Diagnostic imaging in the management of patients with metabolic syndrome

The Kidney in Obesity: Current Evidence, Perspectives and Controversies

PURPOSE OF REVIEW

As obesity and chronic kidney disease (CKD) remain a public health issue, we aim to elaborate on their complex relationship regarding pathogenetic mechanisms and therapeutic potential as well. The purpose of this review is to enhance our understanding of the interplay between obesity and CKD in order to timely diagnose and treat obesity-related CKD.

RECENT FINDINGS

Obesity and CKD pose significant intertwined challenges to global health, affecting a substantial portion of the population worldwide. Obesity is recognized as an independent risk factor, intricately contributing to CKD pathogenesis through mechanisms such as lipotoxicity, chronic inflammation, and insulin resistance. Recent evidence highlights additional factors including hemodynamic changes and intestinal dysbiosis that exacerbate kidney dysfunction in obese individuals, leading to histologic alterations known as obesity-related glomerulopathy (ORG). This narrative review synthesizes current knowledge on the prevalence, pathophysiology, clinical manifestations, and diagnostic strategies of obesity-related kidney disease. Furthermore, it explores mechanistic insights to delineate current therapeutic approaches, future directions for managing this condition and controversies. By elucidating the multifaceted interactions between obesity and kidney health, this review aims to inform clinical practice and stimulate further research to address this global health epidemic effectively.

New Perspectives on Obesity-Associated Nephropathy from Pathophysiology to Therapeutics: Revealing the Promise of GLP-1 RA Therapy

Obesity represents a substantial risk factor for a multitude of metabolic disorders, which seriously threatens human life and health. As the global obesity epidemic intensifies, obesity-related nephropathy (ORN) has attracted great attention. ORN arises from both physical/mechanical and non-physical insults to the glomerular and tubular structures precipitated by obesity, culminating in structural impairments and functional aberrations within the kidneys. Physical injury factors include changes in renal hemodynamics, renal compression, and mechanical stretching of podocytes. Non-physical injury factors include overactivation of the RAAS system, insulin resistance, lipotoxicity, inflammation, and dysregulation of bile acid metabolism. Exploring molecules that target modulation of physical or nonphysical injury factors is a potential approach to ORN treatment. ORN is characterized clinically by microproteinuria and pathologically by glomerulomegaly, which is atypical and makes early diagnosis difficult. Investigating early diagnostic markers for ORN thus emerges as a critical direction for future research. Additionally, there is no specific drug for ORN in clinical treatment, which mainly focuses on weight reduction, mitigating proteinuria, and preserving renal function. In our review, we delineate a progressive therapeutic approach involving enhancements in lifestyle, pharmacotherapy, and bariatric surgery. Our emphasis underscores glucagon-like peptide-1 receptor agonists (GLP-1 RAs) as poised to emerge as pivotal therapeutic modalities for ORN in forthcoming clinical avenues.

Non-invasive mapping of brown adipose tissue activity with magnetic resonance imaging

Thermogenic brown adipose tissue (BAT) has a positive impact on whole-body metabolism. However, in vivo mapping of BAT activity typically relies on techniques involving ionizing radiation, such as [18F]fluorodeoxyglucose ([18F]FDG) positron emission tomography (PET) and computed tomography (CT). Here we report a noninvasive metabolic magnetic resonance imaging (MRI) approach based on creatine chemical exchange saturation transfer (Cr-CEST) contrast to assess in vivo BAT activity in rodents and humans. In male rats, a single dose of the β3-adrenoceptor agonist (CL 316,243) or norepinephrine, as well as cold exposure, triggered a robust elevation of the Cr-CEST MRI signal, which was consistent with the [18F]FDG PET and CT data and 1H nuclear magnetic resonance measurements of creatine concentration in BAT. We further show that Cr-CEST MRI detects cold-stimulated BAT activation in humans (both males and females) using a 3T clinical scanner, with data-matching results from [18F]FDG PET and CT measurements. This study establishes Cr-CEST MRI as a promising noninvasive and radiation-free approach for in vivo mapping of BAT activity.

