Obesity and metabolic syndrome-related chronic kidney disease in nondiabetic, nonhypertensive adults

A mendelian randomization study revealing that metabolic syndrome is causally related to renal failure

Background

The onset and progression of chronic kidney disease (CKD) has been linked to metabolic syndrome (MetS), with the results of recent observational studies supporting a potential link between renal failure and MetS. The causal nature of this relationship, however, remains uncertain. This study thus leveraged a Mendelian Randomization (MR) approach to probe the causal link of MetS with renal failure.

Methods

A genetic database was initially used to identify SNPs associated with MetS and components thereof, after which causality was evaluated through the inverse variance weighted (IVW), MR-Egger regression, and weighted media techniques. Results were subsequently validated through sensitivity analyses.

Results

IVW (OR = 1.48, 95% CI = 1.21-1.82, P =1.60E-04) and weighted median (OR = 1.58, 95% CI =1.15-2.17, P = 4.64E-03) analyses revealed that MetS was linked to an elevated risk of renal failure. When evaluating the specific components of MetS, waist circumference was found to be causally related to renal failure using the IVW (OR= 1.58, 95% CI = 1.39-1.81, P = 1.74e-11), MR-Egger (OR= 1.54, 95% CI = 1.03-2.29, P = 0.036), and weighted median (OR= 1.82, 95% CI = 1.48-2.24, P = 1.17e-8). The IVW method also revealed a causal association of hypertension with renal failure (OR= 1.95, 95% CI = 1.34-2.86, P = 5.42e-04), while renal failure was not causally related to fasting blood glucose, triglyceride levels, or HDL-C levels.

Conclusion

These data offer further support for the existence of a causal association of MetS with kidney failure. It is thus vital that MetS be effectively managed in patients with CKD in clinical settings, particularly for patients with hypertension or a high waist circumference who are obese. Adequate interventions in these patient populations have the potential to prevent or delay the development of renal failure.

[Triglyceride-glucose product is an independent risk factor for predicting chronic kidney disease in middle-aged and elderly population: a prospective cohort study]

OBJECTIVE

To explore the correlation of triglyceride-glucose product (TyG) index with chronic kidney disease (CKD) in elderly population in Lanzhou (Gansu Province, China).

METHODS

From May to September, 2011, a total of 3868 middleaged and elderly individuals without CKD from 3 communities in Lanzhou were selected as the cohort study population and were followed for an average of 3.1 years (from June, 2014 to August, 2015). After excluding those with missing follow-up data, a total of 3439 individuals were included for analysis, who were divided according to the quartile of TyG index into Q1 group (TyG≤8.47), Q2 group (TyG 8.48-8.84), Q3 group (TyG 8.85-9.20) and Q4 group (TyG>9.20). The estimated glomerular filtration rate (eGFR) and urinary albumin/creatinine ratio (UACR) were used to evaluate the renal function of the participants.

RESULTS

In this cohort, a high TyG index was found to correlate with a high risk of CKD (P < 0.05). Analysis of the follow-up data showed that the TyG index was significantly higher in patients who developed CKD during the follow-up than in those without CKD (P < 0.05). Logistic regression analysis showed that TyG index was an independent risk factor for abnormal eGFR and CKD (P < 0.05).

CONCLUSION

A high TyG index is an independent risk factor for CKD in middle-aged and elderly population.

The Influencing Factors of Bacterial Resistance Related to Livestock Farm: Sources and Mechanisms

