The liver and the kidney: two critical organs influencing the atherothrombotic risk in metabolic syndrome

Evaluation for Performance of Body Composition Index Based on Quantitative Computed Tomography in the Prediction of Metabolic Syndrome

Objective: We aimed to evaluate the performance of predicting metabolic syndrome (MS) using body composition indices obtained by quantitative computed tomography (QCT). Methods: In this cross-sectional study, data were collected from 4745 adults who underwent QCT examinations at a Chongqing teaching hospital between July 2020 and March 2022. Visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), total abdominal fat (TAT), abdominal muscle tissue (AMT), and liver fat content (LFC) were measured at the L2-L3 disc level using specialized software, and the skeletal muscle index (SMI) were calculated. The correlations between body composition indicators were analyzed using the Pearson correlation analysis. Receiver operating characteristic (ROC) curve analysis and area under the curve (AUC) were used to assess these indicators' predictive potential for MS. Results: VAT and TAT exhibited the best predictive ability for MS, with AUCs of 0.797 [95% confidence interval (CI): 0.779-0.815] and 0.794 (95% CI: 0.775-0.812) in males, and 0.811 (95% CI: 0.785-0.836) and 0.802 (95% CI: 0.774-0.830) in females. The AUCs for VAT and TAT were the same but significantly higher than body mass index and other body composition measures. SAT also demonstrated good predictive power in females [AUC = 0.725 (95%CI: 0.692-0.759)] but fair power in males [AUC = 0.6673 (95%CI: 0.650-0.696)]. LFC showed average predictive ability, AMT showed average predictive ability in males but poor ability in females, and SMI had no predictive ability. Correlation analysis revealed a strong correlation between VAT and TAT (males: r = 0.95, females: r = 0.89). SAT was strongly correlated with TAT only in females (r = 0.89). In the male group, the optimal thresholds for VAT and TAT were 207.6 and 318.7 cm2, respectively; in the female group, the optimal thresholds for VAT and TAT were 128.0 and 269.4 cm2, respectively. Conclusions: VAT and TAT are the best predictors of MS. SAT and LFC can also be acceptable to make predictions, whereas AMT can only make predictions of MS in males.

Naringenin suppresses aluminum-induced experimental hepato-nephrotoxicity in mice through modulation of oxidative stress and inflammation

Aluminum is a widely used metal substance in daily life activities that has been shown to cause severe hepato-nephrotoxicity with long-term exposure. Natural dietary flavonoids are being utilized as a newer pharmaceutical approach against various acute and chronic diseases. Naringenin (NAR) has shown efficient therapeutic properties, including effects against metal toxicities. However, the protective efficacy of NAR on aluminum chloride (AlCl3)-induced hepato-renal toxicity needs investigation as aluminum has shown serious environmental toxicity and bioaccumulation behavior. In this study, mice were treated with AlCl3 (10 mg/kg b.w./day) to assess toxicities, and a group of mice were co-treated with NAR (10 mg/kg b.w./day) to assess the protective effects of NAR against hepato-nephrotoxicity. The levels of blood serum enzymes, oxidative stress biomarkers, inflammatory cytokines, and the apoptosis marker caspase-3 were measured using histological examinations. NAR treatment in AlCl3-treated mice resulted in maintained levels of liver and kidney function enzymes and lipid profiles. NAR treatment attenuated oxidative stress by regulating the levels of nitric oxide, advance oxidation of protein products, protein carbonylation, and lipid peroxidation. NAR also replenished reduced antioxidant enzymes such as superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and reduced the levels of glutathione and oxidized glutathione. NAR regulated the levels of pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α) and elevated the levels of anti-inflammatory cytokines (IL-4, IL-10, and IFN-γ). The histological study further confirmed the protective effects of NAR against AlCl3-induced hepato-renal alterations. NAR decreased the expression of caspase-3 as a mechanism of protective effects against apoptotic damage in the liver and kidney of AlCl3-treated mice. In summary, this study demonstrated the antioxidant and anti-inflammatory properties of NAR, leading to the suppression of AlCl3-triggered hepato-renal apoptosis and histological alterations. The results suggest that aluminum toxicity needs to be monitored in daily life usage, and supplementation of the natural dietary flavonoid naringenin may help maintain liver and kidney health.