Obesity - Standards, trends and advances

Obesity continues to be a significant global health concern, giving rise to various complications. This review article explores the current standards and emerging innovations in diagnosing and treating obesity, including recent disease name change, staging system or therapeutic goals. This narrative review has been based on recent scientific articles from PubMed database, limiting the scope of topics to current standards and upcoming developments and breakthroughs in the diagnosis and treatment of obesity. The educational and informative nature of the review has been maintained in order to make the information presented accessible to both researchers and clinical practitioners. The recognition of diverse obesity phenotypes has prompted a paradigm shift towards a complex and patient-centered approach to diagnosis and therapy. Pharmacotherapy for obesity is evolving rapidly, with ongoing research focusing on novel molecular targets and metabolic pathways. Promising developments include dual or triple incretin analogs, oral incretin drugs, neurotransmitter-based therapies, muscle mass-increasing treatments, and therapies targeting visceral adipose tissue browning. Despite current evidence-based international standards, the field of obesity diagnosis and treatment continues to expand, with new diagnostic tools and pharmacotherapies potentially replacing current practices. Therapeutic management should be tailored to individual patients, considering obesity phenotype, health status, lifestyle, and preferences. Looking ahead, the future holds promising opportunities for obesity management, but further research is required to assess the efficacy and safety of emerging therapies. A multifactorial and personalized approach will be pivotal in addressing the diverse challenges posed by obesity.

Unraveling Adipose Tissue Dysfunction: Molecular Mechanisms, Novel Biomarkers, and Therapeutic Targets for Liver Fat Deposition

Adipose tissue (AT), once considered a mere fat storage organ, is now recognized as a dynamic and complex entity crucial for regulating human physiology, including metabolic processes, energy balance, and immune responses. It comprises mainly two types: white adipose tissue (WAT) for energy storage and brown adipose tissue (BAT) for thermogenesis, with beige adipocytes demonstrating the plasticity of these cells. WAT, beyond lipid storage, is involved in various metabolic activities, notably lipogenesis and lipolysis, critical for maintaining energy homeostasis. It also functions as an endocrine organ, secreting adipokines that influence metabolic, inflammatory, and immune processes. However, dysfunction in WAT, especially related to obesity, leads to metabolic disturbances, including the inability to properly store excess lipids, resulting in ectopic fat deposition in organs like the liver, contributing to non-alcoholic fatty liver disease (NAFLD). This narrative review delves into the multifaceted roles of WAT, its composition, metabolic functions, and the pathophysiology of WAT dysfunction. It also explores diagnostic approaches for adipose-related disorders, emphasizing the importance of accurately assessing AT distribution and understanding the complex relationships between fat compartments and metabolic health. Furthermore, it discusses various therapeutic strategies, including innovative therapeutics like adipose-derived mesenchymal stem cells (ADMSCs)-based treatments and gene therapy, highlighting the potential of precision medicine in targeting obesity and its associated complications.

Combining Fat-to-Muscle Ratio and Alanine Aminotransferase/Aspartate Aminotransferase Ratio in the Prediction of Cardiometabolic Risk: A Cross-Sectional Study

PURPOSE

Altered body composition and liver enzymes are known to be related to cardiometabolic risk. Our study aimed to evaluate the association between fat-to-muscle ratio (FMR), alanine aminotransferase/aspartate aminotransferase (ALT/AST) ratio and cardiometabolic risk.

METHODS

In total, 1557 participants aged ≥40 years were included. A bioelectrical impedance analyzer (BIA) was used to measure fat mass and muscle mass. We created a cardiometabolic risk score with one point for each cardiometabolic risk factor, including elevated triglycerides (TGs), decreased high-density lipoprotein cholesterol (HDL-C), elevated blood pressure (BP), and abnormal blood glucose, yielding a score of 0-4 for each participant (≥2 for high-risk and <2 for low-risk). Logistic regression analyses were used to analyze the relationship between FMR, ALT/AST ratio and cardiometabolic risk.

