Metabolic clearance rate of insulin across the glucose tolerance spectrum by race and ethnicity in youth with obesity.

Objective: Despite β-cell failure in youth with dysglycemia (i.e., impaired glucose tolerance [IGT] and type 2 diabetes), fasting insulin (FI) concentrations are elevated.

Exercise Adherence in Hispanic Adolescents with Obesity or Type 2 Diabetes.

Purpose: Hispanic adolescents experience high rates of obesity and type 2 diabetes. The purpose of this study was to examine adherence to a 16-week personalized exercise intervention and the perception of family support for exercise, benefits and barriers to exercise and overall health in Hispanic adolescents diagnosed with obesity or type 2 diabetes.

Design And Methods: Using a secondary analysis of a larger feasibility trial, data from 21 Hispanic adolescents, 13 with T2D and 8 who were obese and 14 that completed the entire 16-week study (7 T2D; 7 obese) were analyzed.

β-cell function, incretin response, and insulin sensitivity of glucose and fat metabolism in obese youth: Relationship to OGTT-time-to-glucose-peak.

Background: In adults, the time-to-glucose-peak at or after 30 minutes during an oral glucose tolerance test (OGTT) identifies physiologically distinct groups with differences in insulin sensitivity, β-cell function and risk for type 2 diabetes. In obese non-diabetic adolescents, we investigated if the OGTT-time-to-glucose-peak also reflects incretin and free fatty acid (FFA) responses besides insulin sensitivity and β-cell function, measured by the clamp.

Methods: Obese adolescents (n = 278) were categorized according to their OGTT-time-to-glucose-peak by Early-peak (at 30 minutes) vs Late-peak (>30 minutes) groups.

Elementary school classroom physical activity breaks: student, teacher, and facilitator perspectives.

Current physical activity (PA) guidelines recommend that children accumulate at least 60 min of PA each day, and that adults should collaborate across sectors to increase opportunities for PA. Implementing brief classroom PA breaks (CPABs) is one way to help increase daily PA. The primary purpose of this study was to determine perceptions of a 14-wk CPAB program among elementary school children, in the first through fourth grades ( n = 254), at a suburban elementary school, and their teachers ( n = 18).

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.

Objective: Adipose tissue insulin resistance is one of the pathophysiological components of type 2 diabetes. Herein we investigated: ) adipose insulin resistance index (Adipose-IR) (calculated as fasting insulin × free fatty acids [FFAs]) in youth across the spectrum of adiposity from normal weight to obese and the spectrum from normal glucose tolerance (NGT) to impaired glucose tolerance (IGT) to type 2 diabetes, ) the relationship of Adipose-IR with physical and metabolic characteristics, and ) the predictive power of Adipose-IR for determining dysglycemia in youth.

Research Design And Methods: A total of 205 youth had fasting glucose, insulin, FFA, Adipose-IR, body composition, visceral adipose tissue (VAT), leptin, and adiponectin evaluated.

Patterns of Physical Activity Adherence by Adolescents With Diabetes or Obesity Enrolled in a Personalized Community-Based Intervention.

Purpose: The purpose of this study was to determine the feasibility of a personalized, 16-week community-based physical activity intervention for adolescents with diabetes or obesity and examine the weekly patterns of adherence to the intervention.

Methods: Physical activity adherence was evaluated throughout the intervention using accelerometers in 46 adolescents with type 1 diabetes (N = 22), type 2 diabetes (N = 12), or obesity (N = 12) (age, 14.4 ± 1.

Impaired Lipolysis, Diminished Fat Oxidation, and Metabolic Inflexibility in Obese Girls With Polycystic Ovary Syndrome.

Context: Metabolic flexibility reflects the ability to switch from lipid to carbohydrate oxidation during insulin stimulation manifested in increased respiratory quotient (RQ). Little is known about adipose tissue metabolism and metabolic flexibility in adolescent girls with polycystic ovary syndrome (PCOS).

Objective: We investigated whole-body lipolysis, substrate oxidation, and metabolic flexibility in obese girls with PCOS vs obese girls without PCOS.

Increased Lipolysis, Diminished Adipose Tissue Insulin Sensitivity, and Impaired β-Cell Function Relative to Adipose Tissue Insulin Sensitivity in Obese Youth With Impaired Glucose Tolerance.

