Assessment of insulin sensitivity from measurements in fasting state and during an oral glucose tolerance test in obese children

Determinants of childhood and adolescent obesity and it's effect on metabolism in South Indian population

OBJECTIVES

The primary objective is to determine the risk factors underlying the development of childhood and adolescent obesity. The secondary objective is to determine the predictors of metabolic syndrome (MetS) in childhood and adolescent obesity and its metabolic alterations in the South Indian population.

METHODS

This is a cross-sectional study conducted over two years. We have screened 3,195 school children and adolescents from lower and lower-middle socioeconomic groups. From this pool, by random cluster sampling technique, we have included 166 overweight and obese individuals and 38 control subjects. We have analyzed their sociodemographic, dietary, lifestyle, anthropometric, clinical, and metabolic parameters.

RESULTS

The prevalence of overweight and obesity in rural areas was 14.2 and 7.6 %, respectively, and in urban areas, it was 16.1 and 8.8 %, respectively. The age distribution of the control and study group is 12.3 ± 1.5 and 13.0 ± 1.9 years with a male-to-female ratio of 1.4:1 and 1.6:1, respectively. Our study found a higher average consumption of energy-dense food and screen time in the obese group compared to the control group. The average outdoor play time was 1.5 h per day in the control group and less than 0.5 h per day in the obese group. In our study, the waist-to-height ratio (WHtR) optimum cutoff value of 0.56, has 95 % sensitivity and 84 % specificity, effectively identifying MetS cases. HOMA-IR optimum cutoff value of 2.25, has 96 % sensitivity and 72 % specificity. The triglyceride-glucose index (TGI) optimum cutoff value of 4.51, has 92 % sensitivity and 88 % specificity indicating a strong balance between correctly identifying positive and negative MetS cases.

CONCLUSIONS

Our study found that even in lower socioeconomic status, there is a higher prevalence of childhood and adolescent obesity due to an urbanized lifestyle in rural areas, a sedentary lifestyle, higher consumption of low-cost energy-dense foods, and higher screening time in this electronic era. We also conclude that WHtR is a simple anthropometric marker that predicts MetS more effectively than BMI and WHR among children and adolescents. HOMA-IR and TGI are effective biochemical markers to identify metabolically unhealthy obesity early.

Does prednisone use in pregnant women with rheumatoid arthritis induce insulin resistance in the offspring?

OBJECTIVES

The use of long-term corticosteroids during pregnancy has been growing over the past decades. Corticosteroids can be given when an auto-inflammatory disease like rheumatoid arthritis (RA) is too active. Several studies have shown that long-term corticosteroids use in pregnancy is associated with maternal and fetal adverse outcomes, like preeclampsia, shorter gestational age, lower birth weight, and rapid catch-up growth. These last two outcomes could influence the insulin resistance later in life. Our objective was to investigate whether prednisone use in pregnant women with RA induces insulin resistance in offspring.

METHODS

One hundred three children were included after their mother had participated in a prospective cohort study on RA and pregnancy. Forty-two children were in utero exposed to prednisone and 61 were non-exposed. To assess insulin resistance, we measured homeostasis model of assessment insulin resistance (HOMA-IR) and serum adiponectin and lipid levels, corrected for body fat distribution.

RESULTS

An average of 6 mg prednisone on a daily use gave no difference in mean HOMA-IR (SD) between the children who were prednisone-exposed in utero (1.10 (0.84)) and those non-exposed (1.09 (0.49)). No difference was found in mean adiponectin level, body fat distribution, or lipid levels such as total cholesterol, fasting triglyceride, or high-density lipoprotein.

CONCLUSION

Children who are prednisone-exposed in utero (low dose) have no increased risk for insulin resistance at the age of approximately 7 years. These findings are reassuring because the prednisone use during pregnancy is increasing worldwide. Further research has to be performed to evaluate if the insulin resistance remains absent in the future. Key Points • What is already known on this topic-long-term corticosteroids use in pregnancy is associated with fetal adverse outcomes, like lower birth weight and rapid catch-up growth which can influence the insulin resistance later in life. • What this study adds-long-term corticosteroids use in pregnant women with rheumatoid arthritis has no increased risk for insulin resistance in the offspring. • How this study might affect research, practice, or policy-findings are reassuring because prednisone use during pregnancy is increasing worldwide. Further research should evaluate if the insulin resistance remains absent in the future.

Metabolism and memory: α-synuclein level in children with obesity and children with type 1 diabetes; relation to glucotoxicity, lipotoxicity and executive functions

Background/Objectives

Children with obesity and those with type 1diabetes (T1D) exhibit subtle neurocognitive deficits, the mechanism of which remains unknown. α-synuclein plays a fundamental role in neurodegeneration. Moreover, its role in glucose and lipids metabolism is emerging. This study aims to assess whether α-synuclein is correlated with the degree of neurodegeneration in children with obesity and those with T1D in comparison to healthy controls and correlate it to various neurocognitive and metabolic parameters.

Subjects/Methods

Forty children with obesity, 40 children with T1D and 40 matched-healthy controls were assessed for anthropometric measurements and blood-pressure. Cognitive evaluation was performed using Stanford–Binet scale and Barkley Deficits in Executive Functioning (EF) Scale-Children and Adolescents. α-synuclein, fasting lipids and glucose were measured with calculation of the homeostatic model of insulin-resistance and estimated-glucose disposal rate.

Results

Children with obesity and those with T1D had significantly higher α-synuclein (p < 0.001) and total EF percentile (p = 0.001) than controls. α-synuclein was negatively correlated to total IQ (p < 0.001 and p = 0.001), and positively correlated with total EF percentile (p = 0.009 and p = 0.001) and EF symptom count percentile (p = 0.005 and p < 0.001) in children with T1D and obesity, respectively. Multivariate-regression revealed that α-synuclein was independently related to age (p = 0.028), diabetes-duration (p = 0.006), HbA1C% (p = 0.034), total IQ (p = 0.013) and EF symptom count percentile (p = 0.003) among children with T1D, and to diastolic blood-pressure percentile (p = 0.013), waist/hip ratio SDS (p = 0.007), total EF percentile (P = 0.033) and EF symptom count percentile (p < 0.001) in children with obesity.

Conclusion

α-synuclein could have a mechanistic role in neurocognitive deficit among children with obesity and T1D.

DNMT3A and TET2; Potential Estimates of Generic DNA Methylation in Children and Adolescents with Obesity; Relation to Metabolic Dysregulation

INTRODUCTION

The role of DNA methylation in metabolic dysregulation is emerging. However, the functional role of methylation in obesity and metabolic dysregulation is poorly understood.

AIM

The aim of this study was to compare DNA methyltransferase-3A (DNMT3A) and ten-eleven translocase-2 (TET2) levels in children and adolescents with obesity to normal-weighed children and adolescents and to correlate them to various metabolic parameters.

METHODS

Fifty children and adolescents with obesity were compared to 50 matched normal-weighed children and adolescents. Participants underwent assessment for anthropometric measurements, Tanner staging, acanthosis nigricans, and mean blood pressure percentile on three different occasions. TET2, DNMT3A, fasting lipids, and insulin were measured with calculation of the homeostatic model assessment insulin resistance (HOMA-IR).

RESULTS

The median BMI SDS of the studied children and adolescents with obesity was 3.40, their mean TET2 was 178.40 ng/mL, and their mean DNMT3A was 2.18 ng/mL. TET2 is significantly lower (p = 0.009), while DNMT3A is significantly higher (p < 0.001) in children and adolescents with obesity than controls. Children and adolescents with obesity and insulin resistance have significantly lower TET2 (p = 0.012) and significantly higher DNMT3A (p = 0.013) than those without insulin resistance. Diastolic blood pressure percentile and HOMA-IR are positively correlated to DNMT3A (p < 0.001) and negatively correlated to TET-2 (p < 0.001). Multivariate logistic regression analysis revealed that TET2 and DNMT3A are independently associated with diastolic blood pressure percentile (p = 0.03 and p = 0.014, respectively) and HOMA-IR (p = 0.003 and p = 0.001, respectively).

CONCLUSIONS

Children and adolescents with obesity have significantly higher DNMT3A and significantly lower TET2 than controls. This is more evident in those having insulin resistance than those without. DNMT3A and TET2 are independently associated with systemic hypertension and insulin resistance in children with obesity.

Reversibility of pancreatic β-cells dysfunction after vitamin D and calcium supplementation: a pilot study in a population of obese and prepubescent North-African children

The mechanisms of diabetogenesis in children remain largely obscure. This study aimed to determine the impact of vitamin D and calcium supplementation on pancreatic β-cells function in terms of insulin secretion and sensitivity. This was a quasi-experimental study involving 30 obese and prepubescent Tunisian children (57% boys). During three months, the children received calcium and vitamin D supplementation at therapeutic doses. An oral glucose tolerance test (OGTT) was performed at the beginning and at the end of the study. The following metabolic definitions were applied: i) hyperinsulinism: insulinemia sum > 300 μ UI/ml during OGTT, ii) insulin-resistance: homeostatic model assessment of insulin-resistance > 2, iii) normal glycaemic profile: normal plasma levels during OGTT without any spike, and iv) pancreatic β-cells dysfunction reversibility: disappearance of the aforementioned disorders. The means ± standard-deviation of age and body mass index were 10.87 ± 1.9 years, and 30.17 ± 4.99 kg/m², respectively. All children were at the stage of hyperinsulinism associated with insulin-resistance. These disturbances were noted even in children having a normal glycaemic profile at OGTT. After calcium and vitamin D supplementation, glycaemic profile as well as insulin-secretion improved significantly (p < 0.0001). Hyperinsulinism and insulin-resistance decreased significantly by 56.67% (p < 0.0001) and 70.00% (p < 0.0001), respectively. Complete reversibility of these two disorders was noted in 26.6% of children. To conclude, in obese and prepubescent children, vitamin D and calcium supplementation led to the reversibility of the pancreatic β-cells dysfunction.

