Decreased beta-cell function in overweight Latino children with impaired fasting glucose
ABSTRACT To determine whether overweight Latino children with impaired fasting glucose (IFG) (> or = 100 mg/dl) have increased insulin resistance or decreased beta-cell function compared with those with normal fasting glucose (NFG).
We studied 207 healthy overweight Latino children, aged 8-13 years, with a family history of type 2 diabetes. Fasting and 2-h glucose and insulin were assessed by oral glucose tolerance test. Insulin sensitivity (S(i)), the acute insulin response to glucose (AIRg), and the disposition index (DI; an index of beta-cell function) were determined using the insulin-modified intravenous glucose tolerance test and minimal modeling. Body composition was determined by dual-energy X-ray absorptiometry.
There were no differences in body composition between NFG (n = 182) and IFG (n = 25) children. Compared with children with NFG, children with IFG had higher fasting and 2-h glucose values and higher fasting insulin. After adjusting for covariates, children with IFG had no difference in S(i) but 15% lower DI than NFG children (2,224 +/- 210 vs. 2,613 +/- 76, P < 0.05). Multivariate linear regression showed that AIRg and DI, but not S(i), were significant predictors of fasting blood glucose.
In overweight Latino adolescents with a family history of type 2 diabetes, IFG is associated with impaired beta-cell function and therefore may identify children likely to be at risk for progression to type 2 diabetes. The actual risk of progression of IFG to type 2 diabetes remains to be determined by prospective longitudinal studies.
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ABSTRACT: Background:We previously reported that more frequent eating in overweight minority youth was linked to lower visceral adiposity and circulating triglycerides. The aim of this study was to examine this issue in more detail by assessing the relationship between eating frequency and adiposity and metabolic disease risk in a cohort of exclusively overweight Hispanic youth.Methods:This analysis included 191 overweight (⩾85th percentile BMI) Hispanic youth (8-18y) with the following cross-sectional measures: height, weight, BMI, dietary intake via multiple 24-h recalls, body composition via dual-energy X-ray absorptiometry, lipids, and insulin action (insulin sensitivity, acute insulin response (AIR) and disposition index (DI), a measure of beta cell function) via a frequently sampled intravenous glucose tolerance test. Each eating occasion (EO) was defined as ⩾50 calories and ⩾15 minutes from any prior EO. Infrequent Eaters (IEs) were classified as any subject who ate <3 EOs on any dietary recall (n=32), whereas Frequent Eaters (FEs) always consumed ⩾3 EOs (n=159).Results:Using analyses of covariance, FEs compared to IEs consumed 23% more calories per day (P⩽0.01), ate 40% more often, and consumed 19% less calories per EO (P⩽0.01). FEs also exhibited 9% lower BMI z-scores (P⩽0.01), 9% lower waist circumferences (P⩽0.01), 29% lower fasting insulin (P=0.02), 31% lower HOMA-IR values (P=0.02), and 19% lower triglycerides (P⩽0.01), as well as an 11% higher AIR (P=0.02) and 31% higher DI (P=0.01). The following a priori covariates were included: Tanner, sex, body fat, and reported energy intake.Conclusion:These findings suggest that increased eating frequency is related to decreased obesity and metabolic disease risk in overweight Hispanic youth, despite increases in energy intake.International Journal of Obesity accepted article preview online, 20 May 2014; doi:10.1038/ijo.2014.81.International journal of obesity (2005) 05/2014; 39(1). DOI:10.1038/ijo.2014.81 · 5.39 Impact Factor
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ABSTRACT: Type 2 diabetes risk and its relationship to free fatty acid (FFA) exposure and visceral fat by prediabetes status in minority adolescents have yet to be explored. Therefore, the objective of this study was to examine the association of circulating FFA under varying conditions with prediabetes in Latino adolescents and to determine the relative relationships of FFA and visceral adiposity to insulin sensitivity, secretion, and β-cell function. Overweight or obese, but otherwise healthy Latino adolescent males and females (n = 164, 14.2 ± 2.5 years), were recruited for assessment of prediabetes, abdominal fat, and FFA levels taken at a fasting state (FFAF), during an OGTT (FFAOGTT), and overnight (FFANOCTURNAL). Prediabetic adolescents had a higher FFAF than those with normal glucose tolerance when controlling for age, sex, pubertal status, total percent body fat, and visceral fat. FFAOGTT and FFANOCTURNAL did not differ between participants with prediabetes and those with normal glucose tolerance after adjusting for covariates. Visceral fat was independently related to insulin sensitivity and secretion in pubertal adolescents; however, in post-pubertal adolescents, FFAF and visceral fat were both independent and negatively related to β-cell function. These results support a plausible progression of the lipotoxicity theory of diabetes development during the pubertal transition.Acta Diabetologica 08/2014; DOI:10.1007/s00592-014-0634-7 · 3.68 Impact Factor
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ABSTRACT: There is an urgent need for innovative and developmentally appropriate lifestyle interventions to promote healthy lifestyle behaviors and to prevent the early onset of type 2 diabetes and cardiovascular disease risk in obese Latino adolescents. Guided imagery offers promise to reduce stress and promote lifestyle behavior change to reduce disease risk in obese adolescents. Our objectives were: 1) To pilot test a new 12-wk lifestyle intervention using a randomized trial design in obese Latino adolescents, in order to determine the effects of the mind-body modality of Interactive Guided ImagerySM (IGI), over and above those of a didactic lifestyle education, on insulin resistance, eating and physical activity behaviors, stress and stress biomarkers; and 2) To explore the role of intervention-related changes in stress and stress biomarkers on changes in metabolic outcomes, particularly insulin resistance. Obese (BMI > 95th percentile), Latino adolescents (n = 35, age 14-17) were randomized to receive either 12 weekly sessions of a lifestyle education plus guided imagery program (GI), or lifestyle education plus a digital storytelling computer program (DS). Between-group differences in behavioral, biological, and psychological outcomes were assessed using unpaired T-tests and ANCOVA in the 29 subjects who completed the intervention. The GI group demonstrated significant reductions in leisure sedentary behavior (p < .05) and increases in moderate physical activity (p < .05) compared to DS group, and a trend toward reduced caloric intake in GI vs DS (p = .09). Salivary cortisol was acutely reduced by stress-reduction guided imagery (p < .01). There were no group differences in adiposity, insulin resistance, perceived stress, or stress biomarkers across the 12-week intervention, though decrease in serum cortisol over the course of the intervention was associated with improved insulin sensitivity (p = .03) independent of intervention group and other relevant co-variates. The improvements in physical activity and stress biomarkers following this pilot intervention support the role of guided imagery in promoting healthy lifestyle behavior change and reducing metabolic disease risk in obese Latino adolescent populations. Future investigations will be needed to determine the full effects of the Imagine HEALTH intervention on insulin resistance, stress, and stress biomarkers.Trial registration: Clinicaltrials.gov Registry #: NCT01895595.BMC Complementary and Alternative Medicine 01/2014; 14(1):28. DOI:10.1186/1472-6882-14-28 · 1.88 Impact Factor