Adipose Tissue Insulin Resistance in Youth on the Spectrum From Normal Weight to Obese and From Normal Glucose Tolerance to Impaired Glucose Tolerance to Type 2 Diabetes

Adipose Tissue Insulin Resistance Correlates with Disease Severity in Pediatric Metabolic Dysfunction-Associated Steatotic Liver Disease: A Prospective Cohort Study

OBJECTIVES

To assess the role of adipose tissue insulin resistance (Adipo-IR) in the pathogenesis of pediatric metabolic dysfunction-associated steatotic liver disease (MASLD) and to determine Adipo-IR evolution during a lifestyle intervention program.

STUDY DESIGN

In this prospective cohort study, children and adolescents with severe obesity were recruited between July 2020 and December 2022 at an inpatient pediatric rehabilitation center. Treatment consisted of dietary intervention and physical activity. Liver steatosis and fibrosis were evaluated using ultrasound examination and transient elastography with controlled attenuation parameter and liver stiffness measurement. Every 4-6 months, anthropometric measurements, serum biochemical analysis, ultrasound examination, and elastography were repeated. Adipo-IR was estimated by the product of the fasting serum insulin times the fasting free fatty acid concentration, and hepatic IR by the Homeostatic Model Assessment for Insulin Resistance (HOMA-IR), respectively.

RESULTS

Of 200 patients with obesity, 56% had evidence of steatosis on ultrasound examination and 26% were diagnosed with fibrosis (≥F2). Adipo-IR increased progressively from lean controls to patients with obesity to patients with MASLD and MASLD with fibrosis. Adipo-IR was already increased in patients with only mild steatosis (P = .0403). Patients with more insulin-sensitive adipose tissue exhibited a lower liver fat content (P < .05) and serum alanine transaminase levels (P = .001). Adipo-IR correlated positively with visceral adipose tissue weight, waist circumference, and the visceral adipose tissue/gynoid adipose tissue ratio (P < .001), but not with total body fat percentage (P = .263). After 4-6 months of lifestyle management, both MASLD and Adipo-IR improved.

CONCLUSIONS

Our data suggest that Adipo-IR is associated with the presence of pediatric MASLD, particularly steatosis.

Insulin resistance in the adipose tissue predicts future vascular resistance: The Hiroshima Study on Glucose Metabolism and Cardiovascular Diseases

BACKGROUND AND AIMS

Diameter, plaque score, and resistance index (RI) in the common carotid artery (CCA) are indicators of arterial remodeling, atherosclerosis, and vascular resistance, respectively. This study investigated the longitudinal association between adipose tissue insulin resistance or serum free fatty acid (FFA) levels and the CCA parameters.

METHODS

This retrospective cohort analysis included 1089 participants (mean age 57.6 years; 40.0 % women) with data on health checkups from January 1982 to March 2003 and carotid artery ultrasonography from January 2015 to June 2019. Baseline serum FFA and immunoreactive insulin levels were assessed before and 30, 60, and 120 min after glucose ingestion. Adipose insulin resistance index (Adipo-IR) was calculated as the product of fasting serum insulin and FFA levels. An RI value >0.75 was defined as high RI.

RESULTS

A significant association was found between Adipo-IR and RI; however, Adipo-IR showed no association with CCA diameter or plaque score. The incidence of high RI increased with Adipo-IR quartile (Q) groups (47.3 % in Q1, 52.8 % in Q2, 53.3 % in Q3, 62.4 % in Q4; Cochrane-Armitage test for trend, p < 0.001). In multivariate analysis, Adipo-IR levels (Q4 vs. Q1 odds ratio: 1.67, 95 % confidence interval: 1.12-2.51) were positively associated with high RI incidence. Moreover, a significant association was found between RI and serum FFA levels after glucose intake, but not fasting FFA levels.

CONCLUSIONS

Future vascular resistance was predicted by insulin resistance in the adipose tissue. After glucose intake, serum FFA levels may significantly impact vascular resistance development.

Beyond Obesity and Overweight: The Clinical Assessment and Treatment of Excess Body Fat in Children : Part 1 - Insulin Resistance as the Root Cause of Pediatric Obesity

PURPOSE OF REVIEW

Pediatric obesity and comorbidities related to insulin resistance continue to be a growing public health crisis. If lifestyle measures are unsuccessful, pharmacological and surgical interventions are offered. In this paper, we describe the driving force of the obesity crisis: hyperinsulinemia and the development of insulin resistance. We give historical background of key policy issues which have contributed to this pandemic as well as the physiologic mechanisms of insulin resistance. The prevalence of obesity will continue to rise unless the root cause of hyperinsulinemia is addressed.

RECENT FINDINGS

Current research on insulin resistance demonstrates that a decreased consumption of carbohydrates is an effective first-line dietary intervention for the treatment of obesity and related metabolic diseases. Evidence shows it is safe and beneficial. A low-carbohydrate eating pattern can be helpful to address pediatric obesity. However, there must be policy guardrails in place to ensure that this is a sustainable and viable option for children and their families. There must be a change in the nutritional environment to help individuals battle the chronic disease of obesity.

Estimating insulin sensitivity and β-cell function from the oral glucose tolerance test: validation of a new insulin sensitivity and secretion (ISS) model

Efficient and accurate methods to estimate insulin sensitivity (SI) and β-cell function (BCF) are of great importance for studying the pathogenesis and treatment effectiveness of type 2 diabetes (T2D). Existing methods range in sensitivity, input data, and technical requirements. Oral glucose tolerance tests (OGTTs) are preferred because they are simpler and more physiological than intravenous methods. However, current analytical methods for OGTT-derived SI and BCF also range in complexity; the oral minimal models require mathematical expertise for deconvolution and fitting differential equations, and simple algebraic surrogate indices (e.g., Matsuda index, insulinogenic index) may produce unphysiological values. We developed a new insulin secretion and sensitivity (ISS) model for clinical research that provides precise and accurate estimates of SI and BCF from a standard OGTT, focusing on effectiveness, ease of implementation, and pragmatism. This model was developed by fitting a pair of differential equations to glucose and insulin without need of deconvolution or C-peptide data. This model is derived from a published model for longitudinal simulation of T2D progression that represents glucose-insulin homeostasis, including postchallenge suppression of hepatic glucose production and first- and second-phase insulin secretion. The ISS model was evaluated in three diverse cohorts across the lifespan. The new model had a strong correlation with gold-standard estimates from intravenous glucose tolerance tests and insulin clamps. The ISS model has broad applicability among diverse populations because it balances performance, fidelity, and complexity to provide a reliable phenotype of T2D risk.NEW & NOTEWORTHY The pathogenesis of type 2 diabetes (T2D) is determined by a balance between insulin sensitivity (SI) and β-cell function (BCF), which can be determined by gold standard direct measurements or estimated by fitting differential equation models to oral glucose tolerance tests (OGTTs). We propose and validate a new differential equation model that is simpler to use than current models and requires less data while maintaining good correlation and agreement with gold standards. Matlab and Python code is freely available.

MiR-143-3p/FNDC5 axis: a novel regulator of insulin sensitivity

PURPOSE

Insulin resistance is a key hallmark in type 2 diabetes. In recent decades, there have been numerous studies of the causes of insulin resistance. microRNAs (miRNAs) participate in the regulation of multiple aspects of energy metabolism and miR-143-3p has been shown to induce insulin resistance. We aimed to predict the downstream targets of miR-143-3p and found a miR-143-3p binding site on the 3'-untranslated region of FNDC5 (Fibronectin type III domain containing 5) mRNA.

METHODS

We first confirmed that FNDC5 mRNA is a target of miR-143-3p using a double luciferase experiment, then constructed a prokaryotic expression system for the mature form of FNDC5, irisin, and expressed and purified irisin protein. We transfected a miR-143-3p mimic into HepG2-NTCP (Na+-taurocholate cotransporting polypeptide) cells using an NTCP targeting vector, then 24 h later, the glucose concentration of the culture medium, western blot analysis was analyzed. We next co-incubated the cells transfected with the miR-143-3p mimic with irisin for 12 h following by the assay of glucose uptake and AKT phosphorylation.

RESULTS

The glucose concentration of the culture medium was higher than that associated with control miRNA-transfected cells (p < 0.01). Western blot analysis showed that the miR-143-3p mimic significantly reduced the expression of FNDC5 (p < 0.05) and the phosphorylation of AKT (Protein kinase B) (p < 0.05), implying impaired insulin signaling. which increased the glucose uptake (p < 0.0001) and AKT phosphorylation in the cells (p < 0.05).

CONCLUSION

We conclude that FNDC5 is a direct target of miR-143-3p and that miR-143-3p induces insulin resistance by reducing its expression.

Dapagliflozin or Saxagliptin in Pediatric Type 2 Diabetes

BACKGROUND: Incidence of type 2 diabetes (T2D) in children and adolescents is increasing, but treatment options are limited. METHODS: This was a 26-week, phase 3 trial with a 26-week extension among patients (10 to 17 years of age) with uncontrolled T2D (A1C 6.5 to 10.5%) receiving metformin, insulin, or both. Participants were randomly assigned 1:1:1 to 5 mg of dapagliflozin (N=81), 2.5 mg of saxagliptin (N=88), or placebo (N=76). Patients in active treatment groups with A1C ≥7% at week 12 were further randomly assigned 1:1 at week 14 to continue the dose or up-titrate to a higher dose (10 mg of dapagliflozin or 5 mg of saxagliptin). The primary end point was change in A1C at week 26. Safety was assessed over 52 weeks. RESULTS: At week 26, the difference versus placebo in adjusted mean change in A1C was −1.03 percentage points (95% confidence interval [CI], −1.57 to −0.49; P<0.001) for dapagliflozin and −0.44 percentage points (95% CI, −0.93 to 0.05; P=0.078) for saxagliptin. Adverse events (AEs) and serious AEs occurred in 72.8% and 8.6% of patients receiving dapagliflozin, 69.3% and 8.0% of patients receiving saxagliptin, and 71.1% and 6.6% of patients receiving placebo. Severe hypoglycemia occurred in 4.9%, 4.5%, and 7.9% of patients in each group, respectively. Over 52 weeks, the most common AE was headache (dapagliflozin 14.8%; placebo 5.3%). Most events were mild and none was considered serious or resulted in discontinuation. CONCLUSIONS: Dapagliflozin, but not saxagliptin, showed significant improvement in A1C compared with placebo. Nonserious headaches were more common in participants treated with dapagliflozin than in those receiving placebo. (Funded by AstraZeneca; ClinicalTrials.gov number, NCT03199053.)