RESULTS

FMR and ALT/AST ratio were significantly higher in the high-risk group than in the low-risk group (P<0.001). FMR and ALT/AST ratio were both positively correlated with a higher cardiometabolic risk score and the presence of each cardiometabolic risk factor. In subgroup analyses categorized according to FMR and ALT/AST ratio cutoffs, the high-FMR/high-ALT/AST group had the highest cardiometabolic risk (OR=8.51; 95% CI 4.46-16.25 in women and OR=5.09; 95% CI 3.39-7.65 in men) after adjusting for confounders.

CONCLUSION

FMR and ALT/AST ratio were positively associated with cardiometabolic risk. Combining these two indicators improved the prediction of cardiometabolic risk.

Pulse-Echo Quantitative US Biomarkers for Liver Steatosis: Toward Technical Standardization

Excessive liver fat (steatosis) is now the most common cause of chronic liver disease worldwide and is an independent risk factor for cirrhosis and associated complications. Accurate and clinically useful diagnosis, risk stratification, prognostication, and therapy monitoring require accurate and reliable biomarker measurement at acceptable cost. This article describes a joint effort by the American Institute of Ultrasound in Medicine (AIUM) and the RSNA Quantitative Imaging Biomarkers Alliance (QIBA) to develop standards for clinical and technical validation of quantitative biomarkers for liver steatosis. The AIUM Liver Fat Quantification Task Force provides clinical guidance, while the RSNA QIBA Pulse-Echo Quantitative Ultrasound Biomarker Committee develops methods to measure biomarkers and reduce biomarker variability. In this article, the authors present the clinical need for quantitative imaging biomarkers of liver steatosis, review the current state of various imaging modalities, and describe the technical state of the art for three key liver steatosis pulse-echo quantitative US biomarkers: attenuation coefficient, backscatter coefficient, and speed of sound. Lastly, a perspective on current challenges and recommendations for clinical translation for each biomarker is offered.

Obesity-related glomerulopathy: Current approaches and future perspectives

Obesity-related glomerulopathy (ORG) is a silent comorbidity which is increasing in incidence as the obesity epidemic escalates. ORG is associated with serious health consequences including chronic kidney disease, end-stage renal disease (ESRD), and increased mortality. Although the pathogenic mechanisms involved in the development of ORG are not fully understood, glomerular hemodynamic changes, renin-angiotensin-aldosterone system (RAAS) overactivation, insulin-resistance, inflammation and ectopic lipid accumulation seem to play a major role. Despite albuminuria being commonly used for the non-invasive evaluation of ORG, promising biomarkers of early kidney injury that are emerging, as well as new approaches with proteomics and metabolomics, might permit an earlier diagnosis of this disease. In addition, the assessment of ectopic kidney fat by renal imaging could be a useful tool to detect and evaluate the progression of ORG. Weight loss interventions appear to be effective in ORG, although large-scale trials are needed. RAAS blockade has a renoprotective effect in patients with ORG, but even so, a significant proportion of patients with ORG will eventually progress to ESRD despite therapeutic efforts. It is noteworthy that certain antidiabetic agents such as sodium-glucose cotransporter 2 inhibitors (SGLT2i) or glucagon-like peptide-1 receptor agonists (GLP-1 RAs) could be useful in the treatment of ORG through different pleiotropic effects. In this article, we review current approaches and future perspectives in the care and treatment of ORG.

