Subcutaneous Adipose Tissue Levels Research Articles

Adults with metabolically healthy overweight or obesity present more brown adipose tissue and higher thermogenesis than their metabolically unhealthy counterparts

There is a subset of individuals with overweight/obesity characterized by a lower risk of cardiometabolic complications, the so-called metabolically healthy overweight/obesity (MHOO) phenotype. Despite the relatively higher levels of subcutaneous adipose tissue and lower visceral adipose tissue observed in individuals with MHOO than individuals with metabolically unhealthy overweight/obesity (MUOO), little is known about the differences in brown adipose tissue (BAT). This study included 53 young adults (28 women) with a body mass index (BMI) ≥25kg/m2 which were classified as MHOO (n=34) or MUOO (n=19). BAT was assessed through a static 18F-FDG positron emission tomography/computed tomography scan after a 2-h personalized cooling protocol. Energy expenditure, skin temperature, and thermal perception were assessed during a standardized mixed meal test (3.5h) and a 1-h personalized cold exposure. Body composition was assessed by dual-energy x-ray absorptiometry, energy intake was determined during an ad libitum meal test and dietary recalls, and physical activity levels were determined by a wrist-worn accelerometer. Participants with MHOO presented higher BAT volume (+124%, P=0.008), SUVmean (+63%, P=0.001), and SUVpeak (+133%, P=0.003) than MUOO, despite having similar BAT mean radiodensity (P=0.354). In addition, individuals with MHOO exhibited marginally higher meal-induced thermogenesis (P=0.096) and cold-induced thermogenesis (+158%, P=0.050). Moreover, MHOO participants showed higher supraclavicular skin temperature than MUOO during the first hour of the postprandial period and during the cold exposure, while no statistically significant differences were observed in other skin temperature parameters. We observed no statistically significant differences between MHOO and MUOO in thermal perception, body composition, outdoor ambient temperature exposure, resting metabolic rate, energy intake, or physical activity levels. Adults with MHOO present higher BAT volume and activity than MUOO. The higher meal- and cold-induced thermogenesis and cold-induced supraclavicular skin temperature are compatible with a higher BAT activity. Overall, these results suggest that BAT presence and activity might be linked to a healthier phenotype in young adults with overweight or obesity. See acknowledgments section.

Increased OCT3 Expression in Adipose Tissue With Aging: Implications for Catecholamine and Lipid Turnover and Insulin Resistance in Women.

Catecholamine-stimulated lipolysis is reduced with aging, which may promote adiposity and insulin resistance. Organic cation transporter 3 (OCT3), which is inhibited by estradiol (E2), mediates catecholamine transport into adipocytes for degradation, thus decreasing lipolysis. In this study, we investigated the association of OCT3 mRNA levels in subcutaneous adipose tissue (SAT) with aging and markers of insulin resistance in women. SAT biopsies were obtained from 66 women with (19) or without (47) type 2 diabetes (age 22-76 years, 20.0-40.1 kg/m2). OCT3 mRNA and protein levels were measured for group comparisons and correlation analysis. SAT was incubated with E2 and OCT3 mRNA levels were measured. Associations between OCT3 single nucleotide polymorphisms (SNPs) and diabetes-associated traits were assessed. OCT3 mRNA and protein levels in SAT increased with aging. SAT from postmenopausal women had higher levels of OCT3 than premenopausal women, and there was a dose-dependent reduction in OCT3 mRNA levels in SAT treated with E2. OCT3 mRNA levels were negatively associated with markers of insulin resistance, and ex vivo lipolysis. OCT3 SNPs were associated with BMI, waist to hip ratio, and circulating lipids (eg, triglycerides). OCT3 mRNA and protein levels in SAT increased with aging, and mRNA levels were negatively associated with markers of insulin resistance. E2 incubation downregulated OCT3 mRNA levels, which may explain lower OCT3 mRNA in premenopausal vs postmenopausal women. High OCT3 protein levels in adipose tissue may result in increased catecholamine degradation, and this can contribute to the reduction in lipolysis observed in women with aging.

Empagliflozin treatment differentially modifies visceral and subcutaneous adipose tissue lipidomes and pro-inflammatory cytokines in zucker fatty diabetic rats

Abstract EMPA-REG OUTCOME (Empagliflozin, Cardiovascular Outcome Event Trial) trial highlighted the relevance of pharmacological inhibition of sodium-glucose cotransporter 2 (SGLT2) for the treatment of patients with type 2 diabetes mellitus (T2DM) and/or cardiovascular disease. Although the pathways through which SGLT2 inhibitors exert a beneficial effect on the cardiovascular system are still unknown, it has been suggested that energy metabolism regulation and a reduction of systemic inflammation could be some of the mechanisms implicated. Available data also suggests that empagliflozin treatment could be able to exert regulatory effects on adipose tissue (AT) depots. The aim of our study was to evaluate the impact of empagliflozin treatment on the lipidome of visceral (VAT) and subcutaneous adipose tissue (SAT) depots in a rat model of obesity and T2DM. Diabetic obese Zucker Fatty (ZDF) rats were treated with 30 mg/kg/day of empagliflozin p.o for 6 weeks. The lipidomes of VAT and SAT depots were analyzed using ultra-high performance liquid chromatography coupled to mass spectrometry. Empagliflozin's effect on pro-inflammatory markers in AT was analyzed by RT-PCR. In VAT, 18 metabolites were significantly altered in empagliflozin-treated rats vs. controls. Nearly all diglycerides tested (13 of 14) were significantly increased in treated rats, as the most notable altered chemical class. Furthermore, 3 oxidized fatty acids (FA) and FA like gadoleic acid and linoleic acid were also significantly increased. In SAT, a total of 14 metabolites were significantly altered. Most of them (13 of 14) were glycerophospholipids. Significantly lower levels of 4 lysophosphatidylethanolamines, 4 lysophosphatidylcholines, and 3 lysophosphatidylinositols and higher levels of 2 phosphatidylcholines were shown. In contrast to VAT, a significant decrease in most of these metabolites was observed in empagliflozin-treated samples. Several ratios of metabolites were also calculated to infer the potential enzyme activities related to lipid metabolism in both VAT and SAT. However, the ratios studied were only statistically significant in VAT of empagliflozin-treated rats vs. control, where the main potential enzyme activities altered were desaturases and elongases. Empagliflozin treatment also reduces the expression of the pro-inflammatory cytokines interleukin-1 beta (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNFα) and monocyte-chemotactic protein-1 (MCP-1) in VAT, with no changes in SAT, except for interleukin-13 (IL-13), which also decreases compared to untreated diabetic ZDF rats. In conclusion, empagliflozin increased oxidized FA and diglycerides in VAT and decreased glycerophospholipid levels in SAT. The anti-inflammatory effect of empagliflozin in VAT is not observed in SAT. The effect of empagliflozin on the regulation of the adipose tissue lipidome and inflammatory profile is different depending on the localization of the depots. Funding Acknowledgement Type of funding sources: Private company. Main funding source(s): Boehringer Ingelheim Pharma GmbH and Co