Reversal of insulin resistance by Ficus benghalensis bark in fructose-induced insulin-resistant rats

ETHNOPHARMACOLOGICAL RELEVANCE

Bark of Ficus benghalensis L. (family: Moraceae), commonly known as Banyan is recorded as Nyagrodha in Ayurvedic Pharmacopeia of India to manage burning sensation, obesity, diabetes, bleeding disorders, thirst, skin diseases, wounds, and dysmenorrhoea. However, the effect of F. benghalensis bark over glycolysis, gluconeogenesis, and appetite regulation in insulin-resistant pathogenesis has not been reported yet.

AIM OF THE STUDY

The present study aimed to investigate the effect of hydroalcoholic extract of F. benghalensis bark in gluconeogenesis, glycolysis, and appetite regulation in fructose-induced insulin resistance in experimental rats.

MATERIALS AND METHODS

Male Wister rats were supplemented with fructose in drinking water (10% w/v for 42 days and 20% w/v for next 12 days; a total of 54 days); insulin resistance was confirmed via the elevated area under the curve of the glucose during oral glucose tolerance test after 54 days and was subjected with extract treatment for next 30 days. After 30 days of treatment, animals were fasted to perform oral glucose and insulin tolerance test to estimate glucose and insulin levels. The blood sample was collected for biochemical estimation and the liver homogenate was prepared to estimate hepatic enzymes and enzymatic and non-enzymatic anti-oxidant biomarkers followed by histopathological evaluation. Also, glycogen content was quantified in gastrocnemius muscle and liver homogenates. Further, reported bioactives from the F. benghalensis were retrieved from the ChEBI database and docked against hexokinase, phosphofructokinase, glucose-6-phosphatase, lactate dehydrogenase, and fructose-1,6-biphosphatase to identify the probable lead hits against the enzymes involved in gluconeogenesis.

RESULTS

Treatment with the F. benghalensis bark extract significantly increased the body weight and food intake and significantly decreased fructose supplemented water intake. Further, treatment with extract significantly increased the exogenous glucose clearance and well responded to the exogenous insulin. Further, extract treatment improved lipid metabolism, ameliorated plasma leptin, and multiple enzymatic and non-enzymatic antioxidant biomarkers. Likewise, it also improved gluconeogenesis mediated pathogenesis of non-alcoholic fatty liver injury. Additionally, molecular docking also identified mucusisoflavone A and B as lead hits in downregulating gluconeogenesis.

CONCLUSION

Hydroalcoholic extract of F. benghalensis bark may prevent insulin resistance by downregulating gluconeogenesis and improving the appetite in fructose-induced insulin-resistant rats.

Impact of Insulin Resistance on Cardiometabolic Risk Factors and an Anthropometry-Based Predictive Nomogram for Insulin Resistance Among Adolescents in China

OBJECTIVE

We aimed to investigate the impact of insulin resistance (IR), as determined by the homeostasis model assessment of insulin resistance (HOMA-IR), on cardiometabolic risk factors (CMRFs), and develop an anthropometry-based predictive nomogram for IR among adolescents in China.

DESIGN

Data were acquired from a cross-sectional study with a stratified cluster sampling method, conducted among adolescents in Northeast China.

PARTICIPANTS

A total of 882 adolescents (aged 12-16 years, 468 boys) were included.

MEASUREMENTS

All participants underwent anthropometric and biochemical examinations. The thresholds of IR included the 90th percentile of the HOMA-IR for adolescents with a normal body mass index (BMI) and fasting plasma glucose (FPG) level within each sex group (Cutoff A), and the 75th percentile for all participants of the same sex (Cutoff B).

RESULTS

The HOMA-IR was associated with CMRFs. IR, as defined by both cutoffs A and B, was significantly associated with most CMRFs, except decreased HDL-C levels. Excellent concordance (κ = 0.825) was found between these two criteria in diagnosing IR. However, IR using cutoff A, was more closely associated with cardiometabolic risk. The incidence of IR, as defined by cutoff A, was 18.93% and increased from 10.99% to 43.87% based on the different BMI categories. Further, an anthropometry-based predictive model for IR, incorporating sex, age, waist-to-hip ratio, weight and BMI, was developed and presented as a nomogram.

CONCLUSIONS

IR among adolescents is strongly related to cardiometabolic risk. We developed an anthropometry-based predictive nomogram for IR among adolescents, which may facilitate health counselling and self-risk assessments.

Hyperandrogenemia in Early Adulthood Is an Independent Risk Factor for Abnormal Glucose Metabolism in Middle Age

CONTEXT

The role of androgen excess as a contributing factor to abnormal glucose metabolism (AGM) and insulin resistance in women remains controversial.

OBJECTIVE

To investigate whether hyperandrogenemia (HA) estimated by serum testosterone (T) level and free androgen index (FAI) at ages 31 and 46 years is associated with insulin resistance, insulin secretion and AGM by age 46.

DESIGN

Prospective study including 5889 females followed at ages 31 and 46 years.

SETTING

General community.

PARTICIPANTS

Women with HA were compared with normoandrogenic women at ages 31 and 46 years.

INTERVENTION

None.

MAIN OUTCOME MEASUREMENTS

AGM, including prediabetes and type 2 diabetes mellitus, homeostatic model assessments of insulin resistance (HOMA-IR) and of pancreatic β-cell function (HOMA-B).

RESULTS

At age 31 years, HA women displayed increased HOMA-IR (P = 0.002), HOMA-B (P = 0.007), and higher fasting insulin (P = 0.03) than normoandrogenic women after adjusting for body mass index (BMI). At age 46 years, there was a nonsignificant trend toward higher fasting glucose (P = 0.07) and glycated hemoglobin A1 (P = 0.07) levels in HA women. Women in the highest T quartile (odds ratio [OR] = 1.80; 95%CI, 1.15-2.82) at age 31 years and in the 2 highest FAI quartiles at ages 31 (Q4: OR = 3.76; 95% CI, 2.24-6.32) and 46 (Q4: OR = 2.79; 95% CI, 1.74-4.46) years had increased risk for AGM, independently of BMI, when compared with women in Q1. SHBG was inversely associated with AGM (at age 31 years: Q4: OR = 0.37; 95% CI, 0.23-0.60, at age 46 years: Q4: OR = 0.28; 95% CI, 0.17-0.44).

CONCLUSION

Hyperandrogenemia and low SHBG in early and middle age associates with AGM independently of BMI.

The relation between increased carotid intima-media thickness with fibrin monomers in obese children

AIM

This study aimed to investigate the association between carotid intima-media changes that play a part in the atherosclerotic process in childhood obesity and fibrin monomers as an important indicator of fibrin plaque.

METHODS

This is a cross-sectional study of obese children and non-obese healthy control subjects. Height, weight, body mass index, waist/hip ratio, systolic/diastolic blood pressures were recorded, in addition, biochemistry, haemogram, fibrin monomers and d-dimer were measured in both groups. Right and left common carotid intima-media thicknesses were measured by ultrasonography and mean carotid intima-media thickness was calculated.

RESULTS

Obese children (n = 89, 46.1% girls, median age: 12.6 ± 2.3 years) and healthy control group (n = 40, 52.5% girls, median age: 13.2 ± 2.2 years) were comparable in terms of gender, age and puberty stage. Mean carotid intima-media thickness was higher in obese children than the healthy control group (P = .002). There was no difference between the two groups in terms of fibrin monomers and d-dimer levels. In obese children, there was a weak negative correlation between mean carotid intima-media thickness and fibrin monomers (P = .030, r = -0.233).

CONCLUSION

In obese children, mean carotid intima-media thickness was determined higher, as an early indicator of atherosclerosis. We want to emphasise that obese children are at risk for cardiovascular disease and should be evaluated in terms of atherosclerosis. This study investigates the relation between increased carotid intima-media thickness and fibrin monomers, in children, the first time in Literature.

Prenatal exposure to persistent organic pollutants and markers of obesity and cardiometabolic risk in Spanish adolescents

BACKGROUND

Prenatal exposure to persistent organic pollutants (POPs) has been linked to cardiometabolic (CM) risk factors in childhood, but there are no studies evaluating the persistence of these associations into adolescence, a period of relevant changes in endocrine-dependent organ systems and rapid increases in lean and fat mass. We examined the associations of prenatal POP exposures with body mass index (BMI) from age 4 to 18 years, and with other CM risk markers in adolescence.

