Sc Fat Research Articles

\u03c9-3PUFA supplementation ameliorates adipose tissue inflammation and insulin-stimulated glucose disposal in subjects with obesity: a potential role for apolipoprotein E

BackgroundLong chain omega-3 polyunsaturated fatty acids (ω-3PUFA) supplementation in animal models of diet-induced obesity has consistently shown to improve insulin sensitivity. The same is not always reported in human studies with insulin resistant (IR) subjects with obesity.ObjectiveWe studied whether high-dose ω-3PUFA supplementation for 3 months improves insulin sensitivity and adipose tissue (AT) inflammation in IR subjects with obesity.MethodsThirteen subjects (BMI = 39.3 ± 1.6 kg/m2) underwent 80 mU/m2·min euglycemic-hyperinsulinemic clamp with subcutaneous (Sc) AT biopsy before and after 3 months of ω-3PUFA (DHA and EPA, 4 g/daily) supplementation. Cytoadipokine plasma profiles were assessed before and after ω-3PUFA. AT-specific inflammatory gene expression was evaluated on Sc fat biopsies. Microarray analysis was performed on the fat biopsies collected during the program.ResultsPalmitic and stearic acid plasma levels were significantly reduced (P < 0.05) after ω-3PUFA. Gene expression of pro-inflammatory markers and adipokines were improved after ω-3PUFA (P < 0.05). Systemic inflammation was decreased after ω-3PUFA, as shown by cytokine assessment (P < 0.05). These changes were associated with a 25% increase in insulin-stimulated glucose disposal (4.7 ± 0.6 mg/kg ffm•min vs. 5.9 ± 0.9 mg/kg ffm•min) despite no change in body weight. Microarray analysis identified 53 probe sets significantly altered post- ω-3PUFA, with Apolipoprotein E (APOE) being one of the most upregulated genes.ConclusionHigh dose of long chain ω-3PUFA supplementation modulates significant changes in plasma fatty acid profile, AT, and systemic inflammation. These findings are associated with significant improvement of insulin-stimulated glucose disposal. Unbiased microarray analysis of Sc fat biopsy identified APOE as among the most differentially regulated gene after ω-3PUFA supplementation. We speculate that ω-3PUFA increases macrophage-derived APOE mRNA levels with anti-inflammatory properties.

MON-695 Multiple Recurrent Lipomatoses with Thiazolidinedione Therapy in Familial Partial Lipodystrophy, Dunnigan Variety (FPLD2)

Background: FPLD2, a rare autosomal dominant disorder due to heterozygous missense mutations in LMNA, is characterized by gradual loss of subcutaneous (sc) fat from the limbs starting during late childhood and predisposition to metabolic complications, such as diabetes, dyslipidemia and hepatic steatosis. Some patients, especially females, accumulate excess sc fat in the chin, neck, supraclavicular and perineal regions. We report disfiguring and disabling lipomatoses in unusual locations with thiazolidinedione therapy in two women with FPLD2. Clinical Cases: A 57-year-old white female with FPLD2, due to heterozygous p.R482Q LMNA mutation, developed recurrent large lipomatoses in the axillae at age 33 years, and later in the posterior neck (buffalo hump), mons pubis and above sacrum. She developed diabetes at age 30 and was started on pioglitazone 45 mg daily, which was switched to rosiglitazone 8 mg daily at age 43 years. Supra-sacral lipomatoses were approximately 40 cm X 20 cm bilaterally and continued to grow despite lipectomy and multiple liposuctions. Rosiglitazone was stopped at age 56 years, and she reported no further increase in the size of lipomatoses. Her other medications included colesevelam, atorvastatin, metformin, glimepiride, lisinopril, losartan, hydrochlorothiazide, aspirin, insulin and dulaglutide. Her 54-year-old younger sister with FPLD2 (heterozygous p.R482Q LMNA mutation) was treated with lisinopril, metoprolol, atorvastatin, liraglutide, and insulin glargine and aspart, but no history of taking thiazolidinediones, and she never developed any lipomatoses. Another 43-year-old white female with FPLD2, due to heterozygous p.S583L LMNA mutation, was noticed to have lipomatous deposits in the axillae, medial gluteal region, labia and perineal regions. She developed diabetes mellitus at age 36 years and took metformin for 6 years and pioglitazone 30 mg daily for one year before she noticed the lipomatoses. Her other medications included atorvastatin, aldactone and vitamin D3. Pioglitazone was stopped and after one year, she reported reduction in the size of lipomatoses. Conclusion: Thiazolidinediones are selective peroxisomal proliferator-activated receptor-γ agonists and induce weight gain by increasing fat mass, especially subcutaneous depots. Our cases suggest that thiazolidinediones can cause undesired growth of non-lipodystrophic adipose tissue in patients with FPLD2 and thus should be avoided.