Abdominal adipose tissue associates with adiponectin and TNF in middle-aged healthy men

Background and Aims : Backgroun: Adipokines, including adiponectin, visfatin and TNF (tumor necrosis factor)-α, are highly active bio-peptides involved in glucose metabolism, insulin regulation and the development and progression of obesity and its associated diseases. It includes, among others Aim: In this cross-sectional study, we aimed to investigate whether gene expression levels in subcutaneous adipose tissue (SAT) of selected adipokines and their corresponding circulating levels associate with the amount of AT in superficial (sSAT), deep (dSAT) and visceral (VAT) AT, assessed by computed tomography (CT). Any association with glucometabolic variables were also exploredMethods: Methods: In 103 healthy Caucasian men, fasting venous blood and SAT samples from the gluteal region were collected. Ninety-four of the participants underwent CT assessment of the abdominal AT, which was divided into VAT and superficial - and deep subcutaneous AT (sSAT and dSAT). Circulating levels were measured by ELISA and AT gene-expression by PCR. Insulin sensitivity was determined by glucose clamp, assessing glucose disposal rate (GDR).Results: Results: Circulating adiponectin and TNF gene expression correlated inversely and positively to sSAT, dSAT and VAT (r=-0.266 to -0.276, p<0.05 for all) and (r=0.323 - 0.368, p<0.05 for all), respectively, with strongest correlations to the amount of AT in sSAT and dSAT. Circulating adiponectin correlated inversely to insulin, C-peptide and waist circumference (r=-456 to -0.373, p<0.001) and positively to GDR (r=0.356, p<0.001). AT-expressed visfatin correlated inversely to insulin and C-peptide (r=-0.370 and r=-0.404, p<0.001).Conclusions: Conclusion: Increased amount of AT is associated with low levels of adiponectin and increased levels of TNF. Background and Aims : Backgroun: Adipokines, including adiponectin, visfatin and TNF (tumor necrosis factor)-α, are highly active bio-peptides involved in glucose metabolism, insulin regulation and the development and progression of obesity and its associated diseases. It includes, among others Aim: In this cross-sectional study, we aimed to investigate whether gene expression levels in subcutaneous adipose tissue (SAT) of selected adipokines and their corresponding circulating levels associate with the amount of AT in superficial (sSAT), deep (dSAT) and visceral (VAT) AT, assessed by computed tomography (CT). Any association with glucometabolic variables were also explored Methods: Methods: In 103 healthy Caucasian men, fasting venous blood and SAT samples from the gluteal region were collected. Ninety-four of the participants underwent CT assessment of the abdominal AT, which was divided into VAT and superficial - and deep subcutaneous AT (sSAT and dSAT). Circulating levels were measured by ELISA and AT gene-expression by PCR. Insulin sensitivity was determined by glucose clamp, assessing glucose disposal rate (GDR). Results: Results: Circulating adiponectin and TNF gene expression correlated inversely and positively to sSAT, dSAT and VAT (r=-0.266 to -0.276, p<0.05 for all) and (r=0.323 - 0.368, p<0.05 for all), respectively, with strongest correlations to the amount of AT in sSAT and dSAT. Circulating adiponectin correlated inversely to insulin, C-peptide and waist circumference (r=-456 to -0.373, p<0.001) and positively to GDR (r=0.356, p<0.001). AT-expressed visfatin correlated inversely to insulin and C-peptide (r=-0.370 and r=-0.404, p<0.001). Conclusions: Conclusion: Increased amount of AT is associated with low levels of adiponectin and increased levels of TNF.

Serum and Adipose Dipeptidyl Peptidase 4 in Cardiovascular Surgery Patients: Influence of Dipeptidyl Peptidase 4 Inhibitors.

Dipeptidyl peptidase 4 (DPP-4) is a novel adipokine and may be involved in the association between adipose tissue and metabolic syndrome. We investigated DPP-4 and adiponectin levels in the serum, subcutaneous adipose tissue (SAT), and epicardial adipose tissue (EAT), and their relationship with preoperative factors, as well as comparing the DPP-4 levels in SAT and EAT with and without DPP-4 inhibitors. This study included 40 patients (25 men, age 67.5 ± 13.8 years). The serum adipokine, DPP-4, and adiponectin levels in SAT and EAT were measured using ELISA and Western blotting. The DPP-4 and adiponectin levels were significantly higher in the SAT than in the EAT. The serum DPP-4 and DPP-4 activity levels had no correlation with the DPP-4 levels in the SAT and EAT, but the DPP-4 levels in the SAT and EAT had a positive correlation. The DPP-4 levels in the SAT were positively correlated with atherosclerosis, diabetes mellitus, DPP-4-inhibitor use, and fasting blood glucose. The DPP-4 levels in the EAT showed a negative correlation with eGFR and a positive correlation with atrial fibrillation. The DPP-4 activity in the serum had a lower tendency in the group taking DPP-4 inhibitors than in the group not taking them. DPP-4 inhibitors may suppress angiogenesis and adipose-tissue hypertrophy.

