Abdominal subcutaneous and visceral adipose tissue and insulin resistance in the Framingham heart study

The subcutaneous adipose transcriptome identifies a molecular signature of insulin resistance shared with visceral adipose

OBJECTIVE

The objective of this study was to identify the transcriptional landscape of insulin resistance (IR) in subcutaneous adipose tissue (SAT) in humans across the spectrum of obesity.

METHODS

We used SAT RNA sequencing in 220 individuals with metabolic phenotyping.

RESULTS

We identified a 35-gene signature with high predictive accuracy for homeostatic model of IR that was expressed across a variety of non-immune cell populations. We observed primarily "protective" IR associations for adipocyte transcripts and "deleterious" associations for macrophage transcripts, as well as a high concordance between SAT and visceral adipose tissue (VAT). Multiple SAT genes exhibited dynamic expression 5 years after weight loss surgery and with insulin stimulation. Using available expression quantitative trait loci in SAT and/or VAT, we demonstrated similar genetic effect sizes of SAT and VAT on type 2 diabetes and BMI.

CONCLUSIONS

SAT is conventionally viewed as a metabolic buffer for lipid deposition during positive energy balance, whereas VAT is viewed as a dominant contributor to and prime mediator of IR and cardiometabolic disease risk. Our results implicate a dynamic transcriptional architecture of IR that resides in both immune and non-immune populations in SAT and is shared with VAT, nuancing the current VAT-centric concept of IR in humans.

Subcutaneous and Visceral Adipose Tissue Reference Values From the Framingham Heart Study Thoracic and Abdominal CT

BACKGROUND

Computed tomography (CT) captures the quantity, density, and distribution of subcutaneous and visceral (SAT and VAT) adipose tissue compartments. These metrics may change with age and sex.

OBJECTIVE

The study aims to provide age-, sex-, and vertebral level-specific reference values for SAT on chest CT and for SAT and VAT on abdomen CT.

MATERIALS AND METHODS

This secondary analysis of an observational study describes SAT and VAT measurements in participants of the Framingham Heart Study without known cancer diagnosis who underwent at least 1 of 2 CT examinations between 2002 and 2011. We used a previously validated machine learning-assisted pipeline and rigorous quality assurance to segment SAT at the fifth, eighth, and tenth thoracic vertebra (T5, T8, T10) and SAT and VAT at the third lumbar vertebra (L3). For each metric, we measured cross-sectional area (cm2) and mean attenuation (Hounsfield units [HU]) and calculated index (area/height2) (cm2/m2) and gauge (attenuation × index) (HU × cm2/m2). We summarized body composition metrics by age and sex and modeled sex-, age-, and vertebral level-specific reference curves.

RESULTS

We included 14,898 single-level measurements from up to 4 vertebral levels of 3797 scans of 3730 Framingham Heart Study participants (1889 [51%] male with a mean [standard deviation] age of 55.6 ± 10.6 years; range, 38-81 years). The mean VAT index increased with age from 65 (cm2/m2) in males and 29 (cm2/m2) in females in the <45-year-old age group to 99 (cm2/m2) in males and 60 (cm2/m2) in females in >75-year-old age group. The increase of SAT with age was less pronounced, resulting in the VAT/SAT ratio increasing with age. A free R package and online interactive visual web interface allow access to reference values.

CONCLUSIONS

This study establishes age-, sex-, and vertebral level-specific reference values for CT-assessed SAT at vertebral levels T5, T8, T10, and L3 and VAT at vertebral level L3.

Association of visceral adipose tissue with albuminuria and interaction between visceral adiposity and diabetes on albuminuria

AIMS

To explore the correlation between visceral adipose tissue and albuminuria, and whether there is interaction between visceral adipose tissue and diabetes on albuminuria.

METHODS

The study subjects were adult subjects (age ≥ 18 years) from the National Health and Nutrition Examination Surveys (NHANES) database of the USA in 2017-2018. Visceral fat area (VFA) was measured by dual-energy X-ray absorptiometry (DXA). Subjects were divided into three groups according to VFA: low (VFA 0-60cm2), medium (VFA 60-120 cm2) and high (VFA ≥ 120 cm2). Albuminuria was defined as urinary albumin-to-creatinine ratio (UACR) ≥ 30 mg/g. The statistical analysis software used is STATA 17.0.

RESULTS

Data pertaining to 2965 participants (2706 without albuminuria) were included in the analysis. High VFA is an independent risk factor for albuminuria (OR 1.367, 95% CI 1.023-1.827). In the low-VFA group, there is no significant association between diabetes and albuminuria (OR 1.415, 95% CI 0.145-13.849). In the medium-VFA group, diabetes is an independent risk factor for albuminuria (OR 2.217, 95% CI 1.095-4.488). In the high-VFA group, diabetes is also an independent risk factor for albuminuria (OR 5.150, 95% CI 3.150-8.421). There is an additive interaction between high VFA (VFA ≥ 120 cm2) and diabetes on the effect of albuminuria (RERI 3.757, 95% CI 0.927-6.587, p = 0.009), while no multiplication interaction (OR 1.881, 95% CI 0.997-1.023, p = 0.141).

CONCLUSIONS

High VFA may represent an independent risk factor for albuminuria. The amount of visceral fat may affect the effect of diabetes on albuminuria. The higher the visceral fat, the stronger the correlation between diabetes and albuminuria should be present. We suppose an additive interaction between VFA and diabetes on the effect of albuminuria.

Adiponectin and TNFα in relation to glucometabolic control in patients with type 2 diabetes mellitus

Background

The correlation of adiponectin and serum tumor necrosis factor alpha (TNFα) with glucometabolic parameters in diabetes mellitus (DM) needs further studies. We aimed in this study to evaluate the relationship between adiponectin and TNFα with glucometabolic parameters in patients with type 2 DM (T2DM).

Methods

We conducted a cross-sectional study in the Department of Physiology, College of Medicine, King Saud University, Saudi Arabia. The sample size was 117 from the diabetes clinic of King Abdul-Aziz University hospital through the convenience sampling technique. Subjects were grouped into control (healthy) subjects (53) with no chronic diseases and the diabetic group (64) with confirmed T2DM. Socio-demographic data were collected along with the serum blood sample to analyze the variables.

Results

Adiponectin was significantly high in healthy subjects compared to the diabetic group (control: 14.4 ± 4.3, T2DM: 11.0 ± 4.1, P = 0.000), while TNFα was higher in the T2DM group (7.8 ± 2.7) than in the control group (6.6 ± 2.9, P = 0.024). TNFα was negatively correlated with adiponectin in the control group (-0.279) and in diabetic subjects (-0.311) and positively correlated with HbA1c in the diabetic group (0.319) and triglycerides (0.252). Adiponectin was positively correlated with HDL in the control group (0.252) and in diabetic subjects (0.326). There was an inverse correlation between TNFα and adiponectin.

Conclusion

Adiponectin is higher in healthy subjects than in diabetic patients, while TNFα is higher in diabetic patients. In addition, adiponectin is positively correlated with HDL in healthy as well as diabetic patients. TNFα is positively correlated with HbA1c and triglycerides.

The Renoprotective Mechanisms of Sodium-Glucose Cotransporter-2 Inhibitors (SGLT2i)-A Narrative Review

Chronic kidney disease (CKD) is a noncommunicable condition that has become a major healthcare burden across the globe, often underdiagnosed and associated with low awareness. The main cause that leads to the development of renal impairment is diabetes mellitus and, in contrast to other chronic complications such as retinopathy or neuropathy, it has been suggested that intensive glycemic control is not sufficient in preventing the development of diabetic kidney disease. Nevertheless, a novel class of antidiabetic agents, the sodium-glucose cotransporter-2 inhibitors (SGLT2i), have shown multiple renoprotective properties that range from metabolic and hemodynamic to direct renal effects, with a major impact on reducing the risk of occurrence and progression of CKD. Thus, this review aims to summarize current knowledge regarding the renoprotective mechanisms of SGLT2i and to offer a new perspective on this innovative class of antihyperglycemic drugs with proven pleiotropic beneficial effects that, after decades of no significant progress in the prevention and in delaying the decline of renal function, start a new era in the management of patients with CKD.

Adipocyte Mitochondria: Deciphering Energetic Functions across Fat Depots in Obesity and Type 2 Diabetes

Adipose tissue, a central player in energy balance, exhibits significant metabolic flexibility that is often compromised in obesity and type 2 diabetes (T2D). Mitochondrial dysfunction within adipocytes leads to inefficient lipid handling and increased oxidative stress, which together promote systemic metabolic disruptions central to obesity and its complications. This review explores the pivotal role that mitochondria play in altering the metabolic functions of the primary adipocyte types, white, brown, and beige, within the context of obesity and T2D. Specifically, in white adipocytes, these dysfunctions contribute to impaired lipid processing and an increased burden of oxidative stress, worsening metabolic disturbances. Conversely, compromised mitochondrial function undermines their thermogenic capabilities, reducing the capacity for optimal energy expenditure in brown adipocytes. Beige adipocytes uniquely combine the functional properties of white and brown adipocytes, maintaining morphological similarities to white adipocytes while possessing the capability to transform into mitochondria-rich, energy-burning cells under appropriate stimuli. Each type of adipocyte displays unique metabolic characteristics, governed by the mitochondrial dynamics specific to each cell type. These distinct mitochondrial metabolic phenotypes are regulated by specialized networks comprising transcription factors, co-activators, and enzymes, which together ensure the precise control of cellular energy processes. Strong evidence has shown impaired adipocyte mitochondrial metabolism and faulty upstream regulators in a causal relationship with obesity-induced T2D. Targeted interventions aimed at improving mitochondrial function in adipocytes offer a promising therapeutic avenue for enhancing systemic macronutrient oxidation, thereby potentially mitigating obesity. Advances in understanding mitochondrial function within adipocytes underscore a pivotal shift in approach to combating obesity and associated comorbidities. Reigniting the burning of calories in adipose tissues, and other important metabolic organs such as the muscle and liver, is crucial given the extensive role of adipose tissue in energy storage and release.

Associations of childhood BMI, general and visceral fat mass with metabolite profiles at school-age

BACKGROUND

Childhood obesity increases metabolic disease risk. Underlying mechanisms remain unknown. We examined associations of body mass index (BMI), total body fat mass, and visceral fat mass with serum metabolites at school-age, and explored whether identified metabolites improved the identification of children at risk of a metabolically unhealthy phenotype.

METHODS

We performed a cross-sectional analysis among 497 children with a mean age of 9.8 (95% range 9.1, 10.6) years, participating in a population-based cohort study. We measured BMI, total body fat mass using DXA, and visceral fat mass using MRI. Serum concentrations of amino-acids, non-esterified-fatty-acids, phospholipids, and carnitines were determined using LC-MS/MS. Children were categorized as metabolically healthy or metabolically unhealthy, according to BMI, blood pressure, lipids, glucose, and insulin levels.