SUN-LB111 Comparison of Phenotype and Metabolic Abnormalities Among Familial Partial Lipodystrophy Due to LMNA or PPARG Variants

Familial partial lipodystrophy (FPLD), a rare autosomal dominant disorder, is characterized by marked loss of subcutaneous (sc) fat from the extremities, and predisposition to insulin resistance, diabetes mellitus, dyslipidemia and hepatic steatosis. FPLD2 and FPLD3 due to causal variants in LMNA and PPARG, respectively, are the two most common subtypes. Due to extremely rare prevalence of FPLD3 and limited reports in the literature, whether there are phenotypic differences between the two subtypes remain unclear. Therefore, we compared the anthropometric measurements and prevalence of metabolic abnormalities among 32 FPLD3 subjects (4 M, 28 F; mean ± SD age, 41 ± 17.2 y; body mass index (BMI), 26 ± 4.0 kg/m2) with 271 FPLD2 subjects (66 M, 205 F; age, 37.4 ± 17.0 y; BMI, 26 ± 5.0 kg/m2) from two referral centers in the United States. As compared to those with FPLD2, FPLD3 subjects had borderline higher prevalence of hypertriglyceridemia (66% vs 84%; P = 0.063), but significantly higher prevalence of diabetes (44% vs 72%; P = 0.004), past history of acute pancreatitis (13% vs 52%; P <0.001), and polycystic ovarian syndrome (26% vs 52%; P = 0.011). As compared to FPLD2, FPLD3 subjects had similar fasting triglyceride levels (median 208 vs 255 mg/dL; P=0.15), but lower high-density lipoprotein cholesterol levels (median 37.5 vs 30 mg/dL; P = 0.001), higher fasting glucose (median 95 vs 115 mg/dL; P = 0.05) and HbA1c (median 5.7 vs 7.0 %; P = 0.005) levels. Regional body fat was measured by dual energy X-ray absorptiometry in 19 FPLD3 and 105 FPLD2 subjects. In comparison to FPLD2, FPLD3 subjects had higher total fat (median 21.6% vs 26.1 %; P = 0.018); upper limb fat (median 20.3% vs 27.3%; P = 0.003) and lower limb fat (median 16.0% vs 20.8%; P = 0.007). Skinfold thickness measurements by calipers also revealed less severe fat loss from both the upper and lower extremities in FPLD3 subjects compared to FPLD2 subjects. As compared to FPLD2, FPLD3 subjects had significantly higher triceps skinfold thickness (median 5.5 mm vs 7.5 mm; P = 0.015); and thigh skinfold thickness (median 5.8 mm vs 11.3 mm; P = 0.001). There were no significant differences in the prevalence of fatty liver, plasma alanine aminotransferase and aspartate aminotransferase levels in the two subtypes. We conclude that compared to FPLD2 subjects, those with FPLD3 have milder lipodystrophy phenotype but paradoxically present with more severe metabolic complications, especially diabetes, dyslipidemia and polycystic ovarian syndrome. It is likely that this discrepancy could be due to early recognition of FPLD2 because of severe fat loss versus initial diagnosis of FPLD3 subjects due to severe metabolic complications leading to discovery of milder fat loss.

Developmentally Driven Changes in Adipogenesis in Different Fat Depots Are Related to Obesity.

Subcutaneous (sc) and visceral (vis) adipose tissue (AT) contribute to the variability in pathophysiological consequences of obesity and adverse fat distribution. To gain insights into the molecular mechanisms distinguishing vis and sc fat, we compared the transcriptome during differentiation of immortalized adipocytes from murine epididymal (epi) and inguinal (ing) AT. RNA was extracted on different days of adipogenesis (−2, 0, 2, 4, 6, 8) and analyzed using Clariom™ D mouse assays (Affymetrix) covering >214,900 transcripts in >66,100 genes. Transcript Time Course Analysis revealed 137 differentially expressed genes. The top genes with most divergent expression dynamics included developmental genes like Alx1, Lhx8, Irx1/2, Hoxc10, Hoxa5/10, and Tbx5/15. According to pathway analysis the majority of the genes were enriched in pathways related to AT development. Finally, in paired samples of human vis and sc AT (N = 63), several of these genes exhibited depot-specific variability in expression which correlated closely with body mass index and/or waist-to-hip ratio. In conclusion, intrinsically programmed differences in gene expression patterns during adipogenesis suggest that fat depot specific regulation of adipogenesis contributes to individual risk of obesity.