Association of serum uric acid concentration with components of pediatric metabolic syndrome: A systematic review and meta-analysis

Background:

Hyperuricemia is implicated in the pathogenesis of inflammatory diseases and metabolic disorders. Metabolic syndrome (MetS) in childhood is one of the most important causes of different noncommunicable diseases in adulthood. This study aimed to systematically review the association between serum uric acid (UA) concentration and components of pediatric MetS.

Materials and Methods:

In this meta-analysis and systematic review, related articles were gathered by searching English databases including PubMed, Web of Science, Scopus, and Google Scholar. We used the following keywords: uric acid, metabolic syndrome, hypertension, fasting blood sugar (FBS), hyperglycemia; the search was limited to English language and included observational and cohort studies performed among children or adolescents. Pooled relative risks (odds ratio [OR]) and corresponding 95% confidence interval (95% CI) were extracted. A random-effect model was used.

Results:

On the basis of 34 eligible studies, the pooled correlation between UA with metabolic components including FBS (r = 0.24, 95% CI = 0.09–0.40), fasting insulin (r = 0.26, 95% CI = 0.15–0.37), and hyperglycemia (r for triglyceride and UA = 0.23, 95% CI = 0.19–0.38) (r for high-density lipoprotein and UA = −0.28, 95% CI = −0.37 to −0.20) was statistically significant. The association of both diastolic blood pressure (DBP) and systolic blood pressure (SBP) was statistically significant with UA (r for SBP and UA = 0.34, 95% CI = 0.24–0.43; r for DBP and UA = 0.18, 95% CI = 0.11–0.25). The OR between risk of abdominal obesity with UA was statistically significant (OR = 2.62, 95% CI = 1.41–3.84).

Conclusion:

Serum UA concentration is associated with major components of the pediatric MetS. Its measurement and control should be underscored in at-risk children and adolescents.

Calcium Phosphate Bions Cause Intimal Hyperplasia in Intact Aortas of Normolipidemic Rats through Endothelial Injury

Calcium phosphate bions (CPBs) are formed under blood supersaturation with calcium and phosphate owing to the mineral chaperone fetuin-A and representing mineralo-organic particles consisting of bioapatite and multiple serum proteins. While protecting the arteries from a rapid medial calcification, CPBs cause endothelial injury and aggravate intimal hyperplasia in balloon-injured rat aortas. Here, we asked whether CPBs induce intimal hyperplasia in intact rat arteries in the absence of cardiovascular risk factors. Normolipidemic Wistar rats were subjected to regular (once/thrice per week over 5 weeks) tail vein injections of either spherical (CPB-S) or needle-shaped CPBs (CPB-N), magnesium phosphate bions (MPBs), or physiological saline (n = 5 per group). Neointima was revealed in 3/10 and 4/10 rats which received CPB-S or CPB-N, respectively, regardless of the injection regimen or blood flow pattern in the aortic segments. In contrast, none of the rats treated with MPBs or physiological saline had intimal hyperplasia. The animals also did not display signs of liver or spleen injury as well as extraskeletal calcium deposits. Serum alanine/aspartate transaminases, interleukin-1β, MCP-1/CCL2, C-reactive protein, and ceruloplasmin levels did not differ among the groups. Hence, CPBs may provoke intimal hyperplasia via direct endothelial injury regardless of their shape or type of blood flow.

Liver stiffness assessed by transient elastography as a potential indicator of chronic kidney disease in patients with nonalcoholic fatty liver disease

BACKGROUND

This study was designed to determine the diagnostic value of liver stiffness measured by transient elastography (TE) in identifying chronic kidney disease (CKD) in individuals with ultrasonography-diagnosed NAFLD.

METHODS

A total of 1439 adult patients with ultrasonography-diagnosed NAFLD between October 2015 and August 2017 in China-Japan union hospital of Jilin university were initially eligible. According to the exclusion criteria, 24 patients were excluded, and eventually, a total of 1415 patients were included in the study. The AST/ALT ratio and FIB-4 score were calculated from blood tests, and liver stiffness was measured using TE.