Bacterial resistance is a complex scientific issue. To manage this issue, we need to deeply understand the influencing factors and mechanisms. Based on the background of livestock husbandry, this paper reviews the factors that affect the acquisition of bacterial resistance. Meanwhile, the resistance mechanism is also discussed. “Survival of the fittest” is the result of genetic plasticity of bacterial pathogens, which brings about specific response, such as producing adaptive mutation, gaining genetic material or changing gene expression. To a large extent, bacterial populations acquire resistance genes directly caused by the selective pressure of antibiotics. However, mobile resistance genes may be co-selected by other existing substances (such as heavy metals and biocides) without direct selection pressure from antibiotics. This is because the same mobile genetic elements as antibiotic resistance genes can be co-located by the resistance determinants of some of these compounds. Furthermore, environmental factors are a source of resistance gene acquisition. Here, we describe some of the key measures that should be taken to mitigate the risk of antibiotic resistance. We call on the relevant governments or organizations around the world to formulate and improve the monitoring policies of antibiotic resistance, strengthen the supervision, strengthen the international cooperation and exchange, and curb the emergence and spread of drug-resistant strains.

The ratio of triglycerides to high-density lipoprotein cholesterol is associated with the risk of chronic kidney disease in Korean men

Dyslipidemia is nephrotoxic and can result in the development of chronic kidney disease (CKD). The ratio of triglycerides (TG) to high-density lipoprotein cholesterol (HDL-C) (TG/HDL-C ratio) is well-correlated with insulin resistance and cardiovascular events. The aim of this study is to examine the association between the TG/HDL-C ratio and CKD in Korean adults. This study was retrospectively designed based on the National Health Insurance Service-National Health Screening cohort. Seventy three thousand and fifty-two participants aged between 40 and 79 years old at baseline (2009-2010) were included in the final analyses. The study population was classified into three tertile groups (T₁ , T₂ , and T₃ ) according to the TG/HDL-C ratio by sex. Adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for CKD were calculated using Cox proportional hazard regression models. The median follow-up duration was 5.9 years. Higher tertile groups of the TG/HDL-C ratio had lower estimated glomerular filtration rates in both sexes. The cumulative incidence of CKD of T₁ , T₂ , and T₃ was 11.89%, 12.90%, and 12.91%, respectively, in men and 10.17%, 10.61%, and 14.87%, respectively, in women (all p values < 0.001). Compared with T₁ of the TG/HDL-C ratio, the HRs (95% CIs) of T₂ and T₃ for CKD were 1.212 (1.118-1.315) and 1.183 (1.087-1.287), respectively, in men and 0.895 (0.806-0.994) and 1.038 (0.937-1.150), respectively, in women after being fully adjusted. Higher TG/HDL-C ratios were positively associated with CKD development in men, while middle levels of TG/HDL ratios reduced the CKD incidence in women.

Effect of Dietary Copper on Intestinal Microbiota and Antimicrobial Resistance Profiles of Escherichia coli in Weaned Piglets

Copper is an essential microelement for animals, and not only it has been used as a feed additive at pharmacological doses in swine production to improve growth performance, but it also has an effect on intestinal microbes by enhancing host bacterial resistance. However, there are few reports on the effects of pharmacological doses of copper on intestinal microorganisms and the antimicrobial resistance profiles of pathogenic bacteria, such as Escherichia coli, in pigs. Therefore, this study aimed to investigate the effects of pharmacological doses of copper on the microbial communities in the hindgut and the antimicrobial resistance profiles of E. coli in weaned piglets. Twenty-four healthy weaned piglets aged 21 ± 1 days and with an average weight of 7.27 ± 0.46 kg were randomly divided into four groups. The control group was fed a basal diet, while the treatment groups were fed a basal diet supplemented with 20, 100, or 200 mg copper/kg feed, in the form of CuSO₄. Anal swabs were collected at 0, 21, and 42 days of the trial, and E. coli was isolated. Meanwhile, the contents of the ileum and cecum from the control and 200 mg copper/kg feed groups were collected at 21 and 42 days for microbial community analysis and E. coli isolation. All isolated E. coli strains were used for antimicrobial resistance profile analysis. A pharmacological dose of copper did not significantly change the diversity, but significantly affected the composition, of microbial communities in the ileum and cecum. Moreover, it affected the microbial metabolic functions of energy metabolism, protein metabolism, and amino acid biosynthesis. Specifically, copper treatment increased the richness of E. coli in the hindgut and the rates of E. coli resistance to chloramphenicol and ciprofloxacin. Moreover, the rate of E. coli resistance to multiple drugs increased in the ileum of pigs fed a pharmacological dose of copper. Thus, a pharmacological dose of copper affected the composition of the microbial community, increased the antimicrobial resistance rates of intestinal E. coli, and was most likely harmful to the health of piglets at the early stage after weaning.