Despite evidence of insulin resistance and β-cell dysfunction in glucose metabolism in youth with prediabetes, the relationship between adipose tissue insulin sensitivity (ATIS) and β-cell function remains unknown. We investigated whole-body lipolysis, ATIS, and β-cell function relative to ATIS (adipose disposition index [DI]) in obese youth with impaired glucose tolerance (IGT) versus normal glucose tolerance (NGT). Whole-body lipolysis (glycerol appearance rate [GlyRa], [H]glycerol at baseline and during a hyperinsulinemic-euglycemic clamp), lipid oxidation (indirect calorimetry), insulin secretion (2-h hyperglycemic clamp), and body composition (dual-energy X-ray absorptiometry) were examined.

Anti-Müllerian Hormone in Obese Adolescent Girls With Polycystic Ovary Syndrome.

Purpose: Anti-Müllerian hormone (AMH) is proposed as a biomarker of polycystic ovary syndrome (PCOS). This study investigated: (1) AMH concentrations in obese adolescents with PCOS versus without PCOS; (2) the relationship of AMH to sex steroid hormones, adiposity, and insulin resistance; and (3) the optimal AMH value and the multivariable prediction model to determine PCOS in obese adolescents.

Methods: AMH levels were measured in 46 obese PCOS girls and 43 obese non-PCOS girls.

Maternal excess gestational weight gain and infant waist circumference: a 2-y observational study.

Background: The purpose of this study was to examine the effects of gestational weight gain (GWG) and infant feeding practices on infant growth parameters in infants from 6 to 24 mo of age.

Methods: Forty mother-infant pairs were recruited after delivery and followed up to 24 mo postpartum. GWG was calculated as prepregnancy weight subtracted from weight at delivery.

The Shape of the Glucose Response Curve During an Oral Glucose Tolerance Test Heralds Biomarkers of Type 2 Diabetes Risk in Obese Youth.

Objective: The shape of the glucose response curve during an oral glucose tolerance test (OGTT), monophasic versus biphasic, identifies physiologically distinct groups of individuals with differences in insulin secretion and sensitivity. We aimed to verify the value of the OGTT-glucose response curve against more sensitive clamp-measured biomarkers of type 2 diabetes risk, and to examine incretin/pancreatic hormones and free fatty acid associations in these curve phenotypes in obese adolescents without diabetes.

Research Design And Methods: A total of 277 obese adolescents without diabetes completed a 2-h OGTT and were categorized to either a monophasic or a biphasic group.

Distinguishing characteristics of metabolically healthy versus metabolically unhealthy obese adolescent girls with polycystic ovary syndrome.

Objective: To investigate the key physical, metabolic, hormonal and cardiovascular characteristics of metabolically healthy obese (MHO) versus unhealthy obese (MUHO) girls with polycystic ovary syndrome (PCOS).

Design: Cross-sectional study.

Setting: Research center.

Differences in β-cell function and insulin secretion in Black vs. White obese adolescents: do incretin hormones play a role?

Black youth are at higher risk for type 2 diabetes (T2D) than their White peers. Previously we demonstrated that for the same degree of insulin sensitivity, Black youth have an upregulated β-cell function and insulin hypersecretion, in response to intravenous (iv) glucose, compared with Whites. To investigate if the same holds true during an oral glucose challenge and because of the important role of glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) in augmenting insulin secretion, we examined β-cell function and incretin hormones in 85 Black and 78 White obese adolescents, with normal glucose tolerance (NGT), during a 2-h oral glucose tolerance test (OGTT) with mathematical modeling of plasma glucose and C-peptide concentrations to assess β-cell glucose sensitivity (βCGS), rate sensitivity, potentiation factor, and insulin sensitivity.

β-cell function, incretin effect, and incretin hormones in obese youth along the span of glucose tolerance from normal to prediabetes to type 2 diabetes.

Using the hyperglycemic and euglycemic clamp, we demonstrated impaired β-cell function in obese youth with increasing dysglycemia. Herein we describe oral glucose tolerance test (OGTT)-modeled β-cell function and incretin effect in obese adolescents spanning the range of glucose tolerance. β-Cell function parameters were derived from established mathematical models yielding β-cell glucose sensitivity (βCGS), rate sensitivity, and insulin sensitivity in 255 obese adolescents (173 with normal glucose tolerance [NGT], 48 with impaired glucose tolerance [IGT], and 34 with type 2 diabetes [T2D]).

Polycystic ovary syndrome and nonalcoholic fatty liver in obese adolescents: association with metabolic risk profile.

Objective: To investigate the relationship between liver fat and in vivo insulin sensitivity, body composition, abdominal adiposity, and lipid metabolism in obese adolescent girls with polycystic ovary syndrome (PCOS).

Design: Cross-sectional case-control study.

Setting: Research center.

Personalized exercise for adolescents with diabetes or obesity.

Objective: This study examined adherence to a personalized, community-based exercise intervention by sedentary adolescents with type 1 or type 2 diabetes or those with obesity.