Abdominal Adipose Tissue Associates With Adiponectin and TNFα in Middle-Aged Healthy Men.

IntroductionAdipokines are highly active biopeptides involved in glucose metabolism, insulin regulation and the development and progression of obesity and its associated diseases. It includes, among others, adiponectin, visfatin and tumor necrosis factor alpha (TNFα). The sources of adipokines and their associations with glucometabolic variables are not completely understood.AimIn this cross-sectional study, we aimed to investigate whether gene expression levels in subcutaneous adipose tissue (SAT) of selected adipokines and their corresponding circulating levels associate with the amount of AT in superficial (sSAT), deep (dSAT) and visceral AT (VAT), assessed by computed tomography (CT). Any association with glucometabolic variables were also explored.MethodsIn 103 healthy Caucasian men, aged 39.5 years, fasting venous blood and SAT samples from the gluteal region were collected. Ninety-four of the participants underwent CT assessment of the abdominal AT, which was divided into VAT, sSAT and dSAT. Circulating levels of adipokines were measured by ELISA and AT gene-expression by PCR. Insulin sensitivity was determined by glucose clamp, assessing glucose disposal rate (GDR).ResultsCirculating adiponectin and TNFα gene expression correlated inversely and positively to the amount of AT in all three compartments (r=-0.266 to -0.276, p<0.05 for all) and (r=0.323 - 0.368, p<0.05 for all), respectively, with strongest correlations to the amount in sSAT and dSAT. When dividing AT compartments into quartiles, a tendency was observed towards lower circulating adiponectin and higher TNFα gene expression levels, respectively, with increasing amount of sSAT and dSAT. Circulating adiponectin correlated inversely to insulin, C-peptide and waist circumference (r=-456 to -0.373, p<0.001) and positively to GDR (r=0.356, p<0.001). AT-expressed visfatin correlated inversely to insulin and C-peptide (r=-0.370 and r=-0.404, p<0.001).ConclusionIncreased amount of AT is associated with lower levels of adiponectin and increased levels of TNFα AT expression.

ATGL is a biosynthetic enzyme for fatty acid esters of hydroxy fatty acids

Branched fatty acid (FA) esters of hydroxy FAs (HFAs; FAHFAs) are recently discovered lipids that are conserved from yeast to mammals1,2. A subfamily, palmitic acid esters of hydroxy stearic acids (PAHSAs), are anti-inflammatory and anti-diabetic1,3. Humans and mice with insulin resistance have lower PAHSA levels in subcutaneous adipose tissue and serum1. PAHSA administration improves glucose tolerance and insulin sensitivity and reduces inflammation in obesity, diabetes and immune-mediated diseases1,4–7. The enzyme(s) responsible for FAHFA biosynthesis in vivo remains unknown. Here we identified adipose triglyceride lipase (ATGL, also known as patatin-like phospholipase domain containing 2 (PNPLA2)) as a candidate biosynthetic enzyme for FAHFAs using chemical biology and proteomics. We discovered that recombinant ATGL uses a transacylation reaction that esterifies an HFA with a FA from triglyceride (TG) or diglyceride to produce FAHFAs. Overexpression of wild-type, but not catalytically dead, ATGL increases FAHFA biosynthesis. Chemical inhibition of ATGL or genetic deletion of Atgl inhibits FAHFA biosynthesis and reduces the levels of FAHFA and FAHFA-TG. Levels of endogenous and nascent FAHFAs and FAHFA-TGs are 80–90 per cent lower in adipose tissue of mice in which Atgl is knocked out specifically in the adipose tissue. Increasing TG levels by upregulating diacylglycerol acyltransferase (DGAT) activity promotes FAHFA biosynthesis, and decreasing DGAT activity inhibits it, reinforcing TGs as FAHFA precursors. ATGL biosynthetic transacylase activity is present in human adipose tissue underscoring its potential clinical relevance. In summary, we discovered the first, to our knowledge, biosynthetic enzyme that catalyses the formation of the FAHFA ester bond in mammals. Whereas ATGL lipase activity is well known, our data establish a paradigm shift demonstrating that ATGL transacylase activity is biologically important.

Association between MRI-based visceral adipose tissues and metabolic abnormality in a Chinese population: a cross-sectional study