RESULTS

Higher BMI and total body fat mass were associated with altered concentrations of branched-chain amino-acids, essential amino-acids, and free carnitines. Higher BMI was also associated with higher concentrations of aromatic amino-acids and alkyl-lysophosphatidylcholines (FDR-corrected p-values < 0.05). The strongest associations were present for Lyso.PC.a.C14.0 and SM.a.C32.2 (FDR-corrected p-values < 0.01). Higher visceral fat mass was only associated with higher concentrations of 6 individual metabolites, particularly Lyso.PC.a.C14.0, PC.aa.C32.1, and SM.a.C32.2. We selected 15 metabolites that improved the prediction of a metabolically unhealthy phenotype, compared to BMI only (AUC: BMI: 0.59 [95% CI 0.47,0.71], BMI + Metabolites: 0.91 [95% CI 0.85,0.97]).

CONCLUSIONS

An adverse childhood body fat profile, characterized by higher BMI and total body fat mass, is associated with metabolic alterations, particularly in amino acids, phospholipids, and carnitines. Fewer associations were present for visceral fat mass. We identified a metabolite profile that improved the identification of impaired cardiometabolic health in children, compared to BMI only.

Metabolic Score for Insulin Resistance and New-Onset Type 2 Diabetes in a Middle-Aged and Older Adult Population: Nationwide Prospective Cohort Study and Implications for Primary Care

BACKGROUND

The metabolic score for insulin resistance (METS-IR) has emerged as a noninsulin-based index for the approximation of insulin resistance (IR), yet longitudinal evidence supporting the utility of METS-IR in the primary prevention of type 2 diabetes mellitus (T2DM) remains limited.

OBJECTIVE

We aimed to investigate the longitudinal association between METS-IR, which combines fasting plasma glucose (FPG), lipid profiles, and anthropometrics that can be routinely obtained in resource-limited primary care settings, and the incidence of new-onset T2DM.

METHODS

We conducted a closed-cohort analysis of a nationwide, prospective cohort of 7583 Chinese middle-aged and older adults who were free of T2DM at baseline, sampled from 28 out of 31 provinces in China. We examined the characteristics of participants stratified by elevated blood pressure (BP) at baseline and new-onset T2DM at follow-up. We performed Cox proportional hazard regression analysis to explore associations of baseline METS-IR with incident T2DM in participants overall and in participants stratified by baseline BP. We also applied net reclassification improvement and integrated discrimination improvement to examine the incremental value of METS-IR.

RESULTS

During a mean follow-up period of 6.3 years, T2DM occurred in 527 participants, among which two-thirds (332/527, 62.9%; 95% CI 58.7%-67.1%) had baseline FPG<110 mg/dL. A SD unit increase in baseline METS-IR was associated with the first incidence of T2DM (adjusted hazard ratio [aHR] 1.33, 95% CI 1.22-1.45; P<.001) in all participants. We obtained similar results in participants with normal baseline BP (aHR 1.41, 95% CI 1.22-1.62; P<.001) and elevated baseline BP (aHR 1.29, 95% CI 1.16-1.44; P<.001). The predictive capability for incident T2DM was improved by adding METS-IR to FPG. In study participants with new-onset T2DM whose baseline FPG was <126 mg/dL and <110 mg/dL, 62.9% (332/527; 95% CI 60%-65.9%) and 58.1% (193/332; 95% CI 54.3%-61.9%) of participants had baseline METS-IR above the cutoff values, respectively.

CONCLUSIONS

METS-IR was significantly associated with new-onset T2DM, regardless of baseline BP level. Regular monitoring of METS-IR on top of routine blood glucose in clinical practice may add to the ability to enhance the early identification of primary care populations at risk for T2DM.

Single-cell Analysis of Subcutaneous Fat Reveals Pro-fibrotic Cells that Correlate with Visceral Adiposity in HIV

CONTEXT

Cardiometabolic diseases are common in persons with HIV (PWH) on antiretroviral therapy (ART), which has been attributed to preferential lipid storage in visceral adipose tissue (VAT) compared with subcutaneous adipose tissue (SAT). However, the relationship of SAT-specific cellular and molecular programs with VAT volume is poorly understood in PWH.

OBJECTIVE

We characterized SAT cell-type specific composition and transcriptional programs that are associated with greater VAT volume in PWH on contemporary ART.

METHODS

We enrolled PWH on long-term ART with a spectrum of metabolic health. Ninety-two participants underwent SAT biopsy for bulk RNA sequencing and 43 had single-cell RNA sequencing. Computed tomography quantified VAT volume and insulin resistance was calculated using HOMA2-IR.

RESULTS

VAT volume was associated with HOMA2-IR (p < 0.001). Higher proportions of SAT intermediate macrophages (IMs), myofibroblasts, and MYOC + fibroblasts were associated with greater VAT volume using partial Spearman's correlation adjusting for age, sex, and body mass index (ρ=0.34-0.49, p < 0.05 for all). Whole SAT transcriptomics showed PWH with greater VAT volume have increased expression of extracellular matrix (ECM)- and inflammation-associated genes, and reduced expression of lipolysis- and fatty acid metabolism-associated genes.

CONCLUSIONS

In PWH, greater VAT volume is associated with higher proportion of SAT IMs and fibroblasts, and a SAT ECM and inflammatory transcriptome, which is similar to findings in HIV-negative persons with obesity. These data identify SAT cell-type specific changes associated with VAT volume in PWH that could underlie the high rates of cardiometabolic diseases in PWH, though additional longitudinal studies are needed to define directionality and mechanisms.

Visceral Fat Area and Subcutaneous Fat Area Increase in Hyperthyroidism Patients After Treatment-A Single-Group Repeated-Measures Trial

Purpose

There is evidence that long-term vascular risk remains increased in patients with hyperthyroidism even after normalization of thyroid function, and the mechanisms that regulate this risk are unclear. The aim of this study was to assess how visceral fat area and subcutaneous fat area change after hyperthyroidism treatment, and to further explore the relationship between thyroid hormones, abdominal fat area (visceral fat area and subcutaneous fat area), and lipids.

Patients and Methods

50 patients with newly diagnosed Graves' disease were selected. Anthropometric parameters (weight, height, body mass index, waist circumference, neck circumference), laboratory parameters (thyroid hormones, lipid metabolism indices), abdominal fat area (visceral fat area and subcutaneous fat area), and drug dose were collected. Measurements were made at baseline, 6 and 12 months after treatment. We used linear mixed-effects models for analysis.

Results

The results showed that the following indexes changed significantly at different time points: visceral fat area, subcutaneous fat area, free triiodothyronine, free thyroxine, thyroid stimulating hormone, total cholesterol, high-density lipoprotein, low-density lipoprotein, body weight, neck circumference, body mass index, waist circumference, and drug dose (All P<0.001). We found that free triiodothyronine and free thyroxine were significantly negatively associated with abdominal fat area (P<0.01). There was no significant correlation between drug dose and abdominal fat area (P>0.05). Total cholesterol and low-density lipoprotein were significantly positively associated with abdominal fat area (P<0.01). However, high-density lipoprotein (P=0.06) was not correlated with abdominal fat area. Moreover, the results showed a significant negative correlation between thyroid hormones and lipids (P<0.001).

Conclusion

After anti-thyroid medicine treatment, patients had elevated visceral fat area and subcutaneous fat area and altered lipid profiles. These changes may be one of the reasons why metabolic and cardiovascular diseases remain increased after thyroid function is restored.

Characteristics of Abdominal Visceral Adipose Tissue, Metabolic Health and the Gut Microbiome in Adults

CONTEXT

Compared with the relatively benign effects of increased subcutaneous adipose tissue (SAT), increased visceral adipose tissue (VAT) volume is a causal risk factor for hypertension, hyperlipidemia, type 2 diabetes, and cardiovascular disease. In rodents, increased VAT volume and triglyceride density and ectopic lipid accumulation in kidneys and liver have been induced by alterations in the gut microbiome. However, few studies have characterized these relationships in humans.

OBJECTIVE

To evaluate the tissue triglyceride content of VAT and SAT, liver, kidneys, and pancreas in male and female adults and assess associations with markers of glucose tolerance, serum insulin, and lipids and characteristics of the gut microbiome.

METHODS

Cross-sectional observational study of healthy human adults (n = 60) at a clinical research center. Body mass index (BMI), body composition, and oral glucose tolerance were assessed. Microbiome analysis was conducted on stool samples using 16S rRNA v3 amplicon sequencing. The triglyceride content of VAT, SAT, liver, kidney and pancreas were determined by assessing proton density fat fraction (PDFF) with magnetic resonance imaging (MRI).

RESULTS

Higher VAT PDFF and the ratio of VAT to SAT PDFF were related to higher BMI, HbA1c, HOMA-IR, non-high-density lipoprotein cholesterol, plasma triglycerides, low-density lipoprotein (LDL) cholesterol, and lower high-density lipoprotein (HDL) cholesterol. A higher VAT PDFF and VAT to SAT PDFF ratio were associated with lower alpha diversity and altered beta diversity of the gut microbiome. Differences in VAT were associated with higher relative abundance of the phylum Firmicutes, lower relative abundance of the phylum Bacteroidetes, and enrichment of the bacterial genera Dorea, Streptococcus, and Solobacterium.

CONCLUSION

VAT PDFF measured with MRI is related to impaired glucose homeostasis, dyslipidemia, and differences in the gut microbiome, independently of the total body fat percentage.

Monocyte Chemoattractant Protein-1 (MCP-1), Activin-A and Clusterin in Children and Adolescents with Obesity or Type-1 Diabetes Mellitus

Inflammation plays a crucial role in diabetes and obesity through macrophage activation. Macrophage chemoattractant protein-1 (MCP-1), activin-A, and clusterin are chemokines with known roles in diabetes and obesity. The aim of this study is to investigate their possible diagnostic and/or early prognostic values in children and adolescents with obesity and type-1 diabetes mellitus (T1DM).

METHODS

We obtained serum samples from children and adolescents with a history of T1DM or obesity, in order to measure and compare MCP-1, activin-A, and clusterin concentrations.

RESULTS

Forty-three subjects were included in each of the three groups (controls, T1DM, and obesity). MCP-1 values were positively correlated to BMI z-score. Activin-A was increased in children with obesity compared to the control group. A trend for higher values was detected in children with T1DM. MCP-1 and activin-A levels were positively correlated. Clusterin levels showed a trend towards lower values in children with T1DM or obesity compared to the control group and were negatively correlated to renal function.

CONCLUSIONS

The inflammation markers MCP-1, activin-A, and clusterin are not altered in children with T1DM. Conversely, obesity in children is positively correlated to serum MCP-1 values and characterized by higher activin-A levels, which may reflect an already established systematic inflammation with obesity since childhood.

