Avocado Consumption for 12 Weeks and Cardiometabolic Risk Factors: A Randomized Controlled Trial in Adults with Overweight or Obesity and Insulin Resistance.

BACKGROUND: Diets emphasizing unsaturated fat and high fiber are associated with reducing cardiometabolic risk factors. Avocados are rich in MUFA and PUFA fats and fiber. OBJECTIVES: Assess replacement of carbohydrate energy with avocado energy for 12 wk on glucose homeostasis and cardiometabolic risk factors in self-selecting free-living adults who are overweight or with obesity and have insulin resistance. METHODS: In a single-center, randomized, 2-arm, controlled, 12-wk parallel trial, adults [n = 93; male/female: 39/54; mean ± SD age: 42 ± 12 y; BMI: 32.6 ± 3.9 (in kg/m2);  HOMA-IR: 2.7 ± 1.7] were counseled to exchange avocado (AV) or control food (C; low fat, low fiber, energy matched) for carbohydrate food in their usual diet for 12 wk. The primary outcome was the change in Matsuda Insulin Sensitivity Index (MISI) after 12-wk interventions. Secondary outcomes were changes in fasting and post-oral glucose tolerance test glycemic variables, fasting lipids, endothelial activation and inflammation markers. Automated Self-Administered 24-h Dietary Assessment Tool captured weekly dietary intake. Intervention effects were mainly determined by ANCOVA using PC-SAS version 9.4. RESULTS: Dietary total, MUFA, and PUFA fat; fiber; and vegetable intake were higher in the AV group compared with the C group (P < 0.05), and no change in body weight or composition was observed (P > 0.05). Differences between the changes in MISI after AV compared with C were not different (Δ0-12 wk, P = 0.1092). Differences in fasting insulin (Δ0-12 wk, P = 0.0855) and improved glycated hemoglobin (Δ0-12 wk, P = 0.0632) after AV compared with C were suggested. C-reactive protein was significantly lower after AV compared with C at 12 wk (P = 0.0418). Select biomarkers of endothelial activation and lipoproteins by NMR were also influenced by AV compared with C food intake. CONCLUSIONS: Avocado intake was associated with a healthier dietary pattern and trends favoring improved glucose control and reduced biomarkers of cardiometabolic risk when replacing avocado energy for carbohydrate energy in free-living adults who are overweight or with obesity and have insulin resistance. This trial was registered at clinicaltrials.gov as NCT02695433.

The single-point insulin sensitivity estimator (SPISE) index is a strong predictor of abnormal glucose metabolism in overweight/obese children: a long-term follow-up study.

PURPOSE: To investigate the relationship between the single-point insulin sensitivity estimator (SPISE) index, an insulin sensitivity indicator validated in adolescents and adults, and metabolic profile in overweight/obese children, and to evaluate whether basal SPISE is predictive of impaired glucose regulation (IGR) development later in life. METHODS: The SPISE index (= 600 × HDL0.185/Triglycerides0.2 × BMI1.338) was calculated in 909 overweight/obese children undergoing metabolic evaluations at University of Cagliari, Italy, and in 99 normal-weight, age-, sex-comparable children, selected as a reference group, together with other insulin-derived indicators of insulin sensitivity/resistance. 200 overweight/obese children were followed-up for 6.5 [3.5-10] years, data were used for longitudinal retrospective investigations. RESULTS: At baseline, 96/909 (11%) overweight/obese children had IGR; in this subgroup, SPISE was significantly lower than in normo-glycaemic youths (6.3 ± 1.7 vs. 7 ± 1.6, p < 0.001). The SPISE index correlated positively with the insulin sensitivity index (ISI) and the disposition index (DI), negatively with age, blood pressure, HOMA-IR, basal and 120 min blood glucose and insulin (all p values < 0.001). A correlation between SPISE, HOMA-IR and ISI was also reported in normal-weight children. At the 6.5-year follow-up, lower basal SPISE-but not ISI or HOMA-IR-was an independent predictor of IGR development (OR = 3.89(1.65-9.13), p = 0.002; AUROC: 0.82(0.72-0.92), p < 0.001). CONCLUSION: In children, low SPISE index is significantly associated with metabolic abnormalities and predicts the development of IGR in life.

Insulin Sensitivity Is Associated with Lipoprotein Lipase (LPL) and Catenin Delta 2 (CTNND2) DNA Methylation in Peripheral White Blood Cells in Non-Diabetic Young Women.