SAT-087 Familial Generalized Lipodystrophy in Two Siblings Due to Homozygous p.Arg545His LMNA Mutation

Background: Homozygous mutations in lamin A/C (LMNA) gene are extremely rare and have been reported to cause mandibuloacral dysplasia type A, Emery-Dreifuss muscular dystrophy-3, Charcot-Marie-Tooth axonal neuropathy type 2B1, progeroid syndrome and severe familial partial lipodystrophy. We report a novel syndrome of familial generalized lipodystrophy due to homozygous p.Arg545His LMNA mutation in two sisters. Clinical Cases: The proband, a 18.5-year-old Hispanic female, was diagnosed with speech delay at age 4 years; and developed lipodystrophy and acanthosis nigricans at age 10. She was diagnosed with diabetes and elevated serum aspartate and alanine aminotransferases at 11 years of age; and extreme hypertriglyceridemia (serum triglycerides >10,000 mg/dL), xanthomas and three episodes of acute pancreatitis at 14 years of age. Her liver biopsy showed hepatocytes with pleomorphic and enlarged mitochondria and variably enlarged glycogenated nuclei, with macro-vesicular and micro-vesicular steatosis in 2% of hepatocytes. At age 16, she had severe metabolic abnormalities despite low fat diet, metformin 1000 mg, insulin > 600 units, fish oil 4 g, gemfibrozil 600 mg, and lisinopril 10 mg per day. Subcutaneous metreleptin 2.5 mg/d was initiated which improved glycemic control, liver enzymes and triglycerides, with no further episode of acute pancreatitis. She currently takes metreleptin and insulin 140 units daily. She recently developed right hydrosalpinx, 1.8 cm posterior uterine fibroids, and 2.1 cm endometriosis. Her 17-year-old sister had speech delay in infancy, and recurrent pyelonephritis, and lost sc fat in early childhood. She developed hypothyroidism, elevated transaminases, and diabetes at age 10, 14, and 16 years, respectively. She had one episode of acute pancreatitis and an incidental 6.8 cm ovarian cyst was found at age 16 years. Both of them have generalized loss of sc fat, more from the extremities than from the trunk, thin lips with perioral pigmentation, dry skin, short 5th finger with clindodactyly, and bilateral ankle contractures. The proband also had bilateral knee contractures. They have no acro-osteolysis, buffalo hump, double chin, myopathy or neuropathy. Whole exome sequencing of both the patients revealed homozygous mutation chr1:156107470G>A, p.Arg545His (rs142191737, minor allele frequency 0.000038 in Latinos) in LMNA (http://gnomad.broadinstitute.org). The mother and a younger brother are both heterozygous for p.Arg545His variant and are healthy without any lipodystrophy. Conclusions: Homozygous p.Arg545His LMNA mutation results in a novel syndrome of childhood-onset familial generalized lipodystrophy with early onset diabetes, hypertriglyceridemia, and hepatic steatosis, speech delay and joint contractures. Metreleptin therapy may be helpful in improving metabolic derangements.

SUN-135 Dual Energy X-Ray Absorptiometry (DEXA) as a Diagnostic Tool for Familial Partial Lipodystrophy, Dunnigan Variety (FPLD2)

FPLD2 is a rare autosomal dominant disorder characterized by loss of subcutaneous (sc) fat from the extremities but increased fat deposition in the face, neck and abdomen. Most FPLD2 patients (~75%) have “typical” heterozygous missense LMNA mutations affecting the arginine 482 residue and have severe loss of sc fat from the extremities and develop moderate to severe metabolic complications. Other patients have “atypical” mutations with variable loss of sc fat from the extremities and mild to severe metabolic complications. Since genetic testing is expensive, the diagnosis of FPLD2 is usually missed or delayed. Thus, there exists a need for an objective screening tool which can aid in the diagnosis of FPLD2. Therefore, we determined the predictive value of skinfold thickness measurements and various DEXA-based regional body fat parameters for diagnosis of FPLD2. We compared body fat data of 49 adult females (F) and 5 males (M) with FPLD2 to the sex- and age-matched controls (2,459 F, 3,459 M) from the National Health and Nutrition Examination Survey (NHANES) 2005-2010. Thirty nine patients had “typical” heterozygous p.R482W or p.R482Q LMNA mutation. The other heterozygous LMNA mutations included p.R582S (n = 1), p.R582H (n = 1), p.S583L (n = 3), p.R349W (n = 1), p.R25L (n = 1), p.G523R (n = 2), p.D192V (n = 1), p.L241P (n = 1), p.R62G (n = 2) and p.K515E (n = 2). The mean ± SD age and body mass index of affected F was 42 ± 13.5 y and 25.6 ± 4.5 kg/m2, respectively; and of affected M was 45.4 ± 11.6 y and 29.2 ± 7.0 kg/m2, respectively. Hypertriglyceridemia and diabetes mellitus were present in 74% and 52% of the FPLD2 patients, respectively. Our data revealed that the lower limb fat %, as well as the ratio of lower limb fat %/ truncal fat %, in all affected females were ≤ 1st percentile (%ile) of the controls, except in two patients, one of whom had a p.G523R mutation, and the other had a p.R482Q mutation but had an unusual excess fat accumulation in the medial part of the thighs and knees. All FPLD2 females had triceps skinfold thickness values ≤ 1st %ile of NHANES except in three patients. The subscapular skinfold thickness values in females on the other hand, were between the 5th to 99th %ile of NHANES. Unfortunately, data for thigh skinfold thickness were not available from NHANES. The lower limb fat % in affected males was below 25th %ile of controls. We conclude that DEXA-derived lower limb fat % and the ratio of lower limb fat %/ truncal fat % are the best predictors of FPLD2 diagnosis in females but not in males. Women with values of lower limb fat % (~ 20% or less) and the ratio of lower limb fat %/ truncal fat % (~ 0.85 or less), both of which are below the 1st %ile of NHANES data, should be further evaluated for diagnosis of FPLD2, especially if presenting with metabolic complications.

