Biochemical Phenomena, Metabolism, and Nutrition Commons^™

Dna Methylation Markers Of Insulin Resistance Surrogate Measures In The Atherosclerosis Risk In Communities (Aric) Study, Jeewoen Shin, Jan Bressler, Megan L Grove, Michael Brown, Elizabeth Selvin, James S Pankow, Myriam Fornage, Alanna C Morrison, Chloé Sarnowski

Faculty, Staff and Student Publications

Insulin resistance (IR) is a risk factor for cardiovascular diseases and type 2 diabetes. Associations between DNA methylation (DNAm) and IR have been less studied in African ancestry (AA) populations than those of European ancestry (EA). We aimed to identify associations between whole blood DNAm and IR in up to 1,811 AA and 964 EA participants from the Atherosclerosis Risk in Communities (ARIC) study. We quantified IR using three surrogate measures: the homeostasis model assessment of insulin resistance (HOMA-IR), the triglyceride-glucose index (TyG), and the triglyceride glucose-body mass index (TyG-BMI). We used ancestry-stratified linear regression models to conduct epigenome-wide association …

Metabolic Clearance Rate Of Insulin Across The Glucose Tolerance Spectrum By Race And Ethnicity In Youth With Obesity, Wonhee Cho, Fida Bacha, Hala Tfayli, Sojung Lee, Sara F Michaliszyn, Joon Young Kim, Silva Arslanian

Children’s Nutrition Research Center Staff Publications

Objective: Despite β-cell failure in youth with dysglycemia (i.e., impaired glucose tolerance [IGT] and type 2 diabetes), fasting insulin (FI) concentrations are elevated. Herein, we examined the following: 1) metabolic clearance rate of insulin (MCRI) in youth with obesity and normal glucose tolerance (NGT) versus those with IGT versus those with type 2 diabetes; 2) racial and ethnic differences in insulin dynamics; and 3) metabolic/adiposity correlates of MCRI.

Methods: A total of 206 youth underwent assessment of fasting glucose, FI, MCRI and peripheral insulin sensitivity (PIS), first-phase insulin secretion, disposition index, body composition, and abdominal adiposity.

Results: In type 2 …

Insulin Clearance At Randomisation And In Response To Treatment In Youth With Type 2 Diabetes: A Secondary Analysis Of The Today Randomised Clinical Trial, Kristen J Nadeau, Silva A Arslanian, Fida Bacha, Sonia Caprio, Lily C Chao, Ryan Farrell, Kara S Hughan, Maria Rayas, Melinda Tung, Kaitlyn Cross, Laure El Ghormli

Children’s Nutrition Research Center Staff Publications

Aims/hypothesis: Insulin resistance and compensatory hyperinsulinaemia are core features leading to beta cell failure in youth-onset type 2 diabetes. Insulin clearance (IC) is also a key regulator of insulin concentrations, but few data exist on IC in youth-onset type 2 diabetes. In a secondary analysis of our Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) randomised clinical trial, we investigated potential sex-, race-, ethnicity- and treatment-related differences in IC in youth-onset type 2 diabetes and aimed to identify metabolic phenotypes associated with IC at baseline and in response to metformin, metformin plus a lifestyle intervention, and metformin …

The Role Of The Triglyceride-Glucose Index As A Biomarker Of Cardio-Metabolic Syndromes, Verena Gounden, Sridevi Devaraj, Ishwarlal Jialal

Faculty, Staff and Students Publications

BACKGROUND: The Triglyceride-glucose (TyG) index represents a simple, cost-effective, and valid proxy for insulin resistance. This surrogate marker has also been proposed as a predictor of metabolic and cardiovascular disease (CVD). In this descriptive review, we aimed to assess the utility of the TyG index as a predictive biomarker of cardiometabolic diseases.