RESULTS

The liver stiffness measured by TE, FIB-4 score, ALT/AST ratio were significantly elevated in CKD patients, compared with those without CKD (P < 0.001). The areas under the curve (AUROC) of liver stiffness, FIB-4 score and AST/ALT ratio were 0.694 (0.670-0.718), 0.707 (0.682-0.730), 0.712 (0.688-0.736), showing no statistically significant difference between these three tests. Further, multivariate analysis identified four independent risk factors for CKD: age, diabetes mellitus, serum uric acid, and liver stiffness. Also, the performance of these four independent variables taken together in a logistic regression model for identifying CKD was 0.834 (AUROC; 95%CI: 0.814-0.853), showing a higher diagnostic performance than that of a single application of liver stiffness.

CONCLUSIONS

Liver stiffness assessed by TE is a potential indicator for CKD in ultrasonography-diagnosed NAFLD patients. Further, a four-variable model (liver stiffness, age, serum uric acid, and diabetes mellitus) could be a useful tool for identifying subjects at high risk for CKD in NAFLD patients.

High serum levels of C-reactive protein (CRP) predict beneficial decrease of visceral fat in obese females after sleeve gastrectomy

BACKGROUND & AIMS

Gender-related differences represent an emerging investigation field to better understand obesity heterogeneity and paradoxically associated cardiovascular (CV) risk. Here, we investigated if high-sensitivity C-reactive protein (hs-CRP) might differently affect adiposity and predict the clinical response to bariatric surgery in obese males and females.

METHODS AND RESULTS

In 110 morbidly obese patients undergoing laparoscopic sleeve gastrectomy, hs-CRP as well as anthropometric assessment of adiposity, completed by electric bioimpedance and ultrasonography quantification of visceral fat area (VFA), were measured before and one year after surgery. As compared to males, obese female showed less severe overweight and prevalent subcutaneous fat deposition, but higher circulating hs-CRP. In obese females, hs-CRP was associated with VFA at baseline, independently of body mass index (BMI) and visceral adiposity index (OR 1.022 [95% CI 1.001-1.044]; p = 0.039). Based on decreases and increases in hs-CRP levels after surgery, two distinct subgroups of females were identified. Post-surgery decreases in hs-CRP was predominantly observed in patients with higher baseline levels of hs-CRP and associated with greater reduction of weight, BMI, fat and lean mass, VFA and visceral to subcutaneous fat ratio. Finally, we observed that high baseline values of hs-CRP were able to predict VFA reduction one-year after surgery, independently of BMI and visceral adiposity index (VAI) loss (OR 1.031 [95% CI 1.009-1.053]; p = 0.005).

CONCLUSION

In obese females, hs-CRP levels might be a promising biomarker of visceral fat amount and dysfunction, in addition to predict the effectiveness of bariatric surgery in terms of loss of VFA one-year after surgery.

Association Between Urinary Alpha1-Microglobulin Levels and Nonalcoholic Fatty Liver Disease: A Cross-Sectional Study

BACKGROUND

We aimed to explore the association between urinary alpha1-microglobulin (A1M) levels and nonalcoholic fatty liver disease (NAFLD) in a Chinese population.

STUDY

We performed a cross-sectional study among 2,215 Chinese who attended their annual health examination at First Affiliated Hospital, College of Medicine, Zhejiang University. Urinary A1M-creatinine ratio and other clinical and laboratory parameters were measured.

RESULTS

A total of 20.9% of subjects fulfilled the diagnostic criteria of NAFLD. NAFLD subjects had significantly higher urinary A1M-creatinine ratios. These levels were positively associated with NAFLD prevalence. The association between A1M-creatinine ratio and NAFLD was independent of hyperglycemia status. Stepwise regression showed that urinary A1M-creatinine ratio was significantly associated with the risk for NAFLD. Urinary A1M-creatinine ratio was an independent factor predicting advanced fibrosis (FIB-4 ≥1.3) in NAFLD patients.

CONCLUSIONS

Our results showed a significant association between urinary A1M-creatinine ratio and NAFLD.

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.