Hyperglycaemia and type 2 diabetes (T2D) are associated with impaired insulin secretion and/or insulin action. Since few studies have addressed the relation between DNA methylation patterns with elaborated surrogates of insulin secretion/sensitivity based on the intravenous glucose tolerance test (IVGTT), the aim of this study was to evaluate the association between DNA methylation and an insulin sensitivity index based on IVGTT (calculated insulin sensitivity index (CSi)) in peripheral white blood cells from 57 non-diabetic female volunteers. The CSi and acute insulin response (AIR) indexes, as well as the disposition index (DI = CSi × AIR), were estimated from abbreviated IVGTT in 49 apparently healthy Chilean women. Methylation levels were assessed using the Illumina Infinium Human Methylation 450k BeadChip. After a statistical probe filtering, the two top CpGs whose methylation was associated with CSi were cg04615668 and cg07263235, located in the catenin delta 2 (CTNND2) and lipoprotein lipase (LPL) genes, respectively. Both CpGs conjointly predicted insulin sensitivity status with an area under the curve of 0.90. Additionally, cg04615668 correlated with homeostasis model assessment insulin-sensitivity (HOMA-S) and AIR, whereas cg07263235 was associated with plasma creatinine and DI. These results add further insights into the epigenetic regulation of insulin sensitivity and associated complications, pointing the CTNND2 and LPL genes as potential underlying epigenetic biomarkers for future risk of insulin-related diseases.

Relation of NT-probnp levels and cardiovascular disease risk factors in lean women with polycystic ovary syndrome.

Women with polycystic ovary syndrome (PCOS) often have cardiovascular disease (CVD) risk factors. N-terminal fragment of brain natriuretic peptide (Nt-probnp) is used as a diagnostic and prognostic marker for CVD. The aim of this study was to evaluate whether Nt-probnp is increased in lean PCOS patients. A total of 110 lean (BMI < 25 kg/m2) PCOS patients and 80 age and BMI matched healthy lean controls were included in this study. Serum Homeostatic Model Assessment-Insulin Resistance (HOMA-IR), Matsuda insulin sensitivity index (ISI), Nt-probnp, C-reactive protein (CRP), androgen and lipid levels were measured. Serum Nt-probnp levels were significantly higher in the PCOS group. Hyperandrogenic PCOS patients had higher Nt-probnp levels. There were significant correlations between serum Nt-probnp and total testosterone, total cholesterol, HOMA and Matsuda levels. Linear regression analysis showed that Matsuda ISI and fasting insulin levels significantly affected the Nt-probnp levels (R2 of the model = 0.763; p<.0001). IMPACT STATEMENT What is already known on this subject? Many risk factors for cardiovascular disease (CVD) including insulin resistance, dyslipidaemia, hypertension and hyperandrogenism may be found in young women with polycystic ovary syndrome (PCOS), although evidence for CVD in lean women with PCOS is limited. N-terminal fragment of brain natriuretic peptide (NT-probnp) is a high predictive marker regarding of CVD, especially in patients without overt CVD. There have been contradictory results regarding Nt-probnp levels in PCOS patients and there have not been any effective studies regarding the relation between CVD risk factors and Nt-probnp levels for lean PCOS patients. What the results of this study add? This study found increased Nt-probnp levels in lean PCOS patients, which may indicate a positive correlation with risk for CVD. Strong relations were also found between Nt-probnp levels and increased insulin resistance, dyslipidaemia, decreased insulin sensitivity and hyperandrogenism. Lean PCOS patients have increased risk factors for CVD, and these risk factors are correlated with Nt-probnp levels. Nt-probnp is more affected by increased fasting insulin and decreased insulin sensitivity. What the implications are of these findings for clinical practice and/or further research? Lean PCOS patients should be evaluated for CVD. Further prospective controlled studies are needed in order to predict the long-term risk of developing CVD in lean PCOS patients.

Effects of vitamin D supplementation on insulin sensitivity and androgen levels in vitamin-D-deficient polycystic ovary syndrome patients.

AIM: The aim of this study was to identify the effects of vitamin D supplementation on insulin sensitivity and androgen levels in vitamin-D-deficient polycystic ovary syndrome (PCOS) patients. METHODS: Sixty-seven vitamin-D-deficient (25-hydroxyvitamin D [25(OH)D] levels below 20 ng/mL) PCOS patients and 54 vitamin-D-deficient non-PCOS volunteer subjects matched for age and body mass index were enrolled to this prospective study. All participants were given 50 000 IU/week cholecalciferol orally for 8 weeks and 1500 IU/day for 4 weeks. Insulin sensitivity was calculated with the Matsuda insulin sensitivity index (ISI) based on an oral glucose tolerance test. Matsuda ISI, gonadal hormones (estrogen, testosterone, androstenedione), and 25(OH)D levels were studied before and at the end of the 12th week of vitamin D load. RESULTS: After vitamin D supplementation, serum androstenedione levels had decreased significantly (P = 0.007) and Matsuda ISI values had increased significantly (P = 0.001) in the PCOS group but no significant changes were seen in those parameters in controls. We observed positive correlations between 25(OH)D levels and Matsuda ISI (r = 0.307; P < 0.01), and negative correlations between 25(OH)D levels and total testosterone (r = -0.306; P < 0.01) and androstenedione (r = -0.275; P < 0.01) levels in the PCOS group. CONCLUSION: Vitamin D supplementation increased insulin sensitivity and decreased androgen levels in vitamin-D-deficient women with PCOS but did not have any effect in vitamin-D-deficient non-PCOS women. These results may indicate the possible role of vitamin D in the complex pathogenesis of PCOS.