Vascular endothelial growth factor B improves impaired glucose tolerance through insulin-mediated inhibition of glucagon secretion

BACKGROUND

Impaired glucose tolerance (IGT) is a homeostatic state between euglycemia and hyperglycemia and is considered an early high-risk state of diabetes. When IGT occurs, insulin sensitivity decreases, causing a reduction in insulin secretion and an increase in glucagon secretion. Recently, vascular endothelial growth factor B (VEGFB) has been demonstrated to play a positive role in improving glucose metabolism and insulin sensitivity. Therefore, we constructed a mouse model of IGT through high-fat diet feeding and speculated that VEGFB can regulate hyperglycemia in IGT by influencing insulin-mediated glucagon secretion, thus contributing to the prevention and cure of prediabetes.

AIM

To explore the potential molecular mechanism and regulatory effects of VEGFB on insulin-mediated glucagon in mice with IGT.

METHODS

We conducted in vivo experiments through systematic VEGFB knockout and pancreatic-specific VEGFB overexpression. Insulin and glucagon secretions were detected via enzyme-linked immunosorbent assay, and the protein expression of phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) was determined using western blot. Further, mRNA expression of forkhead box protein O1, phosphoenolpyruvate carboxykinase, and glucose-6 phosphatase was detected via quantitative polymerase chain reaction, and the correlation between the expression of proteins was analyzed via bioinformatics.

RESULTS

In mice with IGT and VEGFB knockout, glucagon secretion increased, and the protein expression of PI3K/AKT decreased dramatically. Further, in mice with VEGFB overexpression, glucagon levels declined, with the activation of the PI3K/AKT signaling pathway.

CONCLUSION

VEGFB/vascular endothelial growth factor receptor 1 can promote insulin-mediated glucagon secretion by activating the PI3K/AKT signaling pathway to regulate glucose metabolism disorders in mice with IGT.

Unmet Needs in the Treatment of Childhood Type 2 Diabetes: A Narrative Review

Type 2 diabetes (T2D) in youth is a global health concern characterized by an increasing incidence and prevalence, especially among disadvantaged socioeconomic subgroups. Moreover, youth-onset T2D is more aggressive and causes earlier, more severe long-term cardio-renal complications compared with T2D in adults. The therapeutic options available are limited and often inadequate, partially due to the numerous challenges in implementing clinical trials for this vulnerable patient population. Over the last few years, a significant effort has been made to develop new effective drugs for children and adolescents with T2D. Specifically, a number of studies are currently generating new data to address the urgent unmet medical need for optimal management of this disease. This review describes the central features of youth-onset T2D and summarizes the available treatments and ongoing studies in pediatric patients.

Sex differences in the association between adipose insulin resistance and non-alcoholic fatty liver disease in Chinese adults

BACKGROUND

Adipose insulin resistance (Adipo-IR) is associated with multiple metabolic diseases, including non-alcoholic fatty liver disease (NAFLD). The study aimed to evaluate sex differences in the association between Adipo-IR and NAFLD, and further investigated other potential modifiers.

METHODS

This cross-sectional study enrolled adults without diabetes who underwent physical examinations in Beijing Chao-Yang Hospital. We calculated the Adipo-IR index as the product of the fasting insulin and free fatty acid concentration. We categorized Adipo-IR into four groups according to quartiles, using the first interquartile range (Q1) as the reference. Logistic regression was used stratified by the modifiers after adjustment for potential confounders.

RESULTS

There were 5586 participants in the study, 49.8% (n = 2781) of whom were women and 30.4% (n = 1698) with NAFLD. There was a graded positive association between Adipo-IR and NAFLD, with sex (P = 0.01) and hyperlipidemia (P = 0.02) modifying this association. In the hyperlipidemic women, for one unit increase in log-Adipo-IR, the odds of having NAFLD increased by 385% after adjustment for potential confounders (OR = 4.85, 95%CI 3.54-6.73, P < 0.001). However, it turned out that the odds of having NAFLD increased by 131% (OR = 2.31, 95%CI 1.74-3.11, P < 0.001), 216% (OR = 3.16, 95%CI 2.56-3.93, P < 0.001), 181% (OR = 2.81, 95%CI 1.88-4.28, P < 0.001) in normolipidemic men, hyperlipidemic men, and normolipidemic women, respectively. Similarly, the ORs for the association between Adipo-IR and NAFLD in women with age ≥ 50 years were higher than ORs in women with age < 50 years.

CONCLUSIONS

The positive correlation between Adipo-IR and NAFLD was stronger in hyperlipidemic women, compared with normolipidemic or hyperlipidemic men, or normolipidemic women. The association also strengthened for women over 50 years. Treatment strategies targeting Adipo-IR to alleviate NAFLD may be of value, especially in hyperlipidemic women after menopause.

The Role of Childhood Obesity in Early-Onset Type 2 Diabetes Mellitus: A Scoping Review

Childhood obesity is a growing concern worldwide, with significant implications for public health. Of particular interest is its association with the early onset of type 2 diabetes mellitus in children. Exploring this relationship and identifying contributing factors may help strengthen understanding of this complex relationship. Factors such as family history, gender, and sedentary lifestyle, and poor dietary habits, insulin resistance in adipose tissue have been identified as significant contributors to early-onset type 2 diabetes. The rising prevalence of childhood obesity and its association with diabetes necessitates early interventions to mitigate this concerning trend and ensure a lasting impact on public health. This scoping review aims to investigate the relationship between childhood obesity and early-onset type 2 diabetes mellitus while also exploring other contributing factors. We employed a standardized framework for reviews to analyze relevant literature published in English between 2000 and 2021. Only primary research, systematic reviews, and meta-analyses addressing the association between childhood obesity and early-onset type 2 diabetes mellitus were included. The review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) format. Out of the 3614 articles assessed, 17 were ultimately incorporated into this scoping review as they met the inclusion criteria. The majority of the literature primarily represented North American studies, with no inclusion of studies from South America. The findings from these studies have highlighted several factors contributing to type 2 diabetes mellitus development. Most of the studies associated obesity development with hypertension and unfavorable lipid profiles. It is important to acknowledge that these findings are derived from the available literature and may not encompass the entirety of research on childhood obesity and early-onset type 2 diabetes mellitus. Furthermore, the limited regional diversity in the selected studies may restrict the generalizability of these findings to other geographic regions. Additional research involving diverse populations is imperative for a comprehensive understanding of the link between childhood obesity and early-onset type 2 diabetes mellitus. Insulin resistance in adipose tissue among obese individuals contributes to the transition from obesity to type 2 diabetes mellitus. Notably, this transition occurs at approximately half the duration in obese youths compared to obese adults, where it typically takes around a decade. The increasing prevalence of childhood obesity and diabetes mellitus in high-income, low-income, and middle-income countries necessitate collective efforts to reduce the increasing rates of early-onset type 2 diabetes in children. This scoping review, therefore, seeks to underscore the importance of early interventions with regard to ensuring a lasting impact capable of extending into adulthood.

BMI-based obesity classification misses children and adolescents with raised cardiometabolic risk due to increased adiposity

OBJECTIVE

To assess how inaccurately the body mass index (BMI) is used to diagnose obesity compared to body fat percentage (BF%) measurement and to compare the cardiometabolic risk in children and adolescents with or without obesity according to BMI but with a similar BF%.

METHODS

A retrospective cross-sectional investigation was conducted including 553 (378 females/175 males) white children and adolescents aged 6-17 years, 197 with normal weight (NW), 144 with overweight (OW) and 212 with obesity (OB) according to BMI. In addition to BMI, BF% measured by air displacement plethysmography, as well as markers of cardiometabolic risk had been determined in the existing cohort.

RESULTS

We found that 7% of subjects considered as NW and 62% of children and adolescents classified as OW according to BMI presented a BF% within the obesity range. Children and adolescents without obesity by the BMI criterion but with obesity by BF% exhibited higher blood pressure and C-reactive protein (CRP) in boys, and higher blood pressure, glucose, uric acid, CRP and white blood cells count, as well as reduced HDL-cholesterol, in girls, similar to those with obesity by BMI and BF%. Importantly, both groups of subjects with obesity by BF% showed a similarly altered glucose homeostasis after an OGTT as compared to their NW counterparts.

CONCLUSIONS

Results from the present study suggest increased cardiometabolic risk factors in children and adolescents without obesity according to BMI but with obesity based on BF%. Being aware of the difficulty in determining body composition in everyday clinical practice, our data show that its inclusion could yield clinically useful information both for the diagnosis and treatment of overweight and obesity.

Sedentary Time Is Independently Related to Adipose Tissue Insulin Resistance in Adults With or at Risk of Type 2 Diabetes

INTRODUCTION

This cross-sectional study examined associations of device-measured sedentary time and moderate-to-vigorous physical activity (MVPA) with adipose tissue insulin resistance in people with or at high risk of type 2 diabetes (T2DM).

METHOD

Data were combined from six previous experimental studies (within our group) involving patients with T2DM or primary risk factors (median (interquartile range) age, 66.2 (66.0-70.8) yr; body mass index (BMI), 31.1 (28.0-34.4) kg·m -2 ; 62% male; n = 179). Adipose tissue insulin resistance was calculated as the product of fasted circulating insulin and nonesterified fatty acids (ADIPO-IR), whereas sedentary time and MVPA were determined from wrist-worn accelerometery. Generalized linear models examined associations of sedentary time and MVPA with ADIPO-IR with interaction terms added to explore the moderating influence of ethnicity (White European vs South Asian), BMI, age, and sex.