Abstract 432: Differential MicroRNA Expression in Subcutaneous Abdominal and Lower-body Fat Depots

Background: Abdominal fat elevates while lower-body (LB) fat diminishes cardiovascular risk. However, molecular mechanisms differentiating the two fat depots are not completely understood. MicroRNA (miRNA) are important regulators of gene expression with widespread effects on several proteins. Objective: To explore miRNA differences between the two fat depots using unbiased next-generation sequencing (NGS) approach. Methods: Total RNA isolated from paired subcutaneous (sc) fat tissue obtained from abdomen (ABD) and LB (femoral) region of 12 healthy subjects (7 male; age: 27 ± 5 years; BMI: 23.5 ± 3.2 kg/m 2 ) was used to quantify miRNA expression. Body fat distribution was determined using dual-energy X-ray absorptiometry and abdominal computed tomography scans. RNA was prepped using the NEBNext small RNA library prep kit and sequenced using Illumina HiSeq 2000. Raw sequence data were processed using CAP-miRSeq pipeline. miRNA expression between the two depots was evaluated using EdgeR. Relationship between miRNA and regional fat depots were examined using Spearman’s correlation. Adjusted or unadjusted P value &lt;0.05 was considered significant. Results: Using NGS, 383 ± 55 known miRNA with ≥5 raw reads were detected in the study samples. Principal component analysis including all miRNAs showed no any clear separation between ABD or LB fat tissue. However, 37 miRNAs were found to have altered expression in the two depots. miR-196a-5p (log2FC=1.138, p&lt;0.001), miR-146b-5p ( log2FC=1.388, p&lt;0.001), miR-1287 ( log2FC=1.059, p&lt;0.001), miR-1247-5p (1.002, p&lt;0.001), and miR-346 (log2FC =-1.240, p=0.002) were among the top five differentially expressed miRNA in ABD Vs. LB fat. Interestingly, ABD fat tissue expression of miR196a-5p (rho=-0.58, p=0.047) and miR146b-5p (rho=0.76, p=0.004) correlated with visceral fat while miR146b-5p (rho=0.66, p=0.02) and miR1287 (rho=0.79, p=0.002) correlated with ABD sc fat. Conclusions: Several miRNAs are differentially expressed between ABD and LB fat tissue which may partly contribute to depot specific alterations in adipose tissue function and consequent cardiometabolic risk. Furthermore, the associations between miRNA and regional fat depots suggest a functional role of these miRNA in fat distribution.

Pinealectomy Reduces Gene Expression of Caspase 9 in Subcutaneous Adipose Tissue of Rats

Previous studies have shown that pinealectomy induces insulin resistance in rats. The present study aimed to verify whether pinealectomy modulates the expression of apoptosis‐related genes in rat subcutaneous adipose tissue (TA‐Sc). For this purpose, samples from the bank of frozen tissue of animals (Ethics Committee/Institute of Biomedical Sciences (ICB) Protocol No. 896/2017), belonging to the Laboratory of Adipose Tissue Physiology, University of Sao Paulo (USP), were used. The material came from Wistar rats (male and adults), whose were kept at the Experimentation Hall of the Department of Physiology and Biophysics of the ICB/USP and handled according to a certificate approved by the Ethics Committee on the Use of Animals (CEUA)/(03/10/2011, protocol no. 129) and standards established by the National Council for Control of Animal (CONCEA). The rats were housed in polypropylene boxes under controlled environmental conditions (25 ± 2 ºC) and light (12 h light/12 h dark), with water and standard ration for Nuvilab® rodents (Nuvital S/A, Colombo, PR) ad libitum. The animals, when completed 10 weeks old, were anesthetized and submitted to pinealectomy (P) by the method of Hoffman and Reiter (1965) or to the fictitious operation (C) and, following their recovery, they were kept in individual boxes. After four weeks of the surgery (14 weeks old) the animals P and C were killed by decapitation and inguinal TA‐Sc dissected. For the evaluation of gene expression related to apoptosis, samples of the Sc fat pad were submitted to the Total RNA Extraction stages; Synthesis of cDNA by Reverse Transcription and Polymerase Chain Reaction from cDNA (Real Time PCR). PCR reactions were performed by the StepOnePlus® Real Time PCR System (Applied Biosystems). The evaluated genes were: Caspases (3, 8, 9), Bax, Fas and BCL‐2. The data were analyzed according to the requirements of homoscedasticity and normality by means of the Shapiro‐Wilk test and later the Student's t‐test, unpaired and parametric. The 95% confidence interval and p value &lt;0.05 were considered significant. The statistical program used was Graph Pad Prism version 6.0. The results showed that pinealectomy did not alter the expression of the anti and pro‐apoptotic genes evaluated (p&gt; 0.05), with the exception of Caspase 9, whose gene expression was significantly reduced in group P in relation to C (Figure 1). In conclusion, pinealectomy is capable of selectively interfering with the gene expression of the apoptotic pathway, specifically in the caspase activator 9.Support or Funding InformationConselho Nacional de Desenvolvimento Científico e Tecnológico‐CNPqThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Role of Gut Microbiota and Short Chain Fatty Acids in Modulating Energy Harvest and Fat Partitioning in Youth.

