Metabolic syndrome and chronic kidney disease

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.

Comorbidity patterns in cardiovascular diseases: the role of life-stage and socioeconomic status

Cardiovascular diseases stand as a prominent global cause of mortality, their intricate origins often entwined with comorbidities and multimorbid conditions. Acknowledging the pivotal roles of age, sex, and social determinants of health in shaping the onset and progression of these diseases, our study delves into the nuanced interplay between life-stage, socioeconomic status, and comorbidity patterns within cardiovascular diseases. Leveraging data from a cross-sectional survey encompassing Mexican adults, we unearth a robust association between these variables and the prevalence of comorbidities linked to cardiovascular conditions. To foster a comprehensive understanding of multimorbidity patterns across diverse life-stages, we scrutinize an extensive dataset comprising 47,377 cases diagnosed with cardiovascular ailments at Mexico's national reference hospital. Extracting sociodemographic details, primary diagnoses prompting hospitalization, and additional conditions identified through ICD-10 codes, we unveil subtle yet significant associations and discuss pertinent specific cases. Our results underscore a noteworthy trend: younger patients of lower socioeconomic status exhibit a heightened likelihood of cardiovascular comorbidities compared to their older counterparts with a higher socioeconomic status. By empowering clinicians to discern non-evident comorbidities, our study aims to refine therapeutic designs. These findings offer profound insights into the intricate interplay among life-stage, socioeconomic status, and comorbidity patterns within cardiovascular diseases. Armed with data-supported approaches that account for these factors, clinical practices stand to be enhanced, and public health policies informed, ultimately advancing the prevention and management of cardiovascular disease in Mexico.

Association of metabolic syndrome and chronic kidney disease

The prevalence of kidney disease is increasing rapidly worldwide, reflecting rising rates of obesity, diabetes, and associated metabolic syndrome (MetS). Chronic kidney disease and related comorbidities such as obesity, diabetes, and hypertension place a significant financial burden on healthcare systems. Despite the widespread use of RAAS inhibitors, intensive blood pressure and glycemic control, and newer therapeutic options consisting of sodium/glucose cotransporter-2 (SGLT-2) inhibitors or glucagon-like peptide-1 (GLP-1) receptor agonists, a significant risk of progression to end-stage renal disease remains in the high-risk obese and diabetic population. The MetS is a cluster of cardiovascular risk factors that adversely affect the development and progression of chronic kidney failure. According to the criteria of the World Health Organization, it is defined by visceral adiposity, impaired glucose tolerance or insulin resistance, atherogenic dyslipidemia, raised blood pressure, and microalbuminuria with a albumin-to-creatinine ratio ≥30 mg/g. At molecular level MetS is marked by a proinflammatory state and increased oxidative stress leading to various pathophysiological changes causing endothelial dysfunction and a hypercoagulable state. Because the kidney is a highly vascularized organ, it is especially susceptible for those microvascular changes. Therefore, the MetS and its individual components are associated with the premature development, acceleration, and progression of chronic kidney disease. Therefore, it is becoming increasingly important to elucidate the underlying mechanisms of MetS-associated chronic kidney disease in order to develop new strategies for preventing and slowing the progression of renal disease. In this review, we will elucidate (i) the renal structural, hemodynamic, and metabolic changes that occur in obesity and obesity-related kidney injury; (ii) the clinicopathological characteristics of obesity-related kidney injury, primarily focusing on obesity-associated glomerulopathy; (iii) the potential additional factors or predisposing factors that may turn patients more susceptible to renal structural or functional compensatory failure and subsequent injury.

Impact of High Fat Diet and Sex in a Rabbit Model of Carpal Tunnel Syndrome

Carpal tunnel syndrome (CTS) is a common musculoskeletal disorder, characterized by fibrosis of the subsynovial connective tissue (SSCT) mediated by transforming growth factor beta (TGF-β). Risk factors for CTS include metabolic dysfunction and age. Additionally, the incidence of CTS is higher in women. In this study we hypothesized that a high-fat diet (HFD), a common driver of metabolic dysfunction, would promote SSCT fibrosis found in CTS and that this response would be sex dependent. To test this, we examined the effects of HFD and sex on SSCT fibrosis using our established rabbit model of CTS. Forty-eight (24 male, 24 female) adult rabbits were divided into four groups including HFD or standard diet with and without CTS induction. SSCT was collected for histological and gene expression analysis. HFD promoted SSCT thickening and upregulated profibrotic genes, including TGF-β. Fibrotic genes were differentially expressed in males and females. Interestingly while the prevalence of CTS is greater in women than in men, the converse is observed in the presence of metabolic dysfunction. This work recapitulates this clinical observation and begins to elucidate the sex-based differences found in SSCT fibrosis. This knowledge should drive further research and may lead to metabolic and sex specific therapeutic strategies for the treatment of patients with CTS.

The Role of Metabolic Dysfunction-Associated Fatty Liver Disease in Developing Chronic Kidney Disease: Longitudinal Cohort Study

BACKGROUND

The association between metabolic dysfunction-associated fatty liver disease (MAFLD) and chronic kidney disease (CKD) is unclear.

OBJECTIVE

This longitudinal cohort study aimed to test whether MAFLD plays an important role in the development of CKD.

METHODS

This cohort study included 41,246 participants who had undergone 3 or more health examinations from 2008 to 2015 at the People's Hospital of Guangxi Zhuang Autonomous Region, China. Participants were categorized into 2 groups according to whether they presented with or without MAFLD. The occurrence of new-onset CKD was stated as either an estimated glomerular filtration rate of <60 mL/min per 1.73 m² or a higher level of albuminuria during their follow-up appointment. The association between MAFLD and CKD was evaluated using a Cox regression method.

RESULTS

Of the 41,246 participants, 11,860 (28.8%) were diagnosed with MAFLD. Over the course of the 14-year follow-up (median 10.0 years), 5347 (13%) participants experienced a new incident of CKD (135.73 per 10,000 person-years). MAFLD was discovered as an important risk factor for new incidents of CKD (hazard ratio 1.18, 95% CI 1.11-1.26) by using the multivariable Cox proportional hazard regression model. When stratified by gender, the adjusted hazard ratio for the incidence of CKD in men and women with MAFLD were 1.16 (95% CI 1.07-1.26) and 1.32 (95% CI 1.18-1.48), respectively. According to the subgroup analysis results, after adjusting for confounding factors, the MAFLD-related CKD risk was greater in men aged <60 years (P_interaction=.001) and in those with combined dyslipidemia (P_interaction=.02), but this relationship was not found in women (all P_interaction>.05).

CONCLUSIONS

MAFLD plays an important role in the development of new incidents of CKD in the long run.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR2200058543; https://www.chictr.org.cn/showproj.html?proj=153109.

The causal effects of lipid traits on kidney function in Africans: bidirectional and multivariable Mendelian-randomization study

BACKGROUND

Observational studies have investigated the effect of serum lipids on kidney function, but these findings are limited by confounding, reverse causation and have reported conflicting results. Mendelian randomization (MR) studies address this confounding problem. However, they have been conducted mostly in European ancestry individuals. We, therefore, set out to investigate the effect of lipid traits on the estimated glomerular filtration rate (eGFR) based on serum creatinine in individuals of African ancestry.

METHODS

We used the two-sample and multivariable Mendelian randomization (MVMR) approaches; in which instrument variables (IV's) for the predictor (lipid traits) were derived from summary-level data of a meta-analyzed African lipid GWAS (MALG, n = 24,215) from the African Partnership for Chronic Disease Research (APCDR) (n = 13,612) & the Africa Wits-IN-DEPTH partnership for Genomics studies (AWI-Gen) dataset (n = 10,603). The outcome IV's were computed from the eGFR summary-level data of African-ancestry individuals within the Million Veteran Program (n = 57,336). A random-effects inverse variance method was used in our primary analysis, and pleiotropy was adjusted for using robust and penalized sensitivity testing. The lipid predictors for the MVMR were high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, and triglycerides (TG).