Whole-Body MRI-Derived Adipose Tissue Characterization and Relationship to Pulmonary Function Impairment

Background: Specification of adipose tissues by whole-body magnetic resonance imaging (MRI) was performed and related to pulmonary function parameters in a population-based cohort. Methods: 203 study participants underwent whole-body MRI and pulmonary function tests as part of the KORA (Cooperative Health Research in the Augsburg Region) MRI study. Both visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) were derived from the T1-Dixon sequence, and hepatic adipose tissue from the proton density fat fraction (PDFFhepatic). Associations between adipose tissue parameters and spirometric indices such as forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1) and Tiffeneau-index (FEV1/FVC) were examined using multivariate linear regression analysis excluding cofounding effects of other clinical parameters. Results: VAT (β = −0.13, p = 0.03) and SAT (β = −0.26, p < 0.001), but not PDFFhepatic were inversely associated with FEV1, while VAT (β = −0.27, p < 0.001), SAT (β = −0.41, p < 0.001), and PDFFhepatic (β = −0.17, p = 0.002) were inversely associated with FVC. PDFFhepatic was directly associated with the Tiffeneau index (β = 2.46, p < 0.001). Conclusions: In the adjusted linear regression model, VAT was inversely associated with all measured spirometric parameters, while PDFFhepatic revealed the strongest association with the Tiffeneau index. Non-invasive adipose tissue quantification measurements might serve as novel biomarkers for respiratory impairment.

Magnetic Resonance Imaging Assessment of Abdominal Ectopic Fat Deposition in Correlation With Cardiometabolic Risk Factors

PURPOSE

Ectopic fat accumulation and abdominal fat distribution may have different cardiometabolic risk profiles. This study aimed to assess the associations between various magnetic resonance imaging (MRI)-acquired fat depots and cardiometabolic risk factors.

METHODS

A total of 320 subjects with median age of 59 years, 148 men and 172 women, were enrolled in the study. Visceral adipose tissue (VAT) area and fat fraction (FF), subcutaneous adipose tissue (SAT) area and FF at the L1-L2 levels, preperitoneal adipose tissue (pPAT) area and FF, hepatic FF, pancreatic FF, and intramuscular FF were assessed by MRI FF maps. The associations of various MRI-acquired fat depots with blood pressure, glucose, and lipid were examined using sex-stratified linear regression. Logistic regression stratified by sex was used to analyze the association of various MRI-acquired fat depots with the risk of hypertension, T2DM, and dyslipidemia.

RESULTS

The intraclass correlation coefficient (ICC) values were >0.9, which suggested good interobserver and intraobserver agreement. VAT area, V/S, hepatic fat, pancreatic fat, and pPAT rather than SAT area were significantly associated with multiple cardiometabolic risk factors (all p < 0.05). However, the patterns of these correlations varied by sex and specific risk factors. Also, VAT and SAT FF were only significantly associated with multiple cardiometabolic risk factors in women (all p < 0.05).

CONCLUSIONS

VAT, hepatic fat, pancreatic fat, and pPAT were associated with cardiovascular metabolic risk factors independent of BMI. The patterns of these correlations were related to gender. These findings further the understanding of the association between ectopic fat deposition and cardiometabolic risk factors and help to better understand the obesity heterogeneity.

Alanine aminotransferase to aspartate aminotransferase ratio and hepatitis B virus on metabolic syndrome: a community-based study

BACKGROUND

The serum aminotransferase elevation in metabolic syndrome (MetS) reflected hepatosteatosis, but there is a conflict with the coexistence of viral hepatitis, especially for the hepatitis B virus (HBV). Thus, this study aimed to investigate the relationship between the alanine aminotransferase (ALT)/aspartate aminotransferase (AST) ratio, MetS, and HBV infection in a rural Taiwanese population.

METHODS

We conducted a cross-sectional analysis in southern Taiwan between March and December 2019. Multivariable logistic regression analyses adjusted for demographics, education, dietary behaviors, irregular exercise, substance use, and viral markers were performed to investigate the association between the ALT/AST ratio and MetS.