RESULTS

In finally adjusted models, sedentary time was positively associated with ADIPO-IR, with every 30 min of sedentary time associated with a 1.80-unit (95% confidence interval, 0.51-3.06; P = 0.006) higher ADIPO-IR. This relationship strengthened as BMI increased ( β = 3.48 (95% confidence interval, 1.50-5.46), P = 0.005 in the upper BMI tertile (≥33.2 kg·m -2 )). MVPA was unrelated to ADIPO-IR. These results were consistent in sensitivity analyses that excluded participants taking statins and/or metformin ( n = 126) and when separated into the participants with T2DM ( n = 32) and those at high risk ( n = 147).

CONCLUSIONS

Sedentary time is positively related to adipose tissue insulin sensitivity in people with or at high risk of T2DM. This relationship strengthens as BMI increases and may help explain established relationships between greater sedentary time, ectopic lipid, and hyperglycemia.

Role of Growth Hormone in Adipose Tissue Insulin Resistance Amelioration After Bariatric Surgery in Adults with Obesity

Background: Bariatric surgery has a significant effect on weight loss and improves adipose tissue insulin resistance (adipose-IR); however, the underlying mechanism remains unclear. This study aimed to investigate the effect of growth hormone (GH) on adipose-IR improvement after bariatric surgery in patients with obesity. Methods: A prospective cohort study with 1-year follow-up was conducted in the China-Japan Friendship Hospital. Pre- and postoperative variables, including the body mass index (BMI), glucose and lipid metabolic indicators, and the adipose-IR index, were collected and analyzed at baseline and 3, 6, and 12 months after surgery in patients with obesity. Results: In total, seventy-two patients, including 25 males and 47 females, were included in the analysis. Furthermore, bariatric surgery resulted in a sharp decline in BMI (kg/m2) (from 39.45 ± 0.51 to 32.00 ± 0.63 at 3 months, 28.73 ± 0.56 at 6 months, and 27.25 ± 0.68 at 12 months) and adipose-IR index (mmol/L × pmol/L) (from 163.8 ± 9.38 to 94.39 ± 16.63, 43.71 ± 5.13, and 27.92 ± 2.67) and an increase in GH (ng/mL) (from 0.16 ± 0.02 to 0.61 ± 0.10, 1.02 ± 0.19, and 0.89 ± 0.20). Partial correlation analyses were performed with reduced BMI as a control, and elevated GH levels (ΔGH) were found to be positively correlated with reduced adipose-IR (absolute value of Δadipose-IR) index at 3 months (r = 0.413, P = 0.005), 6 months (r = 0.432, P < 0.001), and 12 months (r = 0.375, P = 0.031) after bariatric surgery. Conclusions: Bariatric surgery induces GH elevation and adipose-IR amelioration in patients with obesity. GH might be a potential metabolic regulator associated with adipose-IR improvement in patients with obesity after bariatric surgery.

Maternal Prenatal Factors and Child Adiposity in Associations with Cardiometabolic Risk Factors in Term-Born Chinese Children at the Age of 2 Years

Early growth has long-lasting associations with adult metabolic health. However, the association of adiposity with cardiometabolic risk factors in toddlers remains poorly understood. This study aimed to examine the association of maternal prenatal factors and child adiposity with child cardiometabolic risk factors among boys and girls aged 2 years. This was a birth cohort study of 549 term-born children in Shanghai, China, with follow-up data at the age of 2-years. Child anthropometric and adiposity measurements included weight, length, and skinfold thickness (triceps, subscapular, and abdominal). Child cardiometabolic risk factors included random morning plasma glucose, serum insulin, lipids, and systolic and diastolic blood pressure (SBP, DBP). At 2 years, overweight/obesity (weight-for-length z score, ZWFL > 2) was associated with 12.6 (95%CI 7.7, 17.4) mmHg higher SBP, and 7.9 (4.1, 11.8) mmHg higher DBP in boys, with similar results observed in girls. Maternal hypertensive disorders of pregnancy were associated with 3.0 (0.1, 5.8) higher SBP, 3.17 (0.90, 5.44) mmHg higher DBP, 0.24 (0.01,0.47) mmol/L higher plasma glucose, and 0.26 (0.01,0.51) mmol/L higher serum triglycerides after adjustment for child age, sex, and ZWFL. Maternal hypertensive disorders of pregnancy and child overweight/obesity were associated with higher SBP and DBP at the age of 2 years.

Trends in lipid profiles and control of LDL-C among adults with diabetes in the United States: An analysis of NHANES 2007-2018

BACKGROUND AND AIM

To determine trends in lipid profiles and lipid control in US adults with diabetes and assess variation in these trends across sex and race/ethnicity from 2007 to 2018.

METHODS AND RESULTS

Serial cross-sectional analysis of data from diabetic adults participating in the National Health and Nutrition Examination Survey (NHANES; 2007-2008 to 2017-2018). Among the 6116 participants included (weighted mean age, 61.0 years; 50.7% men), age-adjusted TC (p for trend < 0.001), LDL-C (p for trend < 0.001), TG (p for trend = 0.006), TG/HDL-C (p for trend = 0.014) and VLDL-C (p for trend = 0.015) decreased significantly. Age-adjusted LDL-C levels were consistently higher in women than in men over the study period. Age-adjusted LDL-C improved significantly for diabetic whites and blacks but did not change significantly for the other races/ethnicity. Lipid parameters improved for non-coronary heart disease (CHD) diabetic adults, except for HDL-C, while no lipid parameter significantly changed for diabetic adults with concomitant CHD. Among diabetic adults receiving statin therapy, age-adjusted lipid control remained unchanged from 2007 to 2018, as did adults with concomitant CHD. However, age-adjusted lipid control improved significantly for men (p for trend < 0.01) and diabetic Mexican Americans (p for trend < 0.01). In 2015-2018, female diabetic participants receiving statins had lower odds of achieving lipid control (OR: 0.55; 95% CI: 0.35-0.84; P = 0.006) than men. Differences in lipid control across different races/ethnicities no longer existed.

CONCLUSIONS

Lipid profiles improved in the US adults with diabetes from 2007 to 2018. Although rates of lipid control did not improve nationally in adults receiving statins, these patterns varied by sex and race/ethnicity.

Estimating Insulin Sensitivity and Beta-Cell Function from the Oral Glucose Tolerance Test: Validation of a new Insulin Sensitivity and Secretion (ISS) Model

Efficient and accurate methods to estimate insulin sensitivity (SI) and beta-cell function (BCF) are of great importance for studying the pathogenesis and treatment effectiveness of type 2 diabetes. Many methods exist, ranging in input data and technical requirements. Oral glucose tolerance tests (OGTTs) are preferred because they are simpler and more physiological. However, current analytical methods for OGTT-derived SI and BCF also range in complexity; the oral minimal models require mathematical expertise for deconvolution and fitting differential equations, and simple algebraic models (e.g., Matsuda index, insulinogenic index) may produce unphysiological values. We developed a new ISS (Insulin Secretion and Sensitivity) model for clinical research that provides precise and accurate estimates of SI and BCF from a standard OGTT, focusing on effectiveness, ease of implementation, and pragmatism. The model was developed by fitting a pair of differential equations to glucose and insulin without need of deconvolution or C-peptide data. The model is derived from a published model for longitudinal simulation of T2D progression that represents glucose-insulin homeostasis, including post-challenge suppression of hepatic glucose production and first- and second-phase insulin secretion. The ISS model was evaluated in three diverse cohorts including individuals at high risk of prediabetes (adult women with a wide range of BMI and adolescents with obesity). The new model had strong correlation with gold-standard estimates from intravenous glucose tolerance tests and hyperinsulinemic-euglycemic clamp. The ISS model has broad clinical applicability among diverse populations because it balances performance, fidelity, and complexity to provide a reliable phenotype of T2D risk.

Whole Grain Proso Millet (Panicum miliaceum L.) Attenuates Hyperglycemia in Type 2 Diabetic Mice: Involvement of miRNA Profile

This work aimed to investigate the hypoglycemic effects and underlying mechanism of whole grain proso millet (Panicum miliaceum L.; WPM) on type 2 diabetes mellitus (T2DM). The results showed that WPM supplementation significantly reduced fasting blood glucose (FBG) and serum lipid levels in T2DM mice induced by a high-fat diet (HFD) combined with streptozotocin (STZ), with improved glucose tolerance, liver and kidney injury, and insulin resistance. In addition, WPM significantly inhibited the expression of gluconeogenesis-related genes G6pase, Pepck, Foxo1, and Pgc-1α. Further study by miRNA high-throughput sequencing revealed that WPM supplementation mainly altered the liver miRNA expression profile of T2DM mice by increasing the expression of miR-144-3p_R-1 and miR-423-5p, reducing the expression of miR-22-5p_R-1 and miR-30a-3p. GO and KEGG analyses showed that the target genes of these miRNAs were mainly enriched in the PI3K/AKT signaling pathway. WPM supplementation significantly increased the level of PI3K, p-AKT, and GSK3β in the liver of T2DM mice. Taken together, WPM exerts antidiabetic effects by improving the miRNA profile and activating the PI3K/AKT signaling pathway to inhibit gluconeogenesis. This study implies that PM can act as a dietary supplement to attenuate T2DM.

HOMA-IR mean values in healthy individuals: a population-based study in iranian subjects

Purpose

Homeostasis Model Assessment-estimated Insulin Resistance (HOMA-IR) is an important indicator of insulin resistance. In this population-based investigation, we sought to report the mean value of HOMA-IR in different subgroups of a large population-based database of Iranian healthy subjects.

Methods

This study recruited adult healthy individuals between the ages of 18 to 70 years old to Massoud Medical Laboratory, Tehran, Iran. Fasting insulin was measured by using the Electro Chemiluminescence method using Roche Cobas 6000 e601/602 instrument.