METHODS: A search was conducted in PubMed, and Web of Science to identify cross-sectional and more importantly prospective studies examining the use of the TyG index as a predictive biomarker. The following terms were utilized in addition to the TyG index: "insulin resistance", "metabolic syndrome", "diabetes"; "cardiovascular diseases". …

Deletion Of Mipep In Adipocytes Protects Against Obesity And Insulin Resistance By Boosting Muscle Metabolism, Alexis Diaz-Vegas, Kristen C Cooke, Harry B Cutler, Belinda Yau, Stewart W C Masson, Dylan Harney, Oliver K Fuller, Meg Potter, Søren Madsen, Niamh R Craw, Yiju Zhang, Cesar L Moreno, Melkam A Kebede, G Gregory Neely, Jacqueline Stöckli, James G Burchfield, David E James

Faculty, Staff and Students Publications

Mitochondria facilitate thousands of biochemical reactions, covering a broad spectrum of anabolic and catabolic processes. Here we demonstrate that the adipocyte mitochondrial proteome is markedly altered across multiple models of insulin resistance and reveal a consistent decrease in the level of the mitochondrial processing peptidase miPEP.

OBJECTIVE: To determine the role of miPEP in insulin resistance.

METHODS: To experimentally test this observation, we generated adipocyte-specific miPEP knockout mice to interrogate its role in the aetiology of insulin resistance.

RESULTS: We observed a strong phenotype characterised by enhanced insulin sensitivity and reduced adiposity, despite normal food intake and physical activity. Strikingly, …

Mesenchymal-Specific Alms1 Knockout In Mice Recapitulates Metabolic Features Of Alström Syndrome, Eleanor J Mckay, Ineke Luijten, Xiong Weng, Pablo B Martinez De Morentin, Elvira De Frutos González, Zhanguo Gao, Mikhail G Kolonin, Lora K Heisler, Robert K Semple

Faculty, Staff and Student Publications

OBJECTIVE: Alström Syndrome (AS), caused by biallelic ALMS1 mutations, includes obesity with disproportionately severe insulin resistant diabetes, dyslipidemia, and fatty liver. Prior studies suggest that hyperphagia is accounted for by loss of ALMS1 function in hypothalamic neurones, whereas disproportionate metabolic complications may be due to impaired adipose tissue expandability. We tested this by comparing the metabolic effects of global and mesenchymal stem cell (MSC)-specific Alms1 knockout.

METHODS: Global Alms1 knockout (KO) mice were generated by crossing floxed Alms1 and CAG-Cre mice. A Pdgfrα-Cre driver was used to abrogate Alms1 function selectively in MSCs and their descendants, including preadipocytes. We combined …

An Estrogen Receptor Α-Derived Peptide Improves Glucose Homeostasis During Obesity, Wanbao Yang, Wen Jiang, Wang Liao, Hui Yan, Weiqi Ai, Quan Pan, Wesley A Brashear, Yong Xu, Ling He, Shaodong Guo

Faculty, Staff and Students Publications

Estrogen receptor α (ERα) plays a crucial role in regulating glucose and energy homeostasis during type 2 diabetes mellitus (T2DM). However, the underlying mechanisms remain incompletely understood. Here we find a ligand-independent effect of ERα on the regulation of glucose homeostasis. Deficiency of ERα in the liver impairs glucose homeostasis in male, female, and ovariectomized (OVX) female mice. Mechanistic studies reveal that ERα promotes hepatic insulin sensitivity by suppressing ubiquitination-induced IRS1 degradation. The ERα 1-280 domain mediates the ligand-independent effect of ERα on insulin sensitivity. Furthermore, we identify a peptide based on ERα 1-280 domain and find that ERα-derived peptide …

Increased Plasma Branched Short-Chain Fatty Acids And Improved Glucose Homeostasis: The Microbiome And Insulin Longitudinal Evaluation Study (Miles), Arianne Aslamy, Alexis C Wood, Elizabeth T Jensen, Alain G Bertoni, Patricia A Sheridan, Kari E Wong, Gautam Ramesh, Jerome I Rotter, Yii-Der I Chen, Mark O Goodarzi

Faculty, Staff and Students Publications

Short-chain fatty acids (SCFAs) have been extensively studied for potential beneficial roles in glucose homeostasis and risk of diabetes; however, most of this research has focused on butyrate, acetate, and propionate. The effect on metabolism of branched SCFAs (BSCFAs; isobutyrate, isovalerate, and methylbutyrate) is largely unknown. In a cohort of 219 non-Hispanic White participants and 126 African American participants, we examined the association of BSCFA with dysglycemia (prediabetes and diabetes) and oral glucose tolerance test-based measures of glucose and insulin homeostasis, as well as with demographic, anthropometric, lifestyle, and lipid traits, and other SCFAs. We observed a bimodal distribution of …