Prior exercise alters the difference between arterialised and venous glycaemia: implications for blood sampling procedures.

Oral glucose tolerance and insulin sensitivity are common measures, but are determined using various blood sampling methods, employed under many different experimental conditions. This study established whether measures of oral glucose tolerance and oral glucose-derived insulin sensitivity (insulin sensitivity indices; ISI) differ when calculated from venous v. arterialised blood. Critically, we also established whether any differences between sampling methods are consistent across distinct metabolic conditions (after rest v. after exercise). A total of ten healthy men completed two trials in a randomised order, each consisting of a 120-min oral glucose tolerance test (OGTT), either at rest or post-exercise. Blood was sampled simultaneously from a heated hand (arterialised) and an antecubital vein of the contralateral arm (venous). Under both conditions, glucose time-averaged AUC was greater from arterialised compared with venous plasma but importantly, this difference was larger after rest relative to after exercise (0·99 (sd 0·46) v. 0·56 (sd 0·24) mmol/l, respectively; P<0·01). OGTT-derived ISIMatsuda and ISICederholm were lower when calculated from arterialised relative to venous plasma and the arterialised-venous difference was greater after rest v. after exercise (ISIMatsuda: 1·97 (sd 0·81) v. 1·35 (sd 0·57) arbitrary units (au), respectively; ISICederholm : 14·76 (sd 7·83) v. 8·70 (sd 3·95) au, respectively; both P<0·01). Venous blood provides lower postprandial glucose concentrations and higher estimates of insulin sensitivity, compared with arterialised blood. Most importantly, these differences between blood sampling methods are not consistent after rest v. post-exercise, preventing standardised venous-to-arterialised corrections from being readily applied.

Strawberry and cranberry polyphenols improve insulin sensitivity in insulin-resistant, non-diabetic adults: a parallel, double-blind, controlled and randomised clinical trial.

Plant-derived foods rich in polyphenols are associated with several cardiometabolic health benefits, such as reduced postprandial hyperglycaemia. However, their impact on whole-body insulin sensitivity using the hyperinsulinaemic-euglycaemic clamp technique remains under-studied. We aimed to determine the effects of strawberry and cranberry polyphenols (SCP) on insulin sensitivity, glucose tolerance, insulin secretion, lipid profile, inflammation and oxidative stress markers in free-living insulin-resistant overweight or obese human subjects (n 41) in a parallel, double-blind, controlled and randomised clinical trial. The experimental group consumed an SCP beverage (333 mg SCP) daily for 6 weeks, whereas the Control group received a flavour-matched Control beverage that contained 0 mg SCP. At the beginning and at the end of the experimental period, insulin sensitivity was assessed by a hyperinsulinaemic-euglycaemic clamp, and glucose tolerance and insulin secretion by a 2-h oral glucose tolerance test (OGTT). Insulin sensitivity increased in the SCP group as compared with the Control group (+0·9 (sem 0·5)×10-3 v. -0·5 (sem 0·5)×10-3 mg/kg per min per pmol, respectively, P=0·03). Compared with the Control group, the SCP group had a lower first-phase insulin secretion response as measured by C-peptide levels during the first 30 min of the OGTT (P=0·002). No differences were detected between the two groups for lipids and markers of inflammation and oxidative stress. A 6-week dietary intervention with 333 mg of polyphenols from strawberries and cranberries improved insulin sensitivity in overweight and obese non-diabetic, insulin-resistant human subjects but was not effective in improving other cardiometabolic risk factors.

Selective association of electrocardiographic abnormalities with insulin sensitivity and beta-cell function in type 2 diabetes mellitus: a cross-sectional analysis.