METHODS

We analysed 379 children from the Spanish INMA-Menorca birth cohort study with measured cord blood POP concentrations. We calculated BMI z-scores at ages 4, 6, 11, 14 and 18 years using the WHO growth reference. Body fat % was measured at 11 and 18 years and waist-to-height ratio (WHtR) and blood pressure (BP) at 11, 14 and 18 years. We measured CM biomarkers in fasting blood collected at age 14 years and calculated a CM-risk score as the sum of the sex-, and age-specific z-scores for waist circumference, mean arterial BP, homeostatic model assessment of insulin resistance, fasting blood triglycerides, and high-density lipoprotein cholesterol (HDL-C) (n = 217). Generalised estimating equations and multivariate linear regression models assessed the associations with repeated and single time-point measures, respectively.

RESULTS

Hexachlorobenzene (HCB) exposure in the third tertile, compared to the first tertile, was associated with higher BMI (β = 0.24; 95% CI: 0.01, 0.47) and WHtR z-score (β = 0.27; 95% CI: 0.04, 0.51). A continuous increase in HCB was associated with an elevated body fat % (β per 10-fold increase = 4.21; 95% CI: 0.51, 7.92), systolic BP (β = 0.32; 95% CI: 0.02, 0.64) and diastolic BP z-score (β = 0.32; 95% CI: 0.02, 0.62) across all ages, and with higher CM-risk score (β = 1.59; 95% CI: 0.02, 3.18) and lipid biomarkers (total cholesterol, triglycerides and low-density lipoprotein cholesterol (LDL-C)) at 14 years. Dichlorodiphenyltrichloroethane (p,p'-DDT) exposure was non-monotonically associated with BMI and systolic BP. p,p'-DDE and Σ-polychlorinated biphenyls (PCBs) (sum of congeners 118, 138, 153, 180) were not associated with adiposity or BP. p,p'-DDT exposure was associated with an increased CM-risk score, and ΣPCBs concentrations with LDL-C in all adolescents and with total cholesterol only in girls (p-sex interaction = 0.05).

CONCLUSION

This first longitudinal study from 4 to 18 years suggests that the previously reported POP associations with child BMI persist later in adolescence and that prenatal POP exposures are associated with major risk factors for adult CM syndrome.

Prevalence of Insulin Resistance in Urban Indian School Children Who Are Overweight/Obese: A Cross-Sectional Study

Background: Limited data are available for insulin resistance (IR) in over-weight/obese children from the Indian subcontinent. Identifying predictors of IR in this population is important, as they may be used as a screening tool for future metabolic complications. Materials and Methods: This school-based cross-sectional study was conducted in an Eastern Indian city. Anthropometry and blood pressure measurements were carried out as per the published guidelines. Venous blood samples were taken in a fasting state to measure plasma glucose, insulin, and lipid profile. IR was measured quantitatively by a homeostatic model of assessment (HOMA-IR). Results: A total of 545 (28.2%) children who were overweight or obese were included. The male:female ratio was 1:1.27. The overall prevalence of metabolic syndrome (MS) in these children was 21.8%. Around 32.3% of children had HOMA-IR of ≥2.5, and 22.2% had HOMA-IR of ≥3.16. The mean HOMA-IR in children with MS was 5.46 compared to 2.18 in those without MS. An increased risk of IR with low HDL, high triglyceride, increased waist circumference, and increased BP (both systolic and diastolic) was found. This means that insulin resistance was more common in children who were overweight or obesity and had underlying MS. Conclusions: The present school-based study found a high prevalence of insulin resistance among children who were overweight or obese. This could predict an increased risk of future adverse cardio-vascular events in the studied children. The findings of this study would help in planning and implementing primary prevention programs targeting weight management and lifestyle change in schoolchildren.

Can we use copeptin as a biomarker for masked hypertension or metabolic syndrome in obese children and adolescents?

OBJECTIVES

Copeptin, the C-terminal part of arginine-vasopressin, is increased in hypertensive adolescents and closely associated with metabolic syndrome (MS). We aimed to investigate whether serum copeptin can be used to differentiate masked hypertension (MHT) and MS, and the role of sodium intake, natriuretic peptide response and renin-angiotensin-aldosterone system in MHT and MS in obese youth.

METHODS

Obese children aged 10-18 years with normal office blood pressure measurements were included. Patients with MHT and normotension and those with MS and non-MS were evaluated separately. Biochemical parameters, copeptin, brain natriuretic peptide (BNP), aldosterone, renin, urine sodium, and protein were evaluated. Echocardiography, fundoscopic examination, and ambulatory blood pressure monitoring were performed.

RESULTS

There were 80 (M/F=39/41) obese patients with a mean age of 13.78 ± 1.93 years. The cases with MHT, MS, and concomitant MHT and MS were 53,24, and 13%, respectively. Copeptin levels were similar among patients with and without MHT or MS (p>0.05). However, multivariate analysis revealed that copeptin significantly increased the probability of MHT (OR 1.01, 95% CI=1.001-1.018, p=0.033). Copeptin was positively correlated with daytime systolic and diastolic load, aldosterone, BNP, and urine microalbumin/creatinine levels (p<0.05). Linear regression analyses revealed that copeptin was significantly correlated with BNP regardless of having MHT or MS in obese youth. In the MHT group, 24-h sodium excretion was not significantly correlated with BNP.

CONCLUSION

Copeptin may be a beneficial biomarker to discriminate MHT, but not MS in obese children and adolescents. An insufficient BNP response to sodium intake might be one of the underlying causes of MHT in obese cases.

Differences in omentin-1 levels in term newborns according to birth weight

BACKGROUND

Adipokines are produced by adipose tissue and are involved in metabolic processes. Omentin-1 is an adipokine that has been shown in vitro to possibly be involved in insulin sensitivity modulation. The prenatal stage is a crucial period for development of metabolic diseases in the long term, therefore, small (SGA) and large (LGA) for gestational age newborns have an increased risk of type 2 diabetes and metabolic syndrome later in life.

AIMS

To evaluate the differences in omentin-1 concentrations in umbilical cord blood from healthy term newborns according to birth weight and explore the association between omentin-1 and anthropometry, glucose, insulin and insulin sensitivity.

STUDY DESIGN

This was a secondary analysis of stored umbilical cord blood of term newborns.

SUBJECTS

Newborns classified according to birth weight as SGA (n = 30), adequate for gestational age (AGA) (n = 12) and LGA (n = 34).

OUTCOME MEASURES

An analysis of omentin-1, glucose and insulin were performed.

RESULTS

Differences were found in serum omentin-1 levels (ng/mL) between SGA 328.17 ± 108.04, AGA 253.05 ± 98.25 and LGA 250.91 ± 100.48 (p = 0.009). In the linear regression analysis, the independent variables HOMA-IR, QUICK-I and FGIR were predictors of serum omentin-1 levels (r = 0.175, p = 0.003).

CONCLUSIONS

Omentin-1 cord blood levels have a differentiated behavior according to weight for gestational age with LGA newborns having lower levels and SGA newborns higher levels. HOMA-IR, QUICK-I and FGIR weakly predicted omentin-1 in cord blood, suggesting that omentin-1 possibly has an implication in insulin sensitivity since birth.

Evaluation of Changes in Insulin Sensitivity in Prepubertal Small for Gestational Age Children Treated with Growth Hormone

BACKGROUND

Although growth hormone (GH) therapy for children born small for gestational age (SGA) has been approved for many years, there are still concerns about increasing their risk for insulin resistance and diabetes mellitus type 2. Monitoring of glucose homeostasis is therefore generally recommended, but there is no consensus on either the methods or consequences.

METHODS AND AIMS

The aim of our study was to analyze the oral Glucose Tolerance Tests (oGTTs) which were performed yearly from baseline to 4 years of GH therapy in a collective of 93 SGA children, who were prepubertal during the whole follow-up. We looked for correlations with auxological and laboratory data as well as predictive baseline results for glucose homeostasis during further treatment.

RESULTS

While glucose levels remained constant, insulin secretion increased from baseline to the first year of GH therapy. Insulin sensitivity index (ISI) showed no significant change afterwards; HOMA1, HOMA2, and QUICKI stabilized after the second year. For all indices mean values never reached pathological levels and no cases of diabetes mellitus were induced. Higher gestational age, lower birth length, and older age at start of GH therapy were associated with lower insulin sensitivity. No predictive factors for later insulin resistance could be found.

CONCLUSION

As expected, in GH-treated prepubertal SGA children insulin resistance was induced, but not to pathological levels. No special risk factors for disturbed glucose homeostasis could be identified. Based on our opinion, performing oGTTs in GH-treated SGA children at baseline and in puberty should remain mandatory, but the current study recommendations regarding further surveillance of glucose homeostasis are questionable.

Inappropriate Use of Homeostasis Model Assessment Cutoff Values for Diagnosing Insulin Resistance in Pediatric Studies

Background

Assessing pediatric patients for insulin resistance is one way to identify those who are at a high risk of developing type 2 diabetes mellitus. The homoeostasis model assessment (HOMA) is a measure of insulin resistance based on fasting blood glucose and insulin levels. Although this measure is widely used in research, cutoff values for pediatric populations have not been established.

Objective

To assess the validity of HOMA cutoff values used in pediatric studies published in peer-reviewed journals.