FINDINGS

We found a significant causal association between genetically predicted low-density lipoprotein (LDL) cholesterol and eGFR in African ancestry individuals β = 1.1 (95% CI [0.411-1.788]; p = 0.002). Similarly, total cholesterol (TC) showed a significant causal effect on eGFR β = 1.619 (95% CI [0.412-2.826]; p = 0.009). However, the IVW estimate showed that genetically predicted HDL-C β = -0.164, (95% CI = [-1.329 to 1.00]; p = 0.782), and TG β = -0.934 (CI = [-2.815 to 0.947]; p = 0.33) were not significantly causally associated with the risk of eGFR. In the multivariable analysis inverse-variance weighted (MVIVW) method, there was evidence for a causal association between LDL and eGFR β = 1.228 (CI = [0.477-1.979]; p = 0.001). A significant causal effect of Triglycerides (TG) on eGFR in the MVIVW analysis β = -1.3 ([-2.533 to -0.067]; p = 0.039) was observed as well. All the causal estimates reported reflect a unit change in the outcome per a 1 SD increase in the exposure. HDL showed no evidence of a significant causal association with eGFR in the MVIVW method (β = -0.117 (95% CI [-1.252 to 0.018]; p = 0.840)). We found no evidence of a reverse causal impact of eGFR on serum lipids. All our sensitivity analyses indicated no strong evidence of pleiotropy or heterogeneity between our instrumental variables for both the forward and reverse MR analysis.

INTERPRETATION

In this African ancestry population, genetically predicted higher LDL-C and TC are causally associated with higher eGFR levels, which may suggest that the relationship between LDL, TC and kidney function may be U-shaped. And as such, lowering LDL_C does not necessarily improve risk of kidney disease. This may also imply the reason why LDL_C is seen to be a poorer predictor of kidney function compared to HDL. In addition, this further supports that more work is warranted to confirm the potential association between lipid traits and risk of kidney disease in individuals of African Ancestry.

FUNDING

Wellcome (220740/Z/20/Z).

The impact of metabolic syndrome on chronic kidney disease development. Insights from a big prospective study

BACKGROUND

Chronic kidney disease (CKD) can progress over time and cause renal replacement therapy. Studies showed the association between metabolic syndrome (MetS) and CKD. Current evidence is from cross-sectional studies. There is a need for the robust data from big prospective cohort studies with long-term follow-up. This study investigated the association between CKD and MetS after 18 years of follow-up.

MATERIAL AND METHOD

Among 15,255 participants aged ≥20 years at baseline (1999-2005), after exclusion of CKD, cancer, and use of corticosteroids, 8987 participants entered the study and followed at a three-year cycle up to 2018. All participants were divided into five subgroups: (1) MetS-free, (2) MetS (DM+, HTN-), (3) MetS+ (DM-, HTN+), (4) MetS+ (DM+, HTN+) and (5) MetS+ (DM-, HTN-).

RESULT

At baseline, the mean age of the participants was 39.8 ± 13.3 years; 4996 (55.6%) were females. CKD was developed in 2038 (22.7%) subjects during 18 years of follow-up, of whom 1107 had MetS. After adjusting for the confounding variables, MetS (DM+, HTN+) subgroup had the highest risk of CKD (HR = 1.51, 95% CI = 1.32-1.71). MetS subjects with five components had a higher incidence rate of CKD (HR = 1.43, 95% CI = 1.22-1.68). There was no association between high waist circumference (WC) (HR = 1.08, 95% CI = 0.99-1.19) and high-density lipoprotein (HDL) (HR = 1.07, 95% CI = 0.98-1.18) with CKD.

CONCLUSION

CKD significantly develops in patients with MetS. Metabolic syndrome was associated with the development of chronic kidney disease incidence. Hypertension, diabetes, and age were strong indicators, while abdominal obesity and reduced HDL were not associated with the incidence of CKD.

MAFLD and NAFLD in the prediction of incident chronic kidney disease

Whether metabolic dysfunction-associated fatty liver disease (MAFLD) can replace nonalcoholic fatty liver disease (NAFLD) is under debate. This study evaluated which definition better predicted incident chronic kidney disease (CKD). This was a 5.3-year (range, 2.8-8.3) retrospective cohort study of 21,713 adults who underwent at least two serial health examinations. Cox analyses were used to compare the risk of incident CKD among non-fatty liver disease (FLD) without metabolic dysregulation (MD; reference), non-FLD with MD, MAFLD-only, NAFLD-only, or both-FLD groups. Non-FLD with MD group (hazard ratio [HR] 1.23, 95% confidence interval [CI] 1.00-1.53), both-FLD group (HR 1.50, 95% CI 1.19-1.89), and MAFLD-only group (HR 1.97, 95% CI 1.49-2.60), but not NAFLD-only group (HR 1.06, 95% CI 0.63-1.79) demonstrated an increased risk of CKD. The increased risk of CKD was significant in MAFLD subgroups with overweight/obesity (HR 2.94, 95% CI 1.91-4.55), diabetes (HR 2.20, 95% CI 1.67-2.90), MD only (HR 1.50, 95% CI 1.19-1.89), excessive alcohol consumption (HR 2.71, 95% CI 2.11-3.47), and viral hepatitis (HR 2.38, 95% CI 1.48-3.84). The switch from NAFLD to MAFLD criteria may identify a greater number of individuals at CKD risk. The association was also significant in MAFLD patients with excessive alcohol consumption or viral hepatitis.

Moxonidine ameliorates cardiac injury in rats with metabolic syndrome by regulating autophagy

AIMS

Reduced cardiac autophagy, ischemic injury, sympathetic overactivity, and apoptosis all contribute to metabolic syndrome (MetS)-associated cardiovascular risks. NR4A2, an orphan nuclear receptor NR4A family member, induces autophagy while suppressing apoptosis in myocardial infarction. Moxonidine, a sympathoinhibitor imidazoline1 receptor (I1R) agonist, has beneficial metabolic and hemodynamic effects; however, whether autophagy and/or NR4A2 signaling are involved in moxonidine's cardiovascular effects via I1R activation, is unknown, and is the aim of this study.

MATERIALS AND METHODS

To induce MetS, rats were fed 3 % salt in their diet and 10 % fructose in their drinking water for 12 weeks. MetS-rats were given either moxonidine (6 mg/kg/day, gavage), efaroxan (I1R antagonist, 0.6 mg/kg/day, i.p), both treatments, or vehicles for the last two weeks. Blood pressure, lipid profile, and glycemic control were evaluated. Histopathological examination, circulating cardiac troponin I (c-TnI), proinflammatory interleukin-6 (IL-6), apoptosis (active caspase-3 and Fas-immunostaining), interstitial fibrosis [transforming growth factor-β1 (TGF-β1), Mallory's trichrome staining], and extracellular matrix remodeling [matrix metalloproteinase-9 (MMP-9)], were used to assess cardiac pathology. Cardiac NR4A2 and its downstream factor, p53, as well as autophagic flux markers, SQSTM1/p62, LC3, and Beclin-1 were also determined.

KEY FINDINGS

Moxonidine significantly ameliorated MetS-induced metabolic and hemodynamic derangements and the associated cardiac pathology. Moxonidine restored NR4A2 and p53 myocardial levels and enhanced autophagic flux via modulating SQSTM1/p62, LC3, and Beclin-1. Efaroxan reversed the majority of the moxonidine-induced improvements.