Results

The mean ± SD value of the HOMA-IR index in the studied population was 2.11 ± 0.99 (2.5-97.5% percentiles: 0.66-4.50). In addition, the mean ± SD of HOMA-IR index in male and female groups were 2.35  1.0 (2.5-97.5 percentile: 0.57-4.37) and 2.05 ± 1.0 (2.5-97.5 percentiles: 0.53-4.35), respectively. Interestingly, it was observed a significant increment for the HOMA-IR index in the male group compared with the female group in all age subgroups (P < 0.01).

Conclusions

Our findings showed the mean value of 2.11 ± 0.99 HOMA-IR in the Iranian healthy population. Considering the large sample size in our study, more clinical investigations in terms of ethnicity should be done to provide a precise standardized HOMA-IR index in the Iranian population.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-022-01099-9.

Reduced Growth Hormone Predicts Worsening Adipose Tissue Insulin Resistance in Adults with Obesity

OBJECTIVES

Adipose tissue distribution and glucose metabolism differ from adults with normal weight to adults with obesity. Growth hormone (GH) is closely related to obesity. Few studies have investigated the role of GH in adipose tissue insulin resistance (Adipo-IR). Herein, we investigated GH level and Adipo-IR in adults ranging from normal weight to obesity and the potential association between GH and Adipo-IR.

METHODS

A total of 1,017 participants had their body mass index (BMI), GH, and Adipo-IR evaluated. Based on the BMI, participants were assigned to five groups from normal weight to class 3 obesity; based on the GH level tertiles, participants were divided into low-, medium-, and high-GH groups.

RESULTS

In total, the GH level was negatively correlated with the BMI and Adipo-IR index (r = -0.32 and -0.22, respectively; both p < 0.001). The GH level gradually decreased, and Adipo-IR progressively increased from normal weight to class 3 obesity (all p < 0.001). Compared with the low-GH group, the reductions in the BMI, homeostasis model assessment of insulin resistance index, and homeostasis model assessment of β-cell function were more significant in both medium-GH and high-GH groups (all p < 0.05). Additionally, the Adipo-IR index in the high-GH group was significantly lower than that in the low-GH group (p < 0.001). For the multivariate regression analysis, serum GH concentration was an independent protective factor against Adipo-IR (β = -0.013, 95% CI: -0.025 to -0.001, p = 0.028).

CONCLUSIONS

A marked suppression of GH level occurs in the adults with severe obesity. GH might be an important metabolic regulator associated with Adipo-IR.

Alogliptin: a DPP-4 inhibitor modulating adipose tissue insulin resistance and atherogenic lipid

AIMS

The purpose of this study is to investigate the regulation of adipose tissue insulin resistance with DPP-4 inhibitors in treatment-naive subjects with T2DM and to examine its relation to other diabetic parameters.

SUBJECTS AND METHODS

A total of 147 subjects were treated with alogliptin 12.5-25 mg/day (n = 55), sitagliptin 25-50 mg/day (n = 49), or teneligliptin 10-20 mg/day (n = 43) monotherapy for 3 months. Changes in adipo-IR, a mathematical model used to evaluate adipose tissue insulin resistance, and various diabetic parameters were analyzed in this prospective, non-randomized observational study.

RESULTS

Among these three drugs, only alogliptin significantly reduced adipo-IR (-25.9%, p < 0.004) and some lipid parameters, such as LDL-C, T-C/HDL-C, log(TG)/HDL-C, non-HDL-C/HDL-C, and LDL-C/HDL-C. Subjects in the alogliptin group were divided into two groups with distinct changes in adipo-IR. Group A had a significant decrease in adipo-IR (-56.5%, p < 0.00001, n = 28), whereas group B had an insignificant increase (19.1%, p = 0.055, n = 27). Significant reductions in FBG or HbA1c were observed in groups A and B, respectively. Group A also showed significant reductions in HOMA-R, T-C/HDL-C, TG, log(TG)/HDL-C, non-HDL-C/HDL-C, LDL-C/HDL-C, and FFA, as well as increases in QUICKI or HDL-C. In contrast, group B showed significant reductions in QUICKI or LDL-C, and increases in HOMA-R, insulin, HOMA-B, C-peptide, or CPR-index.

CONCLUSIONS

In contrast to other tested DPP-4 inhibitors, alogliptin demonstrated the ability to down-regulate insulin resistance in adipose tissue, as well as certain atherogenic lipids. This study provides the initial evidence of a DPP-4 inhibitor's potential to regulate adipose tissue insulin resistance. Furthermore, adipo-IR is associated with non-LDL-C lipid parameters instead of glycemic control in those receiving alogliptin.

Adipose Tissue Insulin Resistance Is Not Associated With Changes in the Degree of Obesity in Children and Adolescents

CONTEXT

The "carbohydrate-insulin model" claims that adipose tissue insulin sensitivity explains development of obesity via adipocyte energy storage and/or low postprandial metabolic fuel levels.

OBJECTIVE

We tested whether adipose tissue insulin sensitivity predicts changes in the degree of obesity over time.

METHODS

This secondary analysis of an observational study of youth with obesity included 213 youths at a pediatric weight management clinic. Adipose tissue insulin sensitivity/resistance and whole-body insulin sensitivity were evaluated using oral glucose tolerance test (OGTT)-derived surrogates in the face of changes in the degree of obesity over time. The main outcome measure was change in body mass index (BMI) z score.

RESULTS

Mean BMI z change was 0.05 ± 0.28 (range, -1.15 to 1.19), representing a broad distribution of changes in the degree of obesity over a follow-up period of 1.88 ± 1.27 years. Adipose tissue insulin resistance was not associated with changes in the degree of obesity in univariate or multivariate analyses (adjusted for baseline age, BMI z score, sex, ethnicity, and time of follow-up). Low postprandial free fatty acid concentrations or their suppression during the OGTT were not associated with changes in the degree of obesity in univariate or multivariate analyses. Whole-body insulin sensitivity was not associated with changes in the degree of obesity in univariate or multivariate analyses.

CONCLUSION

In this secondary analysis, in youth with obesity, adipose tissue insulin resistance is not protective from increases of the degree of obesity and skeletal muscle insulin resistance is not associated with increases of the degree of obesity.The analysis was performed using data derived from NCT00000112 and NCT00536250.

The impact of obesity epidemic on type 2 diabetes in children and adolescents: A systematic review and meta-analysis

AIM

To assess the impact of the obesity epidemic on type 2 diabetes (T2D), prediabetes and glycometabolic indices in children and adolescents.

METHODS

We searched four electronic databases (PubMed, Embase, Cochrane and Web of Science). Cross-sectional or cohort studies that reported on obesity and the prevalence of T2D or prediabetes in children and adolescents were reviewed. The study design, sample size and clinical outcomes were extracted from each study. The prevalence of T2D and prediabetes from the studies were pooled using meta-analysis methods.

RESULTS

Meta-analysis of 228184 participants showed that the prevalence of T2D was 1.3% (95% confidence interval (CI), 0.6-2.1%) in obese subjects, which was 13 times that in normal weight subjects (0.1%, 95% CI, 0.01-0.2%). The prevalence of prediabetes in obese subjects was 3 times that in normal subjects at 17.0% (13.0-22.0%) vs. 6.0% (0.01-11.0%). Moreover, BMI was positively correlated with the prevalence of T2D, prediabetes and glycometabolic indices in obese children and adolescents.

CONCLUSION

The pooled results confirm that obesity in children and adolescents leads to statistically significant increases in the prevalence of T2D and prediabetes and in glycometabolic indicator levels.

Higher fasting glucose, triglycerides, resting pulse rate and high-sensitivity C reactive protein in adipose insulin-resistant but normal weight young Japanese women

INTRODUCTION

Adipose insulin-resistant but normal weight phenotype has not been reported and hence was characterized in young Japanese women.

RESEARCH DESIGN AND METHODS

Body composition, a broad range of cardiometabolic health and dietary intake were cross-sectionally measured in 166 normal weight young Japanese women. They were grouped into tertile of adipose tissue-insulin resistance (AT-IR) index (fasting insulin×free fatty acids) and analyzed by analysis of variance and then Bonferroni's multiple comparison procedure.

RESULTS

Body mass index averaged <21 kg/m² and waist <72 cm, and did not differ among three groups of women. Fasting glucose and triglycerides and homeostasis model assessment-insulin resistance were higher in the highest compared with the median and lowest AT-IR tertile. However, there was no difference in fat mass and distribution, high-density lipoprotein cholesterol and blood pressure. In addition, high-sensitivity C reactive protein (hsCRP) and resting pulse rate were higher as well. In multivariate logistic regression analyses, fasting glucose (OR: 1.10, 95% CI: 1.02 to 1.18, p=0.012), fasting triglycerides (OR: 1.04, 95% CI: 1.02 to 1.06, p<0.001), resting pulse rate (OR: 1.07, 95% CI: 1.03 to 1.11, p<0.001) and hsCRP (OR: 2.30, 95% CI: 1.01 to 5.2, p=0.04) were associated with the high AT-IR tertile.

CONCLUSIONS

Adipose insulin-resistant but normal weight phenotype may be associated with increased sympathetic nervous system and low-grade systemic inflammation in addition to glucose and lipid dysmetabolism through mechanisms unrelated to adiposity in young Japanese women.