Methods

Studies published from January 2010 to December 2015 were identified through MEDLINE. Initial screening of abstracts was done to select studies that were conducted in pediatric populations and used HOMA to assess insulin resistance. Subsequent full-text review narrowed the list to only those studies that used a specific HOMA score to diagnose insulin resistance. Each study was classified as using a predetermined fixed HOMA cutoff value or a cutoff that was a percentile specific to that population. For studies that used a predetermined cutoff value, the references cited to provide evidence in support of that cutoff were evaluated.

Results

In the 298 articles analyzed, 51 different HOMA cutoff values were used to classify patients as having insulin resistance. Two hundred fifty-five studies (85.6%) used a predetermined fixed cutoff value, but only 72 (28.2%) of those studies provided a reference that supported its use. One hundred ten studies (43%) that used a fixed cutoff either cited a study that did not mention HOMA or provided no reference at all. Tracing of citation history indicated that the most commonly used cutoff values were ultimately based on studies that did not validate their use for defining insulin resistance.

Conclusion

Little evidence exists to support HOMA cutoff values commonly used to define insulin resistance in pediatric studies. These findings highlight the importance of validating study design elements when training medical students and novice investigators. Using available data to generate population ranges for HOMA would improve its clinical utility.

Insulinaemia and insulin resistance in Caucasian general paediatric population aged 2 to 10 years: Associated risk factors

BACKGROUND

The aim of this study is to determine values of insulinaemia, homeostasis model assessment (HOMA) index and quantitative insulin sensitivity check index (QUICKI) among a population of prepubertal Caucasian children, to analyse factors associated with insulin resistance (IR), and to study its association with cardiovascular risk factors.

MATERIALS AND METHODS

Population-based study conducted on a randomly selected sample of prepubescent Caucasian subjects aged 2.00 to 9.99 years old. Anthropometric measurements, blood pressure, and fasting blood samples were obtained, including fasting glucose, triglycerides, High Density Lipoprotein (HDL)-cholesterol, and insulin. In addition, QUICKI and HOMA indices were calculated. Generalised additive models for location, scale and shape (GAMLSS) was used to calculate centiles curves and multivariate logistic regression analysis to assess factors associated with IR.

RESULTS

A total of 654 subjects were included. Mean values obtained for insulinaemia, HOMA index, and QUICKI were 3.74 μIU/mL, 0.73, and 0.44, respectively, in the overall population and 3.32 μIU/mL, 0.64 and 0.46, respectively, in normal weight subjects. The main factor associated with IR was abdominal obesity (odds ratio [OR] 3.38 [95% CI 1.44-7.94] in the subgroup aged 2.00-5.99 years and OR 9.14 [3.42-24.41] for those aged 6.00-9.99 years). An increased risk of hyperglycaemia (P = 0.043), hypertriglyceridaemia (P < .001), and HDL < p10 (P = 0.021) was described among children aged 2.00 to 5.99 years with IR, and among those aged 6.00 to 9.99 years, IR was associated with an increased risk of hypertriglyceridaemia (P < .001).

CONCLUSION

Abdominal obesity was the main factor associated with IR. Metabolic changes associated with IR seem to be present from early stages of life, which highlights the importance of the prevention, early diagnosis and treatment of obesity.

Population-based cross-sectional study on insulin resistance and insulin-secretory capacity in Japanese school children

AIMS/INTRODUCTION

Little information is available regarding the status of insulin resistance (IR) and insulin deficiency (ID), as well as their relationship with obesity in children using the homeostasis model assessment (HOMA) in a population-based setting.

MATERIALS AND METHODS

The study included a total of 445 ninth-grade children participating in health check-up programs implemented in Tsunan Town, Niigata, Japan (boys/girls, 252/193 [participation rates: 98.1/95.5%]). HOMA of insulin resistance ≥2.5 was defined as IR, and HOMA of β-cell function <40 defined as ID.

RESULTS

The medians (25-75th percentiles) of HOMA of insulin resistance, HOMA of β-cell function, Disposition Index and body mass index in boys were 1.2 (0.8-1.7), 64 (44-93), 52 (43-64) and 19.2 (18.0-20.7) kg/m² , respectively, vs 1.5 (1.0-2.0), 86 (63-120), 60 (50-74) and 20.4 (18.9-22.0) kg/m² , respectively, in girls. The HOMA of insulin resistance, HOMA of β-cell function and Disposition Index values were significantly higher in the girls (P = 0.002, P < 0.001 and P < 0.001, respectively). Those with IR accounted for a significantly higher proportion of girls than boys (15.5/8.7%; P = 0.027); those with obesity accounted for 9.9/10.7% (boys/girls); and those with IR and obesity accounted for 2.4/4.7%. Those with ID accounted for a significantly higher proportion of boys than girls (20.6/8.8%; P = 0.001), whereas those with ID and obesity accounted for a very small proportion of either group (0.4/0.5%).

CONCLUSIONS

The presence of IR was higher among the girls. In contrast, ID was more frequent among the boys. The infrequent presence of ID among children might support the presence of non-obese type 2 diabetes adults in Japan.

The Association Between Changes in Insulin Sensitivity and Consumption of Tobacco and Alcohol in Young Adults: Ordinal Logistic Regression Approach

CONTEXT

Reduced insulin sensitivity is one of the traditional risk factors for chronic diseases such as type 2 diabetes. Reduced insulin sensitivity leads to insulin resistance, which in turn can lead to the development of type 2 diabetes. Few studies have examined factors such as blood pressure, tobacco and alcohol consumption that influence changes in insulin sensitivity over time especially among young adults.

PURPOSE

To examine temporal changes in insulin sensitivity in young adults (18-30 years of age at baseline) over a period of 20 years by taking into account the effects of tobacco and alcohol consumptions at baseline. In other words, the purpose of the present study is to examine if baseline tobacco and alcohol consumptions can be used in predicting lowered insulin sensitivity.

METHOD

This is a retrospective study using data collected by the Coronary Artery Risk Development in Young Adults (CARDIA) study from the National Heart, Lung, and Blood Institute. Participants were enrolled into the study in 1985 (baseline) and followed up to 2005. Insulin sensitivity, measured by the quantitative insulin sensitivity check index (QUICKI), was recorded at baseline and 20 years later, in 2005. The number of participants included in the study was 3,547. The original study included a total of 5,112 participants at baseline. Of these, 54.48% were female, and 45.52% were male; 45.31% were 18 to 24 years of age, and 54.69% were 25 to 30 years of age. Ordinal logistic regression was used to assess changes in insulin sensitivity. Changes in insulin sensitivity from baseline were calculated and grouped into three categories (more than 15%, more than 8.5% to at most 15%, and at most 8.5%), which provided the basis for employing ordinal logistic regression to assess changes in insulin sensitivity. The effects of alcohol and smoking consumption at baseline on the change in insulin sensitivity were accounted for by including these variables in the model.

RESULTS

Daily alcohol consumption (ml/day) at baseline was not associated with changes in insulin sensitivity (OR = 0.998, 95% CI 0.995-1.001), while the number of cigarettes consumed per day at baseline was statistically significantly associated with changes in insulin sensitivity (OR = 1.016, 95% CI 1.007-1.025). Covariates such as age (OR = 1.05, 95% CI 1.031-1.071), mean arterial blood pressure (OR = 0.986, 95% CI 0.977-0.994), body-mass index (OR = 0.951, 95% CI 0.936-0.965), race (OR = 0.840, 95% CI 0.735-0.960), and sex (OR = 0.561, 95% CI 0.483-0.652) were significantly associated with changes in insulin sensitivity.

CONCLUSION

After adjusting for relevant covariates, the daily tobacco consumption at baseline was independently associated with changes in insulin sensitivity. But we were not able to replicate the association between daily alcohol consumption at baseline and changes in insulin resistance reported by other studies. Further studies in different populations and settings are warranted to examine the association between alcohol consumption and changes in insulin resistance.

Evaluation of Nerve Conduction Studies in Obese Children With Insulin Resistance or Impaired Glucose Tolerance

The aim of the study was to investigate nerve conduction studies in terms of neuropathic characteristics in obese patients who were in prediabetes stage and also to determine the abnormal findings. The study included 69 obese adolescent patients between April 2009 and December 2010. All patients and control group underwent motor (median, ulnar, tibial, and peroneal) and sensory (median, ulnar, sural, and medial plantar) nerve conduction studies and sympathetic skin response test. Sensory response amplitude of the medial plantar nerve was significantly lower in the patients with impaired glucose tolerance and insulin resistance. To our knowledge, the present study is the first study demonstrating the development of sensory and autonomic neuropathy due to metabolic complications of obesity in adolescent children even in the period without development of diabetes mellitus. We recommend that routine electrophysiological examinations be performed, using medial plantar nerve conduction studies and sympathetic skin response test.

Systematic review to identify and appraise outcome measures used to evaluate childhood obesity treatment interventions (CoOR): evidence of purpose, application, validity, reliability and sensitivity

BACKGROUND

Lack of uniformity in outcome measures used in evaluations of childhood obesity treatment interventions can impede the ability to assess effectiveness and limits comparisons across trials.

OBJECTIVE

To identify and appraise outcome measures to produce a framework of recommended measures for use in evaluations of childhood obesity treatment interventions.

