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Youth-onset type 2 diabetes (T2D) is becoming increasingly prevalent, especially among Latino youth, and there is limited information on its pathophysiology and causative factors. Here, we describe findings from a longitudinal cohort study in 262 Latino children with overweight/obesity at risk of developing T2D with annual measures of oral and intravenous glucose tolerance (IVGTT), body composition, and fat distribution. Logistic binomial regression was used to identify significant predictors in those who developed T2D compared with matched control participants, and mixed-effects growth models were used to compare rates of change in metabolic versus adiposity measures between groups. Overall conversion rate to T2D at year 5 was 2% (n = 6). Rate of decline in disposition index (DI), measured with an IVGTT, over 5 years was three times higher in case patients (−341.7 units per year) compared with the extended cohort (−106.7 units per year) and 20 times higher compared with control participants (−15.2 units per year). Case patients had significantly higher annual increases in fasting glucose, hemoglobin A1c (HbA1c), waist circumference, and trunk fat, and there was an inverse correlation between rate of decline in DI and rates of increase in adiposity measures. T2D development in at-risk Latino youth is associated with a substantial and rapid decrease in DI that is directly correlated with increases in fasting glucose, HbA1c, and adiposity. Article Highlights Youth-onset type 2 diabetes is becoming increasingly prevalent, especially among Latino youth, and there is limited information on its pathophysiology and causative factors. Overall conversion rate to type 2 diabetes over 5 years was 2%. In youth who converted to type 2 diabetes, disposition index decreased rapidly by 85% compared with that in patients who did not convert during the study period. There was an inverse correlation between rate of decline in disposition index and rates of increase in various adiposity measures.

Youth onset type 2 diabetes (T2D) is becoming increasingly prevalent especially among Latinos, and there is limited information on its pathophysiology and causative factors. Here we describe findings from a longitudinal cohort study in 262 Latino children with overweight/obesity at risk of developing T2D with annual measures of oral and intravenous glucose tolerance (IVGTT), body composition and fat distribution. Logistic binomial regression was used to identify significant predictors in those who developed T2D compared to matched controls, and mixed-effects growth models to compare rates of change in metabolic versus adiposity measures between groups. Overall conversion rate to T2D at year five was 2% (n=6). Rate of decline in disposition index (DI), measured with an IVGTT, over 5 years was 3X higher in cases (─341.7 units/year) compared to the extended cohort (‒106.7 units/year) and 20X higher compared to controls (‒15.2 units/year). Cases had a significantly higher annual increase in fasting glucose, hemoglobin A1c, waist circumference, and trunk fat and there was an inverse correlation between rate of decline in DI and rate of increase in adiposity measures. T2D development in at risk Latino youth is associated with a substantial and rapid decrease in DI that is directly correlated with increase in fasting glucose, HbA1c, and adiposity.

Background: One limitation to studying time limited eating (TLE) in adolescents is difficulty in reliably assessing adherence to fasting periods. Dietary recalls, which are currently used to monitor diet adherence, have been criticized due to potential error in reporting, omission bias and suboptimal compliance. Continuous glucose monitoring (CGM) may be a useful tool to overcome these barriers; however, it requires daily wear and understanding of expected glycemic excursions. The present study examines the feasibility of daily CGM use and its utility as a tool to monitor adherence to fasting periods in a diverse cohort of adolescents with obesity participating in a pilot study of 8-hour TLE. Methods: Twenty adolescents (mean age 16.0+1.3 years, 70% female, 55% Latinx, 75% public insurance) with BMI ≥ 95th percentile, were enrolled in a 12-week study and randomized to: (1) Group 1 (control schedule): 12-hour eating period + blinded CGM, (2) Group 2 (TLE schedule): 8-hour eating period + blinded CGM, or (3) Group 3: 8-hour eating period + CGM with real-time feedback. CGM wear time was calculated as the actual weekly wear time divided by the prescribed wear time. At weeks 0, 4 and 12, CGM data from 7 days of self-reported fasting periods were reviewed to evaluate any glycemic excursions >50 ng/dL. Results: Overall, the mean CGM wear time was 90% (35-100%) with no difference between intervention arms. During self-reported fasting periods, only 4 adolescents had excursions >50 ng/dL, one of whom was diagnosed with type 2 diabetes. The remaining 16 participants had no excursions >50 ng/dL during their fasting periods. Conclusions: These data suggest that CGM may be a feasible tool to monitor adherence to TLE and provide a more accurate assessment of true fasting periods with less opportunity for error and bias when compared to self-report. Larger studies are needed to validate these findings and further explore the use of CGM as a tool in obesity research in adolescents. Disclosure M. Naguib: None. M. I. Goran: None. J. Raymond: None. E. Hegedus: None. C. Wee: None. A. Vidmar: None.

