Serum insulin and other cardiovascular risk indicators in children, adolescents and young adults

Association between being large for gestational age and cardiovascular metabolic health in children conceived from assisted reproductive technology: a prospective cohort study

BACKGROUND

To the best of our knowledge, no study has investigated the potential joint effect of large for gestational age (LGA) and assisted reproductive technology (ART) on the long-term health of children.

METHODS

This was a prospective cohort study that recruited children whose parents had received ART treatment in the Center for Reproductive Medicine, Shandong Provincial Hospital, affiliated to Shandong University, between January 2006 and December 2017. Linear mixed model was used to compare the main outcomes. The mediation model was used to evaluate the intermediary effect of body mass index (BMI).

RESULTS

4138 (29.5%) children born LGA and 9910 (70.5%) children born appropriate for gestational age (AGA) were included in the present study. The offspring ranged from 0.4 to 9.9 years. LGAs conceived through ART were shown to have higher BMI, blood pressure, fasting blood glucose, fasting insulin, and homeostatic model assessment of insulin resistance values, even after controlling for all covariates. The odds of overweight and insulin resistance are also higher in LGA subjects. After adjusting for all covariates, LGAs conceived through ART had BMI and BMI z-scores that were 0.48 kg/m2 and 0.34 units greater than those of AGAs, respectively. The effect of LGA on BMI was identified as early as infancy and remained consistently significant throughout pre-puberty.

CONCLUSIONS

Compared to AGA, LGA children conceived from ART were associated with increased cardiovascular-metabolic events, which appeared as early as infancy and with no recovery by pre-puberty.

Association of daily steps on lipid and glycaemic profiles in children: The mediator role of cardiorespiratory fitness

AIM

To analyse, in schoolchildren, the relationship between daily steps with metabolic parameters; and to examine whether this association is mediated by cardiorespiratory-fitness (CRF).

METHODS

A cross-sectional analysis of baseline data from a feasibility trial was performed in children from two primary schools in Cuenca, Spain. Daily steps were measured using the Xiaomi MI Band 3. Lipid and glycaemic profiles were analysed from blood samples. CRF was assessed using the 20-m shuttle run test. ANCOVA models were used to test the mean differences by daily steps quartiles. Mediation analyses were conducted to examine whether CRF mediates the association between daily steps and lipid and glycaemic parameters.

RESULTS

A total of 159 schoolchildren (aged 9-12 years, 53% female) were included in the analysis. Schoolchildren in the highest daily steps quartiles (>10 000 steps) showed significantly lower triglycerides and insulin levels (p = 0.004 and 0.002, respectively). This association did not remain after controlling for CRF. In mediation analyses, a significant indirect effect was observed through CRF in the relationship between daily steps with triglycerides and insulin.

CONCLUSION

Children who daily accumulate more than 10 000 steps have better lipid and metabolic profile, and CRF mediated their relationship in schoolchildren.

Serum C-peptide level and the risk of cardiovascular diseases mortality and all-cause mortality: a meta-analysis and systematic review

Aims and background

Recently, the serum of C-peptide has been the focus of researchers as a possible predictor of mortality. However, the possible association of serum C-peptide with cardiovascular diseases (CVDs) mortality and all-cause mortality has not been clearly identified. This meta-analysis aimed to assess the relationship between serum C-peptide and the risk of CVDs mortality and all-cause mortality.

Methods

A comprehensive and systematic search was performed in various important databases, including the PubMed, Web of Science, and Scopus to find relevant studies up to November 2022. The reported hazard ratio (HR) [95% confidence interval (CI)] for all studies was converted into log HR, and their SD was calculated. Then to compute the pooled HR, the random-effects model with inverse variance weighting method was performed.

Results

Twenty-three studies were included in the meta-analysis. Fourteen studies reported HR for all-cause mortality, and nine studies for CVDs-related mortality. The pooled results indicate a significant association between serum C-peptide and the risk of all-cause mortality (HR: 1.22; 95% CI: 1.12-1.32, I²= 76.8%; P-value < 0.001). Also, higher serum C-peptide was related to the increased risk of CVDs mortality (HR: 1.38; 95% CI: 1.08-1.77, I²= 81.8%; P-value = 0.012).

Conclusions

Our investigation suggested that an increased level of serum C-peptide is associated with a higher risk of both CVDs and all-cause mortality. Further, large-scale studies and sufficient samples are recommended to present a convincing link between C-peptide and the risk of CVDs and all-cause mortality.

Systematic Review Registration

identifier, CRD42022364842.