Longitudinal changes in body fat and metabolic complications in young people with perinatally acquired HIV

BACKGROUND

The role of body fat on metabolic complications remains poorly understood in young people living with perinatally acquired HIV (YPHIV).

OBJECTIVE

Our objective was to assess the association of changes in adiposity over 2 years with metabolic outcomes in YPHIV.

METHODS

The PHACS Adolescent Master Protocol (AMP) study enrolled YPHIV from 2007 to 2009 across 15 US sites, including Puerto Rico. We included YPHIV aged 7-19 years with body composition data assessed by whole-body dual-energy X-ray absorptiometry (DXA) at baseline and 2 years later. Metabolic outcomes included homeostatic model assessment of insulin resistance (HOMA-IR) and non-high-density lipoprotein cholesterol (non-HDL-C). We fitted linear regression models to assess the association of increase in body fat over 2 years with metabolic outcomes at years 2 and 3.

RESULTS

In all, 232 participants had a second DXA and either HOMA-IR or non-HDL-C measured at year 2. Participant characteristics at the first DXA were: age 12 years (9-14) [median (Q1-Q3)], 69% Black, and median CD4 count 714 cells/μL; 70% with HIV RNA <400 copies/mL. In adjusted analyses for every 1% increase in body fat from baseline to year 2, HOMA-IR was higher by 1.03-fold at year 3 (95% CI: 1.00, 1.05). We observed that for every 1% increase in body fat from baseline to year 2, non-HDL-C was 0.72 mg/dL higher at year 2 (95% CI: -0.04-1.49) and 0.81 mg/dL higher at year 3 (95% CI: -0.05-1.66).

CONCLUSIONS

Increases in adiposity over time may lead to downstream decreased insulin sensitivity and dyslipidaemia in YPHIV.

Chronic Insufficient Sleep in Women Impairs Insulin Sensitivity Independent of Adiposity Changes: Results of a Randomized Trial

OBJECTIVE

Insufficient sleep is associated with type 2 diabetes, yet the causal impact of chronic insufficient sleep on glucose metabolism in women is unknown. We investigated whether prolonged mild sleep restriction (SR), resembling real-world short sleep, impairs glucose metabolism in women.

RESEARCH DESIGN AND METHODS

Women (aged 20-75 years) without cardiometabolic diseases and with actigraphy-confirmed habitual total sleep time (TST) of 7-9 h/night were recruited to participate in this randomized, crossover study with two 6-week phases: maintenance of adequate sleep (AS) and 1.5 h/night SR. Outcomes included plasma glucose and insulin levels, HOMA of insulin resistance (HOMA-IR) values based on fasting blood samples, as well as total area under the curve for glucose and insulin, the Matsuda index, and the disposition index from an oral glucose tolerance test.

RESULTS

Our sample included 38 women (n = 11 postmenopausal women). Values are reported with ±SEM. Linear models adjusted for baseline outcome values demonstrated that TST was reduced by 1.34 ± 0.04 h/night with SR versus AS (P < 0.0001). Fasting insulin (β = 6.8 ± 2.8 pmol/L; P = 0.016) and HOMA-IR (β = 0.30 ± 0.12; P = 0.016) values were increased with SR versus AS, with effects on HOMA-IR more pronounced in postmenopausal women compared with premenopausal women (β = 0.45 ± 0.25 vs. β = 0.27 ± 0.13, respectively; P for interaction = 0.042). Change in adiposity did not mediate the effects of SR on glucose metabolism or change results in the full sample when included as a covariate.

CONCLUSIONS

Curtailing sleep duration to 6.2 h/night, reflecting the median sleep duration of U.S. adults with short sleep, for 6 weeks impairs insulin sensitivity, independent of adiposity. Findings highlight insufficient sleep as a modifiable risk factor for insulin resistance in women to be targeted in diabetes prevention efforts.

Nonalcoholic Fatty Liver Disease Incidence and Remission and Their Predictors During 7 Years of Follow-up Among Finns

CONTEXT

The incidence and remission of nonalcoholic fatty liver disease (NAFLD) are sparsely studied outside Asia.

OBJECTIVE

This prospective study aimed to investigate NAFLD incidence and remission, and their predictors among a general Finnish population.

METHODS

The applied cohort included 1260 repeatedly studied middle-aged participants with data on liver ultrasound and no excessive alcohol intake. Hepatic steatosis was assessed by liver ultrasound with a 7.2-year study interval. Comprehensive data on health parameters and lifestyle factors were available.

RESULTS

At baseline, 1079 participants did not have NAFLD, and during the study period 198 of them developed NAFLD. Of the 181 participants with NAFLD at baseline, 40 achieved NAFLD remission. Taking multicollinearity into account, key predictors for incident NAFLD were baseline age (odds ratio 1.07; 95% CI, 1.02-1.13; P = .009), waist circumference (WC) (2.77, 1.91-4.01 per 1 SD; P < .001), and triglycerides (2.31, 1.53-3.51 per 1 SD; P < .001) and alanine aminotransferase (ALAT) (1.90, 1.20-3.00 per 1 SD; P = .006) concentrations as well as body mass index (BMI) change (4.12, 3.02-5.63 per 1 SD; P < .001). Predictors of NAFLD remission were baseline aspartate aminotransferase (ASAT) concentration (0.23, 0.08-0.67 per 1 SD; P = .007) and WC change (0.38, 0.25-0.59 per 1 SD; P < .001).

CONCLUSION

During follow-up, NAFLD developed for every fifth participant without NAFLD at baseline, and one-fifth of those with NAFLD at baseline had achieved NAFLD remission. NAFLD became more prevalent during the follow-up period. From a clinical perspective, key factors predicting NAFLD incidence and remission were BMI and WC change independent of their baseline level.

Matrix density regulates adipocyte phenotype

Alterations of the extracellular matrix contribute to adipose tissue dysfunction in metabolic disease. We studied the role of matrix density in regulating human adipocyte phenotype in a tunable hydrogel culture system. Lipid accumulation was maximal in intermediate hydrogel density of 5 weight %, relative to 3% and 10%. Adipogenesis and lipid and oxidative metabolic gene pathways were enriched in adipocytes in 5% relative to 3% hydrogels, while fibrotic gene pathways were enriched in 3% hydrogels. These data demonstrate that the intermediate density matrix promotes a more adipogenic, less fibrotic adipocyte phenotype geared towards increased lipid and aerobic metabolism. These observations contribute to a growing literature describing the role of matrix density in regulating adipose tissue function.

Platform for the interdisciplinary study of cardiovascular, metabolic and neurovascular diseases (PICMAN) protocol

Through extensive multisystem phenotyping, the central aim of Project PICMAN is to correlate metabolic flexibility to measures of cardiometabolic health, including myocardial diastolic dysfunction, coronary and cerebral atherosclerosis, body fat distribution and severity of non-alcoholic fatty liver disease. This cohort will form the basis of larger interventional trials targeting metabolic inflexibility in the prevention of cardiovascular disease. Participants aged 21-72 years with no prior manifest atherosclerotic cardiovascular disease (ASCVD) are being recruited from a preventive cardiology clinic and an existing cohort of non-alcoholic fatty liver disease (NAFLD) in an academic medical centre. A total of 120 patients will be recruited in the pilot phase of this study and followed up for 5 years. Those with 10-year ASCVD risk ≥ 5% as per the QRISK3 calculator are eligible. Those with established diabetes mellitus are excluded. Participants recruited undergo a detailed assessment of health behaviours and physical measurements. Participants also undergo a series of multimodality clinical phenotyping comprising cardiac tests, vascular assessments, metabolic tests, liver and neurovascular testing. Blood samples are also being collected and banked for plasma biomarkers, 'multi-omics analyses' and for generation of induced pluripotent stem cells (iPSC). Extensive evidence points to metabolic dysregulation as an early precursor of cardiovascular disease, particularly in Asia. We hypothesise that quantifiable metabolic inflexibility may be representative of an individual in his/her silent, but high-risk progression towards insulin resistance, diabetes and cardiovascular disease. The platform for interdisciplinary cardiovascular-metabolic-neurovascular diseases (PICMAN) is a pilot, prospective, multi-ethnic cohort study.

The predictive significance of lipid accumulation products for future diabetes in a non-diabetic population from a gender perspective: an analysis using time-dependent receiver operating characteristics

Objective

The increasing prevalence of diabetes is strongly associated with visceral adipose tissue (VAT), and gender differences in VAT remarkably affect the risk of developing diabetes. This study aimed to assess the predictive significance of lipid accumulation products (LAP) for the future onset of diabetes from a gender perspective.

Methods

A total of 8,430 male and 7,034 female non-diabetic participants in the NAGALA (NAfld in the Gifu Area, Longitudinal Analysis) program were included. The ability of LAP to assess the risk of future new-onset diabetes in both genders was analyzed using multivariate Cox regression. Subgroup analysis was conducted to explore the impact of potential modifiers on the association between LAP and diabetes. Additionally, time-dependent receiver operator characteristics (ROC) curves were used to assess the predictive power of LAP in both genders for new-onset diabetes over the next 2-12 years.

Results

Over an average follow-up of 6.13 years (maximum 13.14 years), 373 participants developed diabetes. Multivariate Cox regression analysis showed a significant gender difference in the association between LAP and future diabetes risk (P-interaction<0.05): the risk of diabetes associated with LAP was greater in females than males [hazard ratios (HRs) per standard deviation (SD) increase: male 1.20 (1.10, 1.30) vs female 1.35 (1.11, 1.64)]. Subgroup analysis revealed no significant modifying effect of factors such as age, body mass index (BMI), smoking history, drinking history, exercise habits, and fatty liver on the risk of diabetes associated with LAP (All P-interaction <0.05). Time-dependent ROC analysis showed that LAP had greater accuracy in predicting diabetes events occurring within the next 2-12 years in females than males with more consistent predictive thresholds in females.

Conclusions

This study highlighted a significant gender difference in the association between LAP and future diabetes risk. The risk of diabetes associated with LAP was greater in females than in males. Furthermore, LAP showed superior predictive ability for diabetes at different time points in the future in females and had more consistent and stable predictive thresholds in females, particularly in the medium and long term.

DNA methylation of insulin signaling pathways is associated with HOMA2-IR in primary myoblasts from older adults

BACKGROUND

While ageing is associated with increased insulin resistance (IR), the molecular mechanisms underlying increased IR in the muscle, the primary organ for glucose clearance, have yet to be elucidated in older individuals. As epigenetic processes are suggested to contribute to the development of ageing-associated diseases, we investigated whether differential DNA methylation was associated with IR in human primary muscle stem cells (myoblasts) from community-dwelling older individuals.