Introduction: Kiritimati is a remote Pacific Island with a high rate of type 2 diabetes (∼30%), potentially related to high sugar consumption starting early in life. This pilot study aimed to determine the effects of a short-term sugar-reduction intervention in Kiritimati teenagers. Methods: The two high schools on the island were randomly assigned to a 7-day sugar-reduction intervention group (n=46) or control group (n=32). The intervention consisted of installation of a water filter at the school, distribution of individual water bottles, and a sugar-reduction presentation by a registered dietitian. 24-hour diet recalls were conducted at baseline and follow-up. Continuous blood glucose monitors (CGMs; FreeStyle Libre Pro) were used to assess 94 interstitial glucose measures over 14 days. A difference-in-differences analysis was used to address baseline differences between the schools. Data are presented as mean ± SD. Results: At baseline, overweight/obesity prevalence was 50% (control group) vs. 43% (intervention group); age 17.2 ± 1.6 vs. 16.8 ± 1.8 years; mean blood glucose 88.3 ± 7.8 vs. 89.3 ± 31.5 mg/dL; added sugar consumption 122 ± 87 vs. 139 ± 77g/day; and %kcal from added sugars 18.3 ± 10.4 vs. 20.1 ± 9.5%. After the intervention, added sugar consumption decreased to 39 ± 47g (7.3 ± 8.3%kcal) in the intervention group without changing (133 ± 116g/19.2 ± 9.7%kcal) in the control group (time x group interaction p=0.003). However, there were no significant effects on any of the CGM measures. Conclusion: Despite high rates of type 2 diabetes on the island as a whole, blood glucose was normal in high-school teenagers, and was unaffected by the intervention. However, added sugar consumption was high (∼20 %kcal), which was greatly improved after the intervention (∼7 %kcal). This study suggests that a simple sugar-reduction intervention could improve diet quality in teenagers on Pacific Islands with high rates of type 2 diabetes such as Kiritimati. Disclosure J. Plows: None. C. Rios: None. P. Berger: None. R.B. Jones: None. T.L. Alderete: None. S. Steinberg: None. T. Bangao: None. E. Beale: None. M.I. Goran: Advisory Panel; Self; Yumi. Other Relationship; Self; Penguin Random House.