The Cognitive Improvement and Alleviation of Brain Hypermetabolism Caused by FFAR3 Ablation in Tg2576 Mice Is Persistent under Diet-Induced Obesity

Obesity and aging are becoming increasingly prevalent across the globe. It has been established that aging is the major risk factor for Alzheimer’s disease (AD), and it is becoming increasingly evident that obesity and the associated insulin resistance are also notably relevant risk factors. The biological plausibility of the link between high adiposity, insulin resistance, and dementia is central for understanding AD etiology, and to form bases for prevention efforts to decrease the disease burden. Several studies have demonstrated a strong association between short chain fatty acid receptor FFAR3 and insulin sensitivity. Interestingly, it has been recently established that FFAR3 mRNA levels are increased in early stages of the AD pathology, indicating that FFAR3 could play a key role in AD onset and progression. Indeed, in the present study we demonstrate that the ablation of the Ffar3 gene in Tg2576 mice prevents the development of cognitive deficiencies in advanced stages of the disease. Notably, this cognitive improvement is also maintained upon a severe metabolic challenge such as the exposure to high-fat diet (HFD) feeding. Moreover, FFAR3 deletion restores the brain hypermetabolism displayed by Tg2576 mice. Collectively, these data postulate FFAR3 as a potential novel target for AD.

ISPAD Clinical Practice Consensus Guidelines 2022: Type 2 diabetes in children and adolescents

Since the 2018 ISPAD guidelines on this topic, follow-up of large cohorts from around the globe have continued informing the current incidence and prevalence of co-morbidities and complications in young adults with youth-onset type 2 diabetes (T2D). This chapter focuses on the risk factors, diagnosis and presentation of youth-onset T2D, the initial and subsequent management of youth-onset T2D, and management of co-morbidities and complications. We include key updates from the observational phase of the multi-center Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) clinical trial, the SEARCH for Diabetes in Youth (SEARCH) study and new data from the Restoring Insulin Secretion (RISE) study, a head-to-head comparison of youth onset vs adult-onset T2D. We also include an expanded section on risk factors associated with T2D, algorithms and tables for treatment, management, and assessment of co-morbidities and complications, and sections on recently approved pharmacologic therapies for the treatment of youth-onset T2D, social determinants of health, and settings of care given COVID-19 pandemic.

Early-Phase Changes in Serum Free Fatty Acid Levels After Glucose Intake Are Associated With Type 2 Diabetes Incidence: The Hiroshima Study on Glucose Metabolism and Cardiovascular Diseases

OBJECTIVE

Experimental studies suggest that excess serum free fatty acid (FFA) levels result in impaired glucose metabolism. This study investigated the relationship between changes in serum FFA levels after glucose intake and type 2 diabetes risk.

RESEARCH DESIGN AND METHODS

This observational study included 6,800 individuals without diabetes who underwent a 75-g oral glucose tolerance test. Serum FFA levels were measured before and 30 and 60 min after glucose intake. The percentages of changes in serum FFA levels from 0 to 30 and from 30 to 60 min were compared, and a low rate of change in FFA levels was determined using the receiver operating characteristic curve analysis.

RESULTS

Over a mean 5.3-year follow-up period, 485 participants developed type 2 diabetes. After adjusting for plasma glucose levels and indices of insulin resistance and β-cell function, low rates of change in FFA levels at 0-30 min (adjusted odds ratio [aOR] 1.91; 95% CI 1.54-2.37) and 30-60 min (aOR 1.48; 95% CI 1.15-1.90) were associated with the incidence of type 2 diabetes. Stratified analysis revealed that the low rate of change in FFA levels at 30-60 min (aOR 1.97; 95% CI 1.05-3.69) was associated with the incidence of type 2 diabetes even in participants with normal fasting glucose levels or glucose tolerance.

CONCLUSIONS

Changes in serum FFA levels within the 1st h after glucose intake could be a primary predictor of type 2 diabetes. This change may occur prior to the onset of impaired glucose metabolism.

Adipose tissue insulin resistance predicts the incidence of hypertension: The Hiroshima Study on Glucose Metabolism and Cardiovascular Diseases

We investigated the association of adipose tissue insulin resistance with blood pressure and hypertension incidence, comparing it with hepatic and skeletal muscle insulin resistance. The cross-sectional analysis included 6892 general health checkup examinees (mean age: 69.3 years; 51.3% women and 48.7% men) who had no cardiovascular disease. Of those, 3948 normotensive participants (mean age: 68.4 years; 54.8% women and 45.2% men) were enrolled in the retrospective cohort analysis. The adipose insulin resistance index (Adipo-IR) was calculated as the product of fasting serum insulin and free fatty acid levels. A high adipo-IR, high homeostasis model assessment of insulin resistance (HOMA-IR), and low Matsuda index were indicated based on the optimal cutoff values in a receiver operating characteristic curve analysis. Adipo-IR (β = 0.096, P < 0.001), HOMA-IR (β = 0.052, P < 0.001), and Matsuda index (β = -0.055, P < 0.001) were associated with systolic blood pressure in the cross-sectional analysis. Over a mean 5.3-year follow-up period, 1310 participants developed hypertension. A high adipo-IR (adjusted OR, 1.29; 95% CI, 1.11-1.51), but not HOMA-IR or Matsuda index, was significantly associated with the incidence of hypertension. Moreover, the combination of high adipo-IR with high HOMA-IR or low Matsuda index showed no higher odds of hypertension than a high adipo-IR alone. These results suggest that insulin resistance is associated with blood pressure control regardless of the tissue in which it occurs; however, the risk of hypertension is determined by insulin resistance in adipose tissue rather than in liver or muscle tissue.

Soat2 ties cholesterol metabolism to β-oxidation and glucose tolerance in male mice

BACKGROUND

Sterol O-acyltransferase 2 (Soat2) encodes acyl-coenzyme A:cholesterol acyltransferase 2 (ACAT2), which synthesizes cholesteryl esters in hepatocytes and enterocytes fated either to storage or to secretion into nascent triglyceride-rich lipoproteins.

OBJECTIVES

We aimed to unravel the molecular mechanisms leading to reduced hepatic steatosis when Soat2 is depleted in mice.

METHODS

Soat2-/- and wild-type mice were fed a high-fat, a high-carbohydrate, or a chow diet, and parameters of lipid and glucose metabolism were assessed.

RESULTS

Glucose, insulin, homeostatic model assessment for insulin resistance (HOMA-IR), oral glucose tolerance (OGTT), and insulin tolerance tests significantly improved in Soat2-/- mice, irrespective of the dietary regimes (2-way ANOVA). The significant positive correlations between area under the curve (AUC) OGTT (r = 0.66, p < 0.05), serum fasting insulin (r = 0.86, p < 0.05), HOMA-IR (r = 0.86, p < 0.05), Adipo-IR (0.87, p < 0.05), hepatic triglycerides (TGs) (r = 0.89, p < 0.05), very-low-density lipoprotein (VLDL)-TG (r = 0.87, p < 0.05) and the hepatic cholesteryl esters in wild-type mice disappeared in Soat2-/- mice. Genetic depletion of Soat2 also increased whole-body oxidation by 30% (p < 0.05) compared to wild-type mice.

CONCLUSION

Our data demonstrate that ACAT2-generated cholesteryl esters negatively affect the metabolic control by retaining TG in the liver and that genetic inhibition of Soat2 improves liver steatosis via partitioning of lipids into secretory (VLDL-TG) and oxidative (fatty acids) pathways.

Nonalcoholic Steatohepatitis in Children

Nonalcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver disease in children. Although environmental factors are major contributors to early onset, children have both shared and unique genetic risk alleles as compared with adults with NAFLD. Treatment relies on reducing environmental risk factors, but many children have persistent diseases. No medications are approved specifically for the treatment of NAFLD, but some anti-obesity or diabetes treatments may be beneficial. Pediatric NAFLD increases the risk of diabetes and other cardiovascular risk factors. Long-term prospective studies are needed to determine the long-term risk of hepatic and non-hepatic morbidity and mortality in adulthood.

The effects of macronutrients composition on hormones and substrates during a meal tolerance test in drugnaive and sitagliptin-treated individuals with type 2 diabetes: a randomized crossover study

Objective

To evaluate the effect of sitagliptin treatment in early type 2 diabetes mellitus (T2DM) and the impact of different macronutrient compositions on hormones and substrates during meal tolerance tests (MTT).

Methods

Half of the drug-naive patients with T2DM were randomly assigned for treatment with 100 mg of sitagliptin, q.d., or placebo for 4 weeks and then submitted to 3 consecutive MTT intercalated every 48 h. The MTTs differed in terms of macronutrient composition, with 70% of total energy from carbohydrates, proteins, or lipids. After 4 weeks of washout, a crossover treatment design was repeated. Both patients and researchers were blinded, and a repeated-measures ANOVA was employed for statistical analysis.

Results

Sitagliptin treatment reduced but did not normalize fasting and post-meal glucose values in the three MTTs, with lowered area-under-glucose-curve values varying from 7% to 15%. The sitagliptin treatment also improved the insulinogenic index (+86%) and the insulin/glucose (+25%), glucagon-like peptide-1/glucose (+46%) incremental area under the curves. Patients with early T2DM maintained the lowest glucose excursion after a protein- or lipid-rich meal without any major change in insulin, C-peptide, glucagon, or NEFA levels.

Conclusion

We conclude that sitagliptin treatment is tolerable and contributes to better control of glucose homeostasis in early T2DM, irrespective of macronutrient composition. The blood glucose excursion during meal ingestion is minimal in protein- or fat-rich meals, which can be a positive ally for the management of T2DM. Clinical trial no: NCT00881543.

Metabolic inflexibility in youth with obesity: Is it a feature of obesity or distinctive of youth who are metabolically unhealthy?

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 IS (HIS) from hepatic glucose production by [6,6-² H₂ ]glucose, adipose tissue IS (ATIS) from whole-body lipolysis by [² H₅ ]glycerol, RQ (indirect calorimetry) during fasting and a hyperinsulinemic (80 mU/m² /min)-euglycemic clamp were measured. Youth with MUO versus MHO had blunted ΔRQ (p = .035) and lower HIS and ATIS (both p < .0001), while ΔRQ, HIS and ATIS were not different between youth with MHO and NW. In a pair-matched sub-analyses of 30 MUO and 30 MHO the results were similar to the total cohort. Metabolic inflexibility, does not appear to be a feature of obesity per se rather distinctive of youth with MUO, who also have worse HIS and ATIS compared with youth with MHO.