Correlation of uric acid levels and parameters of metabolic syndrome

Hyperuricemia has been described as associated with the risk of development metabolic syndrome; however the relationship between the uric acid level and particular parameters of metabolic syndrome remained unclear. We performed a cross-sectional study on a cohort of 833 dyslipidemic patients and correlated their levels of uric acid with parameters of insulin resistance, lipid metabolism, C-reactive protein, anthropometric parameters. We also defined patients with hypertriglyceridemic waist phenotype and compered their uric acid levels with those without this phenotype. We found that levels of uric acid are associated with parameters of metabolic syndrome. Specifically, dyslipidemia characteristic for metabolic syndrome (low HDL-cholesterol and high triglycerides) correlates better with uric acid levels than parameters of insulin resistance. Also waist circumference correlates better with uric acid levels than body mass index. Patients with hypertriglyceridemic waist phenotype had higher levels of uric acid when compared with patients without this phenotype. Serum uric acid levels are even in low levels linearly correlated with parameters of metabolic syndrome (better with typical lipid characteristics than with parameters of insulin resistance) and could be associated with higher cardiovascular risk.

Non-alcoholic fatty liver disease and cardiovascular risk: Pathophysiological mechanisms and implications

Non-alcoholic fatty liver disease (NAFLD) has become one of the most frequent chronic liver diseases in the Western society and its prevalence is likely to rise even further. An increasing body of evidence shows that NAFLD is not only a potentially progressive liver disease, but also has systemic consequences. More specifically, evidence points out that NAFLD has to be considered as a significant independent risk factor for subclinical and clinical cardiovascular disease (CVD). Long-term follow-up studies demonstrate cardiovascular mortality to be the most important cause of death in NAFLD patients. Moreover, ample evidence associates NAFLD with endothelial dysfunction, increased pulse wave velocity, increased coronary arterial calcifications and increased carotid intima media thickness, all established markers for CVD. Despite of all this evidence, the mechanisms by which NAFLD causally contributes to CVD are not fully elucidated. Furthermore, an extensive overview of all potential pathophysiological mechanisms and the corresponding current data are lacking. In this review we summarise current knowledge, originating from fundamental and clinical research, that mechanistically links NAFLD to CVD. Subsequently, the impact of CVD on current clinical practice and future research in the area of NALFD are discussed.

High serum uric acid and risk of nonalcoholic fatty liver disease: A systematic review and meta-analysis

OBJECTIVES

Emerging evidence connects serum uric acid (SUA) levels to nonalcoholic fatty liver disease (NAFLD). The objective of this study was to systematically evaluate the association between SUA levels and risk of NAFLD by conducting a meta-analysis of available observational studies.

DESIGN AND METHODS

We searched for relevant studies in PubMed, Embase, China National Knowledge Infrastructure, and Wanfang databases until October 2014. All observational studies that evaluated SUA levels and NAFLD risks were included. Pooled adjusted odds ratio (OR) and corresponding 95% confidence intervals (CI) were calculated comparing the highest to lowest SUA category.

RESULTS

Four cross-sectional studies, two prospective studies, and three retrospective studies involving 55,573 participants were identified. In overall risk estimates, the pooled OR of NAFLD occurrence was 1.92 (95% CI: 1.59-2.31) comparing the highest to lowest SUA levels in a random effect model. Subgroup analysis showed that high SUA levels increased the risk of NAFLD in cross-sectional studies (OR: 2.18; 95% CI: 1.58-3.03), retrospective studies (OR 1.82; 95% CI: 1.43-2.33), and prospective studies (OR 1.43; 95% CI: 1.20-1.71). The risk of NAFLD seemed more pronounced among women (OR 1.85; 95% CI: 1.43-2.38) than among men (OR 1.56; 95% CI: 1.30-1.86).

CONCLUSION

This meta-analysis suggests that increased SUA level is associated with an exacerbated risk of NAFLD. This increased risk is probably independent of conventional NAFLD risk factors.

Prevalence of and predictive factors for nonalcoholic fatty liver disease in Sudanese individuals with type 2 diabetes: Is metabolic syndrome the culprit?