Rodent studies demonstrate that compared with diets sweetened with sucrose, high fructose corn syrup (HFCS) produces greater metabolic dysfunction. However, the effects of sustained consumption of HFCS and sucrose have not been adequately compared in humans. The objective of this study was to compare HFCS-, sucrose-, or aspartame- sweetened beverage (-SB) consumption on hepatic lipid content and insulin sensitivity in young adults. In a parallel, double-blinded study, adult men and women (18-40 yrs) were assigned to beverage groups matched for sex, BMI and fasting triglycerides. Inpatient magnetic resonance imaging for hepatic lipid content and oral glucose tolerance tests were performed at baseline and intervention 15 days later. For 12 outpatient days subjects consumed their usual diets with 3 servings/day of HFCS- (n=28) or sucrose-SB (n=24) providing 25% energy requirement (Ereq), or aspartame-SB (n=23). Matched standardized diets were provided during inpatient testing with the sugar in beverages replacing complex carbohydrate during intervention. Hepatic lipid content was increased by consumption of HFCS-SB (LS means of absolute Δ±SEM: 0.5%±0.2, P Consumption of SB providing 25% of Ereq as HFCS or sucrose for 2 weeks increased hepatic lipid content and reduced insulin sensitivity in young adults compared with consumption of aspartame-SB. Disclosure D. Sigala: None. B. Hieronimus: None. C. Price: None. V. Lee: None. M. Nunez: None. V. Medici: None. A.J. Chaudhari: None. J.P. McGahan: None. Y. Abdelhafez: None. N.L. Keim: None. M.I. Goran: Advisory Panel; Self; Yumi. Other Relationship; Self; Penguin Random House. G. Pacini: None. A. Tura: None. P.J. Havel: Research Support; Self; Arrowhead Pharmaceuticals, Inc., Magnamosis, Inc. Other Relationship; Self; None. K.L. Stanhope: None. Funding National Institutes of Health (R01HL091333, R01HL107256)

OBJECTIVE Little attention has been paid to possible intrinsic biological mechanisms for the decline in physical activity that occurs during puberty. This longitudinal observational study examined the association between baseline insulin sensitivity (SI) and declines in physical activity and increases in sedentary behavior in peripubertal minority females over a year. RESEARCH DESIGN AND METHODS Participants were Hispanic and African American girls (n = 55; 76% Hispanic; mean age 9.4 years; 36% obese). SI and other insulin indices were measured at baseline using the frequently sampled intravenous glucose tolerance test. Physical activity was measured on a quarterly basis by accelerometry and self-report. RESULTS Physical activity declined by 25% and time spent in sedentary behaviors increased by ∼13% over 1 year. Lower baseline SI predicted the decline in physical activity measured by accelerometry, whereas higher baseline acute insulin response to glucose predicted the decline in physical activity measured by self-report. Time spent in sedentary behavior increased by ~13% over 1 year, and this was predicted by lower baseline SI. All models controlled for adiposity, age, pubertal stage, and ethnicity. CONCLUSIONS When evaluated using a longitudinal design with strong outcome measures, this study suggests that lower baseline SI predicts a greater decline in physical activity in peripubertal minority females.

OBJECTIVE In adults, 1-h glucose during an oral glucose tolerance test (OGTT) predicts the development of type 2 diabetes independent of fasting and 2-h glucose concentrations. The purpose of the current investigation was to examine the utility of elevated 1-h glucose levels to prospectively predict deterioration in β-cell function and the development of prediabetes in high-risk youth. RESEARCH DESIGN AND METHODS Obese Latino youth with a family history of type 2 diabetes (133 male and 100 female; age 11.1 ± 1.7 years) completed a baseline OGTT and were divided into two groups based upon a 1-h glucose threshold of 155 mg/dL ( RESULTS Over time, the ≥155 mg/dL group exhibited a significantly greater decline in β-cell function compared with youth with a 1-h glucose CONCLUSIONS These data suggest that a 1-h glucose ≥155 mg/dL during an OGTT is an independent predictor of β-cell deterioration and progression to prediabetes among obese Latino youth.