Humanin and diabetes mellitus: A review of in vitro and in vivo studies

Humanin (HN) is a 24-amino acid mitochondrial-derived polypeptide with cyto-protective and anti-apoptotic effects that regulates the mitochondrial functions under stress conditions. Accumulating evidence suggests the role of HN against age-related diseases, such as Alzheimer’s disease. The decline in insulin action is a metabolic feature of aging and thus, type 2 diabetes mellitus is considered an age-related disease, as well. It has been suggested that HN increases insulin sensitivity, improves the survival of pancreatic beta cells, and delays the onset of diabetes, actions that could be deployed in the treatment of diabetes. The aim of this review is to present the in vitro and in vivo studies that examined the role of HN in insulin resistance and diabetes and to discuss its newly emerging role as a therapeutic option against those conditions.

The Influence of Different Types of Diabetes on Vascular Complications

The final outcome of diabetes is chronic complications, of which vascular complications are the most serious, which is the main cause of death for diabetic patients and the direct cause of the increase in the cost of diabetes. Type 1 and type 2 diabetes are the main types of diabetes, and their pathogenesis is completely different. Type 1 diabetes is caused by genetics and immunity to destroy a large number of β cells, and insulin secretion is absolutely insufficient, which is more prone to microvascular complications. Type 2 diabetes is dominated by insulin resistance, leading to atherosclerosis, which is more likely to progress to macrovascular complications. This article explores the pathogenesis of two types of diabetes, analyzes the pathogenesis of different vascular complications, and tries to explain the different trends in the progression of different types of diabetes to vascular complications, in order to better prevent diabetes and its vascular complications.

Association of obesity with serum free fatty acid levels in individuals at different stages of prediabetes

We investigated the associations of prediabetes categories and obesity with serum free fatty acid (FFA) levels and adipose tissue insulin resistance. This study included 5006 male participants (1779, 1025, 629, 874, and 699 with normal fasting glucose/normal glucose tolerance, isolated impaired fasting glucose [IFG], isolated impaired glucose tolerance [IGT], IFG plus IGT, and diabetes, respectively). Serum FFA levels were assessed before and 30, 60, and 120 min after glucose ingestion, and the total area under the FFA curve (AUC_FFA ) was calculated. Adipose insulin resistance index (adipo-IR) was assessed based on fasting FFA and insulin concentrations. Isolated IFG was associated with high fasting FFA levels (OR, 1.35; p < 0.001) and high adipo-IR (OR, 1.82; p < 0.001) only in the nonobesity group. Isolated IGT, IFG plus IGT, and diabetes were associated with high fasting FFA levels, regardless of obesity. Obesity was significantly associated with AUC_FFA , and the duration of obesity-related impairment in lipolysis inhibition after glucose ingestion was prolonged in IFG plus IGT and diabetes. These results suggest that IFG and obesity may overlap in their effects on FFA metabolism whereas IGT has significant effects on FFA independent of obesity. Obesity impact on lipolysis may be involved in worsening glucose metabolism.

Fat-free/lean body mass in children with insulin resistance or metabolic syndrome: a systematic review and meta-analysis

BACKGROUND

Lean / Fat Free Body Mass (LBM) is metabolically involved in active processes such as resting energy expenditure, glucose uptake, and myokine secretion. Nonetheless, its association with insulin sensitivity / resistance / glucose tolerance and metabolic syndrome remains unclear in childhood.

METHODS

The current investigation aimed to examine the differences in fat-free mass /lean body mass according to the presence of insulin sensitivity/insulin resistance/glucose tolerance/metabolic syndrome in children. A systematic search was carried out in Medline/PubMed, Embase, Scopus, Web of Science, and SciELO, covering the period from each database's respective start to 21 June 2021. Two researchers evaluated 7111 studies according to the inclusion criteria: original human studies, written in English or Spanish, evaluating fat-free mass/lean body mass in children and adolescents including both with and without insulin sensitivity/insulin resistance /glucose tolerance and metabolic syndrome and reported the differences between them in terms of fat free mass/lean body mass. The results of the studies were combined with insulin sensitivity, insulin, resistance, glucose tolerance and metabolic syndrome. The standardized mean difference (SMD) in each study was calculated and combined using the random-effects model. Heterogeneity between studies was tested using the index of heterogeneity (I2), leave-one-out sensitivity analyses were performed, and publication bias was assessed using the Egger and Begg tests.

RESULTS

Finally, 15 studies which compared groups defined according to different glucose homeostasis criteria or metabolic syndrome out of 103 eligible studies were included in this systematic review and 12 studies in the meta-analysis. Meta-analysis showed lower fat-free mass/lean body mass percentage in participants with insulin resistance/glucose tolerance/metabolic syndrome (SMD -0.47; 95% CI, - 0.62 to - 0.32) while in mass units (kg), higher values were found in the same group (SMD, 1.01; 95% CI, 0.43 to 1.60).

CONCLUSIONS

Our results identified lower values of fat-free mass/lean body mass (%) in children and adolescents with insulin resistance/glucose tolerance/metabolic syndrome and higher values of fat-free mass/lean body mass when these are expressed in kg. The evidence of the impact of lean mass on children's glucose homeostasis or metabolic syndrome is limited, so future studies research should focus on explaining the effect of fat-free mass/lean body mass on different metabolic outcomes. Moreover, it may be interesting to evaluate the quality (muscle density) or functional (muscle strength) outcomes in addition to both absolute (kg) and relative (%) values in future studies. The systematic review was prospectively registered at PROSPERO (registration number CRD42019124734; available at: http://www.crd.york.ac.uk/prospero [accessed: 05 April 2019]).

Novel Adipokines CTRP1, CTRP9, and FGF21 in Pediatric Type 1 and Type 2 Diabetes: A Cross-Sectional Analysis

INTRODUCTION

Pediatric obesity and diabetes has increased over the last several decades. While the role of common adipokines on metabolic parameters has been well studied in adults, the relationship of novel adipokines and hepatokines in pediatric type 1 (T1D) and type 2 diabetes (T2D) is not well understood. This study assessed novel adipokines C1q/TNF-related proteins (CTRP1 and CTRP9), and hepatokine fibroblast growth factor 21 (FGF21) in youth with T1D and T2D diabetes.

METHODS

Participants (n = 80) with T1D (n = 40) enrolled in the Pediatric Diabetes Consortium (PDC) T1D NeOn registry, and T2D (n = 40) from the PDC T2D registry. Cross-sectional analysis compared adipokines (CTRP1, CTRP9, FGF21) between T1D and T2D, and regression models assessed adipokine relationship with clinical characteristics.

RESULTS

The mean age of the participants was 14.9 ± 2 years, and 50% were female. T2D participants had a shorter diabetes duration (p = 0.0009), higher weight (p < 0.0001), and BMI (p < 0.0001) than T1D participants. CTRP9 levels were higher in T1D (13,903.6 vs. 3,608.5 pg/mL, p = 0.04) than T2D, and FGF21 levels were higher in T2D (113.1 vs. 70.6 pg/mL, p = 0.03) than T1D, with no differences in CTRP1. In regression analysis of T1D, CTRP9 was positively associated with C-peptide (p = 0.006), and FGF21 was positively associated with hemoglobin A1c (p = 0.04). In T2D, CTRP1 was positively associated with HbA1c (p < 0.001) and glucose (p = 0.004), even after controlling for age, sex, and BMI.

CONCLUSIONS

CTRP9 levels are higher in youth with T1D compared to T2D, and FGF21 levels are higher in youth with T2D than T1D. Novel adipokines are related to metabolic homeostasis in the inflammatory milieu of pediatric diabetes.

An update of the consensus statement on insulin resistance in children 2010

In our modern society, where highly palatable and calorie-rich foods are readily available, and sedentary lifestyle is common among children and adolescents, we face the pandemic of obesity, nonalcoholic fatty liver disease, hypertension, atherosclerosis, and T2D. Insulin resistance (IR) is known to be the main underlying mechanism of all these associated health consequences; therefore, the early detection of IR is fundamental for preventing them.A Consensus Statement, internationally supported by all the major scientific societies in pediatric endocrinology, was published in 2010, providing all the most recent reliable evidence to identify the definition of IR in children, its measurement, its risk factors, and the effective strategies to prevent and treat it. However, the 2010 Consensus concluded that further research was necessary to assess some of the discussed points, in particular the best way to measure insulin sensitivity, standardization of insulin measurements, identification of strong surrogate biomarkers of IR, and the effective role of lifestyle intervention and medications in the prevention and treatment of IR.The aim of this review is to update each point of the consensus with the most recent available studies, with the goal of giving a picture of the current state of the scientific literature regarding IR in children, with a particular regard for issues that are not yet fully clarified.

Adipose Tissue Insulin Resistance Is Positively Associated With Serum Uric Acid Levels and Hyperuricemia in Northern Chinese Adults

OBJECTIVE

Adipose tissue plays a crucial role in serum uric acid (UA) metabolism, but the relative contribution of adipose tissue insulin resistance (IR) to serum UA levels and hyperuricemia have not explicitly been illustrated. Herein, we aimed to investigate the association between the adipose tissue insulin resistance index (Adipo-IR) and hyperuricemia in this cross-sectional study. The homeostasis model assessment of insulin resistance (HOMA-IR) index, another widely applied marker to determine systemic IR, was also explored.

METHODS

A total of 5821 adults were included in this study. The relationship between Adipo-IR or HOMA-IR and serum UA levels was assessed by multivariate linear regression. Binary logistic regression analyses were applied to determine the sex-specific association of the Adipo-IR tertiles and HOMA-IR tertiles with hyperuricemia. Participants were then divided into normal BMI (18.5 ≤ BMI < 24) and elevated BMI (BMI ≥ 24) groups for further analysis.