BACKGROUND: We investigated the association of electrocardiographic (ECG) abnormalities with markers of insulin resistance and pancreatic beta-cell dysfunction in a cross-sectional study of type 2 diabetes patients. METHODS: Electrocardiographic criteria were evaluated in the Penn Diabetes Heart Study participants (n = 1671; 64% male; 61% Caucasian), including a sub-sample (n = 710) that underwent oral glucose tolerance testing. The Matsuda Insulin Sensitivity Index and homeostasis model assessment of insulin resistance (HOMA-IR) estimated insulin sensitivity; Insulinogenic Index and homeostasis model assessment of beta-cell function assessed beta-cell function. Multivariable regression modelling was used to analyse associations of ECG changes with these indices. RESULTS: In unadjusted analyses, subjects in the highest quartile of Matsuda index had the lowest prevalence of Q-waves (6.3% versus 15.3%, p = 0.005). In adjusted models, an inverse association was seen between Q-waves and log Matsuda index [one standard deviation increase; OR = 0.59 (95% CI 0.43-0.87 p = 0.001)]. In the full Penn Diabetes Heart Study, there was a direct association between Q-waves and HOMA-IR [one standard deviation increase; OR = 1.43 (95% CI 1.13-1.81, p = 0.003)]. In adjusted models, left ventricular hypertrophy also was inversely associated with Matsuda index and directly with HOMA-IR. Higher Insulinogenic Index scores were associated with a lower prevalence of nonspecific ST changes [OR = 0.78 (95% CI 0.62-0.98, p = 0.032)]. CONCLUSIONS: In type 2 diabetic patients, both oral glucose tolerance testing-derived and HOMA-derived measures of insulin resistance were associated with pathologic Q-waves and left ventricular hypertrophy on ECGs. Copyright © 2016 John Wiley & Sons, Ltd.

Zinc supplementation alleviates hyperglycemia and associated metabolic abnormalities in streptozotocin-induced diabetic rats.

The cause and effect relationship between diabetes and zinc is complex and unclear. This animal study has examined the potential of zinc supplementation in beneficial modulating hyperglycemia, insulin secretion, and metabolic abnormalities associated with diabetes. The study was conducted in streptozotocin-induced diabetic rats. Groups of hyperglycemic rats were subjected to dietary interventions for 6 weeks with zinc supplementation (5 times and 10 times the normal level). Supplemental-zinc-fed diabetic groups showed significant control on hyperglycemia and hypoinsulinemia. There was a significant reduction in protein glycosylation, glucosuria, and urinary excretion of proteins and urea in diabetic animals maintained on a zinc-supplemented diet. Diabetic rats showed significantly higher plasma albumin and lower plasma urea and creatinine levels upon zinc supplementation. Significant alterations in insulin sensitivity indices HOMA-IR, HOMA-B, and QUICKI were also indicated by zinc supplementation. The pathological abnormalities in pancreatic islets of diabetic animals were significantly alleviated by dietary zinc intervention. This study provides the first evidence that zinc supplementation can partially ameliorate the severity of diabetic hyperglycemia and associated metabolic abnormalities, hypoinsulinemia, insulin resistance, and altered pancreatic morphology. Thus, zinc supplementation may offer a significant potential for clinical application in managing diabetic hyperglycemia and related metabolic complications.

Relationship between serum concentrations of persistent organic pollutants and markers of insulin resistance in a cohort of women with a history of gestational diabetes mellitus.

The aim of the present study was to assess the relationship between serum concentrations of several persistent organic pollutants and insulin resistance markers in a cohort of women with a history of gestational diabetes mellitus. ∑POPs was computed as the sum of individual serum POP concentrations. No statistically significant associations were found between levels of any POP and fasting glucose. However, polychlorinated biphenyl (PCB) congeners 138 and 180 were positively associated with 2-h glucose levels and PCB 180 also with fasting immunoreactive insulin (IRI). We also found a positive association of p,p'- dichlorodiphenyldichloroethylene (p,p'- DDE), PCBs (138, 153, and 180), hexachlorobenzene, and ∑POPs with 2-h IRI. Serum concentrations of PCBs (138, 153, and 180), hexachlorobenzene, and ∑POPs were also positively associated with homeostasis model assessment (HOMA2-IR) levels. Moreover, p,p'- DDE, PCBs (138, 153 and 180), hexachlorobenzene, and ∑POPs were negatively associated with Insulin Sensitivity Index (ISI-gly) levels. No significant association was found between glycated hemoglobin and the concentrations of any POP. The removal of women under blood glucose lowering treatment from the models strengthened most of the associations previously found for the whole population. Our findings suggest that exposure to certain POPs is a modifiable risk factor contributing to insulin resistance.

Determining pancreatic ß-cell compensation for changing insulin sensitivity using an oral glucose tolerance test.