OBJECTIVE To examine in obese young adults the influence of ethnicity and subcutaneous adipose tissue (SAT) inflammation on hepatic fat fraction (HFF), visceral adipose tissue (VAT) deposition, insulin sensitivity (SI), β-cell function, and SAT gene expression. RESEARCH DESIGN AND METHODS SAT biopsies were obtained from 36 obese young adults (20 Hispanics, 16 African Americans) to measure crown-like structures (CLS), reflecting SAT inflammation. SAT, VAT, and HFF were measured by magnetic resonance imaging, and SI and β-cell function (disposition index [DI]) were measured by intravenous glucose tolerance test. SAT gene expression was assessed using Illumina microarrays. RESULTS Participants with CLS in SAT (n = 16) were similar to those without CLS in terms of ethnicity, sex, and total body fat. Individuals with CLS had greater VAT (3.7 ± 1.3 vs. 2.6 ± 1.6 L; P = 0.04), HFF (9.9 ± 7.3 vs. 5.8 ± 4.4%; P = 0.03), tumor necrosis factor-α (20.8 ± 4.8 vs. 16.2 ± 5.8 pg/mL; P = 0.01), fasting insulin (20.9 ± 10.6 vs. 9.7 ± 6.6 mU/mL; P < 0.001) and glucose (94.4 ± 9.3 vs. 86.8 ± 5.3 mg/dL; P = 0.005), and lower DI (1,559 ± 984 vs. 2,024 ± 829 ×10−4 min−1; P = 0.03). Individuals with CLS in SAT exhibited upregulation of matrix metalloproteinase-9 and monocyte antigen CD14 genes, as well as several other genes belonging to the nuclear factor-κB (NF-κB) stress pathway. CONCLUSIONS Adipose tissue inflammation was equally distributed between sexes and ethnicities. It was associated with partitioning of fat toward VAT and the liver and altered β-cell function, independent of total adiposity. Several genes belonging to the NF-κB stress pathway were upregulated, suggesting stimulation of proinflammatory mediators.

OBJECTIVE Visceral adipose tissue (VAT) and hepatic fat are associated with insulin resistance and vary by sex and ethnicity. Recently, pancreatic fat fraction (PFF) has also been linked with increasing obesity. Our aim was to assess ethnic and sex differences in PFF and its relationship to other fat depots, circulating free fatty acids (FFA), insulin secretion and sensitivity, and inflammation in obese adolescents and young adults. RESEARCH DESIGN AND METHODS We examined 138 (40 males, 98 females) obese Hispanics and African Americans (13–25 years). Subcutaneous adipose tissue and VAT volumes, hepatic fat fraction (HFF), and PFF were determined by magnetic resonance imaging. Insulin sensitivity and β-cell function were assessed during an intravenous glucose tolerance test. RESULTS Hispanics had higher PFF than African Americans (7.3 ± 3.8 vs. 6.2 ± 2.6%, P = 0.03); this ethnic difference was higher in young adults compared with children and adolescents (ethnicity × age: P = 0.01). Males had higher PFF than females (P < 0.0001). PFF was positively correlated with VAT (r = 0.45, P < 0.0001), HFF (r = 0.29, P < 0.0001), and FFA (r = 0.32, P = 0.001). PFF positively correlated with inflammatory markers but lost significance when adjusted for VAT. In multiple stepwise regression analysis, VAT and FFA were the best predictors of PFF (adjusted R2 = 0.40). There were no significant correlations between PFF and markers of insulin sensitivity or β-cell function. CONCLUSIONS PFF is higher in Hispanics than African Americans, and this difference increases with age. In young obese individuals, PFF is related to VAT, HFF, and circulating FFA, thus possibly contributing to their increased risk for type 2 diabetes and related metabolic disorders.