RESULTS

Both Adipo-IR and HOMA-IR were positively correlated with serum UA (P < 0.001). Compared with the lowest tertile, the risks of hyperuricemia increased across Adipo-IR tertiles (middle tertile: OR 1.52, 95%CI 1.24-1.88; highest tertile: OR 2.10, 95%CI 1.67-2.63) in men after full adjustment (P for trend < 0.001). In women, only the highest tertile (OR 2.09, 95%CI 1.52-2.87) was significantly associated with hyperuricemia. Those associations remained significant in participants with normal BMI status. As for HOMA-IR, only the highest tertile showed positive relationships with hyperuricemia in both genders after full adjustment (P for trend < 0.001). The association between HOMA-IR and hyperuricemia disappeared in men with normal BMI status.

CONCLUSIONS

Adipo-IR was strongly associated with serum UA and hyperuricemia regardless of BMI classification. In men with normal BMI, Adipo-IR, rather than HOMA-IR, was closely associated with hyperuricemia. Altogether, our finding highlights a critical role of adipose tissue IR on serum UA metabolism and hyperuricemia.

Obese patients with higher TSH levels had an obvious metabolic improvement after bariatric surgery

OBJECTIVE

Bariatric surgery has become the most effective treatment for morbid obesity. Increasing evidence showed that bariatric surgery can alleviate insulin resistance and influence thyroid function. This study aimed to investigate the relationship between changes in thyroid function and adipose tissue insulin resistance (adipo-IR) after bariatric surgery.

METHODS

A total of 287 non-diabetic participants with regular thyroid function were recruited and divided into the lean, overweight and obese groups. Among them, 50 morbidly obese patients submitted to bariatric surgery.

RESULTS

The obese group had a higher level of adipo-IR, thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), FT3/free thyroxine (FT4) and metabolism disorders than the lean and overweight groups. BMI was correlated with TSH, FT3, FT3/FT4 and adipo-IR (r = 0.309, 0.315, 0.322 and 0.651, respectively, all P < 0.001). Adipo-IR was significantly correlated with TSH (r = 0.402, P < 0.001), FT3 (r = 0.309, P < 0.001), and FT3/FT4 (r = 0.228, P < 0.05). Bariatric surgery resulted in a sharp decline in BMI, adipo-IR, TSH, FT3 and FT3/FT4 levels, meanwhile, metabolic disorders improved. The decrease in BMI after bariatric surgery was significantly correlated with reductions in adipo-IR (r = 0.577, P < 0.001) and TSH (r = 0.401, P = 0.005). Interestingly, the fasting blood glucose, fasting insulin, adipo-IR and TSH in the higher TSH group decreased more remarkably than in the lower TSH group.

CONCLUSION

Obese individuals with higher TSH levels had an obvious metabolic improvement after bariatric surgery.

Serum vitamin E concentration is negatively associated with body mass index change in girls not boys during adolescence

BACKGROUND

Vitamin E is the most abundant lipid-soluble antioxidants present in plasma; however, the relationship between serum vitamin E and change in body mass index (BMI)-for-age Z scores in adolescents has not been well described.

METHODS

This study is a cross-sectional study. Data were analyzed from 4014 adolescents who participated in the National Health and Nutrition Examination Survey. The nutritional status was calculated by BMI Z scores and was classified into normal weight, overweight, and obese. Multivariable-adjusted logistic regression was used to examine the association between serum vitamin E levels with overweight/obesity. Besides, the interaction effects between potential confounders and vitamin E on obesity were further evaluated.

RESULTS

After adjusting potential confounders, serum vitamin E levels were negatively associated with overweight/obesity in girls but not in boys. Per standard deviation increment in vitamin E concentrations was associated with a 92% decreased risk of obesity in females. Besides, lower quartiles of serum vitamin E were associated with a higher risk of overweight/obesity in girls. Moreover, the inverse association between serum vitamin E levels and obesity was also found in most subgroups through subgroup analysis.

CONCLUSIONS

Our study supports the negative association between serum vitamin E levels and overweight/obesity in adolescents. A higher serum vitamin E level may be associated with a reduced probability of obesity in girls, but not in boys.

Incretin Hormones: Pathophysiological Risk Factors and Potential Targets for Type 2 Diabetes

Type 2 diabetes (T2D) is a multifaceted metabolic disorder associated with distinctive pathophysiological disturbances. One of the pathophysiological risk factors observed in T2D is dysregulation of the incretin hormones, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1). Both hormones stimulate insulin secretion by acting postprandially on pancreatic β-cell receptors. Oral glucose administration stimulates increased insulin secretion in comparison with isoglycemic intravenous glucose administration, a phenomenon known as the incretin effect. While the evidence for incretin defects in individuals with T2D is growing, the etiology behind this attenuated incretin effect in T2D is not clearly understood. Given their central role in T2D pathophysiology, incretins are promising targets for T2D therapeutics. The present review synthesizes the recent attempts to explain the biological importance of incretin hormones and explore potential pharmacological approaches that target the incretins.

Time trends of overweight and obesity among schoolchildren in Kuwait over a 13-year period (2007-2019): repeated cross-sectional study

OBJECTIVES

This study aimed to examine age-specific trends in the prevalence of overweight and obesity in schoolchildren in Kuwait over a 13-year period (2007 to 2019) using the WHO, the Centers for Disease Control and Prevention (CDC) and the International Obesity Taskforce (IOTF) definitions.

DESIGN

Using cross-sectional approach, Kuwait Nutrition Surveillance System (KNSS) objectively measured weight and height of schoolchildren over a 13-year period. Log-binomial regression models were used to examine age-specific trends of obesity and overweight over the study period.

SETTING

Public primary, middle and high schools in all provinces of Kuwait.

PARTICIPANTS

Schoolchildren aged 5-19 years (n 172 603).

RESULTS

According to the WHO definition, the prevalence of overweight and obesity in schoolchildren, respectively, increased from 17·73 % and 21·37 % in 2007 to 20·19 % and 28·39 % in 2019 (Pfor trend < 0·001). There is evidence that the obesity in females (but not males) has levelled off in the period 2014-2019 according to the three definitions of obesity, which is corroborated by a similar trend in the mean of BMI-for-age Z-score.

CONCLUSION

The prevalence of obesity and overweight in schoolchildren in Kuwait has risen over the last 13 years and trends are similar across all definitions. Obesity is no longer increasing at the same pace and there is evidence that the prevalence of obesity in females has plateaued. The current level of childhood overweight and obesity is too high and requires community-based and school-based interventions.

Higher Leptin-to-Adiponectin Ratio Strengthens the Association Between Body Measurements and Occurrence of Type 2 Diabetes Mellitus

Aim: This case-control study aimed to investigate the interrelations of body measurements and selected biomarkers in type 2 diabetes mellitus (T2DM). Methods: We recruited 98 patients with T2DM and 98 controls from 2016 to 2018 in Taiwan. Body measurements were obtained using a three-dimensional body surface scanning system. Four biomarkers related to insulin resistance, adipokines, and inflammation were assayed. A multiple logistic regression model was used to perform multivariable analyses. Results: Four body measurements, namely waist circumference (odds ratio, OR = 1.073; 95% confidence interval, CI = 1.017-1.133), forearm circumference (OR = 1.227; 95% CI = 1.002-1.501), thigh circumference (OR = 0.841; 95% CI = 0.73-0.969), and calf circumference (OR = 1.25; 95% CI = 1.076-1.451), were significantly associated with T2DM. Leptin (OR = 1.09; 95% CI = 1.036-1.146) and adiponectin (OR = 0.982; 95% CI = 0.967-0.997) were significantly associated with T2DM. Six body measurement combinations, namely body mass index, waist-to-hip ratio, waist-to-height ratio, waist-to-thigh ratio, forearm-to-thigh ratio, and calf-to-thigh ratio (CTR), were significantly associated with T2DM. CTR had the strongest linear association with T2DM. Moderating effects of significant biomarkers, namely leptin and adiponectin, were observed. Participants with high leptin-to-adiponectin ratios and in the fourth CTR quartile were 162.2 times more prone to develop T2DM. Conclusions: We concluded that a combination of leptin and adiponectin modulated the strength of the association between body measurements and T2DM while providing clues for high-risk group identification and mechanistic conjectures of preventing T2DM.

Sex Differences in the Effect of Testosterone on Adipose Tissue Insulin Resistance From Overweight to Obese Adults

OBJECTIVE

Adipose tissue distribution and glucose metabolism differ between men and women. Few studies have investigated sex differences in adipose tissue insulin resistance (adipose-IR). Herein, we investigated sex differences in adipose-IR in adults ranging from overweight to obese and the potential factors associated with sex differences in adipose-IR.

METHODS

A total of 424 adults had their body mass index (BMI), adipose-IR, and sex hormones evaluated. Based on BMI, males and females were assigned to 4 groups.

RESULTS

In total, males (n = 156) had higher adipose-IR than females with similar BMI levels (n = 268) (P < 0.05). Adipose-IR progressively increased from overweight to class III obesity in both males and females (all P < 0.0001); however, only in the class III obesity group was the adipose-IR significantly higher in males than in females (P = 0.025). There were significant differences in testosterone between males and females (all P < 0.01); testosterone levels were negatively correlated with adipose-IR (r = -0.333, P < 0.001) in males but positively correlated with adipose-IR (r = 0.216, P < 0.001) in females. For the logistic regression analysis, testosterone was an independent protective factor against adipose-IR in males, with an odds ratio of 0.858 (B = -0.153 [95% CI, 0.743-0.991], P = 0.037).

CONCLUSIONS

Adipose-IR reflects the progressive deterioration in adipose tissue insulin sensitivity from overweight to obesity in both males and females. Males with class III obesity have more severe adipose-IR than similarly obese females. The sex difference is associated with testosterone, and low testosterone levels may contribute to more severe adipose-IR in obese males.