SIGNIFICANCE

The current study suggests that autophagy modulation via I1R activation is involved in moxonidine-mediated cardiac beneficial effects in MetS.

Potential link between high FIB-4 score and chronic kidney disease in metabolically healthy men

Although the association between non-alcoholic fatty liver disease and chronic kidney disease (CKD) has been well known, it is unclear whether Fibrosis-4 (FIB-4) score is a predictor of CKD development. We performed this retrospective cohort study, with a longitudinal analysis of 5-year follow-up data from Japanese annual health check-ups. Participants with CKD (estimated glomerular filtration rate [eGFR] < 60 mL/min/1.73 m² and/or proteinuria) and a habit of alcohol consumption were excluded. The cut-off FIB-4 score was 1.30, indicating increased risk of liver fibrosis. Overall, 5353 participants (men only) were analyzed without exclusion criteria. After propensity score matching, high FIB-4 score (≥ 1.30) was not an independent risk factor for incident CKD (odds ratio [OR] 1.57; 95% confidence interval [CI] 0.97-2.56). However, high FIB-4 score was a significant risk factor for CKD in non-obese (OR 1.92; 95% CI 1.09-3.40), non-hypertensive (OR 2.15; 95% CI 1.16-3.95), or non-smoking (OR 1.88; 95% CI 1.09-3.23) participants. In these participants, FIB-4 score was strongly associated with eGFR decline in the multiple linear regression analysis (β = - 2.8950, P = 0.011). Therefore, a high FIB-4 score may be significantly associated with CKD incidence after 5 years in metabolically healthy participants.

Sirtuin 3 Deficiency Aggravates Kidney Disease in Response to High-Fat Diet through Lipotoxicity-Induced Mitochondrial Damage

Sirtuin 3 (SIRT3) is the primary mitochondrial deacetylase that controls the antioxidant pathway and energy metabolism. We previously found that renal Sirt3 expression and activity were reduced in mice with type 2 diabetic nephropathy associated with oxidative stress and mitochondrial abnormalities and that a specific SIRT3 activator improved renal damage. SIRT3 is modulated by diet, and to assess whether Sirt3 deficiency aggravates mitochondrial damage and accelerates kidney disease in response to nutrient overloads, wild-type (WT) and Sirt3^−/− mice were fed a high-fat-diet (HFD) or standard diet for 8 months. Sirt3^−/− mice on HFD exhibited earlier and more severe albuminuria compared to WT mice, accompanied by podocyte dysfunction and glomerular capillary rarefaction. Mesangial matrix expansion, tubular vacuolization and inflammation, associated with enhanced lipid accumulation, were more evident in Sirt3^−/− mice. After HFD, kidneys from Sirt3^−/− mice showed more oxidative stress than WT mice, mitochondria ultrastructural damage in tubular cells, and a reduction in mitochondrial mass and energy production. Our data demonstrate that Sirt3 deficiency renders mice more prone to developing oxidative stress and mitochondrial abnormalities in response to HFD, resulting in more severe kidney diseases, and this suggests that mitochondria protection may be a method to prevent HFD-induced renal injury.

Association of metabolic dysfunction-associated fatty liver disease with kidney disease

Non-alcoholic fatty liver disease (NAFLD) is characterized by the accumulation of fat in more than 5% of hepatocytes in the absence of excessive alcohol consumption and other secondary causes of hepatic steatosis. In 2020, the more inclusive term metabolic (dysfunction)-associated fatty liver disease (MAFLD) - defined by broader diagnostic criteria - was proposed to replace the term NAFLD. The new terminology and revised definition better emphasize the pathogenic role of metabolic dysfunction and uses a set of definitive, inclusive criteria for diagnosis. Diagnosis of MAFLD is based on evidence of hepatic steatosis (as assessed by liver biopsy, imaging techniques or blood biomarkers and scores) in persons who are overweight or obese and have type 2 diabetes mellitus or metabolic dysregulation, regardless of the coexistence of other liver diseases or excessive alcohol consumption. The known association between NAFLD and chronic kidney disease (CKD) and our understanding that CKD can occur as a consequence of metabolic dysfunction suggests that individuals with MAFLD - who by definition have fatty liver and metabolic comorbidities - are at increased risk of CKD. In this Perspective article, we discuss the clinical associations between MAFLD and CKD, the pathophysiological mechanisms by which MAFLD may increase the risk of CKD and the potential drug treatments that may benefit both conditions.

Optimal Obesity- and Lipid-Related Indices for Predicting Metabolic Syndrome in Chronic Kidney Disease Patients with and without Type 2 Diabetes Mellitus in China

Existing obesity- and lipid-related indices are inconsistent with metabolic syndrome (MetS) in chronic kidney disease (CKD) patients. We compared seven indicators, including waist circumference (WC), body mass index (BMI), visceral fat area (VFA), subcutaneous fat area (SFA), visceral adiposity index (VAI), Chinese VAI and lipid accumulation product (LAP), to evaluate their ability to predict MetS in CKD patients with and without Type 2 diabetes mellitus (T2DM) under various criteria. Multivariate logistic regression analysis was used to investigate the independent associations between the indices and metabolic syndrome among 547 non-dialysis CKD patients, aged ≥18 years. The predictive power of these indices was assessed using receiver operating characteristic (ROC) curve analysis. After adjusting for potential confounders, the correlation between VAI and MetS was strongest based on the optimal cut-off value of 1.51 (sensitivity 86.84%, specificity 91.18%) and 2.35 (sensitivity 83.54%, specificity 86.08%), with OR values of 40.585 (8.683–189.695) and 5.076 (1.247–20.657) for males and females with CKD and T2DM. In CKD patients without T2DM, based on the optimal cut-off values of 1.806 (sensitivity 98.11%, specificity 72.73%) and 3.11 (sensitivity 84.62%, specificity 83.82%), the OR values were 7.514 (3.757–15.027) and 3.008 (1.789–5.056) for males and females, respectively. The area under ROC curve (AUC) and Youden index of VAI were the highest among the seven indexes, indicating its superiority in predicting MetS in both male and female CKD patients, especially those with T2DM.

Sex-specific effects of metformin and liraglutide on renal pathology and expression of connexin 45 and pannexin 1 following long-term high-fat high-sugar diet

The comparative effects of the two commonly used antidiabetic drugs metformin and liraglutide on renal pathology and expression of connexin 45 (Cx45) and pannexin 1 (Panx1) in adult obese rats fed high-fat high-sugar diet (HFHSD) were studied. Considering recent data on the profound influence of sex on metformin and liraglutide effects, we compared the effects of both drugs between male and female animals. 44-week-old Sprague-Dawley rats were separated into 4 groups that were fed: standard diet, HFHSD, HFHSD treated with metformin (s.c., 50 mg/kg/day) and HFHSD treated with liraglutide (s.c., 0.3 mg/kg/day). Treatment with metformin or liraglutide lasted for 14 weeks. Histology and immunohistochemistry were performed to quantify renal pathological changes and Cx45 and Panx1 expression. HFHSD caused thickening of the Bowman's capsule (BC). Both metformin and liraglutide failed to ameliorate the BC thickening; metformin even worsened it. Effects on the tubulointerstitial fibrosis score, BC thickness and Cx45 and Panx1 expression were sex-dependent. We found a 50% increase in mitochondria in proximal tubules of metformin- and liraglutide-treated HFHSD-fed rats, but these effects were not dependent on the sex. This is a first study showing that the effects of metformin and liraglutide on kidney pathology in rats fed HFHSD are mostly sex-dependent and that these effects are not necessarily beneficial. Both drugs changed the Cx45 and Panx 1 expression; hence their effects could be related to amelioration of disruptions in intercellular communication.