Effects And Plasma Proteomic Analysis Of Glp-1ra Versus Cpa/Ee, In Combination With Metformin, On Overweight Pcos Women: A Randomized Controlled Trial, Mingyu Liao, Xing Li, Hao Zhang, Ling Zhou, Liu Shi, Weixin Li, Rufei Shen, Guiliang Peng, Huan Zhao, Jiaqing Shao, Xiujie Wang, Zheng Sun, Hongting Zheng, Min Long

Faculty, Staff and Students Publications

PURPOSE: Polycystic ovary syndrome (PCOS) is characterized by reproductive dysfunctions and metabolic disorders. This study aims to compare the therapeutic effectiveness of glucagon-like peptide-1 receptor agonist (GLP-1RA) + Metformin (Met) versus cyproterone acetate/ethinylestradiol (CPA/EE) + Met in overweight PCOS women and identify potential proteomic biomarkers of disease risk in women with PCOS.

METHODS: In this prospective, open-label randomized controlled trial, we recruited 60 overweight PCOS women into two groups at a 1:1 ratio to receive CPA/EE (2 mg/day: 2 mg cyproterone acetate and 35-μg ethinylestradiol,) +Met (1500 mg/day) or GLP-1 RA (liraglutide, 1.2-1.8 mg/day) +Met (1500 mg/day) for 12 weeks. …

Leptin Decreases Gluconeogenesis And Gluconeogenic Substrate Availability In Patients With Lipodystrophy, Emmanuel Quaye, Shaji Chacko, Megan Startzell, Rebecca J Brown

Children’s Nutrition Research Center Staff Publications

Context: The effects of leptin, an adipocyte-derived hormone that signals overall energy sufficiency, can only be studied in leptin-deficient conditions. In patients with lipodystrophy, a rare disease and unique model of leptin deficiency, treatment with recombinant leptin (metreleptin) improves glycemia and decreases energy expenditure. We hypothesized that these improvements might be mediated by reduced gluconeogenesis (GNG), an energy-requiring process.

Objective: To determine the effects of metreleptin on GNG and GNG substrates.

Methods: This was a single-arm prospective study of metreleptin administration in 15 patients with lipodystrophy, 9 of whom had data on GNG (NIH, 2013-2018). We analyzed total GNG, insulin-mediated …

Associations Between Avocado Intake And Measures Of Glucose And Insulin Homeostasis In Hispanic Individuals With And Without Type 2 Diabetes: Results From The Hispanic Community Health Study/Study Of Latinos (Hchs/Sol), Mackenzie K Senn, Mark O Goodarzi, Gautam Ramesh, Matthew A Allison, Mariaelisa Graff, Kristin L Young, Gregory A Talavera, Amanda C Mcclain, Tanya P Garcia, Jerome I Rotter, Alexis C Wood

Faculty, Staff and Students Publications

BACKGROUND AND AIMS: To investigate associations between avocado intake and glycemia in adults with Hispanic/Latino ancestry.

METHODS AND RESULTS: The associations of avocado intake with measures of insulin and glucose homeostasis were evaluated in a cross-sectional analysis of up to 14,591 Hispanic/Latino adults, using measures of: average glucose levels (hemoglobin A1c; HbA1c), fasting glucose and insulin, glucose and insulin levels after an oral glucose tolerance test (OGTT), and calculated measures of insulin resistance (HOMA-IR, and HOMA-%β), and insulinogenic index. Associations were assessed using multivariable linear regression models, which controlled for sociodemographic factors and health behaviors, and which were stratified by …

Sex Hormone-Binding Globulin (Shbg) Mitigates Er Stress And Improves Viability And Insulin Sensitivity In Adipose-Derived Mesenchymal Stem Cells (Asc) Of Equine Metabolic Syndrome (Ems)-Affected Horses, Nabila Bourebaba, Mateusz Sikora, Badr Qasem, Lynda Bourebaba, Krzysztof Marycz