We aimed at determining the relationship of the gut microbiota and short chain fatty acids with obesity and fat partitioning and at testing potential differences in the ability of gut microbiota to ferment equal amounts of carbohydrates (CHO) between lean and obese youth. We analyzed the gut microbiota of 84 youth in whom body fat distribution was measured by fast-magnetic resonance imaging, de novo lipogenesis (DNL) quantitated using deuterated water, and the capability of gut flora to ferment CHO was assessed by 13C-fructose treatment in vitro. A significant association was found between the Firmicutes to Bacteroidetes ratio, and the abundance of Bacteroidetes and Actinobacteria with body mass index, visceral and SC fat (all P < .05). Plasma acetate, propionate, and butyrate were associated with body mass index and visceral and SC fat (all P < .05) and with hepatic DNL (P = .01, P = .09, P = .04, respectively). Moreover, the rate of CHO fermentation from the gut flora was higher in obese than in lean subjects (P = .018). These data demonstrate that obese youth show a different gut flora composition than lean and that short chain fatty acids are associated with body fat partitioning and DNL. Also, the gut microbiota of obese youth have a higher capability than the gut flora of lean to oxidize CHO.

Perinatal Nicotine Exposure Increases Obesity Susceptibility in Adult Male Rat Offspring by Altering Early Adipogenesis.

The present study aims to evaluate whether perinatal nicotine (NIC) exposure increases obesity susceptibility in adult male rat offspring by altering early adipogenesis. NIC was sc administered (2.0 mg/kg per day) to pregnant rats from gestational day 9 to the time of weaning (postnatal day 28). At weaning, NIC-exposed male pups had an increased body weight and inguinal sc fat mass and a decreased average cell area of adipocyte, which was accompanied by an overexpression of adipogenic and lipogenic genes in the epididymal white adipose tissue. Additionally, the hepatic lipogenic gene levels from NIC-exposed male pups were also affected. At 12 and 26 weeks of age, body weight and fat mass were increased, whereas there was no change in food intake in NIC-exposed male offspring. Adipogenic and lipogenic genes, glucose transporter 4, and leptin mRNA levels were increased, whereas adiponectin mRNA levels were decreased in the epididymal white adipose tissue of NIC-exposed males. The hepatic lipogenic gene expression of NIC-exposed males was increased. NIC-exposed male offspring showed normal glycemia and a higher serum insulin level, homeostasis model assessment of insulin resistance, and homeostasis model assessment of β-cell function. Furthermore, the NIC-exposed male offspring showed higher serum lipids and Castelli index I and lower nonesterified fatty acid. At 26 weeks, in the ip glucose and insulin tolerance tests, the glucose clearance was delayed, and the area under the curve was higher in the NIC-exposed male offspring. In conclusion, perinatal NIC exposure increased obesity susceptibility in adult male rat offspring by altering early adipogenesis.

Adipocyte Browning and Higher Mitochondrial Function in Periadrenal But Not SC Fat in Pheochromocytoma

Patients with pheochromocytoma (pheo) show presence of multilocular adipocytes that express uncoupling protein 1 within periadrenal (pADR) and omental (OME) fat depots. It has been hypothesized that this is due to adrenergic stimulation by catecholamines produced by the pheo tumors. To characterize the prevalence and respiratory activity of brown-like adipocytes within pADR, OME, and SC fat depots in human adult pheo patients. This was an observational cohort study. The study took place in a university hospital. We studied 46 patients who underwent surgery for benign adrenal tumors (21 pheos and 25 controls with adrenocortical adenomas). We characterized adipocyte browning in pADR, SC, and OME fat depots for histological and immunohistological features, mitochondrial respiration rate, and gene expression. We also determined circulating levels of catecholamines and other browning-related hormones. Eleven of 21 pheo pADR adipose samples, but only one of 25 pADR samples from control patients exhibited multilocular adipocytes. The pADR browning phenotype was associated with higher plasma catecholamines and raised uncoupling protein 1. Mitochondria from multilocular pADR fat of pheo patients exhibited increased rates of coupled and uncoupled respiration. Global gene expression analysis in pADR fat revealed enrichment in β-oxidation genes in pheo patients with multilocular adipocytes. No SC or OME fat depots exhibited aspects of browning. Browning of the pADR depot occurred in half of pheo patients and was associated with increased catecholamines and mitochondrial activity. No browning was detected in other fat depots, suggesting that other factors are required to promote browning in these depots.