OBJECTIVE A genome-wide study of adults identified a variant of PNPLA3 (rs738409) associated with ∼twofold higher liver fat. The purpose of this study was to examine the influence of PNPLA3 genotype on liver fat and other related metabolic outcomes in obese Hispanic children and adolescents. RESEARCH DESIGN AND METHODS Three hundred and twenty-seven Hispanics aged 8–18 years were genotyped for rs738409. One hundred and eighty-eight subjects had measures of visceral (VAT) and subcutaneous (SAT) adipose tissue volume and hepatic (HFF) and pancreatic (PFF) fat fraction by magnetic resonance imaging. One hundred and thirty-nine subjects did not have HFF measures but had extensive measures of insulin sensitivity and fasting lipids. RESULTS Liver fat in GG subjects was 1.7 and 2.4 times higher than GC and CC (11.1 ± 0.8% in GG vs. 6.6 ± 0.7% in GC and 4.7 ± 0.9% in CC; P < 0.0001), and this effect was observed even in the youngest children (8–10 years of age). The variant was not associated with VAT, SAT, PFF, or insulin sensitivity or other glucose/insulin indexes. However, Hispanic children carrying the GG genotype had significantly lower HDL cholesterol (40.9 ± 10.9 in CC vs. 37.0 ± 8.3 in CG vs. 35.7 ± 7.4 in GG; P = 0.03) and a tendency toward lower free fatty acid levels (P = 0.06). CONCLUSIONS These results provide new evidence that the effect of the PNPLA3 variant is apparent in Hispanic children and adolescents, is unique to fat deposition in liver as compared with other ectopic depots examined, and is associated with lower HDL cholesterol.

OBJECTIVE—To examine changes in risk factors in overweight and obese Hispanic children at high risk of developing type 2 diabetes. RESEARCH DESIGN AND METHODS—We recruited 128 overweight/obese Hispanic children with a family history of type 2 diabetes primarily from clinics in East Los Angeles. Children were evaluated annually for 4 years with an oral glucose tolerance test, applying American Diabetes Association criteria to define diabetes and pre-diabetes. Insulin sensitivity (Si), acute insulin response (AIR) to glucose, and β-cell function (BCF) were determined from frequently sampled intravenous glucose tolerance tests, and total body fat by dual-energy X-ray absorptiometry and intra-abdominal and subcutaneous abdominal adipose tissue (IAAT and SAAT) by magnetic resonance imaging were assessed in years 1, 2, and 4. RESULTS—No subjects developed type 2 diabetes, 40% never had pre-diabetes, 47% had intermittent pre-diabetes with no clear pattern over time, and 13% had persistent pre-diabetes. At baseline, those with persistent pre-diabetes had lower BCF and higher IAAT. In repeated measures, Si deteriorated regardless of pre-diabetes, and there was a significant effect of pre-diabetes on AIR (42% lower in pre-diabetes; P = 0.01) and disposition index (34% lower in pre-diabetes; P = 0.021) and a significant interaction of pre-diabetes and time on IAAT (greater increase over time in those with pre-diabetes; P = 0.034). CONCLUSIONS—In this group of Hispanic children at high risk of type 2 diabetes, 1) pre-diabetes is highly variable from year to year; 2) the prevalence of persistent pre-diabetes over 3 years is 13%; and 3) children with persistent pre-diabetes have lower BCF, due to a lower AIR, and increasing visceral fat over time.

OBJECTIVE— The purpose of this article was to examine metabolic risk factors for type 2 diabetes in children and adolescents as a function of maternal versus paternal family history of type 2 diabetes and to examine whether differences in these risk factors emerge during adolescent growth. RESEARCH DESIGN AND METHODS— A total of 247 overweight Latino children (baseline age = 11.1 ± 1.7 years) with a parental history of type 2 diabetes were followed annually for 5 years (2.2 ± 1.2 observations/child) with measures of insulin sensitivity, acute insulin response to glucose, and disposition index. Longitudinal linear mixed-effects modeling was used to evaluate the influence of maternal versus paternal family history of type 2 diabetes on changes in diabetes risk factors over age. RESULTS— Insulin sensitivity and the disposition index decreased over age (β = −0.052 and β = −0.033, P < 0 0.01). Acute insulin response to glucose and fasting and 2-h glucose increased (β = 0.019, β = 0.002, and β = 0.003, P < 0.01). Declines in insulin sensitivity were significantly greater in participants whose maternal grandmothers had a history of type 2 diabetes (β = −0.03, P = 0.03). Declines in the disposition index (β = −0.02, P = 0.04) and increases in fasting glucose were significantly influenced by a maternal history of type 2 diabetes (β = 0.60, P < 0.05). CONCLUSIONS— Maternal but not paternal family history for diabetes may have a significant impact on insulin dynamics, becoming more pronounced during growth in overweight Latino adolescents. Further research is clearly warranted.