Faculty, Staff and Student Publications

BACKGROUND: Equine metabolic syndrome (EMS), which encompasses insulin resistance, low-grade inflammation and predisposition to laminitis is a critical endocrine disorder among the most prevalent conditions affecting horses from different breeds. According to the most recent research, low human sex hormone-binding globulin (SHBG) serum levels correlate with an increased risk of obesity, insulin resistance and diabetes, and may contribute to overall metabolic dysregulations. This study aimed to test whether exogenous SHBG could protect EMS affected adipose-derived stromal stem cells (EqASC

METHODS: EqASC

RESULTS: Obtained data demonstrated that exogenous SHBG treatment significantly promoted ASCs cells proliferation, cell cycle and survival with reduced …

Supplementing Glycine And N-Acetylcysteine (Glynac) In Older Adults Improves Glutathione Deficiency, Oxidative Stress, Mitochondrial Dysfunction, Inflammation, Physical Function, And Aging Hallmarks: A Randomized Clinical Trial, Premranjan Kumar, Chun Liu, James Suliburk, Jean W Hsu, Raja Muthupillai, Farook Jahoor, Charles G Minard, George E Taffet, Rajagopal V Sekhar

Faculty, Staff and Students Publications

BACKGROUND: Elevated oxidative stress (OxS), mitochondrial dysfunction, and hallmarks of aging are identified as key contributors to aging, but improving/reversing these defects in older adults (OA) is challenging. In prior studies, we identified that deficiency of the intracellular antioxidant glutathione (GSH) could play a role and reported that supplementing GlyNAC (combination of glycine and N-acetylcysteine [NAC]) in aged mice improved GSH deficiency, OxS, mitochondrial fatty-acid oxidation (MFO), and insulin resistance (IR). To test whether GlyNAC supplementation in OA could improve GSH deficiency, OxS, mitochondrial dysfunction, IR, physical function, and aging hallmarks, we conducted a placebo-controlled randomized clinical trial.

METHODS: Twenty-four …

Supplementing Glycine And N-Acetylcysteine (Glynac) In Older Adults Improves Glutathione Deficiency, Oxidative Stress, Mitochondrial Dysfunction, Inflammation, Physical Function, And Aging Hallmarks: A Randomized Clinical Trial, Premranjan Kumar, Chun Liu, James Suliburk, Jean W Hsu, Raja Muthupillai, Farook Jahoor, Charles G Minard, George E Taffet, Rajagopal V Sekhar

Faculty, Staff and Students Publications

BACKGROUND: Elevated oxidative stress (OxS), mitochondrial dysfunction, and hallmarks of aging are identified as key contributors to aging, but improving/reversing these defects in older adults (OA) is challenging. In prior studies, we identified that deficiency of the intracellular antioxidant glutathione (GSH) could play a role and reported that supplementing GlyNAC (combination of glycine and N-acetylcysteine [NAC]) in aged mice improved GSH deficiency, OxS, mitochondrial fatty-acid oxidation (MFO), and insulin resistance (IR). To test whether GlyNAC supplementation in OA could improve GSH deficiency, OxS, mitochondrial dysfunction, IR, physical function, and aging hallmarks, we conducted a placebo-controlled randomized clinical trial.

METHODS: Twenty-four …

Haploinsufficiency Of Cyp8b1 Associates With Increased Insulin Sensitivity In Humans, Shiqi Zhong, Raphael Chèvre, David Castaño Mayan, Maria Corlianò, Blake J Cochran, Kai Ping Sem, Theo H Van Dijk, Jianhe Peng, Liang Juin Tan, Siddesh V Hartimath, Boominathan Ramasamy, Peter Cheng, Albert K Groen, Folkert Kuipers, Julian L Goggi, Chester Drum, Rob M Van Dam, Ru San Tan, Kerry-Anne Rye, Michael R Hayden, Ching-Yu Cheng, Shaji Chacko, Jason Flannick, Xueling Sim, Hong Chang Tan, Roshni R Singaraja

Children’s Nutrition Research Center Staff Publications

BACKGROUND

Cytochrome P450 family 8 subfamily B member 1 (CYP8B1) generates 12α-hydroxylated bile acids (BAs) that are associated with insulin resistance in humans.