BackgroundPrevious studies have indicated that the deposition of abdominal adipose tissue was associated with the abnormalities of cardiometabolic components. The aim of this study was to examine the relationship of visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT) and metabolic status and the different effects between males and females.MethodsThe 1388 eligible subjects were recruited in a baseline survey of metabolic syndrome in China, from two communities in Hangzhou and Chengdu. Areas of abdominal VAT and SAT were measured by magnetic resonance imaging (MRI). Serum total triglycerides (TG), high-density lipoprotein cholesterol (HDL-C) were measured by an automated biochemical analyzer. Metabolic abnormality (MA) was defined more than one abnormal metabolic components, which was based on the definition of metabolic syndrome (IDF 2005). Multiple logistic regression was used to calculate the odds ratios (ORs) and 95% confidence intervals (95%CI). Predictive value was assessed by area under the curve (AUC), net reclassification improvement (NRI), and integrated discrimination improvement (IDI), respectively.ResultsTheir mean age was 53.8 years (SD: 7.1 years), the mean body mass index (BMI) was 23.7 kg/m2, and 44.8% of the subjects were male. Both male and female with MA had higher VAT levels compared to subjects with normal metabolism (MN), and male had higher SAT levels than female (P < 0.05). Higher VAT was significantly associated with MA with ORs in the fourth quartile (Q4) of 6.537 (95% CI = 3.394–12.591) for male and 3.364 (95% CI = 1.898–5.962) for female (P for trend < 0.05). In female, VAT could increase the risk of metabolic abnormalities, but SAT could increase the risk of MA in the second and fourth quartiles (Q2 and Q4) only at BMI > 24 kg/m2. In male, VAT improved the predictive value of MA compared to BMI and waist circumference (WC), the AUC was 0.727 (95% CI = 0.687–0.767), the NRI was 0.139 (95% CI = 0.070–0.208) and 0.106 (95% CI = 0.038–0.173), and the IDI was 0.074 (95% CI = 0.053–0.095) and 0.046 (95% CI = 0.026–0.066). Similar results were found in female.ConclusionsIn male, VAT and SAT could increase the risk of metabolic abnormalities both at BMI < 24 kg/m2 and at BMI ≥ 24 kg/m2. In female, VAT could increase the risk of metabolic abnormalities but SAT could increase the risk of MA in the second and fourth quartiles (Q2 and Q4) only at BMI > 24 kg/m2. Deposition of abdominal adipose tissue was associated with metabolic abnormalities. VAT improved the predictive power of MA.

The relation of omentin gene expression and glucose homeostasis of visceral and subcutaneous adipose tissues in non-diabetic adults.

Adipose tissue (AT) is a passive reservoir forenergy storageand an active endocrine organ responsible for synthesizing bioactive molecules called adipokines. Omentin is known as an anti-inflammatoryadipokine that can modulate insulin sensitivity. The present study aimed to investigate the relationship between omentin mRNA expression and glucose homeostasis of visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) in non-diabetic adults. VAT and SAT adipose tissues were collected from 137 adults aged ≥ 18years hospitalized for abdominal surgery. Before surgery, preoperative blood samples were taken from the participants to measure fasting plasma glucose, insulin, and triglyceride. BMI, HOMA-IR, HOMA-B, andQUICKI were calculated. Insulin levels were measured with Mercodia kits using enzyme-linked immunosorbent assay (ELISA). In order to obtain omentin mRNA expression, real-time PCR was performed. Overall, 91 (66.4%) subjects were healthy [without insulin resistance (IR)], and 46 (33.6%) participants were with IR. In healthy and IR subjects, omentin gene expression was 1.04 and 2.32, respectively in VAT, and 3.06 and 1.30, respectively, in SAT (P > 0.05). After controlling for age and BMI, linear regression analysis indicated a significant positive association of SAT omentin expression with insulin concentration (β = 0.048; 95% CI 0.009, 0.088, P = 0.017) and HOMA-IR (β = 0.173; 95% CI 0.023, 0.323, P = 0.014). Moreover, a negative association of SAT omentin expression with HOMA-B (β = -0.001; 95% CI 0.002, -0.001, P < 0.001) was observed. This study's finding confirms a direct association between IR with omentin mRNA levels in SAT. Besides, the indicator of insulin sensitivity had an inverse association with omentin gene expression in SAT. This aspect of research suggests that omentin secretion from SAT has a strong link with insulin regulation.

The Longitudinal Association of Alcohol Intake and Cigarette Smoking With Levels of Visceral and Subcutaneous Abdominal Adipose Tissue Depots in Postmenopausal Women

ObjectivesTo examine the longitudinal relation between alcohol intake and cigarette smoking with levels of abdominal visceral (VAT) and subcutaneous adipose tissue (SAT) in postmenopausal women. MethodsWe analyzed data from 9,779 participants (age: 50–79) from a sub-cohort of the Women’s Health Initiative study. VAT and SAT was derived from whole-body DXA scans at baseline and at least 1 follow-up scan visit (year 1, 3, or 6) and validated against MRI (r > .90 respectively). Habitual alcohol intake was assessed at baseline, year 3 and 6, and categorized into never, past, rare (< 1 drink/month), infrequent (<1 drink/week), light (1–3.5 drinks/week), moderate (3.5–7 drinks/week) and heavy (8 + drinks/week) drinkers. Cigarette smoking was concomitantly assessed and categorized as never, past, light (<5 cigarettes/day), moderately heavy (5–14 cigarettes/day) and heavy smokers (15 + cigarettes/day). We used linear mixed models to estimate the longitudinal relationship between time-varying alcohol habits, smoking and VAT and SAT dynamics, adjusting for sociodemographic and diet/lifestyle covariates. ResultsAt baseline, participants with higher alcohol intake had lower VAT and SAT levels. VAT levels increased by 0.30, 0.58, 2.01, 1.27, 1.26, 1.52, and 1.97 cm2 per year in never, past, rare, infrequent, light, moderate and heavy drinkers, with faster increases in higher alcohol intake (compared to never, P < 0.01). We did not observe any statistically significant differences in change rate in SAT levels across alcohol intake groups. When categorizing by smoking habits, current smokers had lower VAT and SAT levels at baseline. Longitudinally, VAT in never, past, light, moderately heavy and heavy smokers increased by 0.76, 1.43, 0.94, 0.43 and 1.77 cm2 per year, with past and heavy smokers increasing faster (compared to never, P < 0.01). Stronger associations were observed for subgroups of age <65 and BMI < 30 kg/m2. SAT areas decreased by 0.93 cm2 per year in never smokers, with slower decrease in past smokers (compared to never, P = 0.02) and similar change rate in other smoking groups. ConclusionsIn postmenopausal women, alcohol intake has a nuanced relation with levels of VAT and SAT, however heavy alcohol intake and heavy smoking were avenues for accumulating greater VAT, the central hypothesized driver of adipose tissue related chronic disease risk. Funding SourcesNIH/NIA.