Plasma glucose, insulin, and C-peptide responses during an OGTT are informative for both research and clinical practice in type 2 diabetes. The aim of this study was to use such information to determine insulin sensitivity and insulin secretion so as to calculate an oral glucose disposition index (DI(OGTT)) that is a measure of pancreatic ß-cell insulin secretory compensation for changing insulin sensitivity. We conducted an observational study of n = 187 subjects, representing the entire glucose tolerance continuum from normal glucose tolerance to type 2 diabetes. OGTT-derived insulin sensitivity (S(I OGTT)) was calculated using a novel multiple-regression model derived from insulin sensitivity measured by hyperinsulinemic euglycemic clamp as the independent variable. We also validated the novel S(I OGTT) in n = 40 subjects from an independent data set. Plasma C-peptide responses during OGTT were used to determine oral glucose-stimulated insulin secretion (GSIS(OGTT)), and DI(OGTT) was calculated as the product of S(I OGTT) and GSIS(OGTT). Our novel S(I OGTT) showed high agreement with clamp-derived insulin sensitivity (typical error = +3.6%; r = 0.69, P < 0.0001) and that insulin sensitivity was lowest in subjects with impaired glucose tolerance and type 2 diabetes. GSIS(OGTT) demonstrated a significant inverse relationship with S(I OGTT). GSIS(OGTT) was lowest in normal glucose-tolerant subjects and greatest in those with impaired glucose tolerance. DI(OGTT) was sequentially lower with advancing glucose intolerance. We hereby derive and validate a novel OGTT-derived measurement of insulin sensitivity across the entire glucose tolerance continuum and demonstrate that ß-cell compensation for changing insulin sensitivity can be readily calculated from clinical variables collected during OGTT.

Abdominal adiposity and insulin resistance in early pregnancy.

BACKGROUND: High pre-pregnancy body mass index is a known risk factor for gestational diabetes mellitus, but the contribution of abdominal adiposity to insulin resistance (IR) in pregnancy is not well understood. We assessed the association between abdominal adiposity in early pregnancy and IR. METHODS: We completed a prospective cohort study of 79 pregnant women. Visceral adipose tissue (VAT) depth was measured by ultrasonography at 11 to 14 weeks' gestation, at the time of routine fetal nuchal translucency assessment. A two-hour 75 g oral glucose tolerance test was subsequently completed at 16 to 22 weeks' gestation and IR was estimated by the homeostatic model assessment of insulin resistance (HOMA-IR) as well as by the insulin sensitivity index. RESULTS: After adjusting for maternal age, parity, ethnicity, and pre-pregnancy BMI, VAT depth explained 42% of the variance in HOMA-IR, which was slightly better than the variance in the multivariable model examining HOMA-IR and pre-pregnancy BMI (40%). For the insulin sensitivity index, the model variance values were 36% and 32%, respectively. CONCLUSION: Measurement of maternal adipose tissue depth at the time of routine first-trimester ultrasonography may provide additional information about maternal IR, beyond pre-pregnancy BMI.

Contexte : Bien que la présence d'un indice de masse corporelle prégrossesse élevé soit un facteur de risque connu pour ce qui est du diabète sucré gestationnel, l'apport de l'adiposité abdominale à l'insulinorésistance (IR) pendant la grossesse n'est pas bien compris. Nous avons évalué l'association entre l'adiposité abdominale aux débuts de la grossesse et l'IR. Méthodes : Nous avons mené une étude de cohorte prospective auprès de 79 femmes enceintes. La profondeur du tissu adipeux viscéral (TAV) a été mesurée par échographie à 11-14 semaines de gestation, dans le cadre de l'évaluation systématique de la clarté nucale fœtale. Une épreuve d'hyperglycémie provoquée par voie orale (deux heures, 75 g) a par la suite été menée à 16-22 semaines de gestation et l'IR a été estimée au moyen du modèle homéostatique d'évaluation de l'insulinorésistance (HOMA-IR), ainsi qu'au moyen de l'indice de sensibilité à l'insuline. Résultats : À la suite de la neutralisation des effets de l'âge maternel, de la parité, de l'ethnicité et de l'IMC prégrossesse, la profondeur du TAV a permis d'expliquer 42 % de la variance constatée dans le cadre du HOMA-IR, ce qui était légèrement mieux qu'en ce qui concerne la variance constatée dans le cadre du modèle multivarié faisant appel au HOMA-IR et à l'IMC prégrossesse (40 %). Pour ce qui est de l'indice de sensibilité à l'insuline, les valeurs quant à la variance pour chacun des modèles ont été de 36 % et de 32 %, respectivement. Conclusion : La mesure de la profondeur du tissu adipeux maternel, au moment de la tenue systématique de l'échographie au cours du premier trimestre, pourrait fournir des renseignements supplémentaires au sujet de l'IR maternelle, au-delà de ce qu'indique l'IMC prégrossesse.

Effects of Consuming Beverages Sweetened with Fructose, Glucose, High-Fructose Corn Syrup, Sucrose, or Aspartame on OGTT-Derived Indices of Insulin Sensitivity in Young Adults.