Lp-PLA2 Selective Inhibitor (Darapladib) Effect In Lowering The Expression Level Of IL-1B And IL-6 In The Renal At Type 2 Diabetes Mellitus

PURPOSE

The aim of this study is to prove that type 2 diabetes mellitus can induce increasing inflammation marker in renal and that the provision of darapladib as Lp-LA2 Inhibitor agents can inhibit inflammation that were measured from the expression of IL-1B and IL-6- type cytokine in renal. This study also discusses the correlation between IL-1B and IL-6- type cytokine expression in renal.

METHODS

Thirty Sprague-Dawley (SD) rats were divided into three main groups; those are negative control group (NC), Type 2 Diabetes Mellitus group (T2DM) given high fat diet (HFD) with streptozotocin intraperitoneal injection (35mg/kg BW) and diabetes mellitus + darapladib group (DM + DP). Each group was treated within two serial treatment time: 8 weeks and 16 weeks. Expressions of IL-1B and IL-6- type cytokine in renal were the markers that we measured by immunofluorosense method.

RESULTS

The administration of darapladib can significantly decrease the expression of IL-1B- type cytokine (p ANOVA = 0.029, p < 0.005) measured in rats' renal both at weeks 8 and 16 in the T2DM group. The Expression of IL-6- type cytokine also showed a significant difference after treated with darapladib both at weeks 8 and 16 in T2DM group with p-value of ANOVA = 0.033, p < 0.005. The Pearson correlation showed a strong correlation (linear regression value was r2 = 0.743).

CONCLUSION

Our results show that atherosclerosis caused by inflammation in renal T2DM SD rats could be inhibited by the administration of darapladib.

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.

Association between waist-to-height ratio and chronic kidney disease in the Taiwanese population

BACKGROUND

Obesity, metabolic syndrome (MS) and chronic kidney disease (CKD) are all becoming increasingly prevalent worldwide. Body mass index (BMI) has traditionally been employed to identify overweight or obese individuals, yet multiple studies have yielded conflicting results when BMI was used to evaluate the association between obesity and CKD.

AIMS

The purpose of this large, population-based, multicentre study was to evaluate the associations of BMI and waist-to-height ratio (WHtR) with CKD.

METHODS

A retrospective study of 41,600 subjects who had physical examinations from January 2010 to December 2011 was performed. Data such as life style and habits were collected by interviews, and systolic and diastolic blood pressure (SBP and DBP), height, body weight, waist circumference, total cholesterol (TC), high-density lipoproteins (HDL), triglycerides (TG), fasting blood glucose and creatinine levels were measured. The association of these factors with CKD was analysed by use of SPSS 15.0 software.

RESULTS

The key findings of this study were that WHtR but not BMI was an independent predictor of CKD. Additionally, SBP was a predictor of CKD in males and females, and TG and TC were independent predictors of CKD in females. Such measures are components of MS, which may also be associated with the development of CKD.

CONCLUSION

WHtR appears to be a better measure of central obesity than BMI, and is an easy-to-use, noninvasive tool for identifying individuals at risk of developing obesity-related CKD, and potentially also MS-related CKD.

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.

Obesity indices and adipokines in non-diabetic obese patients with early stages of chronic kidney disease

Background

The aim of this study was to estimate obesity parameters: waist circumference (WC), waist-to-hip ratio (WHR), weight-to-height ratio (WHtR), visceral adiposity index (VAI), body adiposity index (BAI), and serum adipokines (leptin, adiponectin, resistin) and their associations with estimated glomerular filtration rate (eGFR), serum creatinine, and microalbuminuria (MA) in patients with early stages of CKD and in non-CKD obese patients.