Serum Levels and Adipose Tissue Gene Expression of Cathelicidin Antimicrobial Peptide (CAMP) in Obesity and During Weight Loss.

CAMP (Cathelicidin antimicrobial peptide) is synthesized and secreted by adipocytes and involved in adipose tissue (AT) innate immune response and host defense of subcutaneous AT against Gram positive bacteria. Data on the regulation of CAMP in obesity and during weight loss are scarce and reference values do not exist. Serum CAMP levels (ELISA) and AT gene expression levels (quantitative real time PCR) were investigated in two large and longitudinal (12 months) cohorts of severely obese patients undergoing either a low calorie diet (LCD; n=79) or bariatric surgery (BS; n=156). The impact of metabolic factors on CAMP expression in vitro was investigated in differentiated 3T3-L1 adipocytes. CAMP serum levels significantly increased after BS but not during LCD. Females had lower CAMP serum levels and lower gene expression levels in subcutaneous AT. CAMP was positively correlated to unfavorable metabolic factors/adipokines and negatively to favorable factors/adipokines. CAMP gene expression was higher in subcutaneous than in visceral AT but serum CAMP levels were not correlated to levels of AT gene expression. While certain bile acids upregulated CAMP expression in vitro, high glucose/insulin as well as GLP-1 had an inhibitory effect. There exist gender-specific and AT compartment-specific effects on the regulation of CAMP gene expression. Weight loss induced by BS (but not by LCD) upregulated CAMP serum levels suggesting the involvement of weight loss-independent mechanisms in CAMP regulation such as bile acids, incretins and metabolic factors. CAMP might represent an adipokine at the interface between metabolism and innate immune response.

The relationship between PRDM16 promoter methylation in abdominal subcutaneous and omental adipose tissue and obesity

To explore the relationship between PR domain containing 16 (PRDM16) gene promoter methylation in abdominal subcutaneous adipose tissue (SAT) and omental adipose tissue (OAT) and obesity. Participants were divided into overweight/obesity (33 cases) and normal-weight groups (28 cases). PRDM16 promoter methylation in abdominal SAT and OAT were detected. Two independent sample t test, paired t test were used to analyze. (1) The methylation levels in overweight/obesity group and normal-weight group were different. There were 3 CpG sites different statistically between two groups. To chr1: 2987447 in SAT and chr1: 2986395 in OAT, the methylation level of normal-weight group was higher. While to chr1: 2987450 in OAT, the methylation level of normal-weight group was lower. (2) The methylation levels in SAT and OAT were different. There were 15 CpG sites different statistically in normal-weight group, and 22 CpG sites in overweight/obesity group. There were 7 CpG sites different statistically in both groups with their methylation levels being higher in OAT than that in SAT. (3) There were 9 haplotypes with statistical significance (8 in SAT, 1 in OAT). The methylation degree of PRDM16 gene promoter in abdominal SAT and OAT has the complex relationship with overweight/obesity. The variation of methylation haplotypes combination of multiple sites may play some roles.

1589-P: Testosterone (T) in Early Puberty Predicts Visceral (VAT) and Subcutaneous Adipose Tissue (SAT) in the EPOCH (Exploring Perinatal Outcomes among Children) Cohort

Among adults, higher T predicts lower VAT in men and higher VAT in women, and higher E2 predicts greater SAT in women. The degree to which the association between adiposity and sex steroids is bidirectional is controversial. Using data from a cohort of adolescents, we examined whether sex steroid levels in early puberty influenced VAT and SAT deposition in adolescents. EPOCH participants (n=418, 209 girls and 209 boys) underwent sex steroid measures at visit 1 (mean age 10 years) and magnetic resonance imaging (MRI) assessments of VAT and SAT at visit 1 and visit 2 (mean age 17 years). Using mixed models, we examined whether T and E2 at visit 1 were associated with overall VAT and SAT levels from visit 1 to visit 2. Models adjusted for maternal education and income as well as children’s race, pubertal status, caloric intake, physical activity levels, insulin, leptin, and MRI-measured hepatic fat fraction. Among girls, each unit increase in T was associated with a higher overall VAT (0.16, 95% confidence interval [CI] 0.04, 0.28) and SAT (0.33, 95% CI 0.33, 1.52) levels. Each unit increase in E2 was associated with overall higher SAT (0.56, 95% CI 0.28, 0.83) levels. Among boys, undetectable T was associated with higher VAT (5.12, 95% CI 1.90, 8.36) and lower SAT (-18.85, 95% CI -36.23, -1.46) levels. We conclude that endogenous T and E2 during the pubertal transition significantly influence adolescent adipose tissue deposition in both boys and girls. Future investigations should examine how the use of exogenous sex hormones impacts adipose tissue deposition during this critical period. Additional follow-up is needed to determine how adolescent fat deposition impacts subsequent glucose tolerance in early adulthood. Disclosure C. Kim: Research Support; Spouse/Partner; Apple. K.K. Harrall: None. D.H. Glueck: None. D. Dabelea: None. Funding National Institutes of Health (R01DK068001)

Urocortin 3 Levels Are Impaired in Overweight Humans With and Without Type 2 Diabetes and Modulated by Exercise.