Author(s): Baranowski, T; Cooper, DM; Harrell, J; Hirst, K; Kaufman, FR; Goran, M; Resnicow, K; STOPP-T2D Prevention Study Group | Abstract: ObjectiveThe study was conducted in 12 middle schools to determine the prevalence of diabetes, pre-diabetes, and diabetes risk factors in eighth-grade students who were predominantly minority and evaluate the feasibility of collecting physical and laboratory data in schools.Research design and methodsAnthropometric measurements and fasting and 2-h post-glucose load blood draws were obtained from approximately 1,740 eighth-grade students.ResultsMean recruitment rate was 50% per school, 49% had BMI g or = 85th percentile, 40.5% had fasting glucose g or = 100 mg/dl, 0.4% had fasting glucose g or = 126 mg/dl, and 2.0% had 2-h glucose g or = 140 mg/dl and 0.1% g or = 200 mg/dl. Mean fasting insulin value was 30.1 microU/ml, 36.2% had fasting insulin g or = 30 microU/ml, and 2-h mean insulin was 102.1 microU/ml. Fasting and 2-h glucose and insulin values increased across BMI percentiles, and fasting glucose was highest in Hispanic and Native American students.ConclusionsThere was a high prevalence of risk factors for diabetes, including impaired fasting glucose (g or =100 mg/dl), hyperinsulinism suggestive of insulin resistance (fasting insulin g or = 30 microU/ml), and BMI g or = 85th percentile. These data suggest that middle schools are appropriate targets for population-based efforts to decrease overweight and diabetes risk.

OBJECTIVE—This study aimed to establish whether total fat or central fat was related to measures of insulin in obese Hispanic children with a family history of type 2 diabetes. RESEARCH DESIGN AND METHODS—Subjects were 32 children aged 8–13 years. Visceral fat and subcutaneous abdominal fat were determined by magnetic resonance imaging at the umbilicus and total body fat was determined by dual-energy X-ray absorptiometry. Insulin sensitivity (Si) and acute insulin response (AIR) were determined by frequently sampled intravenous tolerance test with minimal modeling. RESULTS—Mean fasting glucose and insulin, Si, and AIR (± SD) were 5.3 ± 0.3 mmol/l, 206 ± 105 pmol/l, 11.8 ± 5.7 [× 10−4 min−1/(pmol/l)], and 17,175 ± 9,695 (pmol/l × 10 min), respectively. In multivariate regression analysis, total fat mass was independently and positively related to fasting insulin (P < 0.01) and negatively related to Si (P < 0.05) but was not related to AIR. Visceral fat was independently and positively related to fasting insulin (P < 0.05) and AIR (P < 0.01) and negatively related to Si (P < 0.001). CONCLUSIONS—These findings support the hypothesis that specific accumulation of visceral fat in addition to overall adiposity in Hispanic children increases the risk of type 2 diabetes.

OBJECTIVE—To test the utility of homeostasis model assessment (HOMA) in predicting insulin sensitivity [×10− 4 min−1/(μIU/ml)] in children and to develop and compare two new prediction equations for insulin sensitivity in children using demographic and anthropometric measures in the presence or absence of fasting insulin. RESEARCH DESIGN AND METHODS—We studied 156 white and African-American children with complete data (mean age 9.7 ± 1.8 years, 87.8% Tanner Stage 1 or 2). For development of new equations, two-thirds of the children were randomly assigned to a development group, whereas the remaining children were assigned to a cross-validation group. RESULTS—A modified HOMA equation accurately predicted insulin sensitivity, but its utility is similar to fasting insulin alone. Demographic and anthropometric measures alone did not predict insulin sensitivity accurately, even when precise measures of body composition were included in the prediction model. Ethnicity, calf skinfold, and fasting insulin together explained 73% of the variance in insulin sensitivity and accurately predicted insulin sensitivity. The regression of measured versus predicted insulin sensitivity in the cross-validation group was not significantly different from the line of identity (P > 0.05). Mean difference between measured and predicted insulin sensitivity was also not significant (P > 0.05). Some bias was apparent, particularly in white boys. CONCLUSIONS—Ethnicity, calf skinfold, and fasting insulin can accurately predict insulin sensitivity with greater precision than HOMA or fasting insulin alone (R2 = 0.73). Future studies, however, are needed to examine whether a universal equation is possible. A cross-validated prediction equation may be useful in population-based studies when complex measures of insulin sensitivity are not available.