METHODS

We measured DNA methylation (Infinium HumanMethylationEPIC BeadChip) in myoblast cultures from vastus lateralis biopsies (119 males/females, mean age 78.24 years) from the Hertfordshire Sarcopenia Study extension (HSSe) and examined differentially methylated cytosine phosphate guanine (CpG) sites (dmCpG), regions (DMRs) and gene pathways associated with HOMA2-IR, an index for the assessment of insulin resistance, and levels of glycated hemoglobin HbA1c.

RESULTS

Thirty-eight dmCpGs (false discovery rate (FDR) < 0.05) were associated with HOMA2-IR, with dmCpGs enriched in genes linked with JNK, AMPK and insulin signaling. The methylation signal associated with HOMA2-IR was attenuated after the addition of either BMI (6 dmCpGs), appendicular lean mass index (ALMi) (7 dmCpGs), grip strength (15 dmCpGs) or gait speed (23 dmCpGs) as covariates in the model. There were 8 DMRs (Stouffer < 0.05) associated with HOMA2-IR, including DMRs within T-box transcription factor (TBX1) and nuclear receptor subfamily-2 group F member-2 (NR2F2); the DMRs within TBX1 and NR2F2 remained associated with HOMA2-IR after adjustment for BMI, ALMi, grip strength or gait speed. Forty-nine dmCpGs and 21 DMRs were associated with HbA1c, with cg13451048, located within exoribonuclease family member 3 (ERI3) associated with both HOMA2-IR and HbA1c. HOMA2-IR and HbA1c were not associated with accelerated epigenetic ageing.

CONCLUSIONS

These findings suggest that insulin resistance is associated with differential DNA methylation in human primary myoblasts with both muscle mass and body composition making a significant contribution to the methylation changes associated with IR.

Visceral adipose tissue and risk of nonalcoholic fatty liver disease: A Mendelian randomization study

OBJECTIVE

Observational studies have shown that visceral adipose tissue (VAT) can increase the risk of nonalcoholic fatty liver disease (NAFLD). However, the causality of this association remains unclear. Therefore, this study aimed to explore the causal association between VAT and NAFLD.

DESIGN

We obtained single-nucleotide polymorphisms strongly associated with VAT (n = 325,153) from large-scale genome-wide association studies. Summary-level data for NAFLD (2275 cases and 375,002 controls) was available from the FinnGen consortium. We applied two-sample Mendelian randomization (MR) to determine the causal association between VAT and NAFLD. The random-effects inverse-variance weighted (IVW) method was used as the main MR approach, with alternate methods including the weighted median (WM) approach and MR-Egger regression. In addition, we conducted sensitivity analyses to assess the robustness of MR analyses.

RESULTS

Genetically predicted higher VAT mass is causally associated with a higher risk of NAFLD. The three analysis results of MR were as follows: IVW (β = 0.665, odds ratio [OR] = 1.944, 95% confidence interval [CI] = 1.482-2.550, p = 1.58e-06], WM (β = 0.615, OR = 1.849, 95% CI = 1.272-2.689, p = 1.29e-03), and MR-Egger (β = 1.250, OR = 3.490, 95% CI = 1.522-7.998, p = 3.52e-03). In the sensitivity analysis, the data showed heterogeneity (p < 0.05) but no pleiotropy (p = 0.145).

CONCLUSION

This study provided genetic evidence that higher VAT mass causally associated with a higher risk of NAFLD. The amount of VAT could be reduced using a therapeutic strategy for managing NAFLD.

Assessment of correlation between conventional anthropometric and imaging-derived measures of body fat composition: a systematic literature review and meta-analysis of observational studies

BACKGROUND

In studies of the association of adiposity with disease risk, widely used anthropometric measures of adiposity (e.g. body-mass-index [BMI], waist circumference [WC], waist-hip ratio [WHR]) are simple and inexpensive to implement at scale. In contrast, imaging-based techniques (e.g. magnetic resonance imaging [MRI] and dual x-ray absorptiometry [DXA]) are expensive and labour intensive, but can provide more accurate quantification of body fat composition. There is, however, limited evidence about the relationship between conventional and imaging-derived measures of adiposity.

METHODS

We searched Scopus and Web of Science for published reports in English of conventional versus imaging-derived measurements of adiposity. We identified 42 articles (MRI = 22; DXA = 20) that met selection criteria, involving 42,556 (MRI = 15,130; DXA = 27,426) individuals recruited from community or hospital settings. Study-specific correlation coefficients (r) were transformed using Fisher's Z transformation, and meta-analysed to yield weighted average correlations, both overall and by ancestry, sex and age, where feasible. Publication bias was investigated using funnel plots and Egger's test.

RESULTS

Overall, 98% of participants were 18 + years old, 85% male and 95% White. BMI and WC were most strongly correlated with imaging-derived total abdominal (MRI-derived: r = 0.88-; DXA-derived: 0.50-0.86) and subcutaneous abdominal fat (MRI-derived: 0.83-0.85), but were less strongly correlated with visceral abdominal fat (MRI-derived: 0.76-0.79; DXA-derived: 0.80) and with DXA-derived %body fat (0.76). WHR was, at best, strongly correlated with imaging-derived total abdominal (MRI-derived: 0.60; DXA-derived: 0.13), and visceral abdominal fat (MRI-derived: 0.67; DXA-derived: 0.65), and moderately with subcutaneous abdominal (MRI-derived: 0.54), and with DXA-derived %body fat (0.58). All conventional adiposity measures were at best moderately correlated with hepatic fat (MRI-derived: 0.36-0.43). In general, correlations were stronger in women than in men, in Whites than in non-Whites, and in those aged 18 + years.

CONCLUSIONS

In this meta-analysis, BMI and WC, but not WHR, were very strongly correlated with imaging-derived total and subcutaneous abdominal fat. By comparison, all three measures were moderately or strongly correlated with imaging-based visceral abdominal fat, with WC showing the greatest correlation. No anthropometric measure was substantially correlated with hepatic fat. Further larger studies are needed to compare these measures within the same study population, and to assess their relevance for disease risks in diverse populations.

Beneficial Short-Term Effects of Bariatric Surgery on Nutritional Inflammatory Profile and Metabolic Biomarkers

PURPOSE

Bariatric surgery (BS) has several potential metabolic benefits. However, little is known about its impact on changes in the inflammatory potential of diet and its effect on inflammatory and metabolic markers. This study aimed to assess the short-term beneficial effects of BS on dietary inflammatory potential and inflammatory and metabolic markers.

MATERIALS AND METHODS

Participants (n = 20) were evaluated 3 months before and after BS. Body mass, body mass index, anthropometric measurements, fat mass, fat-free mass, visceral fat, skeletal muscle mass, basal metabolic rate, serum lipids, HOMA-IR, QUICKI and inflammatory markers, including leptin, adiponectin, adiponectin/leptin ratio and plasminogen activator inhibitor-1 (PAI-1), were evaluated. Diet data were collected using a 3-day diet record and the dietary inflammatory index (DII®) and energy-adjusted dietary inflammatory index (E-DIITM) scores were computed.

RESULTS

There was a reduction in DII® (2.56 vs 2.13) and E-DIITM (2.18 vs 0.45) indicating an improvement in inflammatory nutritional profile. Moreover, there were increases in the adiponectin/leptin ratio (0.08 vs 0.21) and QUICKI scores (0.31 vs 0.37), and reductions in leptin (36.66 vs 11.41 ng/ml) and HOMA-IR scores (3.93 vs 1.50). There were also improvements in body composition and anthropometric parameters.

CONCLUSIONS

BS promotes changes in metabolic profile, inflammatory state and food intake and these modifications appeared to be associated with improvements in diet-related inflammation, an increase in the adiponectin/leptin ratio and a reduction in leptin. These results contribute to knowledge on the contribution bariatric surgery can make to the treatment of obesity and the reduction of related comorbidities.

Diet-induced Weight Loss and Phenotypic Flexibility Among Healthy Overweight Adults: A Randomized Trial

BACKGROUND

The capacity of an individual to respond to changes in food intake so that postprandial metabolic perturbations are resolved, and metabolism returns to its pre-prandial state, is called phenotypic flexibility. This ability may be a more important indicator of current health status than metabolic markers in a fasting state.

AIM

In this parallel randomized controlled trial study, an energy-restricted healthy diet and 2 dietary challenges were used to assess the effect of weight loss on phenotypic flexibility.

METHODS

Seventy-two volunteers with overweight and obesity underwent a 12-wk dietary intervention. The participants were randomized to a weight loss group (WLG) with 20% less energy intake or a weight-maintenance group (WMG). At weeks 1 and 12, participants were assessed for body composition by MRI. Concurrently, markers of metabolism and insulin sensitivity were obtained from the analysis of plasma metabolome during 2 different dietary challenges-an oral glucose tolerance test (OGTT) and a mixed-meal tolerance test.

RESULTS

Intended weight loss was achieved in the WLG (-5.6 kg, P < 0.0001) and induced a significant reduction in total and regional adipose tissue as well as ectopic fat in the liver. Amino acid-based markers of insulin action and resistance such as leucine and glutamate were reduced in the postprandial phase of the OGTT in the WLG by 11.5% and 28%, respectively, after body weight reduction. Weight loss correlated with the magnitude of changes in metabolic responses to dietary challenges. Large interindividual variation in metabolic responses to weight loss was observed.

CONCLUSION

Application of dietary challenges increased sensitivity to detect metabolic response to weight loss intervention. Large interindividual variation was observed across a wide range of measurements allowing the identification of distinct responses to the weight loss intervention and mechanistic insight into the metabolic response to weight loss.

Effect of the glucagon-like peptide-1 receptor agonist liraglutide, compared to caloric restriction, on appetite, dietary intake, body fat distribution and cardiometabolic biomarkers: A randomized trial in adults with obesity and prediabetes

AIMS

To investigate the hypothesis that weight loss with the glucagon-like peptide-1 receptor agonist (GLP-1RA) liraglutide alone would lead to a greater reduction in the proportion of fat to lean tissue mass when compared to caloric restriction (CR) alone, as well as when compared to treatment with sitagliptin, a dipeptidyl peptidase-4 (DPP-4) inhibitor, that also enhances GLP-1 activity - to determine the independent effects of each treatment.

METHODS

A total of 88 adults with obesity and prediabetes were randomized to 14 weeks of intervention with CR (-390 kcal/d), liraglutide (1.8 mg/d), or the dipeptidyl peptidase-4 inhibitor sitagliptin (100 mg/d) as a weight-neutral comparator. Changes between groups in appetite and hunger ratings measured via visual analogue scales, dietary intakes, body weight, body composition via dual energy x-ray absorptiometry, and resting energy expenditure via indirect calorimetry were assessed using the Kruskal-Wallis test or Pearson's chi-squared test.