Urocortin3 (UCN3) regulates metabolic functions and is involved in cellular stress response. Although UCN3 is expressed in human adipose tissue, the association of UCN3 with obesity and diabetes remains unclear. This study investigated the effects of Type 2 diabetes (T2D) and increased body weight on the circulatory and subcutaneous adipose tissue (SAT) levels of UCN3 and assessed UCN3 modulation by a regular physical exercise. Normal-weight (n = 37) and overweight adults with and without T2D (n = 98 and n = 107, respectively) were enrolled in the study. A subset of the overweight subjects (n = 39 for each group) underwent a supervised 3-month exercise program combining both moderate intensity aerobic exercise and resistance training with treadmill. UCN3 levels in SAT were measured by immunofluorescence and RT-PCR. Circulatory UCN3 in plasma was assessed by ELISA and was correlated with various clinical and metabolic markers. Our data revealed that plasma UCN3 levels decreased in overweight subjects without T2D compared with normal-weight controls [median; 11.99 (0.78–86.07) and 6.27 (0.64–77.04), respectively; p < 0.001], whereas plasma UCN3 levels increased with concomitant T2D [median; 9.03 (0.77–104.92) p < 0.001]. UCN3 plasma levels were independently associated with glycemic index; fasting plasma glucose and hemoglobin A1c (r = 0.16 and r = 0.20, p < 0.05, respectively) and were significantly different between both overweight, with and without T2D, and normal-weight individuals (OR = 2.11 [1.84–4.11, 95% CI] and OR = 2.12 [1.59–3.10, 95% CI], p < 0.01, respectively). Conversely, the UCN3 patterns observed in SAT were opposite to those in circulation; UCN3 levels were significantly increased with body weight and decreased with T2D. After a 3-month supervised exercise protocol, UCN3 expression showed a significant reduction in SAT of both overweight groups (2.3 and 1.6-fold change; p < 0.01, respectively). In conclusion, UCN levels are differentially dysregulated in obesity in a tissue-dependent manner and can be mitigated by regular moderate physical exercise.

Differential metabolic and inflammatory responses to intermittent hypoxia in substrains of lean and obese C57BL/6 mice

AimsThis study was to investigate the degree of susceptibility to intermittent hypoxia (IH), a hallmark of obstructive sleep apnea (OSA), between the two mice inbred lines C57BL/6N (6N) and C57BL/6J (6J). Materials and methodsFour-week old male mice of 6N and 6J substrains (n = 8) were randomized to standard diet (SD) group or high fat (HF) diet group. At the age of 13-week, all two groups of mice were subjected to either air or IH (IH30; thirty hypoxic events per hour) for one week. Key findingsAll mice fed with HF diet exhibited obesity with more body weight and fat mass (percentage to body weight) gain. IH reduced serum LDL, HDL and total cholesterol levels in lean 6J mice. In obese mice, IH lowered obesity-induced serum total cholesterol level in 6J substrain but raised further in 6N substrain. Furthermore, IH caused elevation of serum FFA and MDA levels, and pro-inflammatory cytokines MCP-1 and IL-6 levels in subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) of lean 6J but not lean 6N mice. There was reduced number of adipocytes and elevation of macrophages in SAT and VAT of HF-induced obese mice of both substrains. IH led to increased number of adipocytes and macrophages in SAT of lean 6J mice. SignificanceThe genetic difference between 6N and 6J mice may have direct impact on metabolic and inflammatory responses after IH. Therefore, attention must be given for the selection of C57BL mice substrains in the experimental IH-exposed mouse model.

Intermittent fasting increases energy expenditure and promotes adipose tissue browning in mice.

Intermittent fasting (IF) may limit metabolic adaptations that reduce energy expenditure, potentially by stimulating white adipose tissue (WAT) browning. The aim of this study was to examine the effects of 8 wk of IF on energy metabolism and markers of WAT browning in lean and diet-induced obese mice and in women who were overweight or obese. Male C57 BL/6 J mice were fed chow or a high-fat diet (HFD; 43%) for 8 wk before undergoing IF (3 non-consecutive d/wk) for an additional 8 wk. Food intake, energy expenditure, and inguinal and gonadal fat pads were collected in fed or fasted conditions (22 h, IF mice only). Subcutaneous adipose tissue (SAT) was also collected at baseline, and after 8 wk of IF (in the fed state, and after a 24-h fast), in women with overweight or obesity. Uncoupling protein 1 (UCP1) was assessed by quantitative real-time polymerase chain reaction (mice and humans) and immunohistochemistry (mice). IF reduced body weight and energy intake in HFD fed mice and reduced gonadal and inguinal fat pad weights in both diet groups. IF increased energy expenditure, meal number, Ucp1 mRNA levels in inguinal and gonadal fat depots, and UCP1 protein in inguinal fat in both diet groups on fed days. In women, IF reduced body weight and fat mass, but did not alter UCP1mRNA levels. IF increased energy expenditure and promoted WAT browning in mice but did not alter UCP1 mRNA levels in SAT in women.

Vitamin D receptor in subcutaneous adipose tissue and serum vitamin D levels relate to gestational diabetes mellitus in overweight/obese pregnant women