Association of early protein intake and pre-peritoneal fat at five years of age: Follow-up of a randomized clinical trial

Background and aimsThe double-blind randomized European Childhood Obesity Project (CHOP) demonstrated that reduced protein content in infant formula leads to a lower body mass index (BMI) up to six years of age. Here we aimed at assessing pre-peritoneal fat, a marker of visceral fat, in children participating in the CHOP trial. Methods and resultsHealthy term formula-fed infants in five European countries were randomized either to higher (n = 550) or lower (n = 540) protein formulas in the first year of life. Infants who were exclusively breastfed for at least three months (n = 588) were enrolled as an observational (non randomized) group. At age 5 years, subcutaneous fat (SC) and pre-peritoneal fat (PP) were measured by ultrasound in a subgroup of 275 children. The PP fat layer was thicker in the higher compared to the lower protein group (adjusted estimated difference: 0.058 cm, 95%CI 0.002; 0.115; p = 0.043), while SC fat was not different. Girls showed a thicker SC fat layer than boys. ConclusionsHigher protein intake in formula-fed infants appears to enhance pre-peritoneal fat tissue accumulation at the age of 5 years, but not of subcutaneous fat, which may trigger adverse metabolic and health consequences.

PDE5 Inhibition Ameliorates Visceral Adiposity Targeting the miR-22/SIRT1 Pathway: Evidence From the CECSID Trial.

Visceral adiposity plays a significant role in cardiovascular risk. PDE5 inhibitors (PDE5i) can improve cardiac function and insulin sensitivity in type 2 diabetes patients. To investigate whether PDE5i affect visceral adipose tissue (VAT), specifically epicardial fat (epicardial adipose tissue [EAT]), and what mechanism is involved, using microarray-based profiling of pharmacologically modulated microRNA (miRNAs). Randomized, double-blind, placebo-controlled study in type 2 diabetes. A total of 59 diabetic patients were randomized to receive 100-mg/d sildenafil or placebo for 12 weeks. Fat biopsies were collected in a subgroup of patients. In a parallel protocol, db/db mice were randomized to 12 weeks of sildenafil or vehicle, and VAT was collected. Anthropometric and metabolic parameters, EAT quantification through cardiac magnetic resonance imaging, array of 2005 circulating miRNAs, quantitative PCR, and flow cytometry of VAT. Compared with placebo, sildenafil reduced waist circumference (P = .024) and EAT (P = .045). Microarray analysis identified some miRNAs differentially regulated by sildenafil, including down-regulation of miR-22-3p, confirmed by real-time quantitative PCR (P < .001). Sildenafil's modulation of miR-22-3p expression was confirmed in vitro in HL1 cardiomyocytes. Up-regulation of SIRT1, a known target of miR-22-3p, was found in both serum and sc fat in sildenafil-treated subjects. Compared with vehicle, 12-week sildenafil treatment down-regulated miR-22-3p and up-regulated Sirtuin1 (SIRT1) gene expression in VAT from db/db mice, shifting adipose tissue cell composition toward a less inflamed profile. Treatment with PDE5i in humans and murine models of diabetes improves VAT, targeting SIRT1 through a modulation of miR-22-3p expression.

Mechanisms of Action of Liraglutide in Patients With Type 2 Diabetes Treated With High-Dose Insulin.

The mechanisms of action of incretin mimetics in patients with long-standing type 2 diabetes (T2D) and high insulin requirements have not been studied. To evaluate changes in β-cell function, glucagon secretion, and fat distribution after addition of liraglutide to high-dose insulin. A single-center, randomized, double-blind, placebo-controlled trial. University of Texas Southwestern and Parkland Memorial Hospital clinics. Seventy-one patients with long-standing (median, 17 years) T2D requiring high-dose insulin treatment (>1.5 U/kg/d; average, 2.2 ± 0.9 U/kg/d). Patients were randomized to liraglutide 1.8 mg/d or matching placebo for 6 months. We measured changes in insulin and glucagon secretion using a 4-hour mixed-meal challenge test. Magnetic resonance-based techniques were used to estimate sc and visceral fat in the abdomen and ectopic fat in the liver and pancreas. Glycosylated hemoglobin improved significantly with liraglutide treatment, with an end-of-trial estimated treatment difference between groups of −0.9% (95% confidence interval, −1.5, −0.4%) (P = .002). Insulin secretion improved in the liraglutide group vs placebo, as measured by the area under the curve of C-peptide (P = .002) and the area under the curves ratio of C-peptide to glucose (P = .003). Insulin sensitivity (Matsuda index) and glucagon secretion did not change significantly between groups. Liver fat and sc fat decreased in the liraglutide group vs placebo (P = .0006 and P = .01, respectively), whereas neither visceral nor pancreatic fat changed significantly. Treatment with liraglutide significantly improved insulin secretion, even in patients with long-standing T2D requiring high-dose insulin treatment. Liraglutide also decreased liver and sc fat, but it did not alter glucagon secretion.