DATA SOURCES

Eleven electronic databases were searched between August and December 2011, including MEDLINE; MEDLINE In-Process and Other Non-Indexed Citations; EMBASE; PsycINFO; Health Management Information Consortium (HMIC); Allied and Complementary Medicine Database (AMED); Global Health, Maternity and Infant Care (all Ovid); Cumulative Index to Nursing and Allied Health Literature (CINAHL) (EBSCOhost); Science Citation Index (SCI) [Web of Science (WoS)]; and The Cochrane Library (Wiley) - from the date of inception, with no language restrictions. This was supported by review of relevant grey literature and trial databases.

REVIEW METHODS

Two searches were conducted to identify (1) outcome measures and corresponding citations used in published childhood obesity treatment evaluations and (2) manuscripts describing the development and/or evaluation of the outcome measures used in the childhood intervention obesity evaluations. Search 1 search strategy (review of trials) was modelled on elements of a review by Luttikhuis et al. (Oude Luttikhuis H, Baur L, Jansen H, Shrewsbury VA, O'Malley C, Stolk RP, et al. Interventions for treating obesity in children. Cochrane Database Syst Rev 2009;1:CD001872). Search 2 strategy (methodology papers) was built on Terwee et al.'s search filter (Terwee CB, Jansma EP, Riphagen II, de Vet HCW. Development of a methodological PubMed search filter for finding studies on measurement properties of measurement instruments. Qual Life Res 2009;18:1115-23). Eligible papers were appraised for quality initially by the internal project team. This was followed by an external appraisal by expert collaborators in order to agree which outcome measures should be recommended for the Childhood obesity Outcomes Review (CoOR) outcome measures framework.

RESULTS

Three hundred and seventy-nine manuscripts describing 180 outcome measures met eligibility criteria. Appraisal of these resulted in the recommendation of 36 measures for the CoOR outcome measures framework. Recommended primary outcome measures were body mass index (BMI) and dual-energy X-ray absorptiometry (DXA). Experts did not advocate any self-reported measures where objective measurement was possible (e.g. physical activity). Physiological outcomes hold potential to be primary outcomes, as they are indicators of cardiovascular health, but without evidence of what constitutes a minimally importance difference they have remained as secondary outcomes (although the corresponding lack of evidence for BMI and DXA is acknowledged). No preference-based quality-of-life measures were identified that would enable economic evaluation via calculation of quality-adjusted life-years. Few measures reported evaluating responsiveness.

LIMITATIONS

Proposed recommended measures are fit for use as outcome measures within studies that evaluate childhood obesity treatment evaluations specifically. These may or may not be suitable for other study designs, and some excluded measures may be more suitable in other study designs.

CONCLUSIONS

The CoOR outcome measures framework provides clear guidance of recommended primary and secondary outcome measures. This will enhance comparability between treatment evaluations and ensure that appropriate measures are being used. Where possible, future work should focus on modification and evaluation of existing measures rather than development of tools de nova. In addition, it is recommended that a similar outcome measures framework is produced to support evaluation of adult obesity programmes.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Insulin resistance in patients on valproic acid: relation to adiponectin

OBJECTIVES

To investigate the presence of insulin resistance in obese children with idiopathic epilepsy on valproic acid (VPA) monotherapy in comparison to obese otherwise healthy subjects. Secondary outcome was to explore the relation between adiponectin and insulin resistance among those patients.

MATERIALS AND METHODS

Fifty obese children with generalized idiopathic epilepsy on VPA monotherapy and a control group of 49 obese clinically healthy age and sex-matched children with simple obesity were recruited in the study. Anthropometric assessment, fasting plasma insulin (FI), fasting glucose (FG) and fasting adiponectin levels were measured. Fasting glucose insulin ratio (FGIR) and homoeostasis model assessment for insulin resistance (HOMA-IR) were calculated for both patients and control subjects. Measurement of serum VPA trough level was also performed in patients.

RESULTS

Patients had significantly higher fasting blood glucose, fasting insulin, lower FGIR and higher HOMA-IR values, compared to controls. Mean adiponectin level was significantly lower in patients compared to controls. The duration of treatment with valproic acid negatively correlated with adiponectin (r = -0.285, P = 0.045), but did not correlate with fasting glucose, insulin, FGIR or HOMA-IR. Total daily VPA dose significantly correlated with fasting insulin (r = 0.495, P < 0.001), FGIR (r = -0.525, P < 0.001) and HOMA-IR (r = 0.404, P = 0.004).

CONCLUSION

This study ascertains the relationship between dose and duration of VPA therapy, insulin resistance and the adipocytokine axis. We are reporting the novel proposal that obese VPA-treated children are more insulin resistant and have lower adiponectin levels than obese and otherwise healthy children.

Framework of outcome measures recommended for use in the evaluation of childhood obesity treatment interventions: the CoOR framework

INTRODUCTION

Consensus is lacking in determining appropriate outcome measures for assessment of childhood obesity treatments. Inconsistency in the use and reporting of such measures impedes comparisons between treatments and limits consideration of effectiveness. This study aimed to produce a framework of recommended outcome measures: the Childhood obesity treatment evaluation Outcomes Review (CoOR) framework.

METHODS

A systematic review including two searches was conducted to identify (1) existing trial outcome measures and (2) manuscripts describing development/evaluation of outcome measures. Outcomes included anthropometry, diet, eating behaviours, physical activity, sedentary time/behaviour, fitness, physiology, environment, psychological well-being and health-related quality of life. Eligible measures were appraised by the internal team using a system developed from international guidelines, followed by appraisal from national external expert collaborators.

RESULTS

A total of 25,486 papers were identified through both searches. Eligible search 1 trial papers cited 417 additional papers linked to outcome measures, of which 56 were eligible. A further 297 outcome development/evaluation papers met eligibility criteria from search 2. Combined, these described 191 outcome measures. After internal and external appraisal, 52 measures across 10 outcomes were recommended for inclusion in the CoOR framework.

CONCLUSION

Application of the CoOR framework will ensure greater consistency in choosing robust outcome measures that are appropriate to population characteristics.

Prediction of future risk of insulin resistance and metabolic syndrome based on Korean boy's metabolite profiling

OBJECTIVE

Childhood obesity is strongly related to future insulin resistance and metabolic syndrome. Thus, identifying early biomarkers of obesity-related diseases based on metabolic profiling is useful to control future metabolic disorders. We compared metabolic profiles between obese and normal-weight children and investigated specific biomarkers of future insulin resistance and metabolic syndrome.

METHODS

In all, 186 plasma metabolites were analysed at baseline and after 2 years in 109 Korean boys (age 10.5±0.4 years) from the Korean Child Obesity Cohort Study using the AbsoluteIDQ™ p180 Kit.

RESULTS

We observed that levels of 41 metabolites at baseline and 40 metabolites at follow-up were significantly altered in obese children (p<0.05). Obese children showed significantly higher levels of branched-chain amino acids (BCAAs) and several acylcarnitines and lower levels of acyl-alkyl phosphatidylcholines. Also, baseline BCAAs were significantly positively correlated with both homeostasis model assessment for insulin resistance (HOMA-IR) and continuous metabolic risk score at the 2-year follow-up. In logistic regression analyses with adjustments for degree of obesity at baseline, baseline BCAA concentration, greater than the median value, was identified as a predictor of future risk of insulin resistance and metabolic syndrome.

CONCLUSION

High BCAA concentration could be "early" biomarkers for predicting future metabolic diseases.

Carotid intima media thickness and other cardiovascular risk factors in children with congenital adrenal hyperplasia

PURPOSE

Patients with congenital adrenal hyperplasia (CAH) are at increased risk for cardiovascular disease due to many factors. The aim of this study is to investigate the presence of dyslipidemia, insulin resistance, and subclinical atherosclerosis as indicated by carotid intima media thickness in children with congenital adrenal hyperplasia.

METHODS

Thirty-two children with congenital adrenal hyperplasia (3-17 years) were compared with 32 healthy controls. All underwent anthropometric evaluation, measurement of fasting lipids, glucose, insulin, oral glucose tolerance test (OGTT), homeostasis model assessment for insulin resistance (HOMA-IR), and carotid intima media thickness (CIMT).

RESULTS

Fasting glucose, glucose at 30, 60, 90, and 120 min during OGTT were significantly higher in patients. HOMA-IR was also significantly higher in patients (p = 0.036). Patients had significantly higher CIMT (p = 0.003), and higher systolic blood pressure. (p = 0.04). No significant difference existed in lipid profile. Both systolic and diastolic blood pressures correlated with treatment duration (p = 0.002, p = 0.043, respectively).

CONCLUSION

Children with CAH are at increased risk of insulin resistance, glucose intolerance, early atherosclerosis, and cardiovascular disease. Screening of these patients at an early age is recommended.

Increased leptin/adiponectin ratio and free leptin index are markers of insulin resistance in obese girls during pubertal development

BACKGROUND

Modifications in body fat in obese patients during puberty determine changes in adipokines that affect insulin sensitivity.

AIMS

We hypothesized that the leptin/adiponectin (L/A) ratio and free leptin index (FLI) are good markers of insulin resistance (IR) and total body fat (TBF) during pubertal development.

METHODS

A prospective study of 32 obese girls (OG) and age-matched control girls (CG) was performed. OG were divided into those that maintained a weight loss (WL) of >1 SD of initial body mass index (BMI) (WL group, n = 25) and those without WL (NWL group, n = 7). Oral glucose tolerance tests (OGTT) were performed to evaluate IR. Correlations of adipokines, L/A, and FLI with BMI, waist circumference, percentage of TBF (%TBF) and IR were performed over pubertal development.

