreased (p < 0.05). Abdominal circumference, TG, SBP, DBP, FP were significantly negatively correlated with eGFR, but HDL-C was positively correlated with eGFR (p < 0.05). Diabetes, hyperlipidemia, UA, and SBP were independent risk factors affecting CKD complicated MS, and eGFR were independent protective factors (p < 0.05). The combination of diabetes, hyperlipidemia, UA, SBP, and eGFR exhibited higher prediction value for the CKD patients complicated by MS. There was a certain correlation between between MS components with eGFR and urinary protein in patients with CKD. The early intervention treatment of MS was helpful in delaying the development of CKD and reducing proteinuria.

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.

A Hybrid Risk Factor Evaluation Scheme for Metabolic Syndrome and Stage 3 Chronic Kidney Disease Based on Multiple Machine Learning Techniques

With the rapid development of medicine and technology, machine learning (ML) techniques are extensively applied to medical informatics and the suboptimal health field to identify critical predictor variables and risk factors. Metabolic syndrome (MetS) and chronic kidney disease (CKD) are important risk factors for many comorbidities and complications. Existing studies that utilize different statistical or ML algorithms to perform CKD data analysis mostly analyze the early-stage subjects directly, but few studies have discussed the predictive models and important risk factors for the stage-III CKD high-risk health screening population. The middle stages 3a and 3b of CKD indicate moderate renal failure. This study aims to construct an effective hybrid important risk factor evaluation scheme for subjects with MetS and CKD stages III based on ML predictive models. The six well-known ML techniques, namely random forest (RF), logistic regression (LGR), multivariate adaptive regression splines (MARS), extreme gradient boosting (XGBoost), gradient boosting with categorical features support (CatBoost), and a light gradient boosting machine (LightGBM), were used in the proposed scheme. The data were sourced from the Taiwan health examination indicators and the questionnaire responses of 71,108 members between 2005 and 2017. In total, 375 stage 3a CKD and 50 CKD stage 3b CKD patients were enrolled, and 33 different variables were used to evaluate potential risk factors. Based on the results, the top five important variables, namely BUN, SBP, Right Intraocular Pressure (R-IOP), RBCs, and T-Cho/HDL-C (C/H), were identified as significant variables for evaluating the subjects with MetS and CKD stage 3a or 3b.

Nutrition and quality of life in chronic kidney disease patients: a practical approach for salt restriction

The clinical practice guidelines (CPGs) for nutrition in chronic kidney disease (CKD) were updated after 20 years from the previous guidelines by the Kidney Disease Outcomes Quality Initiative (KDOQI). During this period, the severity of CKD was defined by eGFR and albuminuria by the organization Kidney Disease: Improving Global Outcomes (KDIGO). Main risk factors for CKD such as hypertension, hyperlipidemia, obesity, metabolic syndrome, and diabetes mellitus are closely related to lifestyle. Nutritional management is important to prevent and retard the progression of CKD. Members of the International Society of Renal Nutrition and Metabolism (ISRNM) reviewed the KDOQI CPG draft. ISRNM is an international scientific society comprising members of multiple subspecialties. ISRNM proposed the medical term protein-energy wasting (PEW), which is a keyword in renal nutrition. The prevalence of PEW among dialysis patients is high. The success of dietary therapy depends on adherence to the diet. It has to be palatable, otherwise eating habits will not change. To prevent the development and progression of CKD and PEW, regular consultation with an expert dietitian is required, especially regarding salt and protein restriction. Our cluster-randomized trial showed that intervention by a dietician was effective at retarding the progression of stage 3 CKD. In this review, I focus on salt (sodium) restriction and introduce tips for salt restriction and Japanese kidney-friendly recipes. Due to the lack of randomized controlled trials, nutritional management of CKD inevitably relies on expert opinion. In this regard, well-designed observational studies are needed. Too strict salt restriction may decrease quality of life and result in PEW.

Association of metabolic syndrome traits with urinary biomarkers in Japanese adults

BACKGROUND

Although metabolic syndrome traits are risk factors for chronic kidney disease, few studies have examined their association with urinary biomarkers.

METHODS

Urinary biomarkers, including A-megalin, C-megalin, podocalyxin, albumin, α₁-microglobulin, β₂-microglobulin, and N-acetyl-β-D-glucosaminidase, were cross-sectionally assessed in 347 individuals (52.7% men) with a urine albumin-to-creatinine ratio (ACR)  < 300 mg/g in a health checkup. Metabolic syndrome traits were adopted from the National Cholesterol Education Program (third revision) of the Adult Treatment Panel criteria modified for Asians.

RESULTS

Participants had a mean body mass index, estimated glomerular filtration rate (eGFR), and median ACR of 23.0 kg/m², 74.8 mL/min/1.73 m², and 7.5 mg/g, respectively. In age- and sex-adjusted logistic regression analysis, A-megalin and albumin were significantly associated with the clustering number of metabolic syndrome traits (3 or more). After further adjustment with eGFR, higher quartiles of A-megalin and albumin were each independently associated with the clustering number of metabolic syndrome traits (adjusted odds ratio for A-megalin: 1.30 per quartile, 95% CI 1.03-1.64; albumin: 1.42 per quartile, 95% CI 1.12-1.79).

CONCLUSIONS

Both urinary A-megalin and albumin are associated with the clustering number of metabolic syndrome traits. Further research on urinary A-megalin is warranted to examine its role as a potential marker of kidney damage from metabolic risk factors.

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.

Prediabetes is associated with proteinuria development but not with glomerular filtration rate decline: A longitudinal observational study

AIMS

Diabetes is recognized as the leading cause of chronic kidney disease (CKD); however, the association of prediabetes with CKD remains unclear, in particular, the independent effect of prediabetes on proteinuria or estimated glomerular filtration rate (eGFR) has not been evaluated. This study aimed to investigate the associations of prediabetes with the proteinuria development and with eGFR decline separately in the Japanese general population without CKD.

METHODS

Participants who underwent health check-ups in 2014 and had adequate data after 2 years were retrospectively analysed. A total of 405,487 participants without CKD (eGFR, ≥60 ml min^-1  1.73 m^-2 , with negative or trace urinary protein) at baseline were categorized according to fasting plasma glucose as having diabetes (≥126 mg/dl [7.0 mmol/l]), prediabetes (100-125 mg/dl [5.6-6.9 mmol/l]) or normal glucose level (˂100 mg/dl [5.6 mmol/l]). Logistic regression analysis was used to analyse the effects of prediabetes (vs. normal glucose level) on the proteinuria development (urinary protein of ≥1+) and eGFR decline (˂60 ml min^-1  1.73 m^-2 ) after 2 years.

RESULTS

After 2 years, 7037 participants (1.7%) developed proteinuria alone, 19,015 (4.7%) presented eGFR decline alone and 636 (0.2%) showed both proteinuria and eGFR decline. Compared to normal glucose level and adjusting for prognostic factors, prediabetes was independently associated with the proteinuria development (odds ratio [OR] 1.233; 95% confidence interval [CI] 1.170-1.301], whereas prediabetes was not associated with eGFR decline (OR 0.981; 95% CI 0.947-1.017).

CONCLUSIONS

Prediabetes is associated with the proteinuria development but not with eGFR decline in the general population.

Impact of the COVID-19 Pandemic on Kidney Diseases Requiring Renal Biopsy: A Single Center Observational Study

Background

The coronavirus disease-2019 (COVID-19) pandemic impacted healthcare services for kidney disease patients. Lockdown and social distancing were mandated worldwide, resulting in closure of medical services. The diagnosis of various kidney diseases may have been delayed during the COVID-19 pandemic because non-urgent tests and visits were postponed due to closure of medical services during the lockdown.

Methods

We here report the impact of the COVID-19 pandemic on a total number of 209 native kidney diseases requiring renal biopsy for diagnosis in a retrospective observational study from a tertiary hospital in Germany.

Results

The lockdown period in March and April 2020 primarily affected patients admitted to the normal medical ward with a compensatory increased rate of renal biopsies in the postlockdown phase. In addition, there was a shift toward more patients admitted with hemoglobinuria during the COVID-19 pandemic. This phenomenon of an increased number of patients with hemoglobinuria during the COVID-19 pandemic was specifically observed in a subgroup with hypertensive nephropathy requiring renal biopsy and associated with increased proteinuria, not attributed to the COVID-19 lockdown period itself.