METHODS

To determine whether reduced CYP8B1 activity improves insulin sensitivity, we sequenced CYP8B1 in individuals without diabetes and identified carriers of complete loss-of-function (CLOF) mutations utilizing functional assays.

RESULTS

Mutation carriers had lower plasma 12α-hydroxylated/non–12α-hydroxylated BA and cholic acid (CA)/chenodeoxycholic acid (CDCA) ratios compared with age-, sex-, and BMI-matched controls. During insulin clamps, hepatic glucose production was suppressed to a similar magnitude by insulin, but glucose infusion rates to maintain euglycemia were higher in mutation carriers, indicating …

Risk Of Type 2 Diabetes Among Individuals With Excess Weight: Weight Trajectory Effects, Arthur H Owora, David B Allison, Xuan Zhang, Nana Gletsu-Miller, Kishore M Gadde

Children’s Nutrition Research Center Staff Publications

PURPOSE OF REVIEW: Increased risk of type 2 diabetes mellitus (T2D) among individuals with overweight or obesity is well-established; however, questions remain about the temporal dynamics of weight change (gain or loss) on the natural course of T2D in this at-risk population. Existing epidemiologic evidence is limited to studies that discretely sample and assess excess weight and T2D risk at different ages with limited follow-up, yet changes in weight may have time-varying and possibly non-linear effects on T2D risk. Predicting the impact of weight change on the risk of T2D is key to informing primary prevention. We critically review the …

Genetic Variants In Aldh1l1 And Gldc Influence The Serine-To-Glycine Ratio In Hispanic Children, Sergey A Krupenko, Shelley A Cole, Ruixue Hou, Karin Haack, Sandra Laston, Nitesh R Mehta, Anthony G Comuzzie, Nancy F Butte, V Saroja Voruganti

Children’s Nutrition Research Center Staff Publications

Background: Glycine is a proteogenic amino acid that is required for numerous metabolic pathways, including purine, creatine, heme, and glutathione biosynthesis. Glycine formation from serine, catalyzed by serine hydroxy methyltransferase, is the major source of this amino acid in humans. Our previous studies in a mouse model have shown a crucial role for the 10-formyltetrahydrofolate dehydrogenase enzyme in serine-to-glycine conversion.

Objectives: We sought to determine the genomic influence on the serine-glycine ratio in 803 Hispanic children from 319 families of the Viva La Familia cohort.

Methods: We performed a genome-wide association analysis for plasma serine, glycine, and the serine-glycine ratio …

Insulin Resistance In Depression: A Large Meta-Analysis Of Metabolic Parameters And Variation, Brisa S Fernandes, Estela Salagre, Nitesh Enduru, Iria Grande, Eduard Vieta, Zhongming Zhao

Faculty, Staff and Student Publications

Increased insulin resistance is recognized in psychiatric disorders, such as schizophrenia and bipolar disorder, but its occurrence in depression is less clear. Our aims were to verify if insulin resistance is altered in depression, to test the metabolic subgroup hypothesis of depression and if there are changes with antidepressants. Inclusion criteria were studies including adult subjects with depression and either a control group or follow-up after treatment with antidepressants, and assessing fasting insulin or glucose levels or the Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) index. Seventy studies with 240,704 participants were included. Both insulin levels and the HOMA-IR index …

Organ Fat In Latino Youth At Risk For Type 2 Diabetes, Janiel L Pimentel, Kiley B Vander Wyst, Erica G Soltero, Armando Peña, Houchun H Hu, Smita S Bailey, Amber Pokorney, Stephanie L Ayers, Ana Martinez Valencia, Micah L Olson, Gabriel Q Shaibi

Children’s Nutrition Research Center Staff Publications

Purpose: Obesity in youth increases the risk for type 2 diabetes (T2D) and elevated abdominal adipose tissue and organ fat may be particularly deleterious. The purpose of this study was to examine associations among measures of adiposity including total, visceral, and organ fat (hepatic and pancreatic) and whether these measures were independently associated with glycemia in Latino youth at risk for diabetes.