Childhood cardiovascular risk factors, a predictor of late adolescent overweight

Background:

We conducted a prospective study to elucidate the effects of increased cardiovascular risk factors on future weight gain and also the relation between body mass index (BMI) and other cardiovascular risk factors in children and adolescents.

Materials and Methods:

This study was conducted on 1525 nonobese children and adolescents with an age range of 3-16 years old, participating in the 1^st phase and follow-up phases of Tehran Lipid and Glucose Study. The subjects were evaluated 4 times with a 3-year time interval regarding lipid profile status and BMI, and other cardiovascular disease (CVD) risk factors. All the cases had a BMI <85% and had been appraised in at least two evaluation points.

Results:

Cardiovascular risk factors, high-density lipoprotein (HDL) (P = 0.019), low-density lipoprotein (P = 0.016), triglyceride (TG) (P < 0.001), and blood pressure (BP) (P = 0.001); had significant effects on weight gain. There was also no difference between boys and girls and no age trend for increasing weight in both groups. The associations between BMI with cardiovascular risk factors were assessed cross-sectionally. For both sexes, BMI was significantly correlated to systolic and diastolic BP and TG (P = 0.05). For girls, BMI was significantly related to HDL (P = 0.05) regardless to age, but in boys, the relation of BMI with HDL only increased with age (P = 0.05).

Conclusion:

Increased CVD risk factors are predictors of future overweight in childhood and adolescent and increased weight is linked significantly with dyslipidemia and hypertension in this age group.

The prevalence of Vitamin D deficiency is higher in adult survivors of childhood cancer

BACKGROUND

It is unclear whether the rate of vitamin D deficiency in paediatric cancer survivors is higher than in the background population, and whether this is of pathological significance.

PATIENTS AND METHODS

25OHD was measured in a previously studied group of 208 survivors (n = 108 paediatric 5-17 years, n = 99 adults 18-39 years) and compared with paediatric (5-17 years; n = 132) and adult controls (25-35 years; n = 1393 from the AusDiab cohort) adjusted for age and gender. Relationships with treatment factors (irradiation, bone marrow transplantation and intensity of treatment) along with overweight/obesity (defined by BMI), abdominal adiposity (waist:height ratio >0·5) and hyperinsulinism or abnormal glucose tolerance (HI/aGT) were sought.

RESULTS

25OHD concentrations were similar in paediatric survivors compared with controls (64·3 ± 21·6 nmol/l vs 66·3 ± 22·8 nmol/l), with no effect of age or gender. Adjusted for gender, rates of 25OHD deficiency (<50 nmol/l) were higher in adult survivors compared with AusDiab controls (42·4% vs 20·8%; P < 0·001). Apart from time since diagnosis (P = 0·03), no relationship with treatment factors was detected. In multivariate regression analysis, abdominal adiposity (P = 0·001), but not overweight/obesity by BMI status nor HI/aGT, was associated with significantly lower 25OHD concentrations.

CONCLUSIONS

Adult survivors are at increased risk of abnormalities in vitamin D compared to the background population, probably reflecting longer time since diagnosis. Like others, we have not identified any contributory treatment-related factors. Vitamin D deficiency does not appear to be associated with the development of abnormal glucose tolerance in this population.

Metabolic syndrome in overweight and obese adolescents: a comparison of two different diagnostic criteria

BACKGROUND

Due to the lack of consensus on its definition, the metabolic syndrome (MS) in children and adolescents is not formally recognized. However, several researchers have changed the adult criteria for pediatric standards in order to assess the prevalence.

OBJECTIVE

The aim of this study was to evaluate the frequency of MS and its components according to two of the currently used definitions in overweight and obese adolescents.

METHODS

A cross-sectional study with 232 adolescents with excess weight from a public school of the city of Rio de Janeiro. Anthropometric, blood pressure, and biochemical variables were assessed. MS was defined using two different diagnostic criteria: the National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATPIII) and International Diabetes Federation (IDF).

RESULTS

MS was diagnosed in 40.4 and 24.6% of obese adolescents and 9.4 and 1.9% of overweight adolescents according to the NCEP-ATPIII and IDF criteria, respectively. The degree of agreement, assessed by the κ index, from the definitions adopted in this study was 0.48.

CONCLUSION

The results show a significant difference between the two diagnostic criteria. A higher frequency was found when the NCEP-ATPIII was used, which is of concern given the association of MS with diabetes and cardiovascular disease.

Relationship between major depression and insulin resistance: does