Conclusion

To our knowledge, this is the first report of identifying a subpopulation susceptible to closure of medical services during the COVID-19 pandemic and diagnostic delay of specific kidney diseases. Therefore, the COVID-19 pandemic should be regarded as a risk factor especially in patients with diseases other than COVID-19 primarily admitted to the normal medical ward.

The determinants of complication trajectories in American Indians with type 2 diabetes

BACKGROUNDWe aimed to determine whether metabolic syndrome (MetS) affects longitudinal trajectories of diabetic complications, including neuropathy, cardiovascular autonomic neuropathy (CAN), and kidney disease in American Indians with type 2 diabetes.METHODSWe performed a prospective study where participants underwent annual metabolic phenotyping and outcome measurements. The updated National Cholesterol Education Program criteria were used to define MetS and its individual components, using BMI instead of waist circumference. Neuropathy was defined using the Michigan Neuropathy Screening Instrument index, CAN with the expiration/inspiration ratio, and kidney disease with glomerular filtration rate. Mixed-effects models were used to evaluate associations between MetS and these outcomes.RESULTSWe enrolled 141 participants: 73.1% female, a mean (±SD) age of 49.8 (12.3), and a diabetes duration of 19.6 years (9.7 years) who were followed for a mean of 3.1 years (1.7 years). MetS components were stable during follow-up except for declining obesity and cholesterol. Neuropathy (point estimate [PE]: 0.30, 95% CI: 0.24, 0.35) and kidney disease (PE: -14.2, 95% CI: -16.8, -11.4) worsened over time, but CAN did not (PE: -0.002, 95% CI: -0.006, 0.002). We found a significant interaction between the number of MetS components and time for neuropathy (PE: 0.05, 95% CI: 0.01-0.10) but not CAN (PE: -0.003, 95% CI: -0.007, 0.001) or kidney disease (PE: -0.69, 95% CI: -3.16, 1.76). Systolic blood pressure (SBP, unit = 10 mmHg) was associated with each complication: neuropathy (PE: 0.23, 95% CI: 0.07, 0.39), CAN (PE: -0.02, 95% CI: -0.03, -0.02), and kidney disease (PE: -10.2, 95% CI: -15.4, -5.1).CONCLUSIONIn participants with longstanding diabetes, neuropathy and kidney disease worsened during follow-up, despite stable to improving MetS components, suggesting that early metabolic intervention is necessary to prevent complications in such patients. Additionally, the number of MetS components was associated with an increased rate of neuropathy progression, and SBP was associated with each complication.FUNDINGThe following are funding sources: NIH T32NS0007222, NIH R24DK082841, NIH R21NS102924, NIH R01DK115687, the Intramural Program of the NIDDK, the NeuroNetwork for Emerging Therapies, the Robert and Katherine Jacobs Environmental Health Initiative, the Robert E. Nederlander Sr. Program for Alzheimer's Research, and the Sinai Medical Staff Foundation.TRIAL REGISTRATIONClinicalTrials.gov, NCT00340678.

High Circulating Follicle-Stimulating Hormone Level Is a Potential Risk Factor for Renal Dysfunction in Post-Menopausal Women

OBJECTIVE

Menopause contributes to renal dysfunction in women, which is generally attributed to estrogen withdrawal. In addition to decreased estrogen level, serum follicle-stimulating hormone (FSH) level increases after menopause. This study investigated the association between high circulating FSH level and renal function in post-menopausal women.

METHODS

This observational cross-sectional study included 624 pre-menopausal, 121 peri-menopausal, and 2540 post-menopausal women. The levels of female sex hormones were examined by chemiluminescence and indices of renal function were measured using a clinical chemistry analyzer. The post-menopausal women were grouped into quartiles according to serum FSH levels.

RESULTS

Renal function progressively declined from pre-menopause to peri-menopause to post-menopause, which was accompanied by increasing serum FSH level. In post-menopausal women, serum creatinine level increased with increasing FSH quartile, which was accompanied by a decrease in estimated glomerular filtration rate (eGFR) (p for trend <0.001); moreover, the prevalence of declined eGFR (<90 ml/min/1.73 m²) and chronic kidney disease (CKD; eGFR <60 ml/min/1.73 m²) increased (p for trend <0.001). Even after adjusting for confounders, the odds ratios (ORs) of declined eGFR and CKD increased with increasing FSH quartiles in post-menopausal women. The ORs of declined eGFR (OR=2.19, 95% confidence interval [CI]: 1.63-2.92) and CKD (OR=10.09, 95% CI: 2.28-44.65) in the highest FSH quartile were approximately 2- and 10-fold higher, respectively, than in the lowest FSH quartile (p<0.05). After stratifying post-menopausal women by median age (61 years), the OR for declined eGFR for each FSH quartile in the older group was higher than that for the corresponding FSH quartile in the younger group.

CONCLUSIONS

A high circulating FSH level is an independent risk factor for renal dysfunction in women after menopause. Additionally, aging may aggravate the association of high FSH levels with reduced renal function in post-menopausal women.

Visceral to subcutaneous fat ratio as an indicator of a ≥30% eGFR decline in chronic kidney disease

Whether the visceral-to-subcutaneous fat ratio (V/S ratio) is associated with renal prognosis in patients with chronic kidney disease (CKD) remains unclear. Furthermore, little is known about the effect of sex and the absolute amount of visceral fat accumulation such as visceral fat area (VFA) ≥100 cm² on the V/S ratio in relation to renal prognosis. In this study, 200 patients with CKD were evaluated for renal prognosis. Survival analyses and logistic regression analyses were conducted, generating time-series pseudo-R² values. The mean and percent change of the pseudo-R² values from the 6^th year to the 10^th year (6Y–10Y Mean and 6Y–10Y Change, respectively) were calculated for determining the cut-off points for the medium-term renal prognosis. Multivariate Cox regression analysis revealed that the V/S ratio was significantly associated with renal outcomes and that the VFA category (VFA ≥ 100 cm²) had significant interactions with the V/S ratio regarding renal prognosis. The hazard ratio (HR) of the V/S ratio was higher in the sub-cohort of VFA < 100 cm² than in the sub-cohort of VFA ≥ 100 cm² (HR: 6.42 vs. 1.00). Regarding sex differences, a strong association was noted between the V/S ratio and renal prognosis in women but not in men (HR: 2.40 vs. 1.10). On the other hand, 6Y–10Y Mean of the pseudo-R² values indicated differences in the cut-off points of the V/S ratio between men and women (V/S ratio: 0.75 vs. 0.5). Our findings indicate that it may be clinically meaningful to consider the differences in sex and the amount of VFA ≥100 cm² for the V/S ratio in relation to renal outcomes in patients with CKD. The 6Y–10Y Mean of the pseudo-R² values contributed to determining the cut-off points of the V/S ratio according to the sex difference.

Chronic Microvascular Complications in Prediabetic States-An Overview

A prediabetic state is a major risk factor for the development of diabetes, and, because of an identical pathophysiological background of both conditions, their prevalence increases parallelly and equally fast. Long-term hyperglycemia is the main cause inducing chronic complications of diabetes, yet the range of glucose levels at which they start has not been yet unequivocally determined. The current data show that chronic microvascular complications of diabetes can be observed in patients with abnormal glucose metabolism in whom glycaemia is higher than optimal but below diagnostic criteria for diabetes. Prediabetes is a heterogenous nosological unit in which particular types are differently characterized and show different correlations with particular kinds of complications. Analysis of the latest research results shows the need to continue studies in a larger population and can imply the need to verify the currently employed criteria of diagnosing diabetes and chronic complications of diabetes in people with prediabetes.