Methods: Latino adolescents (47 boys and 32 girls, 13.7 ± 1.4 years) with obesity (BMIz 2.3 ± 0.3) were assessed for total fat by DXA and visceral and organ fat by 3 T magnetic resonance imaging. Glycemic indicators …

Metabolic Inflexibility In Youth With Obesity: Is It A Feature Of Obesity Or Distinctive Of Youth Who Are Metabolically Unhealthy?, Nour Y Gebara, Joon Young Kim, Fida Bacha, Sojung Lee, Silva Arslanian

Children’s Nutrition Research Center Staff Publications

Background:

Individuals with obesity have metabolic inflexibility with diminished fasting fat oxidation and blunted increase in respiratory quotient (RQ) in insulin-stimulated states. However, it is unclear if metabolic inflexibility is a characteristic of obesity per se or is unique to youth who have metabolically unhealthy obesity (MUO) compared with metabolically healthy obesity (MHO).

Objective:

We investigated metabolic flexibility in youth with MUO, MHO and normal weight (NW) and compared their metabolic characteristics.

Patients/Design:

Youth (n=188) were divided, based on cut-off points for in vivo insulin sensitivity (IS) of adolescents with NW, into 137 with MUO and 51 with MHO. Fasting …

Metabolic Inflexibility In Youth With Obesity: Is It A Feature Of Obesity Or Distinctive Of Youth Who Are Metabolically Unhealthy?, Nour Y Gebara, Joon Young Kim, Fida Bacha, Sojung Lee, Silva Arslanian

Faculty, Staff and Students Publications

Individuals with obesity have metabolic inflexibility with diminished fasting fat oxidation and blunted increase in respiratory quotient (RQ) in insulin-stimulated states. However, it is unclear if metabolic inflexibility is a characteristic of obesity per se or is unique to youth who have metabolically unhealthy obesity (MUO) compared with metabolically healthy obesity (MHO). We investigated metabolic flexibility in youth with MUO, MHO and normal weight (NW) and compared their metabolic characteristics. Youth (n = 188) were divided, based on cut-off points for in vivo insulin sensitivity (IS) of adolescents with NW, into 137 with MUO and 51 with MHO. Fasting hepatic …

De Novo Glycine Synthesis Is Reduced In Adults With Morbid Obesity And Increases Following Bariatric Surgery, Hong Chang Tan, Jean W Hsu, E Shyong Tai, Shaji Chacko, Vieon Wu, Chun Fan Lee, Jean-Paul Kovalik, Farook Jahoor

Faculty, Staff and Students Publications

BACKGROUND: Glycine is a dietary non-essential amino acid that is low in obesity and increases following bariatric surgery. However, the exact mechanism responsible remains unclear and it is unknown whether hypoglycinemia is a cause or consequence of insulin resistance.

OBJECTIVE: Using multiple isotopically labeled tracers, we aimed to determine the underlying kinetic changes responsible for hypoglycinemia in obesity by: 1) Comparing glycine kinetics between participants with morbid obesity (BMI ≥ 32.5 kg/m

METHODS: [1,2-

RESULTS: Compared to controls, participants with morbid obesity had significantly lower plasma glycine concentrations at 163 (153-171) vs. 201 (172-227) µmol/L and significantly reduced

CONCLUSION: Hypoglycinemia …

High-Fructose, High-Fat Diet Alters Muscle Composition And Fuel Utilization In A Juvenile Iberian Pig Model Of Non-Alcoholic Fatty Liver Disease, Heather C Spooner, Stefani A Derrick, Magdalena Maj, Rodrigo Manjarín, Gabriella V Hernandez, Deepali S Tailor, Parisa S Bastani, Rob K Fanter, Marta L Fiorotto, Douglas G Burrin, Michael R La Frano, Angelos K Sikalidis, Jason M Blank

Children’s Nutrition Research Center Staff Publications

Non-alcoholic fatty liver disease (NAFLD) is a serious metabolic condition affecting millions of people worldwide. A “Western-style diet” has been shown to induce pediatric NAFLD with the potential disruption of skeletal muscle composition and metabolism. To determine the in vivo effect of a “Western-style diet” on pediatric skeletal muscle fiber type and fuel utilization, 28 juvenile Iberian pigs were fed either a control diet (CON) or a high-fructose, high-fat diet (HFF), with or without probiotic supplementation, for 10 weeks. The HFF diets increased the total triacylglycerol content of muscle tissue but decreased intramyocellular lipid (IMCL) content and the number of …