In adults, visceral fat accumulation is associated with insulin resistance and dyslipidemia. The cause-and-effect nature of these relationships is not clear. The objective of the present study was to determine if similar relationships exist in prepubertal children. Specifically, we determined whether visceral fat was associated with fasting insulin, insulin sensitivity (Si), serum triglyceride (TG) concentration, or serum HDL cholesterol (HDL-C) concentration; whether visceral fat or Si was independently related to lipids; and whether ethnicity influenced the relationship between visceral fat and risk factors. Subjects were 61 prepubertal African-American and Caucasian children. Total body fat was determined by dual-energy X-ray absorptiometry, visceral fat by computed tomography, and insulin sensitivity by the tolbutamide-modified, frequently sampled intravenous glucose tolerance test with minimal modeling. In multiple linear regression analysis (adjusting for total fat, sex, and ethnicity), visceral fat was independently related to TG (P < 0.05) and fasting insulin (P < 0.001), but not Si (P = 0.425). Total body fat was independently related to Si (P < 0.001). Si was independently related to fasting insulin (P < 0.001) but not to TG or HDL-C (P = 0.941 and 0.201, respectively). Si in African-Americans was 42% lower than in Caucasians (0.50 +/- 0.05 vs. 0.86 +/- 0.11 x 10(-5) min(-1) x pmol(-1) x l, mean +/- SE after adjusting for total fat, P < 0.001). Nonetheless, ethnicity was not independently related to either TG or HDL-C (P = 0.075 and 0.619, respectively, after adjusting for total and visceral fat and sex). The slopes of the relationships of total and visceral fat with risk factors did not differ with ethnicity. In conclusion, visceral fat appears metabolically unique in children, being independently associated with elevated TG and insulin but not Si. Obese children and African-American children were more insulin resistant, independent of visceral fat accumulation. Lower Si was associated with higher, faster insulin, but not dyslipidemia. Thus, obesity, visceral fat accumulation, and ethnicity in children may confer negative, but independent, health risks.

OBJECTIVE The purpose of this study was to examine the relationship between changes in insulin sensitivity and subsequent changes in fat mass in obese Hispanic children over 3 consecutive years. RESEARCH DESIGN AND METHODS In a longitudinal research design, insulin sensitivity (Si) of 96 research participants was determined at baseline and 1 year later. Body adiposity was assessed at four assessments. RESULTS The change in Si during the first year of the study was a significant predictor of further fat mass development (P < 0.05). Considering different directions of Si change, Si was a strong predictor for further fat mass development only in the group that decreased their Si (P < 0.05). CONCLUSIONS The results show that the direction of change in insulin sensitivity at an early age is an important independent predictor for further fat mass development and emphasize the importance of insulin sensitivity as a primary target for long-term obesity prevention, as well as the significance of early age intervention.

The recent report by Janseen and Cramp (1), describing the independent associations between cardiorespiratory fitness (CRF) and the metabolic syndrome in adolescents participating in the National Health and Nutrition Examination Survey 1999–2002, addresses a critical issue related to fitness and chronic disease risk in youth. However, the authors’ findings and interpretation should be received with caution. First, the authors suggest that CRF is an objective measure of physical …