Ghrelin Levels and Decreased Kidney Function in Patients with Early Stages of Chronic Kidney Disease Against the Background of Obesity

The importance of kidney damage in obese patients is due to the increasing incidence of nephropathies associated with metabolic disorders, their predisposition to a progressive course of the disease, and the need to optimize early disease detection. The purpose of our work is to study the level of cystatin C, ghrelin, and their interrelation in patients with early stages (I-II) of chronic kidney disease (CKD) against the background of obesity. The indicators of daily microalbuminuria in patients of both groups were studied, and it was found that in patients with stage 2 CKD with obesity, it was 1.2 times higher than in patients with stage 1 CKD with obesity. Patients of the second group revealed a direct middle correlation between daily albuminuria and body mass index (BMI), which indicates deterioration in the functional state of the kidneys against the background of obesity. We obtained an increase in the serum concentration of cystatin C in stage 2 CKD with obesity, reflecting the state of glomerular filtration and the degree of renal function decrease. Correlation analysis showed a positive relation of cystatin C with increased urinary albumin excretion in both groups, plasma creatinine content, BMI, and age. Simultaneously with the increase in the level of cystatin C and the decrease in the glomerular filtration rate, there was an increase in ghrelin levels in stage 2 CKD and the progression of obesity, while such dependence was not seen in stage 1 CKD.

Impaired fasting glucose and development of chronic kidney disease in non-diabetic population: a Mendelian randomization study

INTRODUCTION

Diabetes mellitus is a risk factor of chronic kidney disease (CKD); however, the relationship between fasting glucose and CKD remains controversial in non-diabetic population. This study aimed to assess causal relationship between genetically predicted fasting glucose and incident CKD.

RESEARCH DESIGN AND METHODS

This study included 5909 participants without diabetes and CKD from the Korean Genome Epidemiology Study. The genetic risk score (GRS₉) was calculated using nine genetic variants associated with fasting glucose in previous genome-wide association studies. Incident CKD was defined as estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m² and/or proteinuria (≥1+). The causal relationship between fasting glucose and CKD was evaluated using the Mendelian randomization (MR) approach.

RESULTS

The GRS₉ was strongly associated with fasting glucose (β, 1.01; p<0.001). During a median follow-up of 11.6 years, 490 (8.3%) CKD events occurred. However, GRS₉ was not significantly different between participants with CKD events and those without. After adjusting for confounding factors, fasting glucose was not associated with incident CKD (OR 0.990; 95% CI 0.977 to 1.002; p=0.098). In the MR analysis, GRS₉ was not associated with CKD development (OR per 1 SD increase, 1.179; 95% CI 0.819 to 1.696; p=0.376). Further evaluation using various other MR methods and strict CKD criteria (decrease in the eGFR of ≥30% to a value of <60 mL/min/1.73 m²) found no significant relationship between GRS₉ and incident CKD.

CONCLUSIONS

Fasting glucose was not causally associated with CKD development in non-diabetic population.

Risk of chronic kidney disease defined by decreased estimated glomerular filtration rate in individuals with different prediabetic phenotypes: results from a prospective cohort study in China

OBJECTIVE

We aimed to investigate the effects of prediabetes and its phenotypes of impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and elevated glycated hemoglobin A1c (EHbA1c) on chronic kidney disease (CKD) occurrence, and define the cut-off point of each glycemic index that significantly increases the risk of CKD.

RESEARCH DESIGN AND METHODS

In this prospective cohort study, 6446 non-diabetic subjects aged 40 years and over were followed over a period of 3 years to track the new onset of CKD. Cox regression was used to assess the association of prediabetes and its phenotypes with CKD. Receiver operating characteristic curves were used to define the cut-off point of each glycemic index that significantly increases the occurrence of CKD. Population attributable risk percent was calculated to estimate the contribution of prediabetes to CKD.

RESULTS

Compared to subjects with normal glucose tolerance, patients with prediabetes significantly increased the risk of development of CKD (HR=2.33 (1.19-4.55)). Specifically, this increased risk of CKD development was observed in patients with IFG, IGT and EHbA1c. The cut-off points shown to significantly increase the risk of CKD are fasting plasma glucose of 5.63 mmol/L, 2-hour plasma glucose of 6.80 mmol/L and HbA1c of 5.6%. The contribution of prediabetes to CKD occurrence in the study population was 60.6%.

CONCLUSIONS

This result suggests that the stricter criteria might be needed to define normal plasma glucose level in China that would not be predisposed to diabetic complications, particularly CKD.

Association between Prediabetes and Renal Dysfunction from a Community-based Prospective Study

Objective: Our study aimed to evaluate the association between prediabetes and renal dysfunction, and further assess which of glycemic indices of fasting plasma glucose (FPG), postprandial plasma glucose (PPG) and hemoglobin A1c (HbA1c) has a higher risk of renal dysfunction. Methods: This was a community-based prospective cohort study, which included 7015 participants from Beijing and Taian between May and October in 2015. The outcome was the renal dysfunction defined as estimated glomerular filtration rate (eGFR)<60 mL/min/1.73 m². Univariate and multivariate logistic regression model was performed, and calculated the odds ratio (OR) and 95% confidence interval (95%CI) of renal dysfunction. Receiver operating curve (ROC) analysis was used to predict renal dysfunction for glycemic indices. Results: 121 renal dysfunction cases were identified. We found that the adjusted ORs (95%CI) of renal dysfunction were 1.72 (1.11-2.38), 1.48 (1.09-1.93), 1.97 (1.27-2.89) and 1.35 (1.07-2.13), respectively, for those with prediabetes, impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and elevated HbA1c, compared with individuals with normal glucose tolerance. And IGT presented a higher risk of renal dysfunction than other glycemic indices. The similar results were obtained by performing the subgroup analysis. ROC analysis revealed the PPG had a higher predictive value for renal dysfunction. Conclusion: We found prediabetes was positively associated with the risk of renal dysfunction and PPG had a higher risk and predictive value of renal dysfunction than other glycemic indices of FPG and HbA1c.

Metabolic syndrome is a predictor of decreased renal function among community-dwelling middle-aged and elderly Japanese

PURPOSE

Metabolic syndrome (MetS) is increasing worldwide with the continuous increase in obesity prevalence. Chronic kidney disease (CKD) is also a major public health problem, but there is controversy over whether baseline MetS is a predictor of decreased renal function among Japanese community-dwelling middle-aged and elderly Japanese.

METHODS

We conducted a prospective cohort study designed as part of the Nomura study. We recruited a random sample of 410 men aged 68 ± 8 (mean ± standard deviation; range, 50-95) years and 549 women aged 69 ± 7 (50-84) years during their annual health examination in a single community. We examined the relationship between baseline MetS and renal dysfunction after a 3-year evaluation based on estimated glomerular filtration rate (eGFR_CKDEPI) using the CKD-EPI equations modified by the Japan coefficient. CKD was defined as dipstick-positive proteinuria (> or = 1 +) or a low eGFR_CKDEPI (< 60 mL/min/1.73 m²).

RESULTS

Of the 959 participants, 413 (43.1%) had MetS at baseline. Annual eGFR decline rate was significantly greater in those with MetS than in those without MetS, and the annual eGFR decline rate of < - 1.2 mL/min/1.73 m²/year increased significantly in relation to presence of baseline MetS, especially low HDL cholesterol (HDL-C). Moreover, the incidence rate of CKD after 3 years was 13.5% and increased significantly in relation to presence of baseline MetS, especially its components such as elevated HbA1c. The multivariate-adjusted odd ratio (OR) for CKD in participants with MetS versus those without MetS was 1.55 (0.99-2.43). The multivariate-adjusted ORs for rapid annual eGFR decline rate were significantly high in patients aged ≥ 65 years and presence of medication, regardless of gender and eGFR value.

CONCLUSIONS

Low HDL-C and elevated HbA1c levels correlated significantly with eGFR decline in a short period of 3 years. MetS also showed a significant association with eGFR decline. This study suggests the importance of low HDL-C and elevated HbA1c in the effect of MetS on eGFR decline rather than obesity among Japanese community-dwelling middle-aged and elderly Japanese without CKD.

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.