Tcf7l2 Genetic Variants Do Not Influence Insulin Sensitivity Or Secretion Indices In Autoantibody-Positive Individuals At Risk For Type 1 Diabetes, Maria J Redondo, Megan V Warnock, Ingrid M Libman, Laura E Bocchino, David Cuthbertson, Susan Geyer, Alberto Pugliese, Andrea K Steck, Carmella Evans-Molina, Dorothy Becker, Jay M Sosenko, Fida Bacha, Type 1 Diabetes Trialnet Study Group

Children’s Nutrition Research Center Staff Publications

Objective: We aimed to test whether type 2 diabetes (T2D)-associated TCF7L2 genetic variants affect insulin sensitivity or secretion in autoantibody-positive relatives at risk for type 1 diabetes (T1D).

Research design and methods: We studied autoantibody-positive TrialNet Pathway to Prevention study participants (N = 1,061) (mean age 16.3 years) with TCF7L2 single nucleotide polymorphism (SNP) information and baseline oral glucose tolerance test (OGTT) to calculate indices of insulin sensitivity and secretion. With Bonferroni correction for multiple comparisons, P values < 0.0086 were considered statistically significant.

Results: None, one, and two T2D-linked TCF7L2 alleles were present in 48.1%, 43.9%, and 8.0% of the participants, respectively. Insulin sensitivity …

Ube2i Deletion In Adipocytes Causes Lipoatrophy In Mice, Aaron R Cox, Natasha Chernis, Kang Ho Kim, Peter M Masschelin, Pradip K Saha, Shawn M Briley, Robert Sharp, Xin Li, Jessica B Felix, Zheng Sun, David D Moore, Stephanie A Pangas, Sean M Hartig

Faculty, Staff and Students Publications

OBJECTIVE: White adipose tissue (WAT) expansion regulates energy balance and overall metabolic homeostasis. The absence or loss of WAT occurring through lipodystrophy and lipoatrophy contributes to the development of hepatic steatosis and insulin resistance. We previously demonstrated that sole small ubiquitin-like modifier (SUMO) E2-conjugating enzyme Ube2i represses human adipocyte differentiation. The role of Ube2i during WAT development remains unknown.

METHODS: To determine how Ube2i impacts body composition and energy balance, we generated adipocyte-specific Ube2i knockout mice (Ube2i

RESULTS: Surprisingly, Ube2i

CONCLUSIONS: Our results demonstrate that Ube2i expression in mature adipocytes allows WAT expansion during postnatal growth. Deletion of Ube2i in …

Loss Of Bone Morphogenetic Protein-Binding Endothelial Regulator Causes Insulin Resistance, Hua Mao, Luge Li, Qiying Fan, Aude Angelini, Pradip K Saha, Huaizhu Wu, Christie M Ballantyne, Sean M Hartig, Liang Xie, Xinchun Pi

Faculty, Staff and Students Publications

Accumulating evidence suggests that chronic inflammation of metabolic tissues plays a causal role in obesity-induced insulin resistance. Yet, how specific endothelial factors impact metabolic tissues remains undefined. Bone morphogenetic protein (BMP)–binding endothelial regulator (BMPER) adapts endothelial cells to inflammatory stress in diverse organ microenvironments. Here, we demonstrate that BMPER is a driver of insulin sensitivity. Both global and endothelial cell-specific inducible knockout of BMPER cause hyperinsulinemia, glucose intolerance and insulin resistance without increasing inflammation in metabolic tissues in mice. BMPER can directly activate insulin signaling, which requires its internalization and interaction with Niemann-Pick C1 (NPC1), an integral membrane protein that …

Deficiency Of Stat1 In Cd11c+ Cells Alters Adipose Tissue Inflammation And Improves Metabolic Dysfunctions In Mice Fed A High-Fat Diet, Antu Antony, Zeqin Lian, Xiaoyuan Dai Perrard, Jerry Perrard, Hua Liu, Aaron R Cox, Pradip Saha, Lothar Hennighausen, Sean M Hartig, Christie M Ballantyne, Huaizhu Wu