Changes in metabolic syndrome affect the health-related quality of life of community-dwelling adults

Metabolic syndrome (MetS) is associated with cardiovascular diseases, type 2 diabetes, chronic renal diseases, and all-cause mortality. Furthermore, MetS is associated with poor health-related quality of life (HRQOL). However, the impact of dynamic changes in MetS on changes in the HRQOL was not previously explored. This was an eight-year, prospective cohort study in which 906 middle-aged adults from Shipai, Taipei in northern Taiwan were enrolled during 2009–2010 (baseline). Of those sampled, 427 participants completed the follow-up investigation after 8 years. The HRQOL was measured using the Short Form Health Survey (SF-36). Other variables including age, sex, marital status, level of education, smoking, alcohol consumption, baseline body mass index, and changes in physical activity were adjusted. Compared with adults who never experienced MetS, adults with persistent MetS had a negative change in mental HRQOL (β − 4.20, 95% CI − 7.54 to − 0.86, p = 0.01). The negative changes of persistent MetS on the HRQOL were in the domains of vitality and mental health (β − 4.42, 95% CI − 8.10 to − 0.73 and β − 3.47, 95% CI − 6.90 to − 0.04, respectively). Women and overweight adults were vulnerable to the detrimental effects of persistent MetS. For better HRQOL, more resources should be devoted to reversing MetS in public health.

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.

Juglanin protects against high fat diet-induced renal injury by suppressing inflammation and dyslipidemia via regulating NF-κB/HDAC3 signaling

Obesity is an important factor implicated in chronic kidney disease (CKD). Juglanin (Jug) is a natural compound extracted from the crude Polygonumaviculare, showing anti-inflammatory and anti-diabetic effects. However, whether Jug has protective effects against obesity-induced renal injury, little has been investigated. Herein, we attempted to explore the potential of Jug in mediating obesity-induced kidney disease in high fat diet (HFD)-challenged mice. Our results suggested that chronic HFD feeding markedly increased the body weights of mice compared to the ones fed with normal chow diet (NCD), along with significant glucose intolerance and insulin resistance. However, these metabolic disorders induced by HFD were effectively alleviated by Jug treatments in a dose-dependent manner. Moreover, HFD-challenged mice showed apparent histopathological changes in renal tissues with significant collagen accumulation, which were attenuated by Jug supplementation. In addition, Jug treatment decreased the expression levels of kidney injury molecule-1 (KIM-1), while increased nephrin and podocin expression levels in kidney of HFD-challenged mice, improving the renal dysfunction. Furthermore, HFD led to lipid deposition in kidney samples of mice by enhancing abnormal lipid metabolism. In addition, HFD promoted the releases of circulating pro-inflammatory cytokines, and enhanced the renal inflammation by activating nuclear factor-kappa B/histone deacetylase 3 (NF-κB/HDAC3) signaling. HFD-induced dyslipidemia and inflammation were considerably abrogated by Jug administration in mice. The protective effects of Jug against renal injury were confirmed in palmitate (PA)-stimulated HK2 cells in vitro mainly through suppressing the nuclear translocation of NF-κB and HDAC3, repressing inflammation and lipid accumulation eventually. Hence, Jug could ameliorate HFD-induced kidney injury mainly through blocking the NF-κB/HDAC3 nuclear translocation.

Arterial stiffness in regards to kidney function in middle-aged subjects with metabolic syndrome: Lithuanian high-risk cohort

OBJECTIVE

The current study aimed to check whether early vascular aging, measured as carotid-femoral pulse wave velocity (cfPWV), is related to kidney function, measured as creatinine-based estimated glomerular filtration (eGFR) and urinary albumin-to-creatinine ratio (UACR), in middle-aged subjects with metabolic syndrome.

METHODS

Participants were recruited from Lithuanian high-risk cohort (LitHiR). The cohort consists of middle-aged individuals with high cardiovascular risk but without overt cardiovascular disease. Participants underwent baseline and second visit hemodynamics measurement, including aortic mean arterial pressure (MAP), cfPWV, crPWV, carotid-intima media thickness measurement (CIMT) and biochemical analysis and all fulfilled NCEP/ATPIII criteria for metabolic syndrome diagnosis. First of all, we had determined correlations among hemodynamic measurement and eGFR together with albuminuria, expressed as UACR. Then we compared subjects who experienced significant eGFR decline with the remaining population and determining factors influencing this.

RESULTS

A total of 689 subject data were eligible for analysis. We observed relationship between cfPWV and MAP, crPWV, glucose, BMI, C-reactive protein, waist circumference except kidney function measured as eGFR at the baseline and at the second visit. eGFR was not associated with MAP or albuminuria. Baseline but not second visit UACR significantly positively correlated with cfPWV (r-spearman = 0.146, P = 0.003) and MAP (r-spearman = 0.142, P = 0.005). eGFR decline was mainly observed in subjects with higher baseline eGFR and was independently influenced by increase in cfPWV.

CONCLUSION

In middle-aged subjects with prevalent metabolic syndrome eGFR decline is related to aortic and not peripheral arterial stiffening. Better baseline kidney function could be possibly an effect of glomerular hyperfiltration, and it allows us to conclude that this phenomenon indicates early vascular damage and it should be addressed seriously in metabolic syndrome patients with normal kidney function.

In Silico Prediction of the Mode of Action of Viola odorata in Diabetes

Background

The metabolic syndrome increases the risk of different diseases such as type 2 diabetes. The prevalence of metabolic syndrome has rapidly grown and affected more than 230 million people worldwide. Viola odorata is a traditionally used plant for the treatment of diabetes; however, its mechanism to manage diabetes is still unknown.

Purpose

This study was designed to systematically assess the mechanism of action of Viola odorata in diabetes.

Methods

An extensive literature search was made to establish an ingredient-target database of Viola odorata. Of these, targets related to diabetes were identified and used to develop a protein-protein interaction network (PPIN) by utilizing the STITCH database. The obtained PPIN was assessed through Gene Ontology (GO) enrichment analysis based on ClueGO plugin.

Results

According to the acquired data, there were about 143 chemical constituents present in Viola odorata having 119 protein targets. Of these, 31 targets were established to give the pharmacological effect against diabetes. The UniProt database was used for screening of 31 targets, out of which Homo sapiens contained 22 targets. Ultimately, 207 GO terms, grouped into 41 clusters, were found by gene analysis, and most of them were found to be linked with diabetes. According to findings, several proteins including TP53, BCL2, CDKN1A, 1L6, CCND1, CDKN2A, and RB1 have a significant role in the treatment of diabetes by Viola odorata.

Conclusion

The possible activity of Viola odorata in the management of diabetes may be mediated by several molecular mechanisms, including the glutamine metabolic process, IRE1-mediated unfolded protein response, and pentose metabolic process.

Trace Proteinuria and the Incidence of Overt Proteinuria After Five Years: Results of the Kanagawa Investigation of the Total Checkup Data From the National Database-5 (KITCHEN-5)

Background

Trace proteinuria (TrP), which is usually defined as ± by dipstick urinalysis, is considered as normal and of limited clinical significance. However, the relationship between TrP and overt proteinuria (OP) (≥ +1) in the future is unknown. Therefore, we investigated the association between TrP and future incidence of OP in a community-based cohort study.

Methods

TrP detected during the initial 2 years, which was classified into transient TrP (once/2 years) (T-TrP) and recurrent TrP (twice/2 years) (R-TrP); and the incidence of OP after 5 years were investigated in 292,257 general Japanese people aged 40 - 68 years who attended checkups. To determine TrP and OP, dipstick urinalysis was conducted with visual reading (VR) by medical staff or automated reading (AR) using a machine reader.