Dysfunctional Subcutaneous Fat With Reduced Dicer and Brown Adipose Tissue Gene Expression in HIV-Infected Patients.

HIV patients are at an increased risk for cardiometabolic disease secondary to depot-specific alterations in adipose function, but mechanisms remain poorly understood. The endoribonuclease Dicer has been linked to the modulation of brown and white adipocyte differentiation. We previously demonstrated that Dicer knockout mice undergo transformation of brown adipose tissue to white adipose tissue and develop a lipodystrophic phenotype. We hypothesized reduced Dicer and brown adipose tissue gene expression from nonlipomatous sc fat among HIV patients with a lipodystrophic phenotype. Eighteen HIV (nine with and without lipodystrophic changes in fat distribution, characterized by excess dorsocervical adipose tissue [DCAT]) and nine non-HIV subjects underwent punch biopsy of abdominal sc fat to determine expression of Dicer and other adipose-related genes. HIV subjects with long-duration antiretroviral use demonstrated excess DCAT vs non-HIV subjects (9.8 ± 1.0 vs 6.6 ± 0.8 cm(2), P = .02) with similar body mass index. Dicer expression was decreased in abdominal sc fat of HIV vs non-HIV (4.88 [1.91, 11.93] vs 17.69 [10.72, 47.91], P = .01), as were PPARα, ZIC1, PRDM16, DIO2, and HSP60 (all P ≤ .03). Moreover, the expression of Dicer (2.49 [0.02, 4.88] vs 11.20 [4.83, 21.45], P = .006), brown fat (PPARα [P = .002], ZIC1 [P = .004], LHX8 [P = .03], PRDM16 [P = .0008], PAT2 [P = .008], P2RX5 [P = .02]), beige fat (TMEM26 [P = .004], CD137 [P = .008]), and other genes (DIO2 [P = .002], leptin [P = .003], HSP60 [P = .0004]) was further decreased in abdominal sc fat comparing HIV subjects with vs without excess DCAT. Down-regulation of Dicer in the abdominal sc fat correlated with the down-regulation of all brown and beige fat genes (all P ≤ .01). Our results demonstrate dysfunctional sc adipose tissue marked by reduced Dicer in relationship to the down-regulation of brown and beige fat-related genes in lipodystrophic HIV patients and may provide a novel mechanism for metabolic dysregulation. A strategy to increase browning of white adipose tissue may improve cardiometabolic health in HIV.

Trenbolone Improves Cardiometabolic Risk Factors and Myocardial Tolerance to Ischemia-Reperfusion in Male Rats With Testosterone-Deficient Metabolic Syndrome.

The increasing prevalence of obesity adds another dimension to the pathophysiology of testosterone (TEST) deficiency (TD) and potentially impairs the therapeutic efficacy of classical TEST replacement therapy. We investigated the therapeutic effects of selective androgen receptor modulation with trenbolone (TREN) in a model of TD with the metabolic syndrome (MetS). Male Wistar rats (n=50) were fed either a control standard rat chow (CTRL) or a high-fat/high-sucrose (HF/HS) diet. After 8 weeks of feeding, rats underwent sham surgery or an orchiectomy (ORX). Alzet miniosmotic pumps containing either vehicle, 2-mg/kg·d TEST or 2-mg/kg·d TREN were implanted in HF/HS+ORX rats. Body composition, fat distribution, lipid profile, and insulin sensitivity were assessed. Infarct size was quantified to assess myocardial damage after in vivo ischaemia reperfusion, before cardiac and prostate histology was performed. The HF/HS+ORX animals had increased sc and visceral adiposity; circulating triglycerides, cholesterol, and insulin; and myocardial damage, with low circulating TEST compared with CTRLs. Both TEST and TREN protected HF/HS+ORX animals against sc fat accumulation, hypercholesterolaemia, and myocardial damage. However, only TREN protected against visceral fat accumulation, hypertriglyceridaemia, and hyperinsulinaemia and reduced myocardial damage relative to CTRLs. TEST caused widespread cardiac fibrosis and prostate hyperplasia, which were less pronounced with TREN. We propose that TEST replacement therapy may have contraindications for males with TD and obesity-related MetS. TREN treatment may be more effective in restoring androgen status and reducing cardiovascular risk in males with TD and MetS.

Glucose-Dependent Insulinotropic Polypeptide Is Associated With Lower Low-Density Lipoprotein But Unhealthy Fat Distribution, Independent of Insulin: The ADDITION-PRO Study.