Objective To investigate the differences in the expression of vitamin D receptor (VDR) and serum vitamin D levels in subcutaneous adipose tissue between overweight/obese and normal-weight gravidas, and the relationship between these two indicators and gestational diabetes mellitus (GDM). Methods Women with full-term singleton pregnancies who underwent elective cesarean section in Changzhou Maternal and Child Health Care Hospital Affiliated to Nanjing Medical University from January 2015 to April 2017 were enrolled. Among them, there were 70 cases GDM women, including 35 normal-weight (NW-GDM group) and 35 overweight/obese women (OW-GDM group). During the same period, another 70 pregnant women with normal glucose tolerance who underwent scheduled cesarean delivery were selected as the control group, including 35 normal weight women (NW-control group) and 35 obese/overweight women (OW-control group). Fasting blood samples were collected before operation to determine the levels of different biomarkers, including vitamin D, lipid, fasting blood glucose, fasting insulin and adiponectin, and to calculate the homeostasis model assessment-insulin resistance (HOMA-IR). Two subcutaneous adipose tissue samples of the abdominal wall were taken during the operation to detect the expression and distribution of VDR protein with immunohistochemistry. Meanwhile, VDR mRNA transcription level was quantitatively analyzed using real-time fluorescence quantitative polymerase chain reaction. One-way analysis of variance, LSD, Kruskal-Wallis test, Mann-Whitney U test, Chi-square test and logistic regression analysis were used for statistical analysis. Results (1) The body mass index (BMI) of the OW-control group and the OW-GDM group before pregnancy and delivery were all higher than that of the NW-control group and the NW-GDM group [BMI before pregnancy: (29.2±2.9), (29.4±3.8) vs (21.1±2.3) and (21.9±2.0) kg/m2, F=87.766; BMI before delivery: (35.2±3.4), (35.1±4.3) vs (27.9±2.8) and (28.8±3.3) kg/m2, F=44.827; all P<0.001]. Newborn birth weight and the proportion of diabetic family history in the OW-GDM group were higher comparing to the NW- and OW- control group [(3 893±498) vs (3 501±402) and (3 625±332) g, F=4.751; 22.9%(8/35) vs 5.7%(2/35) and 5.7%(2/35), χ2=7.869; all P<0.05]. (2) In the OW-control group, the fasting insulin level and HOMA-IR were higher and the adiponectin and vitamin D concentration were lower than those in the NW-control group [13.3(12.3-14.5) vs 12.0(10.4-13.3) mmol/L, 2.7(2.4-3.0) vs 2.2(2.0-2.7), (61.8±20.4) vs (74.9±29.3) ng/ml, (21.6±7.2) vs (25.9±7.3) ng/ml; all P<0.05], and similar results were found between the OW-GDM group and the NW-GDM group [15.3(12.3-19.5) vs 12.0(10.1-15.8) mmol/L, 3.4(2.6-4.1) vs 2.6(2.1-3.2), (50.3±22.3) vs (62.1±23.2) ng/ml, (17.1±6.7) vs (20.6±7.9) ng/ml, all P<0.05]. Compared with the NW-control group, the NW-GDM group had higher fasting glucose and lower high density lipoprotein-cholesterol (HDL-C), adiponectin and vitamin D levels [4.6(4.3-5.1) vs 4.3(4.0-4.5) mmol/L, 1.7(1.6-1.9) vs 2.1(1.6~2.4) mmol/L, (62.1±23.2) vs (74.9±29.3) ng/ml, (20.6±7.9) vs (25.9±7.3) ng/ml; all P<0.05]. Compared with the OW-control group, fasting glucose, fasting insulin and HOMA-IR were higher and HDL-C, adiponectin and vitamin D levels were lower in the OW-GDM group [4.7(4.4-5.4) vs 4.5(4.2-4.7) mmol/L, 15.3(12.3-19.5) vs 13.3(12.3-14.5) mmol/L, 3.4(2.6-4.1) vs 2.7(2.4-3.0), 1.6(1.4-1.8) vs 1.9(1.7-2.2) mmol/L, (50.3±22.3) vs (61.8±20.4) ng/ml, (17.1±6.7) vs (21.6±7.2) ng/ml; all P<0.05]. (3)The overall vitamin D deficiency rate during the third trimester of the four groups was 78.6% (110/140), and the figure was 62.8% (22/35), 82.8% (29/35), 77.1% (27/35) and 91.4% (32/35) in the NW-control group, OW-control group, NW-GDM group and OW-GDM group (χ2=8.994, P=0.029), indicating a higher rate in the OW-GDM group than that in the NW-control group (χ2=8.102, P=0.004). (4) VDR was expressed in the nucleus of adipose tissue in all samples and statistic difference in protein expression was found among the four groups. VDR mRNA expression was higher in both GDM subgroups than that in the two control subgroups, and also higher in the two overweight/obese subgroups than in the corresponding normal-weight subgroups. (5)Serum vitamin D level was negatively correlated with fasting blood glucose and pre-pregnancy BMI, and positively correlated with adiponectin (P<0.05). The incidence of GDM was related to family history of diabetes, VDR mRNA, total cholesterol, HDL-C and HOMA-IR. Conclusions GDM and overweight/obese patients had decreased serum vitamin D level and increased VDR in subcutaneous adipose tissue. These two factors are closely related to GDM. Key words: Diabetes, gestational; Obesity; Overweight; Adipose tissue; Receptors, calcitriol; Calcitriol

MON-118 Biochemical and Clinical Correlates of Subcutaneous Adipose mRNA Transcript Levels in Men with T2DM