Results

Overall, T-TrP and R-TrP were observed in 24,782 (8.5%) and 3,767 (1.3%) subjects, respectively. Both types of TrP were prevalent in the detection with AR than VR. The prevalences of T-TrP and R-TrP showed J-shaped relationships against baseline body mass index (BMI), regardless of sex and BMI categories. The incident of OP after 5 years was larger (around 10%) in R-TrP than T-TrP (around 5%): approximately two times. Logistic regression analysis showed that T-TrP and R-TrP were significantly associated with OP, even after adjustment for relevant confounding factors including age, sex, and BMI (odds ratios (95% confidence intervals (CIs)): 2.77 (2.60 - 2.95) and 4.85 (4.34 - 5.43)), which were not largely altered when sub-analysis was conducted according to men and women, non-obesity and obesity, or AR and VR. In all analysis above, the odds ratios (95% CIs) of R-TrP for OP were higher than T-TrP.

Conclusions

Our findings suggest that TrP, particularly R-TrP, is substantially associated with the future incidence of OP, which may be independent of confounding factors and the methods detecting TrP.

Gut bacteria-derived peptidoglycan induces a metabolic syndrome-like phenotype via NF-κB-dependent insulin/PI3K signaling reduction in Drosophila renal system

Although microbiome-host interactions are usual at steady state, gut microbiota dysbiosis can unbalance the physiological and behavioral parameters of the host, mostly via yet not understood mechanisms. Using the Drosophila model, we investigated the consequences of a gut chronic dysbiosis on the host physiology. Our results show that adult flies chronically infected with the non-pathogenic Erwinia carotorova caotovora bacteria displayed organ degeneration resembling wasting-like phenotypes reminiscent of Metabolic Syndrome associated pathologies. Genetic manipulations demonstrate that a local reduction of insulin signaling consecutive to a peptidoglycan-dependent NF-κB activation in the excretory system of the flies is responsible for several of the observed phenotypes. This work establishes a functional crosstalk between bacteria-derived peptidoglycan and the immune NF-κB cascade that contributes to the onset of metabolic disorders by reducing insulin signal transduction. Giving the high degree of evolutionary conservation of the mechanisms and pathways involved, this study is likely to provide a helpful model to elucidate the contribution of altered intestinal microbiota in triggering human chronic kidney diseases.

Genomic Heritabilities and Correlations of 17 Traits Related to Obesity and Associated Conditions in the Japanese Population

Over the past few decades, obesity has become a public health issue of global concern. Even though disparities exist between human populations, e.g., the higher liver fat content of the Japanese despite a lower body mass index (BMI), studies on the genetics of obesity still largely focus on populations of European descent, leading to a dearth of genetic data on non-European populations. In this context, this study aimed to establish a broad picture of the genetic attributes of the Japanese population, by examining a representative sample of 18,889 individuals participating in the Tohoku Medical Megabank Project cohort. We applied linear mixed model methods to 17 traits related to obesity and associated diseases to estimate the heritabilities explained by common genetic variants and the genetic correlations between each pair of traits. These analyses allowed us to quantify the SNP heritability of health indicators such as BMI (0.248 ± 0.032) and HDL cholesterol (0.324 ± 0.031), and to provide one of the few estimates of the SNP heritability of cystatin C in unrelated individuals (0.260 ± 0.025). We discuss potential differences between the Japanese and people of European ancestry with respect to the genetic correlations between urinary biomarkers and adiposity traits, for which large estimates were obtained. For instance, the genetic correlations between urine potassium level and the values for weight, BMI, waist circumference, and waist-to-height ratio ranged from 0.290 to 0.559, much higher than the corresponding estimates in the UK Biobank.

Is there an association between metabolic syndrome and rotator cuff-related shoulder pain? A systematic review

Objectives

Rotator cuff-related shoulder pain (RCRSP) is a common upper limb complaint. It has been suggested that this condition is more common among people with cardiometabolic risk factors. This systematic review has synthesised evidence from case–control, cross-sectional and cohort studies on the association between metabolic syndrome (MetS) and RCRSP.

Design and data sources

Five medical databases (MEDLINE, EMBASE, SCOPUS, CINAHL and AMED) and reference checking methods were used to identify all relevant English articles that considered MetS and RCRSP. Studies were appraised using the Newcastle-Ottawa Scale (NOS). Two reviewers performed critical appraisal and data extraction. Narrative synthesis was performed via content analysis of statistically significant associations.

Results

Three cross-sectional, two case–control and one cohort study met the inclusion criteria, providing a total of 1187 individuals with RCRSP. Heterogeneity in methodology and RCRSP or MetS definition precluded a meaningful meta-analysis. Four of the included studies identified associations between the prevalence of MetS and RCRSP. Studies consistently identified independent cardiometabolic risk factors associated with RCRSP. All studies were level III evidence.

Summary and conclusion

The low-moderate quality evidence included in this review suggests an association between MetS and RCRSP. Most studies demonstrated moderate quality on appraisal. The direction of association and cardiometabolic factors influencing should be investigated by longitudinal and treatment studies. These preliminary conclusions and clinical utility should be treated with caution due to limitations of the evidence base.

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.

A journey from microenvironment to macroenvironment: the role of metaflammation and epigenetic changes in cardiorenal disease

Chronic non-communicable diseases have become a pandemic public problem in the 21st century, causing enormous burden on the economy, health and quality of life of societies. The role of a chronic inflammatory state in the pathogenesis of chronic disease has been more comprehensively recognized by recent findings. The new paradigm ‘metaflammation’ focuses on metabolism-induced (high fat or fructose-based diet or excessive calorie intake) chronic inflammation. There is a close correlation between the increased incidence of chronic kidney disease (CKD) and chronic heart failure with both increased inflammatory marker levels and western-type diet. In this review we describe the concept of metaflammation, its role in the development of CKD and chronic heart disease, the molecular and signalling pathways involved and the therapeutic consequences.

Aerobic interval exercise improves renal functionality and affects mineral metabolism in obese Zucker rats

Obesity, metabolic syndrome, and renal injury are considered risk factors for type 2 diabetes, as well as kidney disease. Functional and structural changes in the kidney as consequence of obesity and metabolic syndrome may lead to impaired mineral metabolism in what is known as chronic kidney disease-mineral and bone disorder. Lifestyle interventions such as physical activity are good strategies to manage these pathologies and therefore, prevent the loss of kidney functionality and related complications in mineral metabolism. In this study, we have used 40 male Zucker rats that were randomly allocated into four different experimental groups, two of them (an obese and a lean one) performed an aerobic interval training protocol, and the other two groups were sedentary. At the end of the experimental period (8 wk), urine, plasma, and femur were collected for biochemical and mineral composition analysis, whereas the kidney was processed for histological studies. The obese rats exhibited albuminuria, glomerulosclerosis, and hypertrophy in glomeruli and renal tubule in some areas, together with alterations in mineral content of plasma but not of femur. The training protocol prevented the generation of albuminuria and glomerulosclerosis, showing a significant action on plasma and bone mineral levels. Therefore, the specific training protocol used in this study was able to prevent the development of diabetic nephropathy and affected the metabolism of certain minerals.

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

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

Long-term quality-of-care score predicts incident chronic kidney disease in patients with type 2 diabetes

Background

Chronic kidney disease (CKD) is a common complication of diabetes, and requires long-term medical care. However, besides the blood glucose level, no reliable method is currently available to link the quality of care and the development of CKD. We therefore developed a long-term quality-of-care score for predicting the occurrence of CKD in patients with type 2 diabetes.