RESULTS

The L/A ratio and FLI were increased in OG at baseline. Both indexes decreased in the WL group as puberty progressed, with no change in CG or NWL. In the WL group, a correlation between L/A and FLI with OGTT and %TBF, and L/A and homeostasis model assessment (HOMA) was found throughout the study.

CONCLUSION

The L/A ratio and FLI are good markers to follow changes in IR and %TBF after WL during puberty. Insulin more accurately reflects the changes in IR than HOMA.

Evaluation of lipid and glucose metabolism and cortisol and thyroid hormone levels in obese appropriate for gestational age (AGA) born and non-obese small for gestational age (SGA) born prepubertal Slovak children

AIM

Obesity is the major determinant of metabolic syndrome. Being born small for gestational age (SGA) may be co-responsible. We aimed at evaluating the association between 1. obesity and 2. being born SGA and the presence of endocrine-metabolic abnormalities in prepubertal Slovak children.

METHODS

The study included 98 children, aged 3-10.9 years: 36 AGA-born obese children (OB), 31 SGA-born children (SGA) and 31 appropriate for gestational age born non-obese children (AGA). Fasting serum levels of glucose, total cholesterol, LDL, HDL, triglycerides, fT4, TSH, cortisol and insulin were determined. HOMA-IR was calculated. Personal data about birth weight and length and family history were collected. Actual anthropometric measurement was done.

RESULTS

In every group, high prevalence of positive family history of metabolic disorder was found. In comparison with AGA children, OB children were taller (p<0.01) with higher body mass index (BMI) (p<0.001), and had increased insulin levels and homeostasis model assessment for insulin resistance (HOMA-IR) (p<0.001), decreased high-density lipoprotein (HDL) (p<0.001), and a trend to higher cortisol levels (p=0.069) was noted. SGA-born children were shorter (p<0.001), with BMI comparable to the AGA group. They had higher glucose levels (p<0.001), a trend to decreased HDL levels (p=0.085) and increased fT4 levels (p<0.001). A three-fold higher occurrence of metabolic abnormalities was present in obese children and twice more metabolic abnormalities were present in SGA-born children in comparison with AGA-born children.

CONCLUSIONS

SGA-born children are more prone to developing endocrine-metabolic abnormalities than non-obese children born AGA, but they are at less risk than obese AGA-born children. We should provide specialized care for obese children already in prepubertal age and pay attention to SGA-born children.

Bariatric surgery in severely obese adolescents improves major comorbidities including hyperuricemia

OBJECTIVE

Serum uric acid (sUA) is believed to contribute to the pathogenesis of metabolic comorbidities like hypertension, insulin-resistance (IR) and endothelial dysfunction (EDF) in obese children. The present pilot study investigated the association between sUA concentrations and loss of body weight following laparoscopic sleeve gastrectomy (LSG) or laparoscopic Roux-en-Y-gastric bypass (RYGB) in severely obese adolescents.

MATERIALS/METHODS

10 severely obese adolescents underwent either LSG (n=5) or RYGB (n=5). 17 normal weight, healthy, age- and gender-matched adolescents served as a normal weight peer group (NWPG). Pre- and 12 months postoperatively, sUA and relevant metabolic parameters (glucose homeostasis, transaminases, lipids) were compared.

RESULTS

Preoperatively, sUA was significantly elevated in patients with severe obesity compared to NWPG. Twelve months after LSG and RYGB, a significant decrease in sUA, BMI, CVD risk factors, hepatic transaminases, and HOMA-IR was observed. Reduction in SDS-BMI significantly correlated with changes in sUA.

CONCLUSIONS

sUA levels and metabolic comorbidities improved following bariatric surgery in severely obese adolescents. The impact of changes in sUA on long-term clinical complications of childhood obesity deserves further study.

A study of insulin resistance by HOMA-IR and its cut-off value to identify metabolic syndrome in urban Indian adolescents

OBJECTIVE

Insulin resistance (IR) and associated metabolic abnormalities are increasingly being reported in the adolescent population. Cut-off value of homeostasis model of assessment IR (HOMA-IR) as an indicator of metabolic syndrome (MS) in adolescents has not been established. This study aimed to investigate IR by HOMA-IR in urban Indian adolescents and to establish cut-off values of HOMA-IR for defining MS.

METHODS

A total of 691 apparently healthy adolescents (295 with normal body mass index (BMI), 205 overweight, and 199 obese) were included in this cross-sectional study. MS in adolescents was defined by International Diabetes Federation (IDF) and Adult Treatment Panel III (ATP III) criteria. IR was calculated using the HOMA model.

RESULTS

Mean height, waist circumference (WC), waist/hip ratio (WHR), waist/height ratio (WHtR), and blood pressure were significantly higher in boys as compared to girls. The HOMA-IR values increased progressively from normal weight to obese adolescents in both sexes. Mean HOMA-IR values increased progressively according to sexual maturity rating in both sexes. HOMA-IR value of 2.5 had a sensitivity of >70% and specificity of >60% for MS. This cut-off identified larger number of adolescents with MS in different BMI categories (19.7% in normal weight, 51.7% in overweight, and 77.0% in obese subjects) as compared to the use of IDF or ATP III criteria for diagnosing MS. Odds ratio for having IR (HOMA-IR of >2.5) was highest with WHtR (4.9, p p<0.0001) and WC (4.8, p p<0.0001), compared to WHR (3.3, p p<0.0001).

CONCLUSIONS

In Indian adolescents, HOMA-IR increased with sexual maturity and with progression from normal to obese. A HOMA-IR cut-off of 2.5 provided the maximum sensitivity and specificity in diagnosing MS in both genders as per ATP III and IDF criteria.

Correcting vitamin D insufficiency improves insulin sensitivity in obese adolescents: a randomized controlled trial

BACKGROUND

Obese adolescents are at a greater risk of vitamin D deficiency because vitamin D is thought to be sequestered by excess adipose tissue. Poor vitamin D status has been associated with a higher prevalence of the metabolic syndrome, type 2 diabetes, or both in adults and adolescents.

OBJECTIVE

The objective was to determine in obese adolescents the efficacy and safety of 4000 IU vitamin D3/d and whether subsequent increased circulating concentrations of 25-hydroxyvitamin D [25(OH)D] are associated with improved markers of insulin sensitivity and resistance and reduced inflammation.

DESIGN

Obese adolescent patients [n = 35; mean ± SD age: 14.1 ± 2.8 y; BMI (in kg/m(2)): 39.8 ± 6.1; 25(OH)D: 19.6 ± 7.1 ng/mL] were recruited from the University of Missouri Adolescent Diabetes and Obesity Clinic and were randomly assigned to receive either vitamin D3 (4000 IU/d) or placebo as part of their standard care. Anthropometric measurements, inflammatory markers (IL-6, TNF-α, C-reactive protein), adipokines (leptin, adiponectin), fasting glucose, fasting insulin, and HOMA-IR values were measured at baseline and at 2 follow-up visits (3 and 6 mo).

RESULTS

After 6 mo, there were no significant differences in BMI, serum inflammatory markers, or plasma glucose concentrations between groups. Participants supplemented with vitamin D3 had increases in serum 25(OH)D concentrations (19.5 compared with 2.8 ng/mL for placebo; P < 0.001), fasting insulin (-6.5 compared with +1.2 μU/mL for placebo; P = 0.026), HOMA-IR (-1.363 compared with +0.27 for placebo; P = 0.033), and leptin-to-adiponectin ratio (-1.41 compared with +0.10 for placebo; P = 0.045). Inflammatory markers remained unchanged.

CONCLUSION

The correction of poor vitamin D status through dietary supplementation may be an effective addition to the standard treatment of obesity and its associated insulin resistance. This trial was registered at clinicaltrials.gov as NCT00994396.

A multi-center controlled trial of growth hormone treatment in children with cystic fibrosis

OBJECTIVES

We evaluated safety and efficacy of recombinant human growth hormone (rhGH) for improving growth, lean body mass (LBM), pulmonary function, and exercise tolerance in children with cystic fibrosis (CF) and growth restriction.

STUDY DESIGN

Multicenter, open-label, controlled clinical trial comparing outcomes in prepubertal children <14 years with CF, randomized in a 1:1 ratio to receive daily rhGH (Nutropin AQ) or no treatment (control) for 12 months, followed by a 6-month observation (month 18). Safety was monitored at each visit, including assessments of glucose tolerance.

RESULTS

Sixty-eight subjects were randomized (control n = 32; rhGH n = 36). Mean height standard deviation score (SDS) in the rhGH group increased by 0.5 ± 0.4 at 12 months (mean ± SD, P < 0.001); the control group height SDS remained unchanged. Weight increased by 3.8 ± 1.8 versus 2.8 ± 1.5 kg, (mean ± SD, P = 0.0356) and LBM increased by 3.8 ± 1.8 versus 2.1 ± 1.4 kg (P = 0.0002) in the rhGH group versus controls, respectively. Forced vital capacity increased by 325 ± 319 in the rhGH group compared with 178 ± 152 ml in controls (mean ± SD, P = 0.032). Forced expiratory volume in 1 sec improved in both groups with a significant difference between groups after adjustment for baseline severity (LS mean ± SE: rhGH, 224 ± 37, vs. controls, 108 ± 40 ml; P = 0.04). There was no difference between groups in exercise tolerance (6-min walk distance) at 1 year. Changes in glucose tolerance for the two groups were similar over the 12-month study period, with three subjects developing IGT and one CFRD in each group. One rhGH-treated patient developed increased intracranial pressure.