Metabolic syndrome status over 2 years predicts incident chronic kidney disease in mid-life adults: a 10-year prospective cohort study

We investigated whether changes in MetS status over two years modify the 10-year risk of CKD and proteinuria. A prospective cohort study was conducted in 7,251 subjects without CKD at baseline. We categorized subjects according to MetS status over two years: non-MetS (no MetS at either visit), intermittent MetS (positive for MetS at one assessment), and persistent MetS (positive for MetS at two assessments). The hazard ratio (HR) of new-onset CKD over 10-year was calculated using Cox models. During the 10-year follow-up period, 923 (12.7%) developed CKD. Compared to the non-MetS group, the fully adjusted HR for new-onset CKD was the highest in the persistent MetS group (HR, 1.53; 95% CI, 1.23-1.90), followed by the intermittent MetS group (HR, 1.29; 95% CI, 1.04-1.59) (P for trend <0.001). The HR for developing proteinuria was 1.79 (95% CI, 1.15-2.79) in the persistent MetS group and 0.70 (95% CI, 0.42-1.19) in the intermittent MetS group when the non-MetS group was considered as the reference group. Temporal changes in MetS status over two years influenced the 10-year risk of incident CKD and proteinuria. Our findings suggest that monitoring and strictly controlling MetS are important in preventing renal function decline.

The Association Between Metabolically Healthy Obesity and the Risk of Proteinuria: The Kansai Healthcare Study

Background

Metabolically healthy obesity seems to be a unique phenotype for the risk of cardiometabolic diseases. However, it is not known whether this phenotype is associated with the risk of proteinuria.

Methods

Study subjects were 9,185 non-diabetic Japanese male workers aged 40–55 years who had no proteinuria, an estimated glomerular filtration rate ≥60 mL/min/1.73 m², no history of cancer, and no use of antihypertensive or lipid-lowering medications at baseline. Obesity was defined as body mass index ≥25.0 kg/m². Metabolic health was defined as the presence of no Adult Treatment Panel III components of the metabolic syndrome criteria, excluding waist circumference, and metabolic unhealth was defined as the presence of one or more metabolic syndrome components, excluding waist circumference. “Consecutive proteinuria” was considered positive if proteinuria was detected twice consecutively as 1+ or higher on urine dipstick at annual examinations to exclude chance proteinuria as much as possible.

Results

During the 81,660 person-years follow-up period, we confirmed 390 cases of consecutive proteinuria. Compared with metabolically healthy non-obesity, metabolically healthy obesity was not associated with the risk of consecutive proteinuria (multiple-adjusted hazard ratio [HR] 0.86; 95% confidence interval [CI], 0.37–1.99), but metabolically unhealthy non-obesity with ≥2 metabolic syndrome components (HR 1.77; 95% CI, 1.30–2.42), metabolically unhealthy obesity with one component (HR 1.71; 95% CI, 1.12–2.61), and metabolically unhealthy obesity with ≥2 metabolic syndrome components (HR 2.77; 95% CI, 2.01–3.82) were associated with an increased risk of consecutive proteinuria.

Conclusions

Metabolically healthy obesity did not increase the risk of consecutive proteinuria in Japanese middle-aged men.

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.

Glomerular Hyperfiltration as Predictor of Cardiometabolic Risk Factors among Children and Adolescents: The Childhood and Adolescence Surveillance and Prevention of Adult-V Study

Background

The prevalence of glomerular hyperfiltration and chronic kidney disease is increasing worldwide in parallel with obesity hypertension epidemic. The effect of increases in glomerular filtrations (GFR) in children with metabolic syndrome has not been studied. The purpose of the present study is to investigate the relationship between GFR and cardiometabolic risk factors in a large sample of pediatric population.

Methods

In this nationwide survey, 3800 participants were selected by cluster random sampling from 30 provinces in Iran. Anthropometric measures, biochemical, and clinical parameters were measured. We also measured estimated GFR (eGFR) using the recently modified Schwartz equations and other known cardiometabolic risk factors such as elevated total cholesterol, high low-density lipoprotein cholesterol (LDL-C), and obesity.

Results

The response rate was 91.5% (n = 3843). The mean and standard deviation (SD) (Mean ± SD) of eGFR for girls, boys, and total population were 96.71 ± 19.46, 96.49 ± 21.69, and 96.59 ± 20 ml/min/1.73 m², respectively. Overall, 38.7% of the participants did not have any cardiometabolic risk factor. In multivariate models, the risk of elevated systolic blood pressure (BP) (odds ratio [OR]: 1.48; 95% confidence interval [CI]: 1.08-2.02), elevated diastolic BP (OR: 1.48; 95% CI: 1.08-2.02), elevated LDL-C (OR: 1.35; 95% CI: 1.07-1.70), and obesity (OR: 1.70; 95%CI: 1.24-2.33) were significantly higher in participants with higher eGFR level than those with the lower level but not with low level of high-density lipoprotein cholesterol (OR: 0.72; 95% CI: 0.60-0.88).

Conclusions

This study demonstrates an association between glomerular hyperfiltration and obesity-related hypertension in a large sample of the Iranian pediatric population, independently of other classical risk factors.

Risk of chronic kidney disease in young adults with impaired glucose tolerance/impaired fasting glucose: a retrospective cohort study using electronic primary care records

Background

The risk of chronic kidney disease (CKD) is known to be elevated in patients with diabetes mellitus but the risk of young adults aged 18 to 40 years with impaired glucose tolerance/impaired fasting glucose (IGT/IFG) developing CKD is not well characterised. Furthermore, progression of IGT/IFG to diabetes and subsequent CKD development is not well understood.

Methods

A retrospective cohort study was undertaken using The Health Improvement Network (THIN) database, a large dataset of electronic patient records. THIN database is jointly managed by IMS Health Real World Evidence Solution (http://www.epic-uk.org/index.html) and In Practice System (InPs). Cases were aged 18 to 40, with a diagnosis of IGT/IFG and registered at a practice contributing to THIN between 2000 and 2015. The study population consisted of 40,092 patients, including 21,454 (53.5%) female and 18,638 (46.5%) male. The median follow-up was approximately 2 years. The outcome was a diagnosis of CKD determined from either clinical coding or laboratory results. For the primary analysis the unadjusted and adjusted relative risk of CKD in IGT/IFG was compared to age, sex and practice matched controls with normoglycaemia. For the secondary analysis we compared the incidence of CKD before to after a diagnosis of type 2 diabetes (T2DM) in the IGT/IFG study cohort.

Results

The Incidence Rate Ratio (IRR) for CKD for IGT/IFG compared to normoglycaemia was 4.0 [95% confidence interval (CI), 3.2 to 5.1, P < 0.001]. The adjusted IRR was 2.6 [95% CI, 2.0 to 3.4, P < 0.001]. The unadjusted IRR was 8.8 [95% CI, 7.7 to 10.0, P < 0.001] after IGT/IFG patients had developed T2DM and the adjusted IRR was 6.3 [95% CI, 5.5 to 7.2, P < 0.001].

Conclusion

Our results show that young IGT/IFG subjects are also at higher risk of developing CKD. This risk is modulated by the degree of baseline renal function and glucose tolerance, being higher in those developing T2DM.

Electronic supplementary material

The online version of this article (10.1186/s12882-018-0834-4) contains supplementary material, which is available to authorized users.

Metabolic Syndrome and Chronic Renal Disease

Background: The influence of metabolic syndrome (MetS) on kidneys is related to many complications. We aimed to assess the association between MetS and chronic renal disease defined by a poor estimated glomerular filtration rate (eGFR) and/or the presence of microalbuminuria/macroalbuminuria.

METHODS

149 patients (77 males/72 females) were enrolled in the study. Chronic renal disease was defined according to KDIGO 2012 criteria based on eGFR category and classified albuminuria. MetS was studied as a dichotomous variable (0 to 5 components) including hypertension, waist circumference, low HDL-cholesterol, high triglycerides, and high glucose. Results: The association between clustering MetS and both classified eGFR and classified albuminuria (x² = 50.3, p = 0.001 and x² = 26.9, p = 0.003 respectively) was found to be significant. The MetS presence showed an odds 5.3-fold (1.6-17.8) higher for low eGFR and 3.2-fold (1.2-8.8) higher for albuminuria in combination with the presence of diabetes mellitus, which also increased the risk for albuminuria by 3.5-fold (1.1-11.3). Albuminuria was significantly associated with high triglycerides, hypertension, high glucose (x² = 11.8, p = 0.003, x² = 11.4, p = 0.003 and x² = 9.1, p = 0.01 respectively), and it was mildly associated with a low HDL-C (x² = 5.7, p = 0.06). A significant association between classified eGFR and both high triglycerides and hypertension (x² = 9.7, p = 0.04 and x² = 16.1, p = 0.003 respectively) was found. Conclusion: The clustering of MetS was significantly associated with chronic renal disease defined by both classified eGFR and albuminuria. The definition of impaired renal function by classified albuminuria was associated with more MetS components rather than the evaluation of eGFR category. MetS may contribute to the manifestation of albuminuria in patients with diabetes mellitus.