RESULTS

Weight loss ≥5% of baseline body weight occurred in 44% of participants in the CR group, 22% of the liraglutide group and 5% of the sitagliptin group (p = 0.02). The ratio of fat to lean mass decreased by 6.5% in the CR group, 2.2% in the liraglutide group, and 0% in the sitagliptin group (p = 0.02). Visceral fat reduced by 9.5% in the CR group, 4.8% in the liraglutide group, and 0% in the sitagliptin group (p = 0.04). A spontaneous reduction in dietary simple carbohydrates in the CR group was associated with improved homeostatic model assessment of insulin resistance score (HOMA-IR).

CONCLUSIONS

Although both liraglutide and CR are valuable strategies for cardiometabolic risk reduction, CR was associated with greater weight loss and more favourable improvements in body composition than treatment with liraglutide alone. Differences in the response to each of these interventions enables patients to be stratified to the most optimal intervention for their personal risk factors.

Adipose Tissue and Plasma Markers Associated with HbA1c Pre- and Post-bariatric Surgery: a Cross-sectional and Cohort Study

PURPOSE

Obesity can be associated with chronic inflammation and dysregulated expression of inflammatory adipokines that contribute to insulin resistance and type 2 diabetes. This may also affect the clinical response to bariatric surgery. Our objective was whether baseline visceral adipose tissue features and plasma adipokine are associated with HbA1c ≥0.06 at the time of Roux-en-Y gastric bypass (RYGB) surgery and with persistently elevated HbA1c at 12 months post-RYGB.

METHODS

During the surgery, adipose biopsies and plasma were collected for adipokine/cytokine profile. Clinical and biochemical measurements were also collected at the time of RYGB and, in those with baseline elevated HbA1c, at 12 months post-RYGB.

RESULTS

In the cross-sectional study, 109 patients (82.6% female; age 49 years; BMI 46.98 kg/m2) participated. Of those with elevated HbA1c at baseline (n = 61), 47 patients had repeated measurements at 12 months post-RYGB (23% drop-out). Using a multivariate logistic regression model, older age (adjusted odds ratio (aOR), 1.14; 95% confidence interval (CI), 1.06-1.22) and higher plasma resistin (aOR, 5.30; 95% CI, 1.25-22.44) were associated with higher odds of HbA1c ≥ 0.06, whereas higher plasma adiponectin (aOR, 0.993; 95% CI, 0.99-0.996) was associated with lower odds of HbA1c ≥0.06. In addition, baseline higher average adipose cell area (aOR, 1.0017; 95% CI, 1.0002-1.0032) and plasma resistin (aOR, 1.0004; 95% CI, 1.0000-1.0009) were associated with higher odds of having persistently elevated HbA1c at 12 months post-RYGB.

CONCLUSION

Our study suggests that baseline plasma adipokine dysregulation, specifically high resistin, and adipocyte hypertrophy may affect the clinical response to RYGB.

Cardiometabolic Parameters 3 Years After Switch to Dolutegravir/Lamivudine vs Maintenance of Tenofovir Alafenamide-Based Regimens

Background

Cardiometabolic outcomes were investigated 3 years after switching to the 2-drug regimen dolutegravir/lamivudine (DTG/3TC) vs continuing 3-/4-drug tenofovir alafenamide (TAF)-based regimens in a multicenter phase 3 noninferiority study based on an open-label randomized design.

Method

Adults with virologically suppressed HIV-1 switched to once-daily DTG/3TC (n = 369) or continued TAF-based regimens (n = 372). Cardiometabolic health parameters were assessed through week 144 via mixed-model repeated measures or logistic regression analyses, adjusting for baseline variables.

Results

At week 144, 13% (42/316) of the DTG/3TC group and 12% (37/303) of the TAF-based regimen group had ≥10% weight gain from baseline (adjusted odds ratio, 1.11; 95% CI, .68-1.80). Adjusted change from baseline in serum leptin, a surrogate marker of adiposity, was similar between groups (treatment ratio, 1.00; 95% CI, .89-1.13). The lipid profile generally favored DTG/3TC in the baseline boosted subgroup. Adjusted odds revealed no clinically meaningful differences between groups: homeostatic model assessment of insulin resistance ≥2 (adjusted odds ratio, 0.79; 95% CI, .50-1.26), metabolic syndrome (International Diabetes Federation criteria, 0.99; .59-1.68), hepatic fibrosis (fibrosis-4 index score ≥1.45, 1.39; .63-3.06), and coronary artery disease risk (Framingham risk score ≥10%, 0.92; .56-1.49). Baseline variables and characteristics associated with odds of each cardiometabolic parameter outcome were consistent with known risk factors, including age, sex, race, and some disease characteristics.

Conclusions

Cardiometabolic health 3 years after switching to DTG/3TC was comparable to that for individuals continuing TAF-based regimens, further supporting DTG/3TC as a robust switch option with a stable metabolic profile.

Trial registration

ClinicalTrials.gov NCT03446573.

Oral ω-3 PUFA supplementation modulates inflammation in adipose tissue depots in morbidly obese women: A randomized trial

OBJECTIVES

Obesity is characterized by local and systemic low-grade inflammatory responses. Adipose tissue macrophages (ATM) play decisive roles in inflammation, insulin signaling, and various metabolic dysfunctions. Diets enriched with ω-3 polyunsaturated fatty acids (PUFAs) have been shown to improve health and mitigate pathologic conditions. However, the effects of ω-3 PUFA on adipose tissue inflammation, ATM number, and phenotype are poorly defined in human obesity. The aim of this study was to examine differences in expression of metabolic-inflammatory markers in omental, mesenteric, and subcutaneous fat depots of obese women supplemented with ω-3 PUFAs for 4 wk compared with a low-calorie diet before bariatric surgery.

METHODS

In a randomized controlled trial, inflammatory markers in the abdominal adipose tissue and the systemic response in obese women were studied. Patients were treated with a 2-wk low-calorie diet (LCD) or a 4-wk ω-3 PUFA-enriched diet (920 mg eicosapentaenoic acid, 760 mg docosahexaenoic acid daily) before laparoscopic bypass surgery. Omental, mesenteric, and subcutaneous adipose tissue biopsies were collected during surgery and analyzed for quantity and phenotype of ATMs, and profiled for adipokines, cytokines, and signal transduction molecules.

RESULTS

The chronic inflammatory state characterized by ATM markers was mostly improved by ω-3 PUFAs in visceral adipose tissue. We observed a decreased expression of CD45, CCL2, and CD68, indicating a lower inflammatory state. In patients with type 2 diabetes, ω-3 PUFAs lowered the expression of Netrin-1.

CONCLUSIONS

Compared with an LCD, a diet enriched with ω-3 PUFAs influences the inflammatory state in different adipose tissue depots, by affecting markers of adipose tissue inflammation, macrophage phenotype, and retention. However, this was not reflected in clinical parameters such as insulin resistance and inflammatory cytokines. Subcutaneous adipose tissue and visceral adipose tissue have different responses to an LCD or a ω-3 PUFA-enriched diet. The presence of diabetes modifies the expression of inflammatory markers.

Effects of concurrent exercise training on body composition, systemic inflammation, and components of metabolic syndrome in inactive academics: a randomised controlled trial

PURPOSE

Low physical activity in the academic workplace may increase the risk of cardiometabolic disease. This randomised controlled trial investigated the effect of 14 weeks of concurrent exercise training (CT) on components of metabolic syndrome, body composition, insulin resistance, and markers of systemic inflammation in inactive academics.

METHODS

59 inactive academics were randomised into a CT (n = 29) or wait-list control group (n = 30). CT performed supervised training at an onsite facility 3 times per week for 14 weeks and cardiometabolic health was assessed pre- and post-intervention. Aerobic capacity was measured via a metabolic cart. Dual-Energy X-ray Absorptiometry measured fat mass, lean mass, and central adiposity. Fasting blood samples were analysed for interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), Homeostatic Model Assessment for Insulin Resistance (HOMA-IR), glucose, and lipid profile.

RESULTS

Following the intervention, there was a decrease in fat mass (mean ± SD;  - 1.3 ± 1.4%), android fat mass (median (IQR);  - 0.06 (0.27) kg), and visceral adipose tissue (median (IQR);  - 66 (110) cm³) in CT, but not control. Lean mass (median (IQR); 1.35 (1.86) kg) and aerobic capacity (mean ± SD; 4.0 ± 3.1 mL/kg/min) increased in CT, but not in control. There were no changes in IL-6, TNF-a, HOMA-IR, glucose, or lipid profile in response to the intervention (P > 0.05). Changes in insulin resistance were positively associated with IL-6 in the control group only (coefficients [95%CI]; 5.957 [2.961, 8.953]).

CONCLUSION

Implementing combined aerobic and resistance exercise training programs in academic institutions may be an appropriate intervention to increase physical activity and reduce risk factors associated with cardiometabolic disease.

TRIAL REGISTRATION

The study was registered with the Australian New Zealand Clinical Trials Registry on the  23rd  of April, 2019 (ACTRN12619000608167).

Long-term Outcome of Body Composition, Ectopic Lipid, and Insulin Resistance Changes With Surgical Treatment of Acromegaly

Context

Acromegaly presents a unique pattern of lower adiposity and insulin resistance in active disease but reduction in insulin resistance despite a rise in adiposity after surgery. Depot-specific adipose tissue masses and ectopic lipid are important predictors of insulin resistance in other populations, but whether they are in acromegaly is unknown. Long-term persistence of body composition changes after surgery is unknown.

Objective

To determine how depot-specific body composition and ectopic lipid relate to insulin resistance in active acromegaly and whether their changes with surgery are sustained long-term.

Methods

Cross-sectional study in patients with active acromegaly and longitudinal study in newly diagnosed patients studied before and in long-term follow-up, 3 (1-8) years (median, range), after surgery. Seventy-one patients with active acromegaly studied cross-sectionally and 28 with newly diagnosed acromegaly studied longitudinally. Main outcome measures were visceral (VAT), subcutaneous (SAT), and intermuscular adipose tissue masses by whole-body magnetic resonance imaging; intrahepatic lipid (IHL) by proton magnetic resonance spectroscopy; insulin resistance measures derived from fasting; and oral glucose tolerance test insulin and glucose levels.

Results

SAT and insulin-like growth factor 1 level, but not VAT or IHL, were independent predictors of insulin resistance in active acromegaly. VAT, SAT, and IHL gains were sustained long-term after surgery. VAT mass rise with surgery correlated inversely with rise in QUICKI while SAT rise correlated with fall in the Homeostatic Model Assessment score.

Conclusion

SAT and disease activity are important predictors of insulin resistance in active acromegaly. Adiposity gains are sustained long-term after surgical treatment and impact on the accompanying improvement in insulin resistance.