(1) Background: Clinical results on the effects of excess sugar consumption on insulin sensitivity are conflicting, possibly due to differences in sugar type and the insulin sensitivity index (ISI) assessed. Therefore, we compared the effects of consuming four different sugars on insulin sensitivity indices derived from oral glucose tolerance tests (OGTT). (2) Methods: Young adults consumed fructose-, glucose-, high-fructose corn syrup (HFCS)-, sucrose-, or aspartame-sweetened beverages (SB) for 2 weeks. Participants underwent OGTT before and at the end of the intervention. Fasting glucose and insulin, Homeostatic Model Assessment-Insulin Resistance (HOMA-IR), glucose and insulin area under the curve, Surrogate Hepatic Insulin Resistance Index, Matsuda ISI, Predicted M ISI, and Stumvoll Index were assessed. Outcomes were analyzed to determine: (1) effects of the five SB; (2) effects of the proportions of fructose and glucose in all SB. (3) Results: Fructose-SB and the fructose component in mixed sugars negatively affected outcomes that assess hepatic insulin sensitivity, while glucose did not. The effects of glucose-SB and the glucose component in mixed sugar on muscle insulin sensitivity were more negative than those of fructose. (4) Conclusion: the effects of consuming sugar-SB on insulin sensitivity varied depending on type of sugar and ISI index because outcomes assessing hepatic insulin sensitivity were negatively affected by fructose, and outcomes assessing muscle insulin sensitivity were more negatively affected by glucose.

Threshold for improvement in insulin sensitivity with adolescent weight loss.

OBJECTIVES: To assess the association of weight loss and insulin sensitivity, glucose tolerance, and metabolic syndrome (MS) in obese adolescents following weight loss treatment, and to determine the threshold amount of weight loss required to observe improvements in these measures. STUDY DESIGN: A randomized, controlled behavioral weight loss trial was conducted with 113 obese adolescents. Changes in fasting insulin, homeostasis model assessment of insulin resistance, whole body insulin sensitivity index (WBISI), body mass index (BMI), and MS criteria were assessed at baseline and at month 4. RESULTS: There was significant improvement in all measures of insulin sensitivity at month 4. Mean fasting insulin dropped from 22.3 to 16.6 µU/mL (P < .0001). Homeostasis model assessment of insulin resistance decreased significantly from 4.9 to 3.7 (P = .001) and WBISI increased significantly from 2.87 to 3.98 (P < .0001). An 8% reduction in BMI led to a significant improvement in WBISI (P = .03) and was the optimal threshold. Fewer individuals met criteria for MS after weight loss (P = .0038), although there were no significant changes in the individual features of the syndrome. CONCLUSIONS: In this trial, weight loss at month 4 was associated with improved insulin sensitivity in obese adolescents. An approximate decrease in BMI of 8% was the threshold level at which insulin sensitivity improved. As more weight loss programs are designed for obese adolescents, it will be important to have reasonable weight loss goals that will yield improvements in metabolic and cardiovascular disease risk factors.

A Cross-Sectional Multicentre Study to Validate Insulin Sensitivity Index Cut-Offs for Detection of Metabolic Syndrome in Indian Adolescents with Type-1 Diabetes.

Background: A previous study compared insulin sensitivity indices for the detection of double diabetes (DD) in Indian adolescents with type-1 diabetes (T1D) and derived a cut-off to predict future risk for the development of metabolic syndrome (MS) in adolescents with T1D. We conducted the current study with the aim to validate these cut-offs for detecting DD among Indian subjects with T1D from various geographical locations. Methods: This multicentric cross-sectional study included 161 Indian adolescents with T1D. Demographic, anthropometric, clinical, and biochemical data were collected using standard protocols. Insulin sensitivity (IS) was calculated using various equations developed to determine insulin sensitivity in subjects with T1D. Metabolic syndrome was diagnosed using International Diabetes Federation (IDF) Consensus Definition 2017. Results: We report 4.3% prevalence of MS in Indian adolescents with T1D with an additional 29.8% of study participants at risk of development of MS. Low High density lipoprotein (HDL) (23.6%) was the commonest abnormal component of the MS definition. Insulin sensitivity calculated by an equation derived by the SEARCH group was the most appropriate index to identify MS and metabolic risk in Indian adolescents with T1D. The proposed cut-off of 5.48 had high specificity, positive predictive value, and negative predictive value in identifying the risk of the development of DD. Conclusions: Insulin sensitivity calculated by the equation proposed by the SEARCH group together with cut-offs derived in earlier study may be used effectively to identify risk of development of MS/DD in Indian adolescents with T1D from various geographical locations.

Abnormal Glucose Metabolism Parameters and the Aggressiveness of Differentiated Thyroid Carcinoma: A Hospital-Based Cross-Section Study in China.