RESULTS

Altogether, 2,416 participants (891 men and 1,525 women; mean age, 64.1 ± 14.9 years) were enrolled. Of the participants, 22.7% (n = 519) were seropositive for viral hepatitis. In the multivariable analysis, age [odds ratio (OR) 1.02, 95% CI 1.01-1.03, p < 0.001], ALT/AST ratio >1 (OR 2.63, 95% CI 2.15-3.21, p < 0.001), education (OR 0.96, 95% CI 0.94-0.98, p < 0.001), and HBV seropositivity (OR 0.70, 95% CI 0.52-0.95, p = 0.021) were associated with the risk of MetS. The area under the curve of the ALT/AST ratio was 0.62 (95% CI 0.60-0.64, p < 0.001), and the cutoff value was >0.852 for the Youden index.

CONCLUSION

An ALT/AST ratio >1 could be a simple index for MetS prediction during community checkups. In contrast to age and betel nut chewing, HBV seropositivity and higher education might be inversely associated with MetS. Aggressive health promotion for MetS prevention has emerged as essential in participants without HBV and with lower education levels. Further large-scale, longitudinal studies are needed to unlink these correlations.

Primary reverse shoulder arthroplasty in patients with metabolic syndrome is associated with increased rates of deep infection

BACKGROUND

Metabolic syndrome (MetS) is an abnormal physiological condition that has been increasingly identified as a risk factor for complications after orthopedic surgery. Given the lack of information on the effect of MetS in shoulder arthroplasty (SA), this investigation analyzed the rates of postoperative complications and implant survivorship free from reoperation and revision in patients with and without MetS.

METHODS

Between 2007 and 2017, data from 4635 adults who underwent a primary SA were collected and classified based on the presence or absence of MetS. MetS was defined as the existence of type 2 diabetes mellitus and a minimum of 2 of the following diagnoses: hyperlipidemia, hypertension, and body mass index ≥ 30 kg/m² within 1 year of surgery. Of the 4635 arthroplasties, 714 were performed in patients with MetS (anatomic total shoulder arthroplasty [aTSA] in 289 and reverse shoulder arthroplasty [RSA] in 425) and 3921 were performed in patients without MetS (aTSA in 1736 and RSA in 2185). Demographic characteristics, complications, reoperations, and revision surgery were compared.

RESULTS

At a mean of follow-up of 4.5 ± 2.3 years, 67 MetS patients (9.4%) and 343 non-MetS patients (8.7%) had sustained at least 1 postoperative complication (P = .851). Rotator cuff failure was the most common complication overall, with 84 cases (1.8%) (15 MetS cases [2.1%] and 69 non-MetS cases [1.8%], P = .851), and in both MetS and non-MetS patients, followed by infection, with 68 cases (1.2%) (10 MetS cases [1.4%] and 58 non-MetS cases [1.2%], P = .913). For aTSAs, the most common complication was rotator cuff failure (84 shoulders, 1.8%); for RSAs, the most common complication was periprosthetic fracture (52 shoulders, 1.1%). In RSAs, the rates of deep infection (1.9% vs. 0.7%, P = .04), instability (3.1% vs. 1.5%, P = .04), and deep venous thrombosis or pulmonary embolism (0.5% vs. 0.3%, P = .03) were found to be significantly higher in patients with MetS than in those without MetS. Reoperations were observed in 36 MetS patients (5%) and 170 non-MetS patients (4.3%) (P = .4). Revisions were performed in 30 MetS patients (4.2%) and 127 non-MetS patients (3.2%) (P = .19). The Kaplan-Meier 5-year rate of survivorship free from reoperation, revision, and prosthetic joint infection was equal between groups.

CONCLUSIONS

A preoperative diagnosis of MetS in patients undergoing primary SA did not significantly increase the risk of postoperative complications, infection, reoperation, or revision following primary SA. However, in the RSA subgroup, complications were significantly more common in patients with MetS. Individual risk factors may be more appropriate than the umbrella diagnosis of MetS prior to aTSA.