Research Design And Methods: We conducted a pretest-posttest investigation to explore the application of an individualized exercise prescription based upon current fitness level for 39 adolescents (20 with type 1 diabetes, 9 with type 2 diabetes, and 10 obese) over 16 weeks in community settings. Subjects were recruited from a university-based pediatric endocrinology clinic in the southwestern United States.

β-Cell lipotoxicity in response to free fatty acid elevation in prepubertal youth: African American versus Caucasian contrast.

Prepubertal African American (AA) youth compared with their Caucasian (C) peers have higher insulin secretion, which correlates positively with free fatty acid (FFA) concentration. In our continued efforts to explain the racial disparity in insulinemia, and because FFAs modulate insulin secretion, we hypothesized that AA youth would have a greater response to FFA-induced β-cell insulin secretion than C youth. We compared the short-term effects of FFA elevation on fasting and glucose-stimulated C-peptide-modeled insulin secretion in prepubertal normal-weight AA versus C peers during a 2-h hyperglycemic clamp (12.

β-Cell lipotoxicity after an overnight intravenous lipid challenge and free fatty acid elevation in African American versus American white overweight/obese adolescents.

Objective: Overweight/obese (OW/OB) African American (AA) adolescents have a more diabetogenic insulin secretion/sensitivity pattern compared with their American white (AW) peers. The present study investigated β-cell lipotoxicity to test whether increased free fatty acid (FFA) levels result in greater β-cell dysfunction in AA vs AW OW/OB adolescents.

Research Design And Methods: Glucose-stimulated insulin secretion was modeled, from glucose and C-peptide concentrations during a 2-hour hyperglycemic (225 mg/dL) clamp in 22 AA and 24 AW OW/OB adolescents, on 2 occasions after a 12-hour overnight infusion of either normal saline or intralipid (IL) in a random sequence.

Metabolomic profiling of amino acids and β-cell function relative to insulin sensitivity in youth.

Context: In longitudinal studies of adults, elevated amino acid (AA) concentrations predicted future type 2 diabetes mellitus (T2DM).

Objective: The aim of the present investigation was to examine whether increased plasma AA concentrations are associated with impaired β-cell function relative to insulin sensitivity [i.e.

HbA(1c) diagnostic categories and β-cell function relative to insulin sensitivity in overweight/obese adolescents.

Objective: The recommended HbA(1c) diagnostic categories remain controversial and their utility in doubt in pediatrics. We hypothesized that alterations in the pathophysiologic mechanisms of type 2 diabetes may be evident in the American Diabetes Association recommended at-risk/prediabetes category (HbA(1c) 5.7 to <6.

Metabolomic profiling of fatty acid and amino acid metabolism in youth with obesity and type 2 diabetes: evidence for enhanced mitochondrial oxidation.

Objective: We compared acylcarnitine (AcylCN) species, common amino acid and fat oxidation (FOX) byproducts, and plasma amino acids in normal weight (NW; n = 39), obese (OB; n = 64), and type 2 diabetic (n = 17) adolescents.

Research Design And Methods: Fasting plasma was analyzed by tandem mass spectrometry, body composition by dual energy X-ray absorptiometry and computed tomography, and total-body lipolysis and substrate oxidation by [(2)H(5)]glycerol and indirect calorimetry, respectively. In vivo insulin sensitivity (IS) was assessed with a 3-h hyperinsulinemic-euglycemic clamp.

Physical activity and sedentary behavior in adolescents with type 1 diabetes.

The purpose of this study was to describe the associations between levels of physical activity measured by accelerometry and changes in fitness, body composition, lipids, and glucose control (i.e., glycosolated hemoglobin [A1C]) in a sample of 16 adolescents with type 1 diabetes participating in a personalized exercise program.

A personalized approach to exercise promotion in adolescents with type 1 diabetes.

Purpose: This exploratory study tested the feasibility of conducting a novel, personalized exercise intervention based upon the current fitness levels of adolescents with type 1 diabetes (T1DM). The relationships of perceptions of benefits and barriers to exercise, exercise self-efficacy and family support to exercise adherence and changes in cardiovascular (CV) fitness, quality of life (QOL), and glycemic control were studied.

Methods: Adolescents who were sedentary received a graded exercise test to determine their current fitness level (VO(2peak)).

Physical fitness, dietary intake, and metabolic control in adolescents with type 1 diabetes.

Purpose: We examined whether physical fitness and dietary intake predicted better glycemic control and lipid profile in adolescents with type 1 diabetes mellitus (T1DM).

Methods: The sample consisted of 109 adolescents with T1DM [age, 15.3 +/- 1.