Purpose: The correlation of abnormal glucose metabolism and thyroid carcinoma, especially the aggressiveness of thyroid cancer, still remains controversial. We conducted this study to investigate the relationship between abnormal glucose metabolism parameters and differentiated thyroid carcinoma (DTC) in the Chinese population. Materials and Methods: The study was designed as a hospital-based case-control study and was approved by the Ethics Committee of our hospital and registered in the Clinical Trial Protocol Registration and Results System (Registration code: NCT03006289). From January 1, 2018 to June 30, 2021, a total of 377 DTC patients were enrolled in the study. Demographic and general characteristics, details of thyroid surgery and histopathological results, hematological test indicators were collected. Glucose metabolism parameters were calculated. Variables were analyzed by t-test, ANOVA, chi-squared analysis and Fisher's exact test. Pearson bi-variate correlation and Spearman's correlation analysis were used for bi-variate analysis. Results: More than 40% of patients with DTC were multifocality, more than half were extra-glandular invasion, and nearly 85% complied by lymph node metastasis. The prevalence of diabetes mellitus (DM) was about 10.08% in DTC patients. It was found that the proportion of postprandial 2 h blood glucose ≥11.1mmol/L and HbA1c ≥6.5% was significantly higher than the known proportion of DM (17.8%, 16.7% vs. 10.08%). Additionally, 87.3% of the DTC patients in this study had varying degrees of insulin resistance. Further analysis found that higher T staging was associated with higher levels of area under curve of C-peptide (P = 0.029), insulin sensitivity index (P = 0.012) and C-peptide sensitivity index (P = 0.016). A delayed peak of insulin secretion was found to be positive related with capsule invasion (r = 0.206, P = 0.004). In patients without a DM history, homeostasis model assessment of insulin resistance (P = 0.017), insulin sensitivity index (P = 0.019) and C-peptide sensitivity index (P = 0.020) were statistic associated with T staging. Also, the glucose metabolism parameter at 3-hour after a meal was related to a larger number of metastatic lymph nodes. Conclusion: Abnormal glucose metabolism, namely, DM, hyperinsulinemia and insulin resistance, were significantly associated with the carcinogensis and aggressiveness of DTC.

Beta cell functionality and hepatic insulin resistance are major contributors to type 2 diabetes remission and starting pharmacological therapy: from CORDIOPREV randomized controlled trial.

In order to assess whether previous hepatic IR (Hepatic-IRfasting) and beta-cell functionality could modulate type 2 diabetes remission and the need for starting glucose-lowering treatment, newly-diagnosed type 2 diabetes participants who had never received glucose-lowering treatment (190 out of 1002) from the CORonary Diet Intervention with Olive oil and cardiovascular PREVention study (a prospective, randomized and controlled clinical trial), were randomized to consume a Mediterranean or a low-fat diet. Type 2 diabetes remission was defined according to the American Diabetes Association recommendation for levels of HbA1c, fasting plasma glucose and 2h plasma glucose after oral glucose tolerance test, and having maintained them for at least 2 consecutive years. Patients were classified according to the median of Hepatic-IRfasting and beta-cell functionality, measured as the disposition index (DI) at baseline. Cox proportional hazards regression determined the potential for Hepatic-IRfasting and DI indexes as predictors of diabetes remission and the probability of starting pharmacological treatment after a 5-year follow-up. Low-Hepatic-IRfasting or high-DI patients had a higher probability of diabetes remission than high-Hepatic-IRfasting or low-DI subjects (HR:1.79; 95% CI 1.06-3.05; and HR:2.66; 95% CI 1.60-4.43, respectively) after a dietary intervention with no pharmacological treatment and no weight loss. The combination of low-Hepatic-IRfasting and high-DI presented the highest probability of remission (HR:4.63; 95% CI 2.00-10.70). Among patients maintaining diabetes, those with high- Hepatic-IRfasting and low-DI showed the highest risk of starting glucose-lowering therapy (HR:3.24;95% CI 1.50-7.02). Newly-diagnosed type 2 diabetes patients with better beta-cell functionality and lower Hepatic-IRfasting had a higher probability of type 2 diabetes remission in a dietary intervention without pharmacological treatment or weight loss, whereas among patients not achieving remission, those with worse beta-cell functionality and higher Hepatic-IRfasting index had the highest risk of starting glucose-lowering treatment after 5 years of follow-up.

Comparison of twenty indices of insulin sensitivity in predicting type 2 diabetes in Japanese Americans: The Japanese American Community Diabetes Study.