Computed tomography findings of metabolic syndrome in patients with acute colonic diverticulitis

INTRODUCTION

Many factors associated with colonic diverticulitis are also part of the clinical definition of the metabolic syndrome. Computed tomography (CT) is commonly performed in symptomatic patients, such as those with suspected or known acute diverticulitis, and could add additional value for the health of these patients by identifying and reporting CT biomarkers of metabolic syndrome, if present and detectable. The purpose of this study was to identify CT biomarkers of metabolic syndrome in patients with acute colonic diverticulitis.

METHODS

We retrospectively reviewed 243 patients (mean-60 yrs, M:F:126:117) diagnosed with colonic diverticulitis on CT between March 2015 and March 2017 for hepatic steatosis, vascular calcifications, abdominal diameters and fat volumes. Criteria of metabolic syndrome were obtained from medical records. Differences in imaging biomarkers were compared using chi-square comparisons stratified by metabolic syndrome, abdominal diameter and fat volume.

RESULTS

Of 243 patients, 33% demonstrated hepatic steatosis and 71% atherosclerotic vascular calcifications on CT. 28% met criteria for metabolic syndrome. Patients with metabolic syndrome had higher occurrence of hepatic steatosis, sagittal diameter ≥ 35 cm, visceral fat > 5000 cm³ and subcutaneous fat > 8300 cm³ (P < 0.05), but not vascular calcifications (P > 0.05).

CONCLUSIONS

CT biomarkers of metabolic syndrome are commonly encountered in patients with acute diverticulitis. Recognizing and reporting these findings can guide towards further evaluation for metabolic syndrome.

Cardiometabolic-Based Chronic Disease, Addressing Knowledge and Clinical Practice Gaps: JACC State-of-the-Art Review

In the second part of this JACC State-of-the-Art Review, an early and sustainable preventive care plan is described for cardiometabolic-based chronic disease. This plan can improve cardiometabolic health by targeting early mechanistic events to decrease the risk for certain cardiovascular diseases (e.g., coronary heart disease, heart failure, and atrial fibrillation). Included are various prevention modalities, intensive lifestyle interventions, pharmacotherapy and cardiovascular outcome trial evidence, and bariatric/metabolic procedures. A tactical approach of implementing published clinical practice guidelines/algorithms for early behavioral, adiposity, and dysglycemia targeting is emphasized, as well as relevant educational and research implications.

The correlation between the MRI-evaluated ectopic fat accumulation and the incidence of diabetes mellitus and hypertension depends on body mass index and waist circumference ratio

The widespread presence of overweight and obesity increases with every decade, and the number of people with body mass index (BMI) >30 kg/m² has doubled in the last 30 years. The aim of the study is to assess the correlation between MRI-evaluated ectopic fat accumulation in pancreas, skeletal muscles and liver and the incidence of type 2 diabetes and hypertension, depending on BMI and waist circumference ratio. This prospective study included 267 consecutive patients who were referred to abdominal MRI and underwent a standard clinical assessment with BMI and waist circumference ratio calculation. Ectopic fat accumulation in pancreas, skeletal muscles and liver was evaluated in magnetic resonance imaging using the fat-water separated Dixon imaging. There were statistically significant differences in mean steatosis of all assessed organs in the group of patients with type 2 diabetes or hypertension in comparison to the non-diabetic group as well as to the group without hypertension. It has been observed that pancreas and skeletal muscles are more susceptible to fat accumulation than liver. According to our results, there is a relation between the fat content in muscles, pancreas and liver, the incidence of type 2 diabetes and hypertension and also body mass index and waist circumference ratio. We believe that future studies should aim to determine whether the use of fat content measurement in certain organs could be used as a biomarker that can enable early detection of reversible metabolic changes, as well as their subsequent monitoring.

Increased hip circumference in individuals with metabolic syndrome affects serum nesfatin-1 levels

Background

This case–control study was conducted to investigate the relationship between serum nesfatin-1 levels and nutritional status and blood parameters in patients diagnosed with metabolic syndrome.