Effects of Microalgae on Metabolic Syndrome

Metabolic syndrome (MetS) is a cluster of metabolic disturbances, including abdominal obesity, hypertension, hypertriglyceridemia, reduced high-density lipoprotein cholesterol (HDL-C) and hyperglycemia. Adopting a healthier lifestyle and multiple drug-based therapies are current ways to manage MetS, but they have limited efficacy, albeit the prevalence of MetS is rising. Microalgae is a part of the human diet and has also been consumed as a health supplement to improve insulin sensitivity, inflammation, and several components of MetS. These therapeutic effects of microalgae are attributed to the bioactive compounds present in them that exhibit antioxidant, anti-inflammatory, anti-obesity, antihypertensive, hepatoprotective and immunomodulatory effects. Therefore, studies investigating the potential of microalgae in alleviating MetS are becoming more popular, but a review on this topic remains scarce. In this review, we discuss the effects of microalgae, specifically on MetS, by reviewing the evidence from scientific literature covering in vitro and in vivo studies. In addition, we also discuss the underlying mechanisms that modulate the effects of microalgae on MetS, and the limitations and future perspectives of developing microalgae as a health supplement for MetS. Microalgae supplementation is becoming a viable approach in alleviating metabolic disturbances and as a unique addition to the management of MetS.

Fully automated CT-based adiposity assessment: comparison of the L1 and L3 vertebral levels for opportunistic prediction

PURPOSE

The purpose of this study is to compare fully automated CT-based measures of adipose tissue at the L1 level versus the standard L3 level for predicting mortality, which would allow for use at both chest (L1) and abdominal (L3) CT.

METHODS

This retrospective study of 9066 asymptomatic adults (mean age, 57.1 ± 7.8 [SD] years; 4020 men, 5046 women) undergoing unenhanced low-dose abdominal CT for colorectal cancer screening. A previously validated artificial intelligence (AI) tool was used to assess cross-sectional visceral and subcutaneous adipose tissue areas (SAT and VAT), as well as their ratio (VSR) at the L1 and L3 levels. Post-CT survival prediction was compared using area under the ROC curve (ROC AUC) and hazard ratios (HRs).

RESULTS

Median clinical follow-up interval after CT was 8.8 years (interquartile range, 5.2-11.6 years), during which 5.9% died (532/9066). No significant difference (p > 0.05) for mortality was observed between L1 and L3 VAT and SAT at 10-year ROC AUC. However, L3 measures were significantly better for VSR at 10-year AUC (p < 0.001). HRs comparing worst-to-best quartiles for mortality at L1 vs. L3 were 2.12 (95% CI, 1.65-2.72) and 2.22 (1.74-2.83) for VAT; 1.20 (0.95-1.52) and 1.16 (0.92-1.46) for SAT; and 2.26 (1.7-2.93) and 3.05 (2.32-4.01) for VSR. In women, the corresponding HRs for VSR were 2.58 (1.80-3.69) (L1) and 4.49 (2.98-6.78) (L3).

CONCLUSION

Automated CT-based measures of visceral fat (VAT and VSR) at L1 are predictive of survival, although overall measures of adiposity at L1 level are somewhat inferior to the standard L3-level measures. Utilizing predictive L1-level fat measures could expand opportunistic screening to chest CT imaging.

The relationship between fat distribution in central region and comorbidities in obese people: Based on NHANES 2011-2018

BACKGROUND

Central obesity is closely related to comorbidity, while the relationship between fat accumulation pattern and abnormal distribution in different parts of the central region of obese people and comorbidity is not clear. This study aimed to explore the relationship between fat distribution in central region and comorbidity among obese participants.

METHODS

We used observational data of NHANES 2011-2018 to identify 12 obesity-related comorbidities in 7 categories based on questionnaire responses from participants. Fat distribution is expressed by fat ratio, including Android, Gynoid, visceral, subcutaneous, visceral/subcutaneous (V/S), and total abdominal fat ratio. Logistic regression analysis were utilized to elucidate the association between fat distribution and comorbidity.

RESULTS

The comorbidity rate was about 54.1% among 4899 obese participants (weighted 60,180,984, 41.35 ± 11.16 years, 57.5% female). There were differences in fat distribution across the sexes and ages. Among men, Android fat ratio (OR, 4.21, 95% CI, 1.54-11.50, P_trend=0.007), visceral fat ratio (OR, 2.16, 95% CI, 1.42-3.29, P_trend<0.001) and V/S (OR, 2.07, 95% CI, 1.43-2.99, P_trend<0.001) were independent risk factors for comorbidity. Among these, there was a "J" shape correlation between Android fat ratio and comorbidity risk, while visceral fat ratio and V/S exhibited linear relationships with comorbidity risk. The Gynoid fat ratio (OR, 0.87, 95%CI, 0.80-0.95, P_trend=0.001) and subcutaneous fat ratio (OR, 0.81, 95%CI, 0.67-0.98, P_trend=0.016) both performed a protective role in the risk of comorbidity. In women, Android fat ratio (OR, 4.65, 95% CI, 2.11-10.24, P_trend=0.020), visceral fat ratio (OR, 1.83, 95% CI, 1.31-2.56, P_trend=0.001), and V/S (OR, 1.80, 95% CI, 1.32-2.45, P_trend=0.020) were also independent risk factors for comorbidity, with a dose-response relationship similar to that of men. Only the Gynoid fat ratio (OR, 0.93, 95% CI, 0.87-0.99, P_trend=0.016) had a protective effect on female comorbidity. This association was also seen in obese participants of different age groups, comorbidity numbers, and comorbidity types, although it was more statistically significant in older, complex comorbidity, cardiovascular, cerebrovascular, and metabolic diseases.

CONCLUSIONS

In the obese population, there were strong correlation between fat distribution in central region and comorbidity, which was affected by sex, age, number of comorbidities, and type of comorbidity.

Excess visceral fat area as an independent risk factor for early postoperative complications in patients with obesity undergoing bariatric surgery

BACKGROUND

Few studies have investigated the correlation between visceral fat area (VFA) and early postoperative complications in patients with obesity undergoing bariatric surgery. This study aimed to investigate the relationship between VFA and early postoperative complications in patients with obesity following bariatric surgery.

METHODS

The study was conducted at a tertiary university hospital. Patients with obesity who underwent laparoscopic sleeve gastrectomy between June 2016 and October 2020 were divided into two groups based on umbilical level VFA: high-VFA group (umbilical level VFA ≥ 100 cm²) and low-VFA group (umbilical level VFA < 100 cm²). Baseline characteristics, intraoperative and postoperative conditions, and early postoperative complications were compared between the groups. The primary outcome was early postoperative complications, and the secondary outcome was postoperative hospital stay.

RESULTS

The study included 152 patients, with 82 patients in the low-VFA group and 70 patients in the high-VFA group. The high-VFA group had a higher incidence of early postoperative complications (14.29% vs. 2.44%, P = 0.013) than the low-VFA group. The length of postoperative hospital stay did not differ significantly between the groups.

CONCLUSIONS

Our study suggests that excess VFA is an independent risk factor for early postoperative complications following bariatric surgery, and VFA may be used in preoperative evaluations.

Partitioning of Persistent Organic Pollutants between Adipose Tissue and Serum in Human Studies

Blood is the most widely used matrix for biomonitoring of persistent organic pollutants (POPs). It is assumed that POPs are homogenously distributed within body lipids at steady state; however, the variability underlying the partitioning of POPs between fat compartments is poorly understood. Hence, the objective of this study was to review the state of the science about the relationships of POPs between adipose tissue and serum in humans. We conducted a narrative literature review of human observational studies reporting concentrations of POPs in paired samples of adipose tissue with other lipid-based compartments (e.g., serum lipids). The searches were conducted in SCOPUS and PUBMED. A meta-regression was performed to identify factors responsible for variability. All included studies reported high variability in the partition coefficients of POPs, mainly between adipose tissue and serum. The number of halogen atoms was the physicochemical variable most strongly and positively associated with the partition ratios, whereas body mass index was the main biological factor positively and significantly associated. To conclude, although this study provides a better understanding of partitioning of POPs to refine physiologically based pharmacokinetic and epidemiological models, further research is still needed to determine other key factors involved in the partitioning of POPs.

Effect of SGLT-2 inhibitors on body composition in patients with type 2 diabetes mellitus: A meta-analysis of randomized controlled trials

OBJECTIVE

Type 2 diabetes mellitus(T2DM) is closely related to sarcopenic obesity(SO). Body composition measurement including body weight, body mass index, waist circumference, percentage body fat, fat mass, muscle mass, visceral adipose tissue and subcutaneus adipose tissue, plays a key role in evaluating T2DM and SO. The weight reduction effect of sodium-glucose cotransporter 2(SGLT-2) inhibitors has been demonstrated. However, there are warnings that SGLT-2 inhibitors should be used with caution because they may increase the risk of sarcopenia. The effect of SGLT-2 inhibitors on body composition in T2DM is inconclusive. In this work, a meta-analysis of randomized controlled trials was conducted to evaluate the effect of SGLT-2 inhibitors on body composition in T2DM.

METHODS

PubMed, the Cochrane Library, EMbase and Web of Science databases were searched by computer. All statistical analyses were carried out with Review Manager version 5. 3. Results were compared by weight mean difference(WMD), with 95% confidence intervals(CI) for continuous outcomes. A random effects model was applied regardless of heterogeneity. The I2 statistic was applied to evaluate the heterogeneity of studies. Publication bias was assessed using Funnel plots.

RESULTS

18 studies with 1430 participants were eligible for the meta-analysis. SGLT-2 inhibitors significantly reduced body weight(WMD:-2. 73kg, 95%CI: -3. 32 to -2. 13, p<0. 00001), body mass index(WMD:-1. 13kg/m2, 95%CI: -1. 77 to -0. 50, p = 0. 0005), waist circumference(WMD:-2. 20cm, 95%CI: -3. 81 to -0. 58, p = 0. 008), visceral fat area(MD:-14. 79cm2, 95%CI: -24. 65 to -4. 93, p = 0. 003), subcutaneous fat area(WMD:-23. 27cm2, 95% CI:-46. 44 to -0. 11, P = 0. 05), fat mass(WMD:-1. 16kg, 95%CI: -2. 01 to -0. 31, p = 0. 008), percentage body fat(WMD:-1. 50%, 95%CI:-2. 12 to -0. 87, P<0. 00001), lean mass(WMD:-0. 76kg, 95%CI:-1. 53 to 0. 01, P = 0. 05) and skeletal muscle mass(WMD:-1. 01kg, 95%CI:-1. 91 to -0. 11, P = 0. 03).