AIMS: We compared 20 previously reported indices of insulin sensitivity derived from samples during an oral glucose tolerance test (OGTT) to determine which was best in predicting incident type 2 diabetes. METHODS: We prospectively followed 418 Japanese Americans without diabetes for 10-11 years. We compared ability to predict incident diabetes of 20 insulin sensitivity indices-9 based on fasting samples, 7 based on 2-h and/or fasting samples, and 4 based on multiple samples (0, 30, 60, 120 min) during an OGTT-by integrated discrimination improvement, category free net reclassification improvement, and area under the receiver operator characteristic curve. RESULTS: There were 95 incident cases of diabetes. The Cederholm and Gutt indices, requiring more than only fasting samples, were the best to predict incident diabetes as judged by integrated discrimination improvement (0.187, 0.184), category free net reclassification improvement (0.962, 1.030), and area under the receiver operator characteristic curve (0.864, 0.863, respectively). Fasting indices were clearly inferior to both the Cederholm and Gutt indices. CONCLUSIONS: Among the 20 indices, the Cederholm and Gutt indices predicted diabetes best but the Gutt index may be preferable because it requires fewer samples during an OGTT.

Risk Factors of Ketosis in Obese Ketosis-Prone Diabetic Patients: A Case-Control Study.

INTRODUCTION: Different types of ketosis-prone obese diabetic patients are seen in the clinic. At present, the mechanism responsible for ketosis onset in these patients remains unclear, and we do not know how these patients should be optimally treated to prevent recurrent ketosis. Therefore, this study aims to investigate risk factors of ketosis in obese ketosis-prone diabetic (OB-KPD) patients. METHODS: In an observational case-control study, primary OB-KPD patients [body mass index (BMI) ≥ 28 kg/m2] were selected as the study group (OB-KPD group), and primary obese type 2 diabetes patients served as the control group (OB-T2DM group). Clinical diagnostic assessments of fasting plasma glucose (FPG), glycated hemoglobin (HbA1c), blood lipid, area under curve of serum C-peptide (AUCC-P) after steamed bread meal, insulin sensitivity index (ISI), ß-hydroxybutyric acid (ß-HB) and free fatty acid (FFA) vlaues of the subjects were collected. Subjects in the OB-KPD group were followed up for 1 year to determine the likelihood of insulin therapy cessation and whether ketosis recurred by assessing clinical chemistry parameters at 1-year follow-up. RESULTS: Seventy-five subjects were screened, of which 15 were not included in the study for several identified clinical reasons. On enrollment, the OB-KPD group displayed significantly higher FPG, HbA1c and FFA levels than the OB-T2DM group (p < 0.01), while AUCC-P and ISI values were significantly lower than in the OB-T2DM group (p < 0.01 and p = 0.03). Statistical analysis showed that increases in ß-HB in the OB-KPD group were associated with increased blood glucose and FFA and decreased AUCC-P and ISI values. Furthermore, decreases in AUCC-P were closely associated with increased blood glucose values. CONCLUSION: The occurrence of ketosis in ketosis-prone obese diabetic patients may be related to glucose and lipid metabolism disorders, increased insulin resistance and decreased ß-cell secretory functions. TRIAL REGISTRATION: This work was registered at the Chinese Clinical Trial Registry with trial registration identifier no. ChiCTR1900025909.

Relationships among pancreatic beta cell function, the Nrf2 pathway, and IRS2: a cross-sectional study.

OBJECTIVES: This study aimed to investigate the relationships among islet function, the Nrf2 pathway, and insulin receptor substrate 2 (IRS2) in type 2 diabetes mellitus (T2DM), prediabetes mellitus (IGR), and normal glucose tolerance (NGT) populations. METHODS: Three hundred cases each were selected for the NGT, IGR, and T2DM groups; FBG, 2hPG, HbA1 c, FINS, TG, TC, HDL-C, and LDL-C levels and serum levels of nuclear factor in E2-related factor 2 (Nrf2), insulin receptor substrate 2 (IRS2), tumor necrosis factor alpha (TNF-α), and heme oxygenase 1 (HO-1) were evaluated. RESULTS: The T2DM group had lower islet ß-cell function index and insulin sensitivity index than the NGT and IGR groups (P < 0.05). The Nrf2, IRS2, and HO-1 levels in the NGT, IGR, and T2DM groups followed a decreasing trend in the order mentioned, whereas the TNF-α levels followed an increasing trend. CONCLUSIONS: Upon impairment of glucose regulation, the expression of TNF-α in the human body increased, which indicated the aggravation of oxidative stress (OS) and the inflammatory response. Islet function was maintained in the pre-diabetic population, and concurrently, the TNF-α, Nrf2, and HO-1 levels were moderately elevated, the expression of IRS2 was marginally inhibited, and the Nrf2 pathway was activated under mild OS stimulus to resist OS, inflammation, and injury, which may have been mediated through PI3 K/AKT. In patients with T2DM, islet function was significantly poorer, TNF-α amplification was enhanced significantly, and Nrf2, HO-1, and IRS2 expression reduced significantly; this suggested that, along with the aggravation of OS and the inflammatory response, Nrf2 pathway activation and HO-1 expression were both inhibited, the antioxidant capacity of the body was reduced, IRS2 degradation increased, and islet function was impaired.