Metabolic Syndrome and Chronic Renal Disease

Background: The influence of metabolic syndrome (MetS) on kidneys is related to many complications. We aimed to assess the association between MetS and chronic renal disease defined by a poor estimated glomerular filtration rate (eGFR) and/or the presence of microalbuminuria/macroalbuminuria.

METHODS

149 patients (77 males/72 females) were enrolled in the study. Chronic renal disease was defined according to KDIGO 2012 criteria based on eGFR category and classified albuminuria. MetS was studied as a dichotomous variable (0 to 5 components) including hypertension, waist circumference, low HDL-cholesterol, high triglycerides, and high glucose. Results: The association between clustering MetS and both classified eGFR and classified albuminuria (x² = 50.3, p = 0.001 and x² = 26.9, p = 0.003 respectively) was found to be significant. The MetS presence showed an odds 5.3-fold (1.6-17.8) higher for low eGFR and 3.2-fold (1.2-8.8) higher for albuminuria in combination with the presence of diabetes mellitus, which also increased the risk for albuminuria by 3.5-fold (1.1-11.3). Albuminuria was significantly associated with high triglycerides, hypertension, high glucose (x² = 11.8, p = 0.003, x² = 11.4, p = 0.003 and x² = 9.1, p = 0.01 respectively), and it was mildly associated with a low HDL-C (x² = 5.7, p = 0.06). A significant association between classified eGFR and both high triglycerides and hypertension (x² = 9.7, p = 0.04 and x² = 16.1, p = 0.003 respectively) was found. Conclusion: The clustering of MetS was significantly associated with chronic renal disease defined by both classified eGFR and albuminuria. The definition of impaired renal function by classified albuminuria was associated with more MetS components rather than the evaluation of eGFR category. MetS may contribute to the manifestation of albuminuria in patients with diabetes mellitus.

Association between kidney function and genetic polymorphisms in atherosclerotic and chronic kidney diseases: A cross-sectional study in Japanese male workers

Background

Several single nucleotide polymorphisms (SNPs) have been implicated in the predisposition to chronic kidney disease (CKD). Atherosclerotic disease is deeply involved in the incidence of CKD; however, whether SNPs related to arteriosclerosis are involved in CKD remains unclear. This study aimed to identify SNPs associated with CKD and to examine whether risk allele accumulation is associated with CKD.

Methods

We conducted a cross-sectional study using data of 4814 male workers to examine the association between estimated glomerular filtration rate (eGFR) and 59 candidate polymorphisms (17 CKD, 42 atherosclerotic diseases). We defined the genetic risk score (GRS) as the total number of risk alleles that showed a significant association in this analysis and examined the relationship with CKD (eGFR < 60 ml/min/1.73m²). Multivariate logistic regression, discrimination by area under the receiver operating characteristic curve, integrated discrimination improvement (IDI), and category-free net reclassification improvement (cNRI) were evaluated.

Results

In total, 432 participants were categorized as having CKD. We found eight candidate SNPs with P value < 0.05 (CX3CR1 rs3732379, SHROOM3 rs17319721, MTP rs1800591, PIP5K1B rs4744712, APOA5 rs662799, BRAP rs3782886, SPATA5L1 rs2467853, and MCP1 rs1024611) in the multivariate linear regression adjusted for age, body mass index, systolic blood pressure, and fasting blood glucose. Among these eight SNPs, BRAP rs3782886 and SPATA5L1 rs2467853 were significantly associated with eGFR (false discovery rate < 0.05). GRS was significantly associated with CKD (odds ratio, 1.17; 95% confidence interval, 1.09–1.26). C-statisics improved from 0.775 to 0.780 but showed no statistical significance. However, adding GRS significantly improved IDI and cNRI (0.0057, P = 0.0028, and 0.212, P < 0.001, respectively).

Conclusions

After adjustment for clinical factors, kidney function was associated with BRAP rs3782886 and SPATA5L1 rs2467853 and the GRS for CKD that we developed was associated CKD.

Impact of screening for metabolic syndrome on the evaluation of obese living kidney donors

BACKGROUND

We report our experience with metabolic syndrome screening for obese living kidney donor candidates to mitigate the long-term risk of CKD.

METHODS

We retrospectively reviewed 814 obese (BMI≥30) and 993 nonobese living kidney donor evaluations over 12 years. Using logistic regression, we explored interactions between social/clinical variables and candidate acceptance before and after policy implementation.

RESULTS

Obese donor candidate acceptance decreased after metabolic syndrome screening began (56.3%, 46.3%, p < 0.01), while nonobese candidate acceptance remained similar (59.6%, 59.2%, p = 0.59). Adjusting for age, gender, race, BMI, and number of prior evaluations, acceptance of obese candidates decreased significantly more than nonobese (p = 0.025). In candidates without metabolic syndrome, there was no significant change in how age, sex, race, or BMI affected a donor candidate's probability of acceptance.

CONCLUSION

Metabolic syndrome screening is a simple stratification tool for centers with liberal absolute BMI cut-offs to exclude potentially higher-risk obese candidates.

Association of matrix γ-carboxyglutamic acid protein levels with insulin resistance and Lp(a) in diabetes: A cross-sectional study

AIMS

The risk of cardiovascular disease (CVD) and mortality is increased in patients with chronic kidney disease (CKD), with a background role of vascular calcification in the development of CVD also reported. Studies have demonstrated that high lipoprotein(a) (Lp(a)) levels accelerate the development of atherosclerolsis and are potentially involved in the vascular calcification. Matrix Gla Protein (MGP) seems to play an important role in vascular calcification. The aim of the study was to examine the potential association of MGP concentrations with Lp(a) and insulin resistance.

METHODS

The study involved 100patients divided in four groups: 25 with both CKD stage 4 and Type2 Diabetes (DM) (Group-A), 25 with CKD4 without DM (Group-B), 25 non uremic patients with DM (Group-C) and 25 healthy subjects (Group-D). Serum glucose, Lp(a), MGP, plasma HBA1c and insulin were measured in all patients. Insulin resistance was estimated by the homeostasis model assessment equation (HOMA-IR).

RESULTS

A significant positive linear association between MGP and Lp(a) levels (r=0.272, p=0.006) was noted, as well as between MGP and HOMA-IR levels (r=0.308, p=0.002). However, no significant linear association between Lp(a) and HOMA-IR levels was recorded. A similar positive association between MGP and insulin levels (r=0.204, p=0.042) was also found.

CONCLUSION

This study concluded that diabetes coexisting with renal disease leads to extreme vascular calcification expressed by elevated MGP levels, resulting in higher frequency of cardiovascular disease in comparison to CKD patients without diabetes. The detected Lp(a) and MGP association in CKD4 patients may also represent the key to the complicated mechanism of their coexisting accelerated atherosclerosis and vascular calcification.

Metabolic syndrome is independently associated with a mildly reduced estimated glomerular filtration rate: a cross-sectional study

Background

Association between metabolic syndrome (MS) and mildly reduced estimated glomerular filtration rates (eGFRs) remains unclear. Therefore, we aimed to evaluate the association between MS and a mildly reduced eGFR in Chinese adults.

Methods

Anthropometric and biochemical examinations were performed in 2992 individuals. The eGFR was calculated from the creatinine level. MS was defined according to the Adult Treatment Panel III criteria as the presence of three or more risk factors. Mildly reduced eGFR was defined as a value between 60 and 90 mL/min/1.73 m². Multiple linear regression and multiple logistic regression analysis were used to evaluate association between metabolic syndrome and estimate glomerular filtration rate.