Material/Methods

67 non-diabetic obese (BMI ≥30 mg/kg²) out-clinic patients (25 males, 42 females), aged from 36.5 to 64 years were divided into 2 groups: Group A (n=15) – patients with early stages of CKD (eGFR between 30 and 60 ml/min/1.73 m² or with MA >20 mg/l in morning urine sample independently from GFR) and Group B – patients without chronic CKD (n=52).

Results

In Group A compared to Group B, BAI and leptin were higher (42.2±7.1 vs. 37.5±7.0; p<0.05 and 51.8±26.7 ng/mL vs. 35.3±24.9 ng/mL; p<0.05; respectively) and negative correlations occurred between eGFR and BAI (r=−0.709; p=0.003), leptin (r=−0.68; p=0.005), and resistin (r=−0.528; p<0.05). In Group B, negative correlations occurred between creatinine and VAI (r=−0.332; p<0.05), BAI (r=−0.619; p<0.0001), leptin (r=−0.676; p<0.0001), and adiponectin (r=−0.423; p=0.002), and between eGFR and resistin (r=−0.276; p<0.05).

Conclusions

BAI may be a valuable obesity parameter as a predictor of early stages of CKD in patients with obesity. Leptin may be an important pathogenic factor in obese patients with early stages of CKD. Resistin is associated with eGFR in obese patients, independently of CKD.

Lipid mediators of inflammation in obesity-related glomerulopathy

The interplay between chronic kidney disease (CKD) and obesity represents the convergence of two of the most common contemporary clinical issues, and is of particular interest and significance in the context of the burden presented by each at present, and the dismal projections associated with both of these conditions for the future. That obesity leads to CKD through its association with other risks, such as hypertension, type 2 diabetes mellitus and atherosclerosis, is well established; however, it is likely that obesity itself is an independent risk factor for the development of CKD. The aetiology of this obesity-related glomerulopathy (ORG) is not clear, but it appears to be strongly influenced by chronic inflammation, manifest as a disturbance of the balance between pro-inflammatory and pro-resolving lipid mediators, adipokines and mononuclear cells. This review examines the association between obesity and CKD, the role of inflammation therein, and the potential for pro-resolving lipid mediators to restore homoeostasis and offer therapeutic potential in ORG.

Comparison of lipid-related ratios for prediction of chronic kidney disease stage 3 or more in Korean adults

Dyslipidemia is implicated in increased cardiovascular risk associated with chronic kidney disease (CKD) and in the progression of renal damage. This study compared 4 different lipid-related ratios (total cholesterol [TC]/high-density lipoprotein cholesterol [HDL-C], triglyceride [TG]/HDL-C, calculated low-density lipoprotein cholesterol [c-LDL-C]/HDL-C, and non-HDL-C/HDL-C ratio) for prediction of CKD stage 3 or more to investigate the association between them. This cross-sectional study included 8,650 adults who participated in the 2007-2008 Korean National Health and Nutrition Examination Survey. The overall prevalence of CKD stage 3 or more was 6.4%. For TG/HDL-C, the prevalence with CKD stage 3 or more increased with increasing quartile group in both sexes (P value for trend = 0.046 in men, 0.002 in women) while other lipid-related ratios showed increasing prevalence only in women. In comparison with the lowest quartile of the lipid-related ratios, only the fourth quartile of TG/HDL-C was associated with the prevalence of CKD stage 3 or more in both sexes after adjustment for multiple covariates (odds ratio [OR] for TG/HDL-C-Q(4), 1.82; 95% CI [confidence interval], 1.09-3.03 in men, OR 2.45; 95% CI, 1.52-3.95 in women). In conclusion, TG/HDL-C is the only lipid-related ratio that is independently associated with CKD stage 3 or more in both sexes of Koreans.