Methods

In this retrospective cohort study, using Taiwan's Longitudinal Cohort of Diabetes Patients Database and the medical records in a medical center, we identified incident patients with type 2 diabetes during 1999-2003 and followed them until 2011. A quality-of-care score (from 0 to 8) was calculated according to process indicators (frequencies of HbA1c and lipid profile testing and urine, foot, and retinal examinations), intermediate outcome indicators (low-density lipoprotein, blood pressure, and HbA1c) and comorbidity of hypertension. We used Cox regression models to evaluate the association between the score and the incidence of CKD.

Results

Of the 4754 patients enrolled, 1407 developed CKD after a mean follow-up of 9.06 years. Compared with the risk of developing a CKD event in patients with scores ≤2, the risk was 69% lower in those with quality-of-care scores ≥5 (hazard ratio [HR] 0.31; 95% confidence interval [CI] 0.25-0.40) and 33% lower in those with scores between 3 and 4 (HR 0.67; 95% CI 0.59-0.77).

Conclusions

Good quality of care can reduce the risk of CKD in patients with type 2 diabetes. The score developed in this study had a significant association with the risk of CKD and thus can be applied to guide the care for these patients.

Potential adverse effects of botanical supplementation in high-fat-fed female mice

BACKGROUND

Insulin resistance underlies metabolic syndrome and is associated with excess adiposity and visceral fat accumulation, which is more frequently observed in males than females. However, in young females, the prevalence of metabolic syndrome is rising, mainly driven by accumulation of abdominal visceral fat. The degree to which sex-related differences could influence the development of insulin resistance remains unclear, and studies of potential therapeutic strategies to combat metabolic syndrome using rodent models have focused predominantly on males. We therefore evaluated the effects of two nutritional supplements derived from botanical sources, an extract of Artemisia dracunculus L. (termed PMI5011) and Momordica charantia (commonly known as bitter melon), on female mice challenged with a high-fat diet in order to determine if dietary intake of these supplements could ameliorate obesity-induced insulin resistance and metabolic inflexibility in skeletal muscle.

METHODS

Body composition, physical activity and energy expenditure, fatty acid oxidation, insulin signaling, and gene and protein expression of factors controlling lipid metabolism and ectopic lipid accumulation were evaluated in female mice fed a high-fat diet supplemented with either PMI5011 or bitter melon. Statistical significance was assessed by unpaired two-tailed t test and repeated measures ANOVA.

RESULTS

PMI5011 supplementation resulted in increased body weight and adiposity, while bitter melon did not induce changes in these parameters. Pyruvate tolerance testing indicated that both supplements increased hepatic glucose production. Both supplements induced a significant suppression in fatty acid oxidation in skeletal muscle homogenates treated with pyruvate, indicating enhanced metabolic flexibility. PMI5011 reduced lipid accumulation in skeletal muscle, while bitter melon induced a downward trend in lipid accumulation in the skeletal muscle and liver. This was accompanied by transcriptional regulation of autophagic genes by bitter melon in the liver.

CONCLUSIONS

Data from the current study indicates that dietary supplementation with PMI5011 and bitter melon evokes a divergent, and generally less favorable, set of metabolic responses in female mice compared to effects previously observed in males. Our findings underscore the importance of considering sex-related variations in responses to dietary supplementation aimed at combating metabolic syndrome.

The relationship between chronic rhinosinusitis and metabolic syndrome

BACKGROUND

This study aimed to investigate the correlation between metabolic syndrome and chronic rhinosinusitis (CRS), with related risk factors for CRS according to data from the Korean National Health and Nutrition Examination Survey (KNHANES).

METHODS

The KNHANES surveyed individuals >19 years of age from January 2010 to December 2011. CRS encompassed "symptom-based CRS" as defined by the European Position Paper on Rhinosinusitis and Nasal Polyps 2012. Metabolic syndrome was diagnosed according to the American Heart Association/National Heart Lung and Blood Institute criteria. A χ2 analysis, univariate analysis, and multivariate analysis were conducted.

RESULTS

A total of 12,015 individuals were analyzed in this study. The prevalence of CRS in the patients with metabolic syndrome (high triglyceride level, reduced high-density lipoprotein level, and elevated blood pressure) was significantly higher than that in patients without metabolic syndrome (14.15 versus 10.16%) (p < 0.05). Allergic rhinitis was the only significant risk factor for CRS found to be associated with metabolic syndrome (p < 0.05).

CONCLUSION

CRS was more prevalent in patients with metabolic syndrome, especially those with allergic rhinitis, than in patients without metabolic syndrome. Accordingly, CRS should be considered in patients with metabolic syndrome and allergic rhinitis.

Cytokine-mediated inflammation mediates painful neuropathy from metabolic syndrome

Painful neuropathy (PN) is a prevalent condition in patients with metabolic syndrome (MetS). However, the pathogenic mechanisms of metabolic syndrome-associated painful neuropathy (MetSPN) remain unclear. In the current study, high-fat-fed mice (HF mice) were used to study MetSPN. HF mice developed MetS phenotypes, including increased body weight, elevated plasma cholesterol levels, and insulin resistance in comparison with control-fat-fed (CF) mice. Subsequently, HF mice developed mechanical allodynia and thermal hyperalgesia in hind paws after 8 wk of diet treatment. These pain behaviors coincided with increased densities of nociceptive epidermal nerve fibers and inflammatory cells such as Langerhans cells and macrophages in hind paw skin. To study the effect of MetS on profiles of cytokine expression in HF mice, we used a multiplex cytokine assay to study the protein expression of 12 pro-inflammatory and anti-inflammatory cytokines in dorsal root ganglion and serum samples. This method detected the elevated levels of proinflammatory cytokines, including tumor necrosis factor (TNF)-α, and interleukin (IL)-6, IL-1β as well as reduced anti-inflammatory IL-10 in lumbar dorsal root ganglia (LDRG) of HF mice. Intraperitoneal administration of IL-10 reduced the upregulation of pro-inflammatory cytokines and alleviated pain behaviors in HF mice without affecting MetS phenotypes. Our findings suggested targeting HF-induced cytokine dysregulation could be an effective strategy for treating MetSPN.

Diet and enteral nutrition in patients with chronic kidney disease not on dialysis: a review focusing on fat, fiber and protein intake

The clinical data available on dietary requirements of patients with chronic kidney disease (CKD) not on dialysis are limited and largely inconclusive in terms of the renal, cardiovascular and nutritional outcomes achievable through dietary modifications. Restriction of protein intake during the early stages of CKD may in fact slow its progression, but at the same time this approach may also lead to protein-energy wasting, if energy intake is not adequate and properly monitored. Unfortunately, compliance to dietary recommendations is traditionally low in this patient population. A switch from saturated to mono- and polyunsaturated fats is generally recognized as advantageous for cardiac health; however, the benefits in term of renal function are largely unknown. Similarly, the association between dietary fiber intake and kidney disease is largely unknown. In fact, while there is evidence on the positive health effects of dietary fibers in the general population, nutritional guidelines for CKD lack formal recommendations concerning fiber intake. This paper reviews data and evidence from clinical trials and meta-analyses on renal and cardiovascular outcomes related to modifications in protein, fat and fiber intake. Suggestions for maintaining nutritional status through patient-oriented dietary patterns and enteral supplementation in CKD patients on conservative therapy are also presented.

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.

HDL Cholesterol, LDL Cholesterol, and Triglycerides as Risk Factors for CKD: A Mendelian Randomization Study

BACKGROUND

High-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, and triglyceride concentrations are heritable risk factors for vascular disease, but their role in the progression of chronic kidney disease (CKD) is unclear.

STUDY DESIGN

2-sample Mendelian randomization analysis of data derived from the largest published lipid and CKD studies.