Background: Altered profiles of subcutaneous adipose tissue gene expression have been independently associated with insulin sensitivity. T2DM has been associated with higher levels of adipokines, inflammatory cytokines and lower plasma sex steroid concentrations. We sought to examine the interplay between these factors, specifically with respect to their associations with mRNA transcript levels in subcutaneous adipose tissue. Methods: Cross-sectional assessment of 162 men with T2DM not treated with insulin (Median age 57 [51 - 61]). Basic anthropometric parameters (including body fat by bioimpedance) were measured. Testosterone, DHT, A4, 17-OHP, E2 and E1 measured by LCMS; TNFα, IL-6, IL-8, IL-1ß, MCP-1, leptin, FSH, LH, SHBG and insulin by ELISA (all fasting) and RT-PCR assessed a panel of 23 gene transcripts in adipose tissue (n = 115). Results: Testosterone (R -.273) & DHT (R -.352) were associated with HOMA-IR independent of BMI but not after adjustment for SHBG. No other biochemical parameters were independently associated with HOMA-IR. Waist circumference (R .351) and HbA1c (R .284) but not IL-6 (R .315) were independently associated with CYP19 expression. HbA1c (R -.222) and A4 (R .207) were independently associated with estrogen receptor α expression. FSH (R -.229) was independently associated with androgen receptor expression. Insulin (R .274) and IL-6 (R .245) were independently associated with adipose leptin expression. Associations with BMI (R .275), DHT (R -.208) and FSH (R -.211) were not significant after adjustment for confounders. Insulin receptor expression was only independently associated with fat mass (R -.378). PPARγ expression was only significantly correlated with HbA1c (R -.204) whilst, after adjustment, MCP-1 expression was only independently associated with percentage fat (R .332). Retinol binding protein 4 expression was independently associated with HbA1c (-.323), MCP-1 (R .297) and FSH (-.254). Conclusion: Circulating sex steroids were not associated with insulin resistance or differences across a wide range of adipose mRNA transcript levels in men with T2DM. Insulin or HbA1c appeared to be a stronger correlate for adipose transcript profiles than circulating adipokines or cytokines. Recent evidence suggests FSH may exert direct effects upon adipose tissue and these findings potentially support this hypothesis.

Effects of abdominal visceral fat compared with those of subcutaneous fat on the association between PM10 and hypertension in Korean men: A cross-sectional study

We assessed whether visceral adipose tissue (VAT) compared with subcutaneous adipose tissue (SAT) has modifying effects on the cross-sectional association between ambient air pollution and hypertension in Korean men. This study included 1,417 adult men who visited a health checkup center. Abdominal fat depots were measured by computed tomography, and we used the annual average concentrations of ambient air pollutants such as particulate matter with an aerodynamic diameter of ≤10 μm (PM10), nitrogen dioxide, sulfur dioxide, and carbon monoxide (CO). The annual mean concentrations of PM10 (odds ratio [OR] = 1.30; 95% confidence interval [CI] = 1.12–1.52) and CO (OR = 1.20; 95% CI = 1.03–1.39) showed a positive association with hypertension. In particular, modifying effects on hypertension were found between PM10 and VAT-related traits such as VAT and visceral-to-subcutaneous fat ratio (VSR). The association between PM10 and hypertension was much stronger in the high-VAT (OR = 1.74; 95% CI = 1.12–2.71) and high-VSR groups (OR = 1.53; 95% CI = 1.23–1.91). However, the strength of association across levels of SAT was not observed (Pint = 0.4615). In conclusion, we found that association between PM10 exposure and hypertension is different by abdominal fat distribution.

Possible involvement of the RARRES2/CMKLR1-system in metabolic and reproductive parameters in Holstein dairy cows

BackgroundIn dairy cows, the energy cost of milk yield results in a negative energy balance (EB) and body fat mobilization that impairs reproductive efficiency. Emerging evidence suggests that the novel adipokines, Retinoic acid receptor responder protein 2 (RARRES2), and its main receptor, Chemokine-like receptor 1 (CMKLR1) are involved in the regulation of metabolic and ovarian functions. So, we investigated in a first experiment the plasma RARRES2, and RARRES2 and CMKLR1 mRNA expression levels in subcutaneous adipose tissue (SAT) and granulosa cells (GC) at different times of body fat mobilization in dairy cows (4, 8, 20 and 44 weeks postpartum, wk. pp. for SAT and 8, 20 and 44 wk. pp. for GC). Then, in a second experiment we examined the effect of high (HE) and low energy (LE) diets on the RARRES2 system and its links with metabolic and reproductive parameters.MethodsThe first experiment included 9 animals fed with HE diet from 4 to 44 wk. pp. and the second one included animals fed either a HE diet (n = 8) or a LE diet (n = 8) from − 4 to 16 wk. peripartum. In both experiments, various metabolic and reproductive parameters were determined and associated with plasma RARRES2 as measured by bovine ELISA. RARRES2 and CMKLR1 mRNA expression levels were analyzed by RT-qPCR in SAT after biopsy and GC after aspiration of follicles.ResultsPlasma RARRES2 levels were higher at 4 wk. pp. as compared to 20 and 44 wk. pp. and they were positively correlated with body fat mobilization and milk yield. RARRES2 and CMKLR1 mRNA expression levels increased from 4 to 8 wk. pp. (fat mobilization, EB < 0) and remained unchanged at 20 and 44 wk. pp. (fat reconstitution, EB > 0) as compared to 4 wk. pp. in SAT. RARRES2 and CMKLR1 mRNA levels decreased from 8 to 44 wk. pp. in GC from small follicles. In the second experiment, plasma RARRES2 increased from − 4 to 8 wk. peripartum similarly in both LE and HE cows. In addition, the area under of plasma RARRES2 curve was highly negatively associated with the number of small follicles obtained in HE animals during the cycle before the first artificial insemination. In SAT of HE cows, RARRES2 mRNA expression decreased at 1 wk. pp. compared to − 4 and 16 wk. peripartum whereas opposite expression patterns were obtained for CMKLR1. Similar results were observed for CMKLR1 mRNA expression in LE cows while there was no variation in RARRES2 mRNA expression. Moreover, RARRES2 mRNA was higher expressed in LE than in HE cows at 1 wk. pp.ConclusionsThe lactation-induced fat and energy mobilization influenced plasma RARRES2 profile and mRNA expression pattern of RARRES2 and CMKLR1 similarly in both SAT and GC. In addition, the energy content of the diet did not affect plasma RARRES2 but it altered RARRES2 mRNA expression in SAT and the area under the curve of plasma RARRES2 that was negatively associated to the number of small follicles in HE animals. Thus, RARRES2 could be a metabolic or ovarian signal involved in the interactions between metabolic and reproductive functions in dairy cows.