Results

After adjusting for several potential confounders, the participants with MS showed a 1.29-fold increased odds ratio for a mildly reduced eGFR compared with those without MS. Additionally, the odds ratios (and 95% confidence intervals (CIs)) for mildly reduced eGFR in participants with elevated triglycerides (TG), decreased high-density lipoprotein (HDL), obesity and elevated fasting blood glucose (FPG) after multivariable adjustment were 1.25 (1.05–1.49), 1.23 (1.03–1.48), 1.22 (1.03–1.45) and 0.64 (0.52–0.78), respectively. The odds ratios (95% CIs) for hyperfiltration in participants with elevated FPG and HbA1c levels after multivariable adjustment were 1.53 (1.30–1.81) and 2.86 (2.00–4.09), respectively.

Conclusions

MS is associated with an increased risk of a mildly reduced eGFR in the Chinese population, and several individual components of MS have different impacts on eGFR levels. MS had dual roles on renal damage.

Trial registration

ChiCTR-TRC-14005029. Registered 28 July 2014.

Electronic supplementary material

The online version of this article (doi:10.1186/s12882-017-0597-3) contains supplementary material, which is available to authorized users.

Metabolic syndrome, serum uric acid and renal risk in patients with T2D

Background and aims

Metabolic Syndrome (Mets) and increased serum uric acid (SUA), are well known renal risk predictors and often coexist in patients with type 2 diabetes (T2D). Whether they independently contribute to the onset of CKD is at present unclear.

Methods and results

Within the AMD Annals database we identified patients with T2D and normal renal function and urine albumin excretion at baseline and regular follow-up visits during a 4-year period. Blood pressure, BMI, HDL, triglycerides, and SUA were available in 14,267 patients. The association between Mets and/or hyperuricemia (HU, top fifth gender specific quintile) and the occurrence of renal outcomes were evaluated.

Results

At baseline 59% of patients (n = 8,408) showed Mets and 18% (n = 2,584) HU. Over the 4-year follow-up, 14% (n = 1,990) developed low eGFR (i.e. below 60 mL/min/1.73 m²), and 26% (n = 3,740) albuminuria. After adjustment for confounders, BP≥130/85, low HDL, triglycerides ≥150 and HU were independently related to the development of low eGFR (1.57, P<0.001; 1.13, P = 0.056; 1.18, P = 0.008; 1.26, P = 0.001) and of albuminuria (1.35, P<0.001; 1.18, P = 0.001; 1.15, P = 0.002; 1.24, P = 0.001), respectively.

The incidence of low eGFR was higher in patients with HU independent of the presence or absence of Mets (21%, OR 1.30, p = 0.009 and 20%, 1.57, p<0.000 respectively), while albuminuria occurred more frequently in those with Mets and HU (32%, OR 1.25, p = 0.005) as compared to the reference group.

Conclusions

HU and Mets are independent predictors of CKD and its individual components in patients with T2D.

The Association Between the Metabolic Syndrome and Metabolic Syndrome Score and Urine Microalbumin/Urine Creatinine Ratio and Glomerular Filtration Rate in Korean Adults With Obesity

OBJECTIVE

This study assessed the association between metabolic syndrome (MetS) and metabolic syndrome score (MSS) and the levels of urine microalbumin-urine creatinine ratio (uACR) and glomerular filtration rate (GFR) in Korean adults with obesity.

METHODS

Analyses of data obtained during the 2012 Korean National Health and Nutrition Examination Survey were restricted to that obtained from 1,612 adults aged ≥20 years with obesity.

RESULTS

After adjusting for relevant variables (excluding age), uACR levels were positively associated with MetS (P < .001) and MSS (P < .001), and GFR levels were inversely associated with MetS (P < .001) and MSS (P < .001). However, when further adjusting for age, uACR levels were positively associated with MetS (P < .001) and MSS (P < .001) levels, but GFR levels were not associated with MetS (P = .632) and MSS (P = .275) levels.

CONCLUSION

MetS and MSS were positively associated with uACR levels in Korean adults with obesity, but were not associated with GFR levels.

Fatty liver associated with metabolic derangement in patients with chronic kidney disease: A controlled attenuation parameter study

BACKGROUND

Hepatic steatosis measured with controlled attenuation parameter (CAP) using transient elastography predicts metabolic syndrome in the general population. We investigated whether CAP predicted metabolic syndrome in chronic kidney disease patients.

METHODS

CAP was measured with transient elastography in 465 predialysis chronic kidney disease patients (mean age, 57.5 years).

RESULTS

The median CAP value was 239 (202-274) dB/m. In 195 (41.9%) patients with metabolic syndrome, diabetes mellitus was more prevalent (105 [53.8%] vs. 71 [26.3%], P < 0.001), with significantly increased urine albumin-to-creatinine ratio (184 [38-706] vs. 56 [16-408] mg/g Cr, P = 0.003), high sensitivity C-reactive protein levels (5.4 [1.4-28.2] vs. 1.7 [0.6-9.9] mg/L, P < 0.001), and CAP (248 [210-302] vs. 226 [196-259] dB/m, P < 0.001). In multiple linear regression analysis, CAP was independently related to body mass index (β = 0.742, P < 0.001), triglyceride levels (β = 2.034, P < 0.001), estimated glomerular filtration rate (β = 0.316, P = 0.001), serum albumin (β = 1.386, P < 0.001), alanine aminotransferase (β = 0.064, P = 0.029), and total bilirubin (β = -0.881, P = 0.009). In multiple logistic regression analysis, increased CAP was independently associated with increased metabolic syndrome risk (per 10 dB/m increase; odds ratio, 1.093; 95% confidence interval, 1.009-1.183; P = 0.029) even after adjusting for multiple confounding factors.

CONCLUSION

Increased CAP measured with transient elastography significantly correlated with and could predict increased metabolic syndrome risk in chronic kidney disease patients.

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.

Association between prediabetes and risk of chronic kidney disease: a systematic review and meta-analysis

AIMS

To assess the effect of prediabetes (impaired fasting glucose and/or impaired glucose tolerance) on the incidence of chronic kidney disease.

METHODS

PubMed and EMBASE were searched (for studies published up to March 2015). Effects estimated from cohort studies reporting the relationship of prediabetes to incident chronic kidney disease [kidney damage (microalbuminuria, albuminuria or proteinuria) and/or decreased glomerular filtration rate] were pooled using a random-effects model meta-analysis.

RESULTS

Nine cohort studies with a total of 185 452, mainly Asian and white, participants were followed for a total of 835 146 person-years. In eight cohort studies defining impaired fasting glucose as fasting glucose 6.1-6.9 mmol/l, the summary relative risk of chronic kidney disease after adjustment for established risk factors was 1.11 (95% CI 1.02-1.21). When a study defining impaired fasting glucose as fasting glucose 5.6-6.9 mmol/dl was added, the overall relative risk of chronic kidney disease was 1.12 (95% CI 1.02-1.21). Exclusion of the only study with information on impaired glucose tolerance did not change the relative risk (1.12; 95% CI 1.02-1.21). There was no evidence of publication bias (P value for Egger test = 0.12).

CONCLUSION

Prediabetes is modestly associated with an increase in chronic kidney disease risk, but this remains to be robustly confirmed. Chronic kidney disease screening among people with prediabetes, and aggressive management of prediabetes in those with chronic kidney disease may be warranted.

Cardiovascular metabolic risk factors and glomerular filtration rate: a rural Chinese population study

METHODS

A total of 2426 study subjects from rural China aged 35 years and above (934 men and 1492 women) were enrolled in a cross-sectional survey. The eGFR calculation was based on the Modification of Diet in Renal Disease (MDRD) equation. The strength of the association between cardiovascular metabolic risk factors and eGFR was analyzed using a linear regression model.

RESULTS

Cardiovascular metabolic risk factors, including age, body weight, waist circumference, fasting plasma glucose (FPG), creatinine (Cr), high-density lipoprotein-cholesterol (HDL-C), total cholesterol (TC), triglyceride (TG), systolic pressure, and diastolic pressure, were associated with eGFR. Additionally, the eGFR level gradually decreased and showed a linear trend with the increase in metabolic syndrome risk factors.

CONCLUSION

Metabolic risk factors are correlated with a reduction in renal function and CKD.

Metabolic syndrome does not always play a critical role in decreased GFR

BACKGROUND

There is a paucity of literature available as to the relationship between different levels of each metabolic syndrome (MetS) component and decreased GFR. In the present study, we aimed to demonstrate whether MetS always plays a critical role in decreased GFR.