Faculty, Staff and Students Publications

CD11c+ macrophages/dendritic cells (MDCs) are increased and display the classically activated M1-like phenotype in obese adipose tissue (AT) and may contribute to AT inflammation and insulin resistance. Stat1 is a key transcription factor for MDC polarization into the M1-like phenotype. Here, we examined the role of Stat1 in obesity-induced AT MDC polarization and inflammation and insulin resistance using mice with specific knockout of Stat1 in MDCs (cKO). Stat1 was upregulated and phosphorylated, indicating activation, early and persistently in AT and AT MDCs of wild-type mice fed a high-fat diet (HFD). Compared with littermate controls, cKO mice fed an HFD (16 …

Metabolic Flexibility Across The Spectrum Of Glycemic Regulation In Youth, Fida Bacha, Sara Klinepeter Bartz, Maurice Puyau, Anne Adolph, Susan Sharma

Children’s Nutrition Research Center Staff Publications

BACKGROUNDMetabolic flexibility (MF) refers to the relative ability to utilize lipid and carbohydrate substrates and to transition between them. It is not clear whether MF is impaired in obese youth and what the determining factors are.METHODSWe investigated the determinants of MF (increased respiratory exchange ratio [ΔRER] under insulin-stimulated conditions) in pubertal youth (n = 104; 15.6 ± 1.8 years) with obesity across the spectrum of glucose tolerance compared with normal weight (NW) controls, including body composition (fat-free mass [FFM], %body fat), visceral adipose fat (VAT) (MRI), glycemia, and insulin sensitivity (IS) [3-hour hyperinsulinemic-euglycemic clamp with measurement of lipolysis ([2H5] glycerol), …

Association Of Baseline Characteristics With Insulin Sensitivity And Β-Cell Function In The Glycemia Reduction Approaches In Diabetes: A Comparative Effectiveness (Grade) Study Cohort, Neda Rasouli, Naji Younes, Kristina M Utzschneider, Silvio E Inzucchi, Ashok Balasubramanyam, Andrea L Cherrington, Faramarz Ismail-Beigi, Robert M Cohen, Darin E Olson, Ralph A Defronzo, William H Herman, John M Lachin, Steven E Kahn

Faculty, Staff and Students Publications

OBJECTIVE: We investigated sex and racial differences in insulin sensitivity, β-cell function, and glycated hemoglobin (HbA

RESEARCH DESIGN AND METHODS: This is a cross-sectional analysis of baseline data from 3,108 GRADE (Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness Study) participants. All had type 2 diabetes diagnosedβ-cell function were evaluated using the HOMA of insulin sensitivity and estimates from oral glucose tolerance tests, including the Matsuda Index, insulinogenic index, C-peptide index, and oral disposition index (DI).

RESULTS: The cohort was 56.6 ± 10 years of age (mean ± SD), 63.8% male, with BMI 34.2 ± 6.7 kg/m

CONCLUSIONS: In the …

Β-Cell Impairment And Clinically Meaningful Alterations In Glycemia In Obese Youth Across The Glucose Tolerance Spectrum, Joon Young Kim, Hala Tfayli, Fida Bacha, Sojung Lee, Nour Gebara, Silva Arslanian

Children’s Nutrition Research Center Staff Publications

Background/aims: In obese youth, it is not clear what degree of β-cell impairment translates to glucose dysregulation commensurate with shifts from normal glucose tolerance (NGT) to impaired glucose tolerance (IGT) to type 2 diabetes. We aimed to investigate the quantitative relationship between β-cell (clamp-measured disposition index [DI]) and OGTT glucose area under the curve (G-AUC) in obese youth across the spectrum of glucose tolerance.

Methods: Data from 152 youth (58 African-American [AA] and 94 American-White [AW]; 73 NGT, 48 IGT, and 31 type 2 diabetes) who completed a 3-h hyperinsulinemic (80 mu/m2/min)-euglycemic clamp, and a 2-h hyperglycemic (225 mg/dL) clamp …