BACKGROUND AND STUDY AIM

Non-alcoholic fatty liver disease (NAFLD) is a common global chronic liver condition. The prevalence of NAFLD among individuals with type 2 diabetes is estimated to be as high as 75%. The aim of this study was to determine the prevalence of NAFLD among individuals with type 2 diabetes in Sudan.

PATIENTS AND METHODS

This was a cross-sectional hospital-based study, which was carried out at the Jabir Abu-Elizz diabetic centre in Khartoum; 167 outpatients with type 2 diabetes were enrolled. NAFLD was diagnosed based on ultrasound, following exclusion of significant alcohol intake and secondary causes of liver diseases. NAFLD was defined as hepatic steatosis in the absence of alcohol intake, medication, previous liver disease and negative results for the serological test for hepatitis B and C. Logistic regression analysis was used to determine independent risk factors for the development of NAFLD in individuals with type 2 diabetes.

RESULTS

The number of female subjects was 89 (53.3%), and most subjects (145, 86.8%) were between the ages of 40 and 70 years. The overall prevalence of fatty liver among individuals with type 2 diabetes was found to be 50.3%. Age, duration of diabetes, hypertension and HbA1c levels appeared to have no impact on the prevalence of NAFLD. The possible predictors of NAFLD were overweight, obesity, central obesity, high triglyceride level and low high-density lipoprotein cholesterol (HDL-c) level. A higher prevalence of NAFLD was observed in individuals with three components of the metabolic syndrome.

CONCLUSION

NAFLD was observed in half of the diabetic population, and its occurrence correlates positively with metabolic syndrome risk factors.

Effect of Non-Alcoholic Fatty Liver Disease on Estimated Glomerular Filtration Rate Could Be Dependent on Age

There is a gap between the association of non-alcoholic fatty liver disease (NAFLD) and renal function in an apparently healthy population. This study aims to assess whether NAFLD is associated with estimated glomerular filtration rate (eGFR) levels and to understand early changes of eGFR in NAFLD. A cross-sectional study was performed among apparently healthy persons who underwent general health screening including laboratory assessments and hepatic ultrasonography from January 2013 to December 2013 at the First Affiliated Hospital of Zhejiang University, College of Medicine, China. This study included 1,193 subjects with a mean age of 48 years. Prevalence of NAFLD was 31.3%. Mean eGFR was significantly lower in NAFLD than in controls (107 ± 19 mL/min/1.73 m(2) vs. 113 ± 23 mL/min/1.73 m(2), P<0.001). Correlation analysis between eGFR and NAFLD related risk factors revealed an inverse correlation between eGFR levels and some NAFLD risk factors (all P<0.01). All subjects were classified into five phases according to age. Average eGFR levels of NAFLD were lower than controls in three phases for subjects with ≤ 50 years of age (all P<0.05), while there were no significant differences on average eGFR levels between NAFLD and controls in two phases for subjects with >50 years of age (Both P>0.05). The eGFR level is significantly associated with NAFLD and its risk factors in an apparently healthy population. Effects of NAFLD on eGFR could be dependent on age.

Translational approaches: From fatty liver to non-alcoholic steatohepatitis

Over the past few decades, non-alcoholic fatty liver disease (NAFLD) has become one, if not the most common, cause of chronic liver disease affecting both adults and children. The increasing number of cases at an early age is the most worrying aspect of this pathology, since it provides more time for its evolution. The spectrum of this disease ranges from liver steatosis to steatohepatitis, fibrosis and in some cases, hepatocellular carcinoma. NAFLD may not always be considered a benign disease and hepatologists must be cautious in the presence of fatty liver. This should prompt the use of the available experimental models to understand better the pathogenesis and to develop a rational treatment of a disease that is dangerously increasing. In spite of the growing efforts, the pathogenesis of NAFLD is still poorly understood. In the present article we review the most relevant hypotheses and evidence that account for the progression of NAFLD to non-alcoholic steatohepatitis (NASH) and fibrosis. The available in vitro and in vivo experimental models of NASH are discussed and revised in terms of their validity in translational studies. These studies must be aimed at the discovery of the still unknown triggers or mediators that induce the progression of hepatic inflammation, apoptosis and fibrosis.