METHODS

A cross-sectional study was conducted between February 2010 and September 2012, with 75,468 adults enrolled undergoing measurements of blood pressure as well as tests of blood and urine samples. Univariate and multivariable logistic regression analyses were performed to estimate the odds ratio (OR) with 95% confidence intervals (CI), and the chi-square test was used for categorical variables and described as a percentage.

RESULTS

Of the 75,468 participants, 350 (0.5%) subjects met criteria for the decreased GFR, with a mean age of 48.79 ± 13.76 years. After adjustment for age, diastolic blood pressure and high-density lipoprotein were inversely related to decreased estimated glomerular filtration rate (eGFR) in multivariable analyses, with an OR (95% CI) of 0.57 (0.39-0.84) and 0.41 (0.24-0.72), respectively. The prevalence rate of CKD in critical group was 0.73% (154 of 21,127) and 0% (0 of 370) in noncritical group. In analysis stratified by the type of MetS components, the differences in noncritical group and the reference group were not statistically significant (χ(2 )=( )1.349, p > 0.05).

CONCLUSIONS

MetS does not always play a critical role in decreased GFR, with different levels of individual components of MetS exerting idiosyncratic effects in decreased eGFR. In fact, patients with abnormal body mass index, high triglycerides, and elevated fasting plasma glucose would not have impact on decreased GFR.

Prediabetes and Risk of Glomerular Hyperfiltration and Albuminuria in the General Nondiabetic Population: A Prospective Cohort Study

BACKGROUND

The role of prediabetes as a risk factor for hyperfiltration and albuminuria in persons who do not develop diabetes is unclear. The lack of evidence is mainly due to the difficulty of accurately assessing the glomerular filtration rate (GFR) in the near-normal range of GFR. We investigated whether prediabetes is an independent risk factor for glomerular hyperfiltration and high-normal urinary albumin-creatinine ratio (ACR) using measured GFR (mGFR) rather than estimated GFR.

STUDY DESIGN

Prospective cohort study based on the Renal Iohexol Clearance Survey in Tromsø 6 (RENIS-T6) and the RENIS Follow-Up Study. Median observation time was 5.6 years.

SETTING & PARTICIPANTS

A representative sample of 1,261 persons without diabetes mellitus (DM) from the general population aged 50 to 62 years.

PREDICTOR

Prediabetes defined by fasting glucose and hemoglobin A1c according to levels suggested by the American Diabetes Association (preDMADA) and the International Expert Committee of 2009 (preDMIEC).

OUTCOMES

Change in mGFR; hyperfiltration defined as mGFR>90th percentile adjusted for age, sex, weight, and height; and high-normal ACR (>10mg/g) at follow-up.

MEASUREMENTS

GFR was measured with iohexol clearance.

RESULTS

Baseline fasting glucose, hemoglobin A1c, and both definitions of prediabetes were predictors of higher mGFR at follow-up and lower annual mGFR decline in multivariable-adjusted regression analyses. Participants with preDMIEC had an OR for hyperfiltration of 1.95 (95% CI, 1.20-3.17) and for high-normal ACR of 1.83 (95% CI, 1.04-3.22) at follow-up. We adjusted for cardiovascular risk factors including ambulatory blood pressure at baseline and change in use of antihypertensive medication between baseline and follow-up.

LIMITATIONS

Only middle-aged white patients participated. There is no consensus on how to define glomerular hyperfiltration.

CONCLUSIONS

Our findings imply an independent role of prediabetes in the development of glomerular hyperfiltration and albuminuria. Prediabetes might be a target for early treatment to prevent chronic kidney disease in chronic hyperglycemia.

Effects of Weight Loss Speed on Kidney Function Differ Depending on Body Mass Index in Nondiabetic Healthy People: A Prospective Cohort

Background

Obesity is associated with diabetes mellitus and cardiovascular diseases. However, it has been reported that weight loss is associated with incident chronic kidney disease (CKD) in healthy males. The purpose of this prospective cohort study is to investigate the effects of weight loss on kidney function in healthy people in terms of body mass index (BMI) and gender.

Methods

A total of 8447 nondiabetic healthy people were enrolled in the Saitama Cardiometabolic Disease and Organ Impairment Study, Japan. Relationships between estimated glomerular filtration rate (eGFR) change, BMI, and BMI change were evaluated using 3D-scatter plots with spline and generalized additive models (GAMs) adjusted for baseline characteristics.

Results

The subjects were stratified into four groups according to BMI. The mean±standard deviations for males and females were, respectively, 40.11±9.49, and 40.3±9.71 years for age and 76.39±17.72 and 71.49±18.4 ml/min/1.73m² for eGFR. GAMs showed that a decreasing BMI change (<-1 kg/m²/year) was associated with a decreasing eGFR change in males with high normal BMIs (22 kg/m²≤BMI<25 kg/m²). A decreasing BMI change (<-2 kg/m²/year) was associated with an increasing eGFR change in overweight males (25 kg/m²≤BMI). Among underweight females (BMI<18.5 kg/m²), decreasing BMI was observed with decreasing eGFR.

Conclusions

These findings suggest that the benefit and risk of weight loss in relation to kidney function differs depending on BMI and weight loss speed, especially in males.

Metabolic syndrome and its components associated with chronic kidney disease

Background:

There is limited information on the relationship between metabolic syndrome (MetS) and chronic kidney disease (CKD) in the Iranian population, a group that has a high prevalence of CKD and obesity. The aim of present study was to determine the relationship between MetS and CKD in West of Iran.

Materials and Methods:

A total of 800 subjects aged more than 35 years admitted from 2011 to 2013 were enrolled in the study. MetS was defined based on the Adult Treatment Panel III criteria, and CKD was defined from the Kidney Disease Outcomes Quality Initiative practice guidelines. Waist circumference and body mass index were calculated, as well, blood samples were taken and lipid profile, plasma glucose levels, and serum creatinine were measured. Data were analyzed with SPSS version 17 (SPSS Inc., Chicago, IL, USA).

Results:

CKD was seen in 14.8% patients with MetS and 8.3% individuals without MetS. MetS was associated with an increased odds ratio (OR) for a glomerular filtration rate <60 ml/min/1.73 m² (OR: 1.91; 95% confidence interval [CI]: 1.22-2.99; P = 0.004). Individuals with 2, 3, 4, and 5 components of the MetS had an increased OR for CKD: 2.19 (95% CI: 0.95-3.62), 2.65 (95% CI: 1.03-4.71), 2.86 (95% CI: 1.08-5.53), and 5.03 (95% CI: 1.80-8.57), respectively, compared with individuals with none of the components.

Conclusion:

We found a high prevalence of CKD in patients with MetS compared with the subject without MetS. Our observations raised major clinical and public health concerns in Iran, where both the MetS and kidney diseases are becoming common.

Sex- and Time-Dependent Patterns in Risk Factors of End-Stage Renal Disease: A Large Austrian Cohort with up to 20 Years of Follow-Up

Objective

We investigated the association between metabolic factors and End-Stage Renal Disease (ESRD) and quantified the magnitude of their influence dependent on sex and time of exposure up to 20 years.

Material and Methods

A prospective cohort study was conducted to determine risk factors for the development of ESRD. From 1988 to 2005 185,341 persons (53.9% women) participated in the “Vorarlberg Health Monitoring and Promotion Programme” (VHM&PP). Data on body mass index (BMI), fasting blood glucose (FBG), systolic (BPsys) and diastolic (BPdia) blood pressure, total cholesterol (TC), triglycerides (TG), gamma-glutamyltransferase (GGT) and smoking status were collected. Data of the population-based VHM&PP were merged with the Austrian Dialysis and Transplant Registry. Cox proportional hazards models were applied to calculate hazard ratios (HRs) for ESRD, stratified by sex and 5-year time intervals.

Results

During a mean follow-up of 17.5 years 403 patients (39.1% women) developed ESRD. Significant risk factors were: BMI (per 1 kg/m²) HR 1.04 (95% CI 1.01–1.06), FBG (per 1 mmol/L) HR 1.09 (1.05–1.12), BPsys (per 5 mmHg) HR 1.10 (1.07–1.14), BPdia (per 5 mmHg) HR 1.09 (1.03–1.15), TG (per 1 mmol/L) HR 1.07 (1.02–1.13), TC (per 1 mmol/L) HR 1.22 (1.13–1.32). We observed a sex-specific risk pattern with an increased ESRD risk for men for increasing TG and smoking, and for women for increasing BMI and GGT. In time interval analyses BPsys and TC were associated with early ESRD onset, whereas BMI, FBG, BPdia and GGT were associated with later onset.