SETTING & PARTICIPANTS

Effect of independent genetic variants significantly associated with lipid concentrations was obtained from the Global Lipids Genetics Consortium (n=188,577), and the effect of these same variants on estimated glomerular filtration rate (eGFR), CKD (defined as eGFR<60mL/min/1.73m²), and albuminuria was obtained from the CKD Genetics Consortium (n=133,814).

FACTOR

Using conventional, multivariable, and Egger Mendelian randomization approaches, we assessed the causal association between genetically determined lipid concentrations and kidney traits.

OUTCOME

eGFR, dichotomous eGFR<60mL/min/1.73m², and albuminuria.

RESULTS

In multivariable analysis, a 17-mg/dL higher HDL cholesterol concentration was associated with an 0.8% higher eGFR (95% CI, 0.4%-1.3%; P=0.004) and lower risk for eGFR<60mL/min/1.73m² (OR, 0.85; 95% CI, 0.77-0.93; P<0.001), while Egger analysis showed no evidence of pleiotropy. There was no evidence for a causal relationship between LDL cholesterol concentration and any kidney disease measure. Genetically higher triglyceride concentrations appeared associated with higher eGFRs, but this finding was driven by a single pleiotropic variant in the glucokinase regulator gene (GCKR). After exclusion, genetically higher triglyceride concentration was not associated with any kidney trait.

LIMITATIONS

Individual patient-level phenotype and genotype information were unavailable.

CONCLUSIONS

2-sample Mendelian randomization analysis of data from the largest lipid and CKD cohorts supports genetically higher HDL cholesterol concentration as causally associated with better kidney function. There was no association between genetically altered LDL cholesterol or triglyceride concentration and kidney function. Further analysis of CKD outcomes in HDL cholesterol intervention trials is warranted.

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.

Serum Gamma-Glutamyl Transferase and Ferritin Synergistically Associated with the Rate of Chronic Kidney Disease

The present study investigated the effects of GGT and SF on the risk of CKD. 1024 participants (436 men and 588 women) were divided into three groups according to GGT and SF levels: group 1 (both GGT and SF not in the fourth quartile), group 2 (only GGT or SF in the fourth quartile), and group 3 (both GGT and SF in the fourth quartile). The risks of CKD in different levels of GGT and SF and in groups 2-3 compared with group 1 were analyzed by multiple logistic regression. GGT or SF in the highest quartile was associated with increased risk of CKD. Such associations attenuated after adjustment for confounding factors. The incidences of CKD, especially albuminuria, increased across the three groups. Correspondingly, malondialdehyde (MDA) levels gradually increased from group 1 to group 3. The risks of CKD were higher in groups 2 and 3 than that in group 1. In group 3, the increased rate was independent of age, BMI, alcohol drinking, diabetes mellitus, hypertension, hypertriglyceridemia, and metabolic syndrome (odds ratios from 1.887 to 2.293, P < 0.05). In summary, this study suggested that GGT and SF synergistically influence the rate of CKD.

Alkaline phosphatase: a novel treatment target for cardiovascular disease in CKD

Cardiovascular disease is the main cause of early death in the settings of chronic kidney disease (CKD), type 2 diabetes mellitus (T2DM), and ageing. Cardiovascular events can be caused by an imbalance between promoters and inhibitors of mineralization, which leads to vascular calcification. This process is akin to skeletal mineralization, which is carefully regulated and in which isozymes of alkaline phosphatase (ALP) have a crucial role. Four genes encode ALP isozymes in humans. Intestinal, placental and germ cell ALPs are tissue-specific, whereas the tissue-nonspecific isozyme of ALP (TNALP) is present in several tissues, including bone, liver and kidney. TNALP has a pivotal role in bone calcification. Experimental overexpression of TNALP in the vasculature is sufficient to induce vascular calcification, cardiac hypertrophy and premature death, mimicking the cardiovascular phenotype often found in CKD and T2DM. Intestinal ALP contributes to the gut mucosal defence and intestinal and liver ALPs might contribute to the acute inflammatory response to endogenous or pathogenic stimuli. Here we review novel mechanisms that link ALP to vascular calcification, inflammation, and endothelial dysfunction in kidney and cardiovascular diseases. We also discuss new drugs that target ALP, which have the potential to improve cardiovascular outcomes without inhibiting skeletal mineralization.

Cardiovascular consequences of metabolic syndrome

The metabolic syndrome (MetS) is defined as the concurrence of obesity-associated cardiovascular risk factors including abdominal obesity, impaired glucose tolerance, hypertriglyceridemia, decreased HDL cholesterol, and/or hypertension. Earlier conceptualizations of the MetS focused on insulin resistance as a core feature, and it is clearly coincident with the above list of features. Each component of the MetS is an independent risk factor for cardiovascular disease and the combination of these risk factors elevates rates and severity of cardiovascular disease, related to a spectrum of cardiovascular conditions including microvascular dysfunction, coronary atherosclerosis and calcification, cardiac dysfunction, myocardial infarction, and heart failure. While advances in understanding the etiology and consequences of this complex disorder have been made, the underlying pathophysiological mechanisms remain incompletely understood, and it is unclear how these concurrent risk factors conspire to produce the variety of obesity-associated adverse cardiovascular diseases. In this review, we highlight current knowledge regarding the pathophysiological consequences of obesity and the MetS on cardiovascular function and disease, including considerations of potential physiological and molecular mechanisms that may contribute to these adverse outcomes.

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.

Nematodes and human therapeutic trials for inflammatory disease

Helminth infections likely provide a protective influence against some immune-mediated and metabolic diseases because helminth infection dramatically decreased in developed countries shortly before the explosive rise in the prevalence of these diseases. The capacity of helminths to activate immune-regulatory circuits in their hosts and to modulate the composition of intestinal flora appears to be the mechanisms of protective action. Animal models of disease show that various helminth species prevent and/or block inflammation in various organs in a diverse range of diseases. Clinical trials have demonstrated that medicinal exposure to Trichuris suis or small numbers of Necator americanus is safe with minor, if any, reported adverse effects. This includes exposure of inflamed intestine to T. suis, asthmathic lung to N. americanus and in patients with atopy. Efficacy has been suggested in some small studies, but is absent in others. Factors that may have led to inconclusive results in some trials are discussed. To date, there have been no registered clinical trials using helminths to treat metabolic syndrome or its component conditions. However, the excellent safety profile of T. suis or N. americanus suggests that such studies should be possible.

Daily Intake of Grape Powder Prevents the Progression of Kidney Disease in Obese Type 2 Diabetic ZSF1 Rats

Individuals living with metabolic syndrome (MetS) such as diabetes and obesity are at high risk for developing chronic kidney disease (CKD). This study investigated the beneficial effect of whole grape powder (WGP) diet on MetS-associated CKD. Obese diabetic ZSF1 rats, a kidney disease model with MetS, were fed WGP (5%, w/w) diet for six months. Kidney disease was determined using blood and urine chemical analyses, and histology. When compared to Vehicle controls, WGP intake did not change the rat bodyweight, but lowered their kidney, liver and spleen weight, which were in parallel with the lower serum glucose and the higher albumin or albumin/globin ratio. More importantly, WGP intake improved the renal function as urination and proteinuria decreased, or it prevented kidney tissue damage in these diabetic rats. The renal protection of WGP diet was associated with up-regulation of antioxidants (Dhcr24, Gstk1, Prdx2, Sod2, Gpx1 and Gpx4) and downregulation of Txnip (for ROS production) in the kidneys. Furthermore, addition of grape extract reduced H₂O₂-induced cell death of cultured podocytes. In conclusion, daily intake of WGP reduces the progression of kidney disease in obese diabetic rats, suggesting a protective function of antioxidant-rich grape diet against CKD in the setting of MetS.