Methods

Thirty patients (case) diagnosed with metabolic syndrome according to National Cholesterol Education Program-Adult Treatment Panel III criteria were included. Thirty healthy subjects (control) matched with patients with metabolic syndrome in terms of age, gender and body mass index were included. Three-day food consumption records were obtained. Anthropometric indices were measured and body composition was determined by bioelectrical impedance method. Biochemical parameters and serum nesfatin-1 levels were measured after 8 hours of fasting.

Results

Serum nesfatin-1 levels were 0.245±0.272 ng/mL in the case group and 0.528±0.987 ng/mL in the control group (p>0.05). There was a positive significant correlation between serum nesfatin-1 levels and body weight, waist and hip circumferences in the case group (p<0.05). Each unit increase in hip circumference measurement affects the levels of nesfatin by 0.014 times. In the control group, there was a positive significant correlation between body weight and serum nesfatin-1 levels (p<0.05). A significant correlation was detected between HbA1c and serum nesfatin-1 levels in the case group (p<0.05). A significant relationship was detected between dietary fibre intake and the serum nesfatin-1 levels in the case group (p<0.05).

Conclusions

Anthropometric indices and blood parameters were correlated with serum nesfatin-1 levels in patients with metabolic syndrome. More clinical trials may be performed to establish the relationship between serum nesfatin-1 levels and nutritional status.

Renal Adiposity Does not Preclude Quantitative Assessment of Renal Function Using Dual-Energy Multidetector CT in Mildly Obese Human Subjects

RATIONALE AND OBJECTIVES

Multidetector computed tomography (MDCT) is useful for measuring in the research setting single-kidney perfusion and function using iodinated contrast time-attenuation curves. Obesity promotes deposition of intrarenal fat, which might decrease tissue attenuation and thereby interfere with quantification of renal function using MDCT. The purpose of this study was to test the hypothesis that background subtraction adequately accounts for intrarenal fat deposition in mildly obese human subjects during renal contrast enhanced dynamic CT.

MATERIALS AND METHODS

We prospectively recruited seventeen human subjects stratified as lean or mildly obese based on body mass index below or over 30 kg/m², respectively. Renal perfusion was quantified from CT-derived indicator-dilution curves after background subtraction. Dual-energy MDCT images were postprocessed to generate iodine and virtual-noncontrast datasets, and the ratios between kidney/aorta CT numbers and iodine values calculated as surrogates of renal function.

RESULTS

Subcutaneous adipose tissue was increased in obese subjects. Virtual-noncontrast maps revealed in obese patients a decrease in basal cortical and medullary attenuation. Overall, basal attenuation inversely correlated with body mass index, in line with renal fat deposition. Contrarily, the kidney/aorta CT attenuation (after background subtraction) and kidney/aorta iodine ratios were similar between lean and obese subjects and correlated directly. These observations show that following background subtraction, the CT number reliably reflects basal tissue attenuation.

CONCLUSION

Therefore, our findings support our hypothesis that background subtraction enables reliable assessment of kidney function in mildly obese subjects using MDCT, despite decreased basal attenuation due to renal adiposity.

Regulatory Peptide Nesfatin-1 and its Relationship with Metabolic Syndrome

Metabolic syndrome is associated with a group of conditions abdominal obesity, high triglyceride levels, reduction in low-density lipoprotein, increased blood pressure, and increased fasting blood glucose. Hence, it poses a risk for type 2 diabetes and cardiovascular diseases. The prevalence of metabolic syndrome increases with age. Nesfatin-1, which affects different systems, has recently been discovered as a regulatory peptide molecule. With the discovery of nesfatin-1, it has been reported to inhibit the intake of nutrients and have significant regulatory effects on energy metabolism. As nesfatin-1 is present in both central and peripheral tissues, it is thought to have many functions. In addition to its suppressive effect on food intake, nesfatin-1 has also been reported to have an effect on the blood glucose level for regulating cardiac functions and affecting obesity by providing weight loss. Considering the effects of nesfatin-1, it may be associated with metabolic syndrome.