Conclusions

Anthropometric and metabolic factors are differentially associated with the long-term risk for ESRD in a sex- and time-dependent manner. Consideration of these patterns in preventive and therapeutic strategies could have an impact on ESRD incidence.

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.

Validity of body impedance analysis for evaluating body composition in patients undergoing long-term hemodialysis

[Purpose] This study assessed changes in body composition before and after dialysis in chronic hemodialysis patients and determined the relationships between various body composition parameters and blood lipid levels in these patients. [Subjects] The cross-sectional study included 19 dialysis outpatients (17 men and 2 women, aged 35–82 years). [Methods] Body mass index, body weight, percent body fat, and percent skeletal muscle were measured before and after dialysis by using body impedance analysis. Blood lipid levels were obtained from patients’ clinical records. The body composition parameters before and after dialysis were compared using paired t-tests. Spearman’s rank correlation coefficients were calculated to determine relationships between the body composition parameters, before and after dialysis, and the blood lipid levels. [Results] All body composition parameters differed significantly before and after dialysis. High-density lipoprotein cholesterol level significantly correlated with all the body composition parameters, whereas total cholesterol, low-density lipoprotein cholesterol, and triglyceride levels significantly correlated with some of these parameters. The correlation coefficients revealed no major differences in the relationships between blood lipid parameters and body compositions before and after dialysis. [Conclusion] Our findings suggest that body composition parameters, whether measured before or after dialysis, can be used to evaluate obesity in longitudinal studies.

Association between Metabolic Syndrome and Microalbuminuria in Korean Adults

Background

We conducted a population-based cross-sectional study of Korean adults to evaluate the association between metabolic syndrome and microalbuminuria as a marker for early-stage chronic kidney disease.

Methods

A total of 8,497 adults (3,625 men and 4,872 women) who participated in the Korea National Health and Nutrition Examination Survey between 2011 and 2012 were included. Metabolic syndrome was defined according to recommendation from a joint interim statement of international organizations published in 2009. Microalbuminuria was defined as a urinary albumin-to-creatinine ratio of 30 to 300 mg/g. The association between metabolic syndrome and microalbuminuria was evaluated using logistic regression analysis with adjustment for covariates while considering sampling weights and the complex survey design.

Results

The prevalence of microalbuminuriain subjects with metabolic syndrome was 11% for men and 14.4% for women, whereas the prevalence in subjects without metabolic syndrome was 3.1% for men and 6.7% for women. Metabolic syndrome was significantly associated with an increased risk of microalbuminuriain both women (odds ratio, 2.79; 95% confidence interval, 2.01 to 3.88) and men (odds ratio, 3.00; 95% confidence interval, 2.11 to 4.27). All components of the metabolic syndrome were associated with a significantly increased risk of microalbuminuria with the strongest association for high blood pressure. The risk of microalbuminuria increased in a dose-dependent manner (P-value for trend < 0.001) with the number of metabolic syndrome components observed for both sexes.

Conclusion

These findings suggest that metabolic syndrome is a risk factor for chronic kidney disease from an early stage.

Insulin resistance is associated with the development of albuminuria in Korean subjects without diabetes

Previous studies have shown that insulin resistance is associated with the development of albuminuria. However, most studies are done on a background of diabetes or metabolic syndrome and there is little data from general population. The aim of this study is to define the effect of insulin resistance on the development of albuminuria in healthy individuals without diabetes. We analyzed 60,047 participants without baseline diabetes or chronic kidney disease, who underwent at least two health maintenance visits at a 2-year interval between 2002 and 2009 at a tertiary hospital in Korea. We measured the incidence of albuminuria at the second examination and calculated the odds ratio for the development of albuminuria according to the quintile of the homeostasis model assessment of insulin resistance (HOMA-IR). After 2 years, 880 cases of incident albuminuria were observed. The cumulative incidences of albuminuria were 1.08, 1.50, 1.35, 1.47, and 1.92% for the 1st to 5th quintiles of HOMA-IR. On multivariate logistic analysis, the odds ratios for incident albuminuria compared to those in the 1st quintile were 1.38 (95% CI 1.10-1.73; P=0.006), 1.23 (95% CI 0.97-1.55; P=0.087), 1.32 (95% CI 1.04-1.67; P=0.020), and 1.66 (95% CI 1.31-2.09; P<0.001) in the 2nd, 3rd, 4th, and 5th quintiles, respectively. A high level of insulin resistance assessed with HOMA-IR was associated with the development of albuminuria in relatively healthy subjects without diabetes. Further research is needed to verify the role of insulin resistance in the development of albuminuria and renal injury.

Association of metabolic syndrome with decreased glomerular filtration rate among 75,468 Chinese adults: a cross-sectional study

Background

The impact of the various elements of metabolic syndrome (MetS) on chronic kidney disease (CKD) has been conflicting. Therefore, in the present study we aimed to examine the association of MetS and its components with decreased glomerular filtration rate (GFR).

Methods

A total of 75,468 urban workers who underwent annual health examinations under the auspices of the local governments between March 2010 and September 2012 at the health examination center of Xuzhou center hospital were enrolled in the cross-sectional survey. Decreased GFR was defined as an estimated GFR <60 mL/min per 1.73 m². The definition of MetS was based on the most-recent interim joint consensus definition, requiring any three of the five components, consisting of elevated blood pressure (BP), fasting plasma glucose (FPG), or triglycerides (TG), reduced high density lipoprotein-cholesterol (HDL-c), and obesity.

Results

MetS was related to the reduced GFR with an odds ratio [95% confidence interval (CI)] of 1.43 (1.13–1.83). In multivariable analyses, individual components of MetS that were independently associated with decreased GFR were elevated BP (OR 1.34, 95% CI 1.00–1.78), low HDL-c (OR 1.88, 95% CI 1.44–2.43), and elevated FPG (OR 1.42, 95% CI 1.09–1.85). The age-adjusted population-attributable risk percent (PARP) for reduced GFR was 27.55%, 19.67% and14.31% for elevated BP, low HDL-c and elevated FPG respectively. The multivariate-adjusted odds ratios (95% CI) of decreased GFR were 1.70(1.11–2.60), 2.38(1.53–3.71), or 4.11(2.42–6.98) for those with 1, 2, or 3 critical elements (versus zero), respectively. The corresponding multivariate-adjusted odds ratios (95% CI) of decreased GFR were 1.11(0.84–1.48) and 0.89(0.63–1.27) for those with 1 or 2 noncritical components (versus zero), respectively.

Conclusions

We concluded that various elements of MetS and the cumulative number of MetS should not be considered indiscriminately as risk factors for reduced GFR.

Metabolic syndrome and chronic kidney disease: Current status and future directions

Metabolic syndrome (MetS) is a term used to denote a combination of selected, widely prevalent cardiovascular disease (CVD)-related risk factors. Despite the ambiguous definition of MetS, it has been clearly associated with chronic kidney disease markers including reduced glomerular filtration rate, proteinuria and/or microalbuminuria, and histopathological markers such as tubular atrophy and interstitial fibrosis. However, the etiological role of MetS in chronic kidney disease (CKD) is less clear. The relationship between MetS and CKD is complex and bidirectional, and so is best understood when CKD is viewed as a common progressive illness along the course of which MetS, another common disease, may intervene and contribute. Possible mechanisms of renal injury include insulin resistance and oxidative stress, increased proinflammatory cytokine production, increased connective tissue growth and profibrotic factor production, increased microvascular injury, and renal ischemia. MetS also portends a higher CVD risk at all stages of CKD from early renal insufficiency to end-stage renal disease. Clinical interventions for MetS in the presence of CKD should include a combination of weight reduction, appropriate dietary modification and increase physical activity, plus targeting of individual CVD-related risk factors such as dysglycemia, hypertension, and dyslipidemia while conforming to relevant national societal guidelines.