The role of Klotho in energy metabolism

A disproportionate expansion of white adipose tissue and abnormal recruitment of adipogenic precursor cells can not only lead to obesity but also impair glucose metabolism, which are both common causes of insulin resistance and diabetes mellitus. The development of novel and effective therapeutic strategies to slow the progression of obesity, diabetes mellitus and their associated complications will require improved understanding of adipogenesis and glucose metabolism. Klotho might have a role in adipocyte maturation and systemic glucose metabolism. Klotho increases adipocyte differentiation in vitro, and mice that lack Klotho activity are lean owing to reduced white adipose tissue accumulation; moreover, mice that lack the Kl gene (which encodes Klotho) are resistant to obesity induced by a high-fat diet. Knockout of Kl in leptin-deficient Lep(ob/ob) mice reduces obesity and increases insulin sensitivity, which lowers blood glucose levels. Energy metabolism might also be influenced by Klotho. However, further studies are needed to explore the possibility that Klotho could be a novel therapeutic target to reduce obesity and related complications, and to determine whether and how Klotho might influence the regulation and function of a related protein, β-Klotho, which is also involved in energy metabolism.

The prevalence of chronic kidney disease in the general population in Romania: a study on 60,000 persons

INTRODUCTION

Chronic kidney disease (CKD) is a major public health problem worldwide, due to its epidemic proportions and to its association with high cardiovascular risk. Therefore, screening for CKD is an increasingly important concept, aiming for early detection and prevention of progression and complications of this disease.

MATERIALS AND METHODS

We studied the prevalence of CKD in the adult population of Iaşi, the largest county in Romania, based on the results of a national general health screening program from 2007 to 2008. The patients were tested for CKD with serum creatinine and urinary dipstick. We used two different methods to estimate the glomerular filtration rate (eGFR): the simplified Modification of Diet in Renal Disease (MDRD) and the CKD Epidemiology Collaboration (CKD-EPI) equations. Based on the Kidney Disease Improving Global Outcomes (KDIGO) criteria, we defined CKD as the presence of either eGFR < 60 ml/min/1.73 m(2) and/or dipstick proteinuria. The classification of CKD by stage was also done according to the KDIGO criteria.

RESULTS

The study population included 60,969 people. The global prevalence of CKD was found to be 6.69% by the MDRD formula and 7.32% when using the CKD-EPI equation. The prevalence of CKD was much higher in women than in men: 9.09% versus 3.7%, by MDRD, and 9.32% versus 4.85%, by CKD-EPI. By age groups, the prevalence of CKD was 0.95% and 0.64% in persons aged 18-44 years old, 4.27% and 3.57% (45-64 years old), 13.36% and 15.34% (65-79 years old), and 23.59% and 34.56% (>80 years old), according to MDRD and CKD-EPI, respectively. By stages, the prevalence of CKD stage 3a (eGFR 59 to 45 ml/min/1.73 m(2)) was 5.72% by MDRD and 5.96% according to CKD-EPI, whereas the prevalence of stages 3b, 4, and 5 taken together (eGFR < 45 ml/min/1.73 m(2)) was 0.96% (MDRD) and 1.35% (CKD-EPI). Patients with CKD were significantly older (71.0 years versus 53.7 years) and had lower levels of serum Hb, total cholesterol, and glutamic pyruvic transaminase, and significantly higher serum creatinine and blood glucose, in comparison with the individuals without CKD. Impaired fasting glucose (106 mg/dl) was found in the CKD population, but not in non-CKD individuals.

CONCLUSIONS

Our study is one of the largest ever reported on the prevalence of CKD worldwide, the first one in Romania, and one of the very few of its kind in Europe (particularly in Eastern Europe). The study showed that the prevalence of CKD in our country is around 7%, which is lower than in other countries; however, this could be underestimated due to population selection bias. The prevalence is similar with the MDRD and the CKD-EPI equations; it increases with age and is much higher in women than in men. Impaired fasting glucose was detected in CKD patients, a finding that should probably raise the awareness of the high cardiovascular risk associated with CKD.