Factors Associated With Insulin Resistance in Adults With HIV Receiving Contemporary Antiretroviral Therapy: a Brief Update

PURPOSE OF REVIEW

This narrative review summarizes recent data on factors associated with insulin resistance (IR) in adults with HIV, including contemporary antiretroviral therapy (ART).

RECENT FINDINGS

IR remains common in persons with HIV, even those receiving contemporary ART. Generalized and abdominal obesity and ectopic fat are correlates of IR, and emerging data have identified associations with biomarkers of inflammation and immune activation. Small studies suggest associations between mitochondria and IR. In ART-naïve individuals, IR increased within 4 weeks of starting ART in persons receiving contemporary boosted protease inhibitors or an integrase inhibitor. The importance of IR in non-diabetic persons with HIV will continue to grow as the population ages and obesity increases. Non-invasive estimates of IR appear to perform well in persons with HIV, but clinically relevant cutoffs are uncertain. Unexpected metabolic effects of newer HIV integrase inhibitors have been reported; thus, careful observation for and studies of IR are still warranted.

Relationship between the insulin resistance and circulating predictive biochemical markers in metabolic syndrome among young adults in western Algeria

AIM

The metabolic syndrome (MetS) becomes increasingly obvious from an early age. The current study aimed at exploring the relationship between insulin resistance and the main biomarkers of MetS in young adult algerian patients.

METHODS

Glucose, HbA1C, total cholesterol (TC), hjgh bensity lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), insulinemia and C-peptide, adipokins (leptin, adiponectin), inflammatory cytokines (IL-6 and TNF-a), us-CRP and GLP-1 were measured by suitable methods. Homeostasis model assessment (HOMA) was used to detect the degree of insulin resistance.

RESULTS

The MetS patients displayed higher glucose, insulin, HbA1c values and impaired lipid profile as judged by increasing TC, TG, LDL-C levels and lower HDL-C. Furthermore, adipokines, HDL-C and CRP contents were significantly higher whilst TG and LDL-C were much lower in MetS female group as compared to male patients suggesting most pronounced metabolic perturbation in the latter group. The probability of a significant correlation between HOMA and studied variables was often higher in female than male subjects. Such was the case for total cholesterol, HDL-cholesterol, triglycerides, adiponectin, interleukin-6, TNF-α and hs-CRP.

CONCLUSION

The high rate of metabolic syndrome among young obese adults is alarming, this requiring extensive investigations in prone subjects.

MRI assessment of ectopic fat accumulation in pancreas, liver and skeletal muscle in patients with obesity, overweight and normal BMI in correlation with the presence of central obesity and metabolic syndrome

Purpose: Obesity, defined as a body mass index (BMI) exceeding 30 kg/m², is a serious health problem, which can be called an epidemic on a global scale and is one of the most important causes of preventable death. The aim of this study was to assess ectopic fat accumulation in pancreas, liver and skeletal muscle in patients with obesity, overweight and normal BMI in correlation with metabolic syndrome (MetS). Patients and methods: The study included 267 consecutive patients who underwent a standard clinical assessment with BMI calculation. Ectopic fat accumulation in pancreas, liver, and skeletal muscle was evaluated by magnetic resonance imaging (MRI) using fat-water separated Dixon imaging. MetS was defined according to the criteria modified by the National Cholesterol Education Program Adult Treatment Panel III Guidelines. Central obesity was defined using gender and ethnic-specific values for waist circumference. Results: There was a statistically significant correlation between the degree of steatosis of the assessed organs and BMI value as well as waist circumference ratio, that determined the degree of central obesity. It was found that the most rapid relative fat accumulation was in muscle, then in pancreas and then in liver. Higher steatosis of pancreas, liver, and muscle was demonstrated depending on the number of the satisfied MetS criteria. Conclusion: Knowing that pancreatic fatty disease is a risk factor for MetS, it seems that assessment and monitoring of ectopic fat accumulation may have important clinical implications and may be used in the prediction of metabolic risk and its early prevention.