CONCLUSION

SGLT-2 inhibitors improve body composition in T2DM including body weight, body mass index, waist circumference, visceral fat area, subcutaneous fat area, percentage body fat and fat mass reduction, but cause adverse effects of reducing muscle mass. Therefore, until more evidence is obtained to support that SGLT-2 inhibitors increase the risk of sarcopenia, not only the benefit on body composition, but also the adverse effect of the reduction in muscle mass by SGLT-2 inhibitors in T2DM should be considered.

Association between long-term air pollution exposure and insulin resistance independent of abdominal adiposity in Korean adults

Significant associations between air pollution (AP) and insulin resistance (IR) have been reported in limited populations or certain patient groups, but few studies have addressed this association in the general population, especially in Asians. Although abdominal fat is a major contributor to IR, previous studies have not fully controlled for its effect in the association between AP and IR. We investigated the association between exposure to AP and IR in Korean adults in the general population and whether this association is maintained even after controlling for the effects of abdominal fat, particularly visceral fat. This was a cross-sectional study. Data were obtained for Korean adults who participated in screening health checkups at Seoul National University Health Examination Center from 2006 to 2014. A total of 4251 men and women aged 22-84 years were included. IR was represented by the homeostasis model assessment of insulin resistance (HOMA-IR). Adiposity traits such as visceral adipose tissue (VAT) and subcutaneous adipose tissue areas were measured by computed tomography. We assessed the annual mean concentrations of air pollutants, including particulate matter with an aerodynamic diameter of 10 µm or less (PM₁₀), nitrogen dioxide, sulfur dioxide, and carbon monoxide. HOMA-IR was significantly associated with increased annual mean exposure to PM₁₀ in both men (β = 0.15; 95% CI 0.09, 0.22) and women (β = 0.16; 95% CI 0.09, 0.23), and these associations were maintained even after controlling for VAT area (both p < 0.05). The adjusted mean HOMA-IR increased gradually with the level of long-term PM₁₀ exposure (low, intermediate, and high exposure) (all p for trend < 0.001) in the subgroup analysis. After adjusting for possible confounding factors, including VAT area, the annual mean exposure to PM₁₀ was significantly associated with the presence of IR in both men (OR 1.18; 95% CI 1.03, 1.35) and women (OR 1.44; 95% CI 1.18, 1.76). Other air pollutants, such as NO₂, SO₂ and CO, did not show any significant associations with HOMA-IR or the presence of IR. Persistent exposure to PM₁₀ is the main independent risk factor for IR and exhibits a dose-dependent association regardless of visceral fatness in both men and women.

Changes in subcutaneous adipose tissue microRNA expression in response to exercise training in obese African women

The mechanisms that underlie exercise-induced adaptations in adipose tissue have not been elucidated, yet, accumulating studies suggest an important role for microRNAs (miRNAs). This study aimed to investigate miRNA expression in gluteal subcutaneous adipose tissue (GSAT) in response to a 12-week exercise intervention in South African women with obesity, and to assess depot-specific differences in miRNA expression in GSAT and abdominal subcutaneous adipose tissue (ASAT). In addition, the association between exercise-induced changes in miRNA expression and metabolic risk was evaluated. Women underwent 12-weeks of supervised aerobic and resistance training (n = 19) or maintained their regular physical activity during this period (n = 12). Exercise-induced miRNAs were identified in GSAT using Illumina sequencing, followed by analysis of differentially expressed miRNAs in GSAT and ASAT using quantitative real-time PCR. Associations between the changes (pre- and post-exercise training) in miRNA expression and metabolic parameters were evaluated using Spearman's correlation tests. Exercise training significantly increased the expression of miR-155-5p (1.5-fold, p = 0.045), miR-329-3p (2.1-fold, p < 0.001) and miR-377-3p (1.7-fold, p = 0.013) in GSAT, but not in ASAT. In addition, a novel miRNA, MYN0617, was identified in GSAT, with low expression in ASAT. The exercise-induced differences in miRNA expression were correlated with each other and associated with changes in high-density lipoprotein concentrations. Exercise training induced adipose-depot specific miRNA expression within subcutaneous adipose tissue depots from South African women with obesity. The significance of the association between exercise-induced miRNAs and metabolic risk warrants further investigation.

Adipose tissue dysfunction and visceral fat are associated with hepatic insulin resistance and severity of NASH even in lean individuals

BACKGROUND & AIMS

Non-alcoholic fatty liver disease (NAFLD) is a heterogeneous disorder, but the factors that determine this heterogeneity remain poorly understood. Adipose tissue dysfunction is causally linked to NAFLD since it causes intrahepatic triglyceride (IHTG) accumulation through increased hepatic lipid flow, due to insulin resistance and pro-inflammatory adipokines release. While many studies in NAFLD have looked at total adiposity (i.e. mainly subcutaneous fat, SC-AT), it is still unclear the possible impact of visceral fat (VF). Thus, we investigated how VF versus SC-AT was related to NAFLD severity in lean, overweight and obese individuals versus lean controls.

METHODS

Thirty-two non-diabetic NAFLD with liver biopsy (BMI 21.4-34.7 kg/m² ) and eight lean individuals (BMI 19.6-22.8 kg/m² ) were characterized for fat distribution (VF, SC-AT and IHTG by magnetic resonance imaging), lipolysis and insulin resistance by tracer infusion, free fatty acids (FFAs) and triglyceride (TAG) concentration and composition (by mass spectrometry).

RESULTS

Intrahepatic triglyceride was positively associated with lipolysis, adipose tissue insulin resistance (Adipo-IR), TAG concentrations, and increased saturated/unsaturated FFA ratio. Compared to controls VF was higher in NAFLD (including lean individuals), increased with fibrosis stage and associated with insulin resistance in liver, muscle and adipose tissue, increased lipolysis and decreased adiponectin levels. Collectively, our results suggest that VF accumulation, given its location close to the liver, is one of the major risk factors for NAFLD.

CONCLUSIONS

These findings propose VF as an early indicator of NAFLD progression independently of BMI, which may allow for evidence-based prevention and intervention strategies.

Relationship between body composition and bone mineral density in postmenopausal women with type 2 diabetes mellitus

BACKGROUND

The aim of the study were to analyze the lumbar volumetric bone mineral density (BMD), fat distribution and changes of skeletal muscle with quantitative computed tomography (QCT) in postmenopausal women with type 2 diabetes mellitus (T2DM), and to evaluate the relationship between body composition and BMD.

METHODS

One hundred seventy-seven postmenopausal women with T2DM and 136 postmenopausal women without diabetes were included in the study and were divided into two groups according to age, 50-65 years age group and over 65 years of age group. The lumbar BMD (L1-L3), visceral fat mass (VFM), visceral fat area (VFA), subcutaneous fat mass (SFM), subcutaneous fat area (SFA), psoas major mass (PMM) and psoas major area (PMA) of each group were compared. Univariable and multivariable linear regression analysis were used to analyze the contribution of each variable to BMD in postmenopausal women with T2DM.

RESULTS

In women aged 50-65, the patients in the T2DM group had higher body mass index (BMI), VFM, VFA, and SFM (p < 0.05), compared with non-T2DM group. Over 65 years old, the BMI, BMD, VFM, VFA, and SFM was found to be much higher in participants with T2DM than in non-T2DM group (p < 0.05). Compared with women aged in 50-65 years old, those over 65 years old had higher VFA and VFM and lower BMD (p < 0.05), whether in the T2DM group or the non-T2DM group. Age, VFA and VFM were negatively correlated with BMD (r = -0.590, p ≤ 0.001; r = -0.179, p = 0.017; r = -0.155, p = 0.040, respectively). After adjusting for age, VFM and VFA were no longer correlated with BMD. No correlations between fat distribution or psoas major muscle and BMD in postmenopausal women with T2DM were observed.

CONCLUSIONS

T2DM can affect abdominal fat deposition in postmenopausal women. Postmenopausal elderly women with diabetes have higher BMD than normal elderly women. There was no correlation between fat distribution or psoas major and BMD in postmenopausal women with diabetes mellitus.

Exercise training enhances muscle mitochondrial metabolism in diet-resistant obesity

Background

Current paradigms for predicting weight loss in response to energy restriction have general validity but a subset of individuals fail to respond adequately despite documented diet adherence. Patients in the bottom 20% for rate of weight loss following a hypocaloric diet (diet-resistant) have been found to have less type I muscle fibres and lower skeletal muscle mitochondrial function, leading to the hypothesis that physical exercise may be an effective treatment when diet alone is inadequate. In this study, we aimed to assess the efficacy of exercise training on mitochondrial function in women with obesity with a documented history of minimal diet-induced weight loss.

Methods

From over 5000 patient records, 228 files were reviewed to identify baseline characteristics of weight loss response from women with obesity who were previously classified in the top or bottom 20% quintiles based on rate of weight loss in the first 6 weeks during which a 900 kcal/day meal replacement was consumed. A subset of 20 women with obesity were identified based on diet-resistance (n=10) and diet sensitivity (n=10) to undergo a 6-week supervised, progressive, combined aerobic and resistance exercise intervention.

Findings

Diet-sensitive women had lower baseline adiposity, higher fasting insulin and triglycerides, and a greater number of ATP-III criteria for metabolic syndrome. Conversely in diet-resistant women, the exercise intervention improved body composition, skeletal muscle mitochondrial content and metabolism, with minimal effects in diet-sensitive women. In-depth analyses of muscle metabolomes revealed distinct group- and intervention- differences, including lower serine-associated sphingolipid synthesis in diet-resistant women following exercise training.

Interpretation

Exercise preferentially enhances skeletal muscle metabolism and improves body composition in women with a history of minimal diet-induced weight loss. These clinical and metabolic mechanism insights move the field towards better personalised approaches for the treatment of distinct obesity phenotypes.

Funding

Canadian Institutes of Health Research (CIHR-INMD and FDN-143278; CAN-163902; CIHR PJT-148634).

Effect of visceral adipose tissue mass on coronary artery disease and heart failure: A Mendelian randomization study

OBJECTIVES

Obesity is associated with coronary artery disease (CAD) and its risk factors in observational studies. This two-sample Mendelian randomization (MR) study investigated the effect of visceral adipose tissue (VAT) mass on coronary artery disease (CAD), myocardial infarction (MI) and heart failure (HF).

METHODS

Genetic variants (220 SNPs, P < 5 × 10^-8) associated with VAT mass were obtained from a genome-wide association study (GWAS) in the UK Biobank. Genetic associations with CAD outcomes including CAD and myocardial infarction (MI) were obtained from the CARDIoGRAMplusC4D 1000 Genomes-based GWAS (including up to 60,801 cases and 123,504 controls) and data on patients with HF were obtained from the HERMES Consortium (47,309 cases and 930,014 controls). The effects of VAT mass on CAD outcomes and HF were estimated using the inverse variance weighted (IVW) method. Sensitivity analysis and multi-variable MR were used to examine the stability of the IVW results.