Composition and Functions of the Gut Microbiome in Pediatric Obesity: Relationships with Markers of Insulin Resistance

The gut microbiome is hypothesized to play a crucial role in the development of obesity and insulin resistance (IR); the pathways linking the microbiome to IR in pediatrics have yet to be precisely characterized. We aimed to determine the relationship between the gut microbiome composition and metabolic functions and IR in children with obesity. In a cross-sectional study, fecal samples from children with obesity (10-16 years old) were collected for taxonomical and functional analysis of the fecal microbiome using shotgun metagenomics. The homeostatic model assessment for insulin resistance (HOMA-IR) was determined using fasting glucose and insulin. Associations between HOMA-IR and α-diversity measures as well as metabolic pathways were evaluated using Spearman correlations; relationships between HOMA-IR and β-diversity were assessed by permutational multivariate analysis of variance. Twenty-one children (nine males; median: age = 12.0 years; BMI z-score = 2.9; HOMA-IR = 3.6) completed the study. HOMA-IR was significantly associated with measures of α-diversity but not with β-diversity. Children with higher HOMA-IR exhibited lower overall species richness, Firmicutes species richness, and overall Proteobacteria species Shannon diversity. Furthermore, HOMA-IR was inversely correlated with the abundance of pathways related to the biosynthesis of lipopolysaccharides, amino acids, and short-chain fatty acids, whereas positive correlations between HOMA-IR and the peptidoglycan biosynthesis pathways were observed. In conclusion, insulin resistance was associated with decreased microbial α-diversity measures and abundance of genes related to the metabolic pathways. Our study provides a framework for understanding the microbial alterations in pediatric obesity.

Adipose Tissue Insulin Resistance Is Longitudinally Associated With Adipose Tissue Dysfunction, Circulating Lipids, and Dysglycemia: The PROMISE Cohort

OBJECTIVE

To determine the association of adipose tissue insulin resistance with longitudinal changes in biomarkers of adipose tissue function, circulating lipids, and dysglycemia.

RESEARCH DESIGN AND METHODS

Adults at risk for type 2 diabetes in the Prospective Metabolism and Islet Cell Evaluation (PROMISE) cohort had up to four assessments over 9 years (n = 468). Adipose tissue insulin resistance was determined using a novel validated index, Adipo-IR, calculated as the product of fasting insulin and nonesterified fatty acids measured at baseline. Fasting serum was used to measure biomarkers of adipose tissue function (adiponectin and soluble CD163 [sCD163]), circulating lipids (total cholesterol, HDL, LDL, triglyceride [TG]), and systemic inflammation (interleukin-6 [IL-6] and tumor necrosis factor-α [TNF-α]). Incident dysglycemia was defined as the onset of impaired fasting glucose, impaired glucose tolerance, or type 2 diabetes at follow-up. Generalized estimating equation (GEE) models were used to assess the relationship of Adipo-IR with longitudinal outcomes.

RESULTS

GEE analyses showed that elevated Adipo-IR was longitudinally associated with adipose tissue dysfunction (adiponectin -4.20% [95% CI -6.40 to -1.95]; sCD163 4.36% [1.73-7.06], HDL -3.87% [-5.15 to -2.57], TG 9.26% [5.01-13.69]). Adipo-IR was associated with increased risk of incident dysglycemia (odds ratio 1.59 [95% CI 1.09-2.31] per SD increase). Associations remained significant after adjustment for waist circumference and surrogate indices for insulin resistance. There were no significant longitudinal associations of Adipo-IR with IL-6, TNF-α, total cholesterol, or LDL.

CONCLUSIONS

Our findings demonstrate that adipose tissue insulin resistance is prospectively associated with adipose tissue function, HDL, TG, and incident dysglycemia.

Altered adipokines in obese adolescents: a cross-sectional and longitudinal analysis across the spectrum of glycemia

Obesity and type 2 diabetes are rapidly increasing in the adolescent population. We sought to determine whether adipokines, specifically leptin, C1q/TNF-related proteins 1 (CTRP1) and CTRP9, and the hepatokine fibroblast growth factor 21 (FGF21), are associated with obesity and hyperglycemia in a cohort of lean and obese adolescents, across the spectrum of glycemia. In an observational, longitudinal study of lean and obese adolescents, we measured fasting laboratory tests, oral glucose tolerance tests, and adipokines including leptin, CTRP1, CTRP9, and FGF21. Participants completed baseline and 2-year follow-up study visits and were categorized as lean (LC, lean control; n = 30), obese normoglycemic (ONG; n = 61), and obese hyperglycemic (OHG; n = 31) adolescents at baseline and lean (n = 8), ONG (n = 18), and OHG (n = 4) at follow-up. Groups were compared using ANOVA and regression analysis, and linear mixed effects modeling was used to test for differences in adipokine levels across baseline and follow-up visits. Results showed that at baseline, leptin was higher in all obese groups (P < 0.001) compared with LC. FGF21 was higher in OHG participants compared with LC (P < 0.001) and ONG (P < 0.001) and positively associated with fasting glucose (P < 0.001), fasting insulin (P < 0.001), Homeostasis Model Assessment-Insulin Resistance Index (HOMA-IR; P < 0.001), and hemoglobin A1c (HbA1c; P = 0.01). CTRP1 was higher in OHG compared with ONG (P = 0.03). CTRP9 was not associated with obesity or hyperglycemia in this pediatric cohort. At 2 years, leptin decreased in ONG (P = 0.003) and FGF21 increased in OHG (P = 0.02), relative to lean controls. Altered adipokine levels are associated with the inflammatory milieu in obese youth with and without hyperglycemia. In adolescence, the novel adipokine CTRP1 was elevated with hyperglycemia, whereas CTRP9 was unchanged in this cohort.NEW & NOTEWORTHY Leptin is higher in obese adolescents and FGF21 is higher in obese hyperglycemic adolescents. The novel adipokine CTRP1 is higher in obese hyperglycemic adolescents, whereas CTRP9 was unchanged in this adolescent cohort.

Hyperinsulinemia and insulin resistance in the obese may develop as part of a homeostatic response to elevated free fatty acids: A mechanistic case-control and a population-based cohort study

Background

It is commonly accepted that in obesity free fatty acids (FFA) cause insulin resistance and hyperglycemia, which drives hyperinsulinemia. However, hyperinsulinemia is observed in subjects with normoglycaemia and thus the paradigm above should be reevaluated.

Methods

We describe two studies: MD-Lipolysis, a case control study investigating the mechanisms of obesity-driven insulin resistance by a systemic metabolic analysis, measurements of adipose tissue lipolysis by microdialysis, and adipose tissue genomics; and POEM, a cohort study used for validating differences in circulating metabolites in relation to adiposity and insulin resistance observed in the MD-Lipolysis study.

Findings

In insulin-resistant obese with normal glycaemia from the MD-Lipolysis study, hyperinsulinemia was associated with elevated FFA. Lipolysis, assessed by glycerol release per adipose tissue mass or adipocyte surface, was similar between obese and lean individuals. Adipose tissue from obese subjects showed reduced expression of genes mediating catecholamine-driven lipolysis, lipid storage, and increased expression of genes driving hyperplastic growth. In the POEM study, FFA levels were specifically elevated in obese-overweight subjects with normal fasting glucose and high fasting levels of insulin and C-peptide.

Interpretation

In obese subjects with normal glycaemia elevated circulating levels of FFA at fasting are the major metabolic derangement candidate driving fasting hyperinsulinemia. Elevated FFA in obese with normal glycaemia were better explained by increased fat mass rather than by adipose tissue insulin resistance. These results support the idea that hyperinsulinemia and insulin resistance may develop as part of a homeostatic adaptive response to increased adiposity and FFA.

Funding

Swedish-Research-Council (2016-02660); Diabetesfonden (DIA2017-250; DIA2018-384; DIA2020-564); Novo-Nordisk-Foundation (NNF17OC0027458; NNF19OC0057174); Cancerfonden (CAN2017/472; 200840PjF); Swedish-ALF-agreement (2018-74560).

Hyperglycemia and Adverse Pregnancy Outcome Follow-Up Study: newborn anthropometrics and childhood glucose metabolism

AIMS/HYPOTHESIS

We aimed to examine associations of newborn anthropometric measures with childhood glucose metabolism with the hypothesis that greater newborn birthweight, adiposity and cord C-peptide are associated with higher childhood glucose levels and lower insulin sensitivity.

METHODS

Data from the international, multi-ethnic, population-based Hyperglycemia and Adverse Pregnancy Outcome (HAPO) Study and the HAPO Follow-Up Study were used. The analytic cohort included 4155 children (mean age [SD], 11.4 [1.2] years; 51.0% male). Multiple linear regression was used to examine associations of primary predictors, birthweight, newborn sum of skinfolds (SSF) and cord C-peptide, from HAPO with continuous child glucose outcomes from the HAPO Follow-Up Study.

RESULTS

In an initial model that included family history of diabetes and maternal BMI during pregnancy, birthweight and SSF demonstrated a significant, inverse association with 30 min and 1 h plasma glucose levels. In the primary model, which included further adjustment for maternal sum of glucose z scores from an oral glucose tolerance test during pregnancy, the associations were strengthened, and birthweight and SSF were inversely associated with fasting, 30 min, 1 h and 2 h plasma glucose levels. Birthweight and SSF were also associated with higher insulin sensitivity (Matsuda index) (β = 1.388; 95% CI 0.870, 1.906; p < 0.001; β = 0.792; 95% CI 0.340, 1.244; p < 0.001, for birthweight and SSF higher by 1 SD, respectively) in the primary model, while SSF, but not birthweight, was positively associated with the disposition index, a measure of beta cell compensation for insulin resistance (β = 0.034; 95% CI 0.012, 0.056; p = 0.002). Cord C-peptide levels were inversely associated with Matsuda index (β = -0.746; 95% CI -1.188, -0.304; p < 0.001 for cord C-peptide higher by 1 SD) in the primary model.

CONCLUSIONS/INTERPRETATION

This study demonstrates that higher birthweight and SSF are associated with greater childhood insulin sensitivity and lower glucose levels following a glucose load, associations that were further strengthened after adjustment for maternal glucose levels during pregnancy. Graphical abstract.