Glucose-dependent insulinotropic polypeptide (GIP) may increase lipid clearance by stimulating lipid uptake. However, given that GIP promotes release of insulin by the pancreas and insulin is anti-lipolytic, the effect may be indirect. In this study we examined the association between GIP and lipid metabolism in individuals with low to high risk of type 2 diabetes and assessed whether the associations were modified by or mediated through insulin. Analyses were based on the Danish cross-sectional ADDITION-PRO study (n = 1405). Lipid metabolism was measured by fasting plasma lipids and obesity including abdominal fat distribution assessed by ultrasonography. GIP and insulin were measured during an oral glucose tolerance test (0, 30 and 120 min). Linear regression analysis was used to study the associations between GIP, plasma lipids, and obesity measures. A doubling in fasting GIP levels was associated with lower low-density lipoprotein in both men (mean [95% CI] -0.10 mmol/l [-0.18--0.03]) and women (-0.14 mmol/l [-0.23--0.04]) and with higher high-density lipoprotein in women (0.06 mmol/l [-0.02-0.10]). In men, a doubling in stimulated GIP was associated with 0.13 cm less 0.01-0.25 sc fat but with more visceral abdominal fat (0.45 cm [0.12-0.78]) and higher waist-hip ratio (0.011 [0.004-0.019]). Contrary to what was previously thought, GIP may be associated with improved low-density lipoprotein clearance but with an unhealthy fat distribution independent of insulin. The effect of GIP on obesity measures was substantially different between men and women. The potential effect of GIP on visceral and sc adipose tissue physiology warrants further examination.

Phenotypic Characterization of Insulin-Resistant and Insulin-Sensitive Obesity.

Whereas insulin resistance and obesity coexist, some obese individuals remain insulin sensitive. We examined phenotypic and metabolic factors associated with insulin sensitivity in both muscle and liver in obese individuals. Sixty-four nondiabetic obese adults (29 males) underwent hyperinsulinemic (15 and 80 mU/m(2) · min)-euglycemic clamps with deuterated glucose. Top tertile subjects for glucose infusion rate during the high-dose insulin clamp were assigned Musclesen and those in the lower two tertiles were assigned Muscleres. Secondarily, top tertile subjects for endogenous glucose production suppression during the low-dose insulin clamp were deemed Liversen and the remainder Liverres. Clinical and laboratory parameters and visceral, subcutaneous, liver, and pancreatic fat were compared. Musclesen and Muscleres had similar body mass index and total fat (P > .16), but Musclesen had lower glycated hemoglobin (P < .001) and systolic (P = .01) and diastolic (P = .03) blood pressure (BP). Despite similar sc fat (P = 1), Musclesen had lower visceral (P < .001) and liver (P < .001) fat. Liversen had lower visceral (P < .01) and liver (P < .01) fat and C-reactive protein (P = .02) than Liverres. When subjects were grouped by both glucose infusion rate during the high-dose insulin clamp and endogenous glucose production suppression, insulin sensitivity at either muscle or liver conferred apparent protection from the adverse metabolic features that characterized subjects insulin resistant at both sites. High-density lipoprotein-cholesterol, 1-hour glucose, systolic BP, and triglycerides explained 54% of the variance in muscle insulin sensitivity. Obese subjects who were insulin sensitive at muscle and/or liver exhibited favorable metabolic features, including lower BP, liver and visceral adiposity. This study identifies factors associated with, and possibly contributing to, insulin sensitivity in obesity.

Myocardial Fat Accumulation Is Independent of Measures of Insulin Sensitivity.

Myocardial steatosis, an independent predictor of diastolic dysfunction, is frequently present in type 2 diabetes mellitus. High free fatty acid flux, hyperglycemia, and hyperinsulinemia may play a role in myocardial steatosis. There are no prior studies examining the relationship between insulin sensitivity (antilipolytic and glucose disposal actions of insulin) and cardiac steatosis. Using a cross-sectional study design of individuals with and without metabolic syndrome (MetSyn), we examined the relationships between cardiac steatosis and the sensitivity of the antilipolytic and glucose disposal actions of insulin. Pericardial fat (PF) volume, intramyocardial and hepatic fat (MF and HF) content, visceral fat (VF) and sc fat content were assessed by magnetic resonance imaging in 77 subjects (49 without MetSyn and 28 with MetSyn). In a subset of the larger cohort (n = 52), peripheral insulin sensitivity index (SI) and adipocyte insulin sensitivity (Adipo-SI) were determined from an insulin-modified frequently sampled iv glucose tolerance test. The Quantitative Insulin Sensitivity Check Index was used as a surrogate for hepatic insulin sensitivity. Individuals with the MetSyn had significantly higher body mass index, total body fat, and MF, PF, HF, and VF content. HF and VF, but not MF, were negatively correlated with the Quantitative Insulin Sensitivity Check Index, Adipo-SI, and SI. Stepwise regression revealed that waist circumference and serum triglyceride levels independently predicted MF and PF, respectively. Adipo-SI and serum triglyceride levels independently predict HF. Myocardial steatosis is unrelated to hepatic, adipocyte, or peripheral insulin sensitivity. Although it is frequently observed in insulin-resistant subjects, further studies are necessary to identify and delineate pathogenic mechanisms that differentially affect cardiac and hepatic steatosis.

Giant mice reveal new roles for GH in regulating the adipose immune microenvironment.

Giant mice reveal new roles for GH in regulating the adipose immune microenvironment.