RESULTS

Our results showed that genetically predicted higher VAT mass was associated with increased risk of CAD (odds ratio [OR] 1.57, 95% confidence interval [CI], 1.44-1.71; P = 7.62 × 10^-24), MI (OR 1.63, 95% CI: 1.48-1.79; P = 3.76 × 10^-24) and HF (OR 1.71, 95% CI: 1.60-1.83; P = 1.72 × 10^-53). These findings remained significant in the sensitivity analysis and multi-variable MR.

CONCLUSION

This MR study suggests that genetic determinants of VAT mass are causally associated with CAD, MI and HF.

A pilot investigation of genetic and epigenetic variation of FKBP5 and response to exercise intervention in African women with obesity

We investigated gluteal (GSAT) and abdominal subcutaneous adipose tissue (ASAT) DNA methylation of FKBP5 in response to a 12-week intervention in African women with obesity, as well as the effect of the rs1360780 single nucleotide polymorphism (SNP) on FKBP5 methylation, gene expression and post-exercise training adaptations in obesity and metabolic related parameters. Exercise (n = 19) participants underwent 12-weeks of supervised aerobic and resistance training while controls (n = 12) continued their usual behaviours. FKBP5 methylation was measured in GSAT and ASAT using pyrosequencing. SNP and gene expression analyses were conducted using quantitative real-time PCR. Exercise training induced FKBP5 hypermethylation at two CpG dinucleotides within intron 7. When stratified based on the rs1360780 SNP, participants with the CT genotype displayed FKBP5 hypermethylation in GSAT (p < 0.05), and ASAT displayed in both CC and CT carriers. CC allele carriers displayed improved cardiorespiratory fitness, insulin sensitivity, gynoid fat mass, and waist circumference (p < 0.05) in response to exercise training, and these parameters were attenuated in women with the CT genotype. These findings provide a basis for future studies in larger cohorts, which should assess whether FKBP5 methylation and/or genetic variants such as the rs1360780 SNP could have a significant impact on responsiveness to exercise interventions.

Neck Circumference as a Screening Tool for Metabolic Syndrome among Lebanese College Students

Metabolic syndrome (MetS) is a cluster of symptoms that, when present, increase the risk for cardiovascular disease. There is a need for reliable screening tools that are ethnically sensitive. Two hundred and sixty-six college students were assessed anthropometrically. They had a fasting blood sample drawn, and blood pressure measured. They then completed a demographic questionnaire and The International Physical Activity Questionnaire (IPAQ). The prevalence of MetS was found to be 10.1% in males and 4.5% in females. Neck circumference (NC) was positively associated with BMI in males (r = 0.55, p < 0.001) and females (r = 0.53, p < 0.001) and was positively associated with hip circumference in both males (r = 0.47, p < 0.001) and females (r = 0.50, p < 0.001) and with waist circumference in males (r = 0.46, p < 0.001) and females (r = 0.49, p < 0.001.) An area under the curve (AUC) was calculated using receiver operating characteristics (ROC), and NC > 38 cm in males and NC> 36 cm in females were found to be appropriate cut-offs for diagnosing MetS. NC is a reliable and non-invasive screening tool that can be used to screen for MetS in males. NC could also serve as an anthropometric instrument to assess abdominal obesity and could be valuable for college students.

Insulin-resistance in paediatric age: Its magnitude and implications

Insulin resistance (IR) is insulin failure in normal plasma levels to adequately stimulate glucose uptake by the peripheral tissues. IR is becoming more common in children and adolescents than before. There is a strong association between obesity in children and adolescents, IR, and the metabolic syndrome components. IR shows marked variation among different races, crucial to understanding the possible cardiovascular risk, specifically in high-risk races or ethnic groups. Genetic causes of IR include insulin receptor mutations, mutations that stimulate autoantibody production against insulin receptors, or mutations that induce the formation of abnormal glucose transporter 4 molecules or plasma cell membrane glycoprotein-1 molecules; all induce abnormal energy pathways and end with the development of IR. The parallel increase of IR syndrome with the dramatic increase in the rate of obesity among children in the last few decades indicates the importance of environmental factors in increasing the rate of IR. Most patients with IR do not develop diabetes mellitus (DM) type-II. However, IR is a crucial risk factor to develop DM type-II in children. Diagnostic standards for IR in children are not yet established due to various causes. Direct measures of insulin sensitivity include the hyperinsulinemia euglycemic glucose clamp and the insulin-suppression test. Minimal model analysis of frequently sampled intravenous glucose tolerance test and oral glucose tolerance test provide an indirect estimate of metabolic insulin sensitivity/resistance. The main aim of the treatment of IR in children is to prevent the progression of compensated IR to decompensated IR, enhance insulin sensitivity, and treat possible complications. There are three main lines for treatment: Lifestyle and behavior modification, pharmacotherapy, and surgery. This review will discuss the magnitude, implications, diagnosis, and treatment of IR in children.

Association between changes in body weight and cardiovascular disease risk factors among obese Japanese patients with type 2 diabetes

Aims/Introduction

We aimed to assess the association between bodyweight reduction and cardiovascular disease risk factors, and to identify the minimum bodyweight reduction associated with significant improvement in cardiovascular disease risk factors among obese Japanese patients with type 2 diabetes.

Materials and Methods

The cohort comprised 1,753 patients with type 2 diabetes and body mass index ≥25 kg/m², who visited our clinic between 2013 and 2016. Multivariable linear regression analysis was carried out to assess the relationship between bodyweight changes and glycated hemoglobin A1c, serum lipids and blood pressure. Analyses of covariance were carried out to compare mean changes in cardiovascular disease risk factors across six groups of bodyweight change, <−5%, −5% to <−3%, −3% to <−1%, −1% to <1% (reference), 1% to <3% and ≥3%.

Results

Log‐transformed bodyweight change had a significantly positive relationship with log‐transformed glycated hemoglobin A1c, triglycerides, low‐density lipoprotein cholesterol and systolic blood pressure changes, and a negative relationship with high‐density lipoprotein cholesterol, after adjusting for sex, age, duration of diabetes, body mass index, use of glucose‐lowering, lipid‐lowering and antihypertensive agents, and changes in the use of these medications. A mean change in glycated hemoglobin A1c was significantly improved only in the <−5% group compared with the reference. Mean changes in triglycerides were improved in all groups, and significantly in the <−5% group.

Conclusions

Bodyweight change was significantly associated with cardiovascular disease risk factor changes, and >5% bodyweight reduction was associated with improved glycated hemoglobin A1c.

Visceral Adipose Tissue and Non-alcoholic Fatty Liver Disease in Patients with Type 2 Diabetes

AIM

To explore the association of visceral adipose tissue (VAT) area and non-alcoholic fatty liver disease (NAFLD) in patients with type 2 diabetes mellitus (T2DM).

METHODS

This was a cross-sectional study comprising 100 patients with T2DM and 100 non-T2DM individuals, matched for age, sex, and body mass index (BMI). Transient elastography was used to assess hepatic steatosis and liver stiffness measurements (LSM). Controlled attenuation parameter (CAP) was used to quantify hepatic steatosis. To distinguish grades of hepatic steatosis, cutoff values were as follows: S1 ≥ 302, S2 ≥ 331, and S3 ≥ 337 dB/m. Moreover, VAT area was measured by dual-energy X-ray absorptiometry in accordance with validated protocols.

RESULTS

CAP score was significantly higher in participants with T2DM (294.61 ± 3.82 vs. 269.86 ± 3.86 dB/ m; P < 0.001). Furthermore, 42% of participants with T2DM had hepatic steatosis (S > S1: 302 dB/m), while this figure was 26% in non-T2DM group (P < 0.003). The mean liver stiffness measurement was also significantly higher in patients with T2DM (5.53 vs. 4.79 kPa; P < 0.001). VAT area was greater in patients with T2DM compared to non-T2DM individuals: 163.79 ± 47.98 cm² versus 147.49 ± 39.09 cm², P = 0.009. However, total and truncal fat mass were not different between the two groups. Age, BMI, waist circumference, ALT, CAP, and LSM were significantly associated with VAT area. BMI and VAT area were the important determinants of steatosis in both groups of participants with and without T2DM. Moreover, the VAT area was associated with the severity of hepatic steatosis and liver stiffness, independent of anthropometric measures of obesity.

CONCLUSION

VAT area is a major determinant of the severity of hepatic steatosis and liver stiffness in patient with T2DM.

Sirt3 Pharmacologically Promotes Insulin Sensitivity through PI3/AKT/mTOR and Their Downstream Pathway in Adipocytes

Sirtuin-3 (Sirt3) is a major mitochondrial deacetylase enzyme that regulates multiple metabolic pathways, and its expression is decreased in diabetes type 1 and type 2 diabetes. This study aimed to elucidate Sirt3′s molecular mechanism in regulating insulin sensitivity in adipocytes that can contribute to the effort of targeting Sirt3 for the treatment of obesity and type 2 diabetes. We found that the Sirt3 activator honokiol (HNK) induced adipogenesis compared to the control, in contrast to Sirt3 inhibitor, 3-TYP. Accordingly, HNK increased expression of adipocyte gene markers, gene-involved lipolysis and glucose transport (GLUT4), while 3-TYP reduced expression of those genes. Interestingly, 3-TYP caused an increase in gene expression of adipocyte-specific cytokines including IL6, resistin, and TNF-α. However, changes in adipocyte-specific cytokines in HNK treated cells were not significant. In addition, HNK stimulated insulin pathway by promoting insulin receptor beta (IRβ) and PI3K/AKT/mTOR pathways, resulting in an increase in phosphorylation of the forkhead family FoxO1/FoxO3a/FoxO4 and glycogen synthase kinase-3 (GSK-3β), opposing 3-TYP. In line with these findings, HNK increased free fatty acid and glucose uptake, contrary to 3-TYP. In conclusion, Sirt3 activator-HNK induced adipogenesis and lipolysis reduced adipocytes specific cytokines. Intriguingly, HNK activated insulin signaling pathway and increased free fatty acid as well as glucose uptake and transport, in sharp contrast to 3-TYP. These results indicate that, via insulin signaling regulation, Sirt3 activation by HNK improves insulin resistance, while Sirt3 inhibition by 3-TYP might precipitate insulin resistance.

Body Composition Predictors of Adverse Postoperative Events in Patients Undergoing Surgery for Long Bone Metastases

Body composition assessed using opportunistic CT has been recently identified as a predictor of outcome in patients with cancer. The purpose of this study was to determine whether the cross-sectional area (CSA) and the attenuation of abdominal subcutaneous adipose tissue, visceral adipose tissue (VAT), and paraspinous and abdominal muscles are the predictors of length of hospital stay, 30-day postoperative complications, and revision surgery in patients treated for long bone metastases.