Stirring the Pot: Can Dietary Modification Alleviate the Burden of CKD?

Diet is one of the largest modifiable risk factors for chronic kidney disease (CKD)-related death and disability. CKD is largely a progressive disease; however, it is increasingly appreciated that hallmarks of chronic kidney disease such as albuminuria can regress over time. The factors driving albuminuria resolution remain elusive. Since albuminuria is a strong risk factor for GFR loss, modifiable lifestyle factors that lead to an improvement in albuminuria would likely reduce the burden of CKD in high-risk individuals, such as patients with diabetes. Dietary therapy such as protein and sodium restriction has historically been used in the management of CKD. Evidence is emerging to indicate that other nutrients may influence kidney health, either through metabolic or haemodynamic pathways or via the modification of gut homeostasis. This review focuses on the role of diet in the pathogenesis and progression of CKD and discusses the latest findings related to the mechanisms of diet-induced kidney disease. It is possible that optimizing diet quality or restricting dietary intake could be harnessed as an adjunct therapy for CKD prevention or progression in susceptible individuals, thereby reducing the burden of CKD.

On the occasion of world kidney day 2017; obesity and its relationship with chronic kidney disease

Context:

Numerous studies have reported the impact of obesity in the incidence of chronic kidney disease (CKD). Some studies have suggested the direct role of obesity in the incidence of CKD, while some other studies suggest an indirect effect caused by the effects of obesity on blood pressure and diabetes.

Evidence Acquisition:

PubMed, EBSCO, Web of Science, directory of open access journals (DOAJ), EMBASE, and Google Scholar have been searched.

Results:

Recent studies have presented more strong evidences on the role of obesity on the incidence of CKD. The double role of obesity in the incidence of CKD has also been mentioned in some studies.

Conclusions:

Such an additional effect arises from the impact of obesity on the incidence of some conditions and diseases such as cardiovascular disease, hypertension, and diabetes, which in turn are involved in the incidence of CKD and are considered as its risk factors.

Homocysteine and hydrogen sulfide in epigenetic, metabolic and microbiota related renovascular hypertension

Over the past several years, hydrogen sulfide (H₂S) has been shown to be an important player in a variety of physiological functions, including neuromodulation, vasodilation, oxidant regulation, inflammation, and angiogenesis. H₂S is synthesized primarily through metabolic processes from the amino acid cysteine and homocysteine in various organ systems including neuronal, cardiovascular, gastrointestinal, and kidney. Derangement of cysteine and homocysteine metabolism and clearance, particularly in the renal vasculature, leads to H₂S biosynthesis deregulation causing or contributing to existing high blood pressure. While a variety of environmental influences, such as diet can have an effect on H₂S regulation and function, genetic factors, and more recently epigenetics, also have a vital role in H₂S regulation and function, and therefore disease initiation and progression. In addition, new research into the role of gut microbiota in the development of hypertension has highlighted the need to further explore these microorganisms and how they influence the levels of H₂S throughout the body and possibly exploiting microbiota for use of hypertension treatment. In this review, we summarize recent advances in the field of hypertension research emphasizing renal contribution and how H₂S physiology can be exploited as a possible therapeutic strategy to ameliorate kidney dysfunction as well as to control blood pressure.

Prevalence of Reduced Kidney Function by Estimated Glomerular Filtration Rate Using an Equation Based on Creatinine and Cystatin C in Metabolic Syndrome and Its Components in Korean Adults

BACKGROUND

It is known that metabolic syndrome (MetS) is associated with chronic kidney disease. We evaluated and compared the prevalence of reduced kidney function in MetS and its components by estimated glomerular filtration rate (eGFR) using an equation based on creatinine (eGFRcr), cystatin C (eGFRcys), and combined creatinine-cystatin C (eGFRcr-cys) in Korean adults.

METHODS

We analyzed data from 3,649 adults who participated in a comprehensive health examination.

RESULTS

Mean values of eGFRcys were higher compared with mean values of eGFRcr (96.1±18.2 mL/min/1.73 m² vs. 91.2±13.6 mL/min/1.73 m²) in total subjects. The prevalence of reduced kidney function increased with age (9.6% for eGFRcys vs. 5.8% for eGFRcr-cys vs. 4.9% for eGFRcr, in subjects aged ≥60 years), and significantly increased with MetS, abdominal obesity, hypertension, high triglyceride, low high density lipoprotein (HDL), and high insulin resistance. The prevalence of MetS, abdominal obesity, hypertension, high insulin resistance, low HDL, and hepatic steatosis was significantly increased in subjects with reduced kidney function. This increased prevalence and the odds ratio of reduced kidney function for prevalence of MetS was highest for eGFRcys, followed by those of eGFRcr-cys, and eGFRcr.

CONCLUSION

The prevalence of reduced kidney function by eGFR was significantly increased in subjects with MetS and its related components. eGFRcys and eGFRcr-cys were superior to eGFRcr in detecting reduced kidney function.

Abdominal Obesity, Race and Chronic Kidney Disease in Young Adults: Results from NHANES 1999-2010

OBJECTIVE

Kidney dysfunction in obesity may be independent of and may precede the development of hypertension and/or diabetes mellitus. We aimed to examine if abdominal obesity is associated with early markers of CKD in a young healthy population and whether these associations differ by race and/or ethnicity.

METHODS

We analyzed data from the NHANES 1999-2010 for 6918 young adults ages 20-40 years. Abdominal obesity was defined by gender criteria of waist circumference. CKD markers included estimated glomerular filtration rate and albuminuria ≥30 mg/g. Race stratified analyses were done overall and in subgroups with normal blood pressures, normoglycemia and normal insulin sensitivity. Awareness of CKD was assessed in participants with albuminuria.

RESULTS

Abdominal obesity was present in over one-third of all young adults and was more prevalent among non-Hispanic blacks (45.4%) versus Mexican-Americans (40.6%) or non-Hispanic whites (37.4%) (P-value = 0.004). Mexican-American young adults with abdominal obesity had a higher odds of albuminuria even among those with normal blood pressure, normal glucose, and normal insulin sensitivity [adjusted odds ratio 4.5; 95% confidence interval (1.6-12.2), p = 0.004]. Less than 5% of young adults with albuminuria of all races and ethnicities had been told they had kidney disease.

CONCLUSION

Abdominal obesity in young adults, especially in Mexican-Americans, is independently associated with albuminuria even with normal blood pressures, normoglycemia and normal insulin levels. Greater awareness of CKD is needed to protect this young population from long-standing exposure to abdominal obesity and early progressive renal disease.

Risk profiles of referred chronic kidney disease patients in a tertiary nephrology centre

Objective:

To determine the risk profile of chronic kidney disease (CKD) patients.

Methods:

This is an observational cross sectional study involving 130 patients for which data was collected prospectively.. Sixty five subjects with an estimated glomerular filtration rate (eGFR) below 120 ml/min/1.73 m² were recruited via random sampling technique from nephrology clinic in a tertiary nephrology referral center. Medical history, demographic data, urinary and serum biochemistry tests were obtained.

Results:

Most of the CKD patients who were referred to the nephrology clinic were asymptomatic. The most common laboratory abnormalities noted among CKD patients were proteinuria, anaemia and hyperkalaemia. Advancing age, pre-existing morbidities such as diabetes mellitus, hypertension and overweight are characteristics that are strongly associated with the referred CKD patients.

Conclusions:

Most of the referred CKD patients are in advanced age with diabetes, hypertension and overweight. Majority of the CKD remained asymptomatic despite in the advance stage of CKD. This strongly calls for cost effective screening for population at risk.

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.