CONCLUSIONS

Treatment with rhGH in prepubertal children with CF was effective in promoting growth, weight, LBM, lung volume, and lung flows, and had an acceptable safety profile.

Visfatin in juvenile obesity - the effect of obesity intervention and sex

BACKGROUND

The association of visfatin, an adipocytokine relevant to the development of inflammation and metabolic disorders, with juvenile obesity needs to be re-established as previously used tests occurred to be nonspecific.

OBJECTIVE

To evaluate visfatin association with a metabolic profile of 88 overweight/obese and 26 lean children/adolescents as well as changes in its levels following weight reduction programme (diet + enhanced physical activity ± metformin).

DESIGN

A case-control and cohort study.

RESULTS

Visfatin was higher in obese than lean and overweight individuals (2·07 vs. 1·53 and 1·47 ng mL(-1) , P = 0·034). Of metabolic syndrome components, central obesity combined with either insulin resistance (IR) or hyperinsulinemia (HI) was associated with increases in circulating visfatin. In girls, visfatin correlated with leptin (r = 0·40, P = 0·009) and thiols (r = -0·36, P = 0·009), which explained 24% in visfatin variability. In boys, visfatin correlated with waist circumference (r = 0·36, P = 0·036), BMI% (r = 0·38, P = 0·025), whole body insulin sensitivity index (r = -0·36, P = 0·036), IL-6 (r = 0·38, P = 0·024) and thiobarbituric acid reactive substances (TBARS) (r = 0·52, P = 0·001), of which IL-6 and TBARS were independent predictors of visfatin elevation, explaining 42% in data variability. Visfatin was significantly lower following weight reduction programme than at baseline (1·43 vs. 1·83 ng mL(-1) , P = 0·033). Visfatin reduction correlated neither with changes in metabolic parameters nor was it affected by metformin. ΔVisfatin correlated exclusively with baseline visfatin (r = 0·612, P < 0·0001), which explained 38% in data variability.

CONCLUSIONS

Central obesity combined with HI/IR contributes to visfatin elevation. Visfatin association with metabolic/biochemical variables is gender dependent. Diet + enhanced physical activity are effective in visfatin reduction, the degree of which depends on baseline visfatin.

Selection of the appropriate method for the assessment of insulin resistance

Insulin resistance is one of the major aggravating factors for metabolic syndrome. There are many methods available for estimation of insulin resistance which range from complex techniques down to simple indices. For all methods of assessing insulin resistance it is essential that their validity and reliability is established before using them as investigations. The reference techniques of hyperinsulinaemic euglycaemic clamp and its alternative the frequently sampled intravenous glucose tolerance test are the most reliable methods available for estimating insulin resistance. However, many simple methods, from which indices can be derived, have been assessed and validated e.g. homeostasis model assessment (HOMA), quantitative insulin sensitivity check index (QUICKI). Given the increasing number of simple indices of IR it may be difficult for clinicians and researchers to select the most appropriate index for their studies. This review therefore provides guidelines and advices which must be considered before proceeding with a study.

Relationship of weight status and cardiometabolic outcomes for adolescents in the TEAMS study

The increase in the prevalence of obesity among youth is alarming. Relationships exist between excess weight and adverse cardiometabolic markers. The aims of this study among adolescents in the Teen Eating and Activity Mentoring in Schools (TEAMS) project were to describe selected demographic characteristics, anthropometric measurements, and laboratory values of middle school students; contrast differences in rates of cardiometabolic markers for participants with body mass index (BMI) ≥ 95th percentile and <95th percentile; examine rates of exceeding cardiometabolic cutoffs by weight status; and predict the odds ratio for one or more adverse cardiometabolic outcomes when BMI ≥95th percentile. Students (N = 151) were significantly more likely to exceed cut-off points for high-density lipoprotein cholesterol (HDL-C) and blood pressure (BP) when BMI was ≥95th percentile. Students whose BMI was ≥the 95th percentile were nearly five times as likely to have the deleterious cardiometabolic outcomes of low HDL-C, high triglycerides, elevated homeostasis model assessment of insulin resistance (HOMA-IR), or elevated systolic BP than those whose BMI was <the 95th percentile. Nurses and other clinicians should view BMI ≥95th percentile as an indicator of other risk factors that merits additional assessments and interventions to improve health.

Circulating adipocyte fatty acid-binding protein, juvenile obesity, and metabolic syndrome

Adipocyte fatty acid-binding protein (A-FABP) links obesity and metabolic syndrome (MetS) and might be targeted in future therapies. Its utility as a MetS biomarker has been suggested in adults but has not been examined in children/adolescents. Our objectives were to identify metabolic parameters associated with A-FABP elevation in children and adolescents and to evaluate the effect of obesity intervention and A-FABP diagnostic utility. A-FABP and anthropometric, metabolic, and inflammatory indices were measured in 31 lean and 114 overweight/obese children and adolescents and reassessed after obesity intervention (1 year; diet and enhanced physical activity, with or without metformin). A-FABP was significantly higher in overweight/ obese than lean individuals, where it correlated with insulin, waist circumference (WC), and 2-h glucose independent of body mass index (BMI), age, gender, and developmental stage. The pattern of A-FABP associations differed between sexes. As a MetS indicator, A-FABP had 68% accuracy. The weight reduction program was effective in reducing A-FABP, BMI%, WC, triglycerides, and cholesterol. In conclusion, elevation in A-FABP is associated with MetS components independent of BMI status and can be reduced by diet and enhanced physical activity. A-FABP as a single MetS biomarker has a moderate accuracy.

Body mass index percentile more sensitive than acanthosis nigricans for screening Native American children for diabetes risk

BACKGROUND

Many Native American tribes use acanthosis nigricans to screen for type 2 diabetes risk. We hypothesized that acanthosis nigricans misses many children at risk for type 2 diabetes.

METHODS

We evaluated 5- to 18-year-old Native American children and youth to assess the sensitivity and specificity of acanthosis nigricans as a marker for insulin resistance.

RESULTS

In a cohort of 161 youth (72 males/89 females), mean age was 10.7 years + 3.9. Mean body mass index (BMI) percentile was 76.8 +/- 23.3, and 54% had a BMI at or above the 85th percentile. Acanthosis nigricans was present in 21.7% of the participants and was more common in 12-to 18-year-olds than in 5 to 11-year-olds (p = .02). Of those with acanthosis nigricans, 82.4% had insulin resistance (homeostatic model assessment of insulin resistance >4), but only 48.3% of those with insulin resistance had acanthosis nigricans. In contrast, BMI at or above the 85th percentile had a high sensitivity (74%) for insulin resistance, even though its specificity was lower (58%).

CONCLUSIONS

The presence of acanthosis nigricans alone was a specific, but not a sensitive, screening tool for identifying youth with insulin resistance. BMI at or above the 85th percentile was a more sensitive screening tool than acanthosis nigricans alone, or acanthosis nigricans and BMI together for identifying children and youth with IR who are at increased risk for type 2 diabetes.

Insulin resistance in obese children and adolescents: HOMA-IR cut-off levels in the prepubertal and pubertal periods

OBJECTIVE

Childhood obesity is associated with an increased risk for insulin resistance. The underlying mechanism for the physiological increase in insulin levels in puberty is not clearly understood. The aim of the present study was to determine the cut-off values for homeostasis model assessment for insulin resistance (HOMA-IR) in obese children and adolescents according to gender and pubertal status.

METHODS

Two hundred and eight obese children and adolescents (141 girls, 127 boys) aged between 5 and 18 years were included in the study. The children were divided into prepubertal and pubertal groups. A standard oral glucose tolerance test (OGTT) was carried out in all children. A total insulin level exceeding 300 μU/mL in the blood samples, collected during the test period, was taken as the insulin resistance criterion. Cut-off values for HOMA-IR were calculated by receiver operating characteristic (ROC) analysis.

RESULTS

In the prepubertal period, the rate of insulin resistance was found to be 37% in boys and 27.8% in girls,while in the pubertal period, this rate was 61.7% in boys and 66.7% in girls. HOMA-IR cut-off values for insulin resistance in the prepubertal period were calculated to be 2.67 (sensitivity 88.2%, specificity 65.5%) in boys and 2.22 (sensitivity 100%, specificity 42.3%) in girls, and in the pubertal period, they were 5.22 (sensitivity 56%, specificity 93.3%) in boys and 3.82 (sensitivity 77.1%, specificity 71.4%) in girls.

CONCLUSIONS

Since gender, obesity and pubertal status are factors affecting insulin resistance, cut-off values which depend on gender and pubertal status, should be used in evaluation of insulin resistance.

Sex hormone-binding globulin levels and metabolic syndrome and its features in adolescents

BACKGROUND

Low levels of sex hormone-binding globulin (SHBG) are associated with obesity, insulin resistance, and metabolic syndrome (MS) in men and women, and it has been suggested that SHBG could be a useful marker for MS risk.

OBJECTIVE

The aim of this study was to analyze the relationship of SHBG levels with MS and its components in Spanish adolescents.

METHODS

The sample population of this cross-sectional study was comprised of 386 male and 429 female adolescents, aged 12-16 yr. Anthropometric parameters and blood pressure (BP) were measured. Total cholesterol, high-density lipoprotein (HDL)-cholesterol, insulin, glucose, and SHBG levels were determined. The pediatric International Diabetes Federation (IDF) definition was used to classify adolescents for MS.

RESULTS

SHBG levels were lower in adolescents with MS or with some MS features. More than 90% of the abdominally obese adolescents were in the lowest and medium SHBG tertiles. In girls, BP was significantly higher in the lowest SHBG tertile than in the two others, whereas in boys BP levels were significantly higher in the lowest and medium tertiles than in the highest one. Insulin levels and homeostasis model assessment (HOMA) index were also significantly higher in the lowest SHBG tertile than in the two others.

CONCLUSIONS

The associations of SHBG with MS and its components, such as abdominal obesity, high BP or insulin levels, are already present in normal adolescents. This may suggest the possibility of using SHBG levels as a biomarker for MS risk in adolescents as well as adults.

Dietary patterns and markers for the metabolic syndrome in Australian adolescents

BACKGROUND AND AIMS

Overweight and other risk factors for cardiovascular disease (CVD) as well as their clustering, are increasingly prevalent among adolescents. We examined dietary patterns, CVD risk factors, and the clustering of these risk factors in 1139 14-year-olds living in Western Australia.

METHODS AND RESULTS

Usual dietary intake was assessed using a food frequency questionnaire. Two dietary patterns, 'Western' and 'Healthy', were identified using factor analysis. Associations between these dietary patterns and BMI, waist circumference, systolic blood pressure, fasting levels of serum glucose, insulin, total cholesterol, HDL-C, LDL-C, triglycerides and insulin resistance were assessed using ANOVA. Cluster analysis identified a high risk group (the 'high risk metabolic cluster') with features akin to adult metabolic syndrome. Belonging to the 'high risk metabolic cluster' was examined in relation to dietary patterns using logistic regression, adjusting for aerobic fitness and socio-demographic factors. Higher 'Western' dietary pattern scores were associated with greater odds for the 'high risk metabolic cluster' (p for trend=0.02) and greater mean values for total cholesterol (p for trend=0.03), waist circumference (p for trend=0.03) and BMI (p for trend=0.02) in girls, but not boys. Scores for the 'Healthy' dietary pattern were not related to the 'high risk metabolic cluster' but were inversely associated with serum glucose in boys and girls (p for trend=0.01 and 0.04, respectively) and were positively associated with HDL-C in boys (p for trend=0.02).

CONCLUSIONS

Dietary patterns are associated with CVD risk factors and the clustering of these risk factors in adolescence.

Two Japanese infants with congenital generalized lipodystrophy due to BSCL2 mutations

BACKGROUND

Congenital generalized lipodystrophy (CGL), Berardinelli-Seip syndrome, is a rare autosomal recessive disorder characterized by the generalized absence of adipose tissue at birth, severe insulin resistance early in life, hypertriglyceridemia, hepatomegaly, and the development of diabetes mellitus during puberty. Recently, two genes, BSCL2 and AGPAT2, were identified as causative genes for CGL. It has been reported that patients with BSCL mutations present with more severe clinical findings than those with AGPAT2 mutations. However, the clinical course of CGL caused by BSCL2 mutations in infancy has not been fully elucidated.

METHODS

Two Japanese infantile patients with CGL from independent families were examined and underwent an oral glucose tolerance test. Insulin resistance and insulin secretion were estimated using the homeostasis model assessment for insulin resistance and the insulinogenic index, respectively. Sequence analysis of the entire coding region of BSCL2 and AGPAT2 was performed.

RESULTS

Both CGL patients presented with normal glycemic profiles after oral glucose tolerance tests; however, the values from the homeostasis model assessment of insulin resistance were elevated and well above the cut-off point for diagnosis of infant insulin resistance in both patients. One patient possessed a known homozygous nonsense mutation in exon 8 (c.823C>T) of BSCL2; the other had a novel homozygous missense mutation in exon 5 (c.560A>G) of BSCL2.

CONCLUSION

Japanese CGL patients with BSCL2 mutations presented with severe insulin resistance, even during infancy, prior to the development of diabetes mellitus.

Effect of recreational physical activity on insulin levels in Mexican/Hispanic children

The effect of increased recreational physical activity in children on insulin levels has not yet been studied. We carried out a randomized controlled trial in 76 children 6-9 years old, 32 of them increased their physical activity and 30 maintained the same level. In the intervention group, after a week of baseline, recreational activity three times/week was programmed for 12 weeks. We compared insulin, homeostatic model assessment (HOMA) index, glucose, HDL-C, LDL-C, triglycerides, and body mass index in both groups. Thereafter, we compared groups of normal weight, overweight, and with obesity in the experimental group. The group of recreational activity increased their median daily steps (15,329 to 19,910) and decreased insulin (p < 0.001) and HOMA index (4.36 vs. 2.39, p < 0.001). The diminution of insulin levels was more significant in the overweight group (p < 0.007). In conclusion, in our group, children who increased physical activity during 12 weeks decrease insulin levels and insulin resistance without change in other metabolic and anthropometric variables.

Short-term effects of growth hormone treatment on the upper airways of non severely obese children with Prader-Willi syndrome

AIMS

The aim of this study was to establish whether short-term GH treatment causes obstructive apnea in patients with Prader-Willi syndrome and normal upper airway patency.

SUBJECTS AND METHODS

We performed an observational longitudinal 6-week GH treatment study. Thirty-four non-severely obese Prader-Willi syndrome patients (20 boys, age range 0.94-11.8 yr, median 2.24 yr) entered an observational longitudinal 6-week study. Sixteen boys received recombinant human GH (rhGH) treatment; the remaining 18 represented the control group and received no treatment. Polysomnography monitoring and othorhinolaringoiatric video endoscopy were performed one night before and after 6 weeks of rhGH treatment (0.03 mg/kg body weight/day). All patients underwent auxologic assessment, fasting blood glucose, insulin and IGF-I evaluation. The main polysomnographic parameter considered was total apnea hypopnea index, consisting of two components: central apnea hypopnea index and obstructive apnea hypopnea index. All patients were free of severe or moderate upper airway obstruction when rhGH treatment began.

RESULTS

After 6 weeks of rhGH therapy, obstructive apnea hypopnea index increased in 8/16 (50%), decreased in 5/16 (31%), and did not change in 3/16 (19%) patients. The changes were not statistically significant. The rhGH-treated group did not differ from the control group for the apnea hypopnea index both before and after 6 weeks of treatment. Adenoids and tonsils showed a slight increase in 1 and 2 patients on rhGH treatment, respectively, and did not change in the untreated patients.

CONCLUSIONS

Our data show that short-term rhGH treatment does not cause restrictions of the upper airways in patients with Prader-Willi syndrome and normal upper airway patency.

Vaspin and its correlation with insulin sensitivity indices in obese children

AIM

The aim of this study was to assess the vaspin and adiponectin concentrations on markers of insulin sensitivity and obesity in pubertal obese children and adolescents.

MATERIAL AND METHODS

Plasma vaspin and adiponectin level and its relationships with body mass index standard deviation score (BMI-SDS), insulin sensitivity and lipids were analyzed in 33 pubertal obese children (19 girls and 14 boys) and 36 healthy control children (18 girls and 18 boys) aged 11-16 years. Insulin resistance was evaluated by homeostasis model assessment (HOMA-IR) and fasting glucose-to-insulin ratio (FGIR). Plasma vaspin and adiponectin concentrations were determined with radioimmunoassay.

RESULTS

Mean vaspin levels were found significantly higher and inversely, adiponectin levels were found significantly lower in obese pubertal group than control subjects. Vaspin levels were positively correlated with BMI-SDS, triglycerides, fasting insulin and HOMA-IR and negatively correlated with adiponectin levels and FGIR. Adiponectin levels were positively correlated with high density lipoprotein-chloesterol, FGIR and negatively correlated with vaspin, BMI-SDS, fasting insulin and HOMA-IR.

CONCLUSION

We found higher vaspin and lower adiponectin levels in obese children and these adipokines were significantly correlated with insulin sensitivity indices in this age.

The Relationship between Changes in Weight Status and Insulin Resistance in Youth

This study examined changes in insulin resistance (IR) in 120 youth over two years. IR was quantified via homeostatic model (HOMA-IR), and weight status changes were quantified via body mass index (BMI). When all participants were considered, the mean HOMA-IR and BMI increased 13.4% and 1.65 units, respectively. Change in BMI z-score and percent change in HOMA-IR were moderately associated (r = 0.39). Follow-up analyses were performed for the following weight groups: NN (normal at baseline and two years later), NO (normal to overweight), ON (overweight to normal), and OO (overweight at both points). The NO group had a greater change in HOMA-IR (+50%) compared to other groups: ON (-8%), NN (+2%), and OO (-0.1%) (P < .05). The association between changes in BMI z-score and HOMA-IR was r = 0.49 when only the NO and ON groups were included. These results reinforce the importance of preventing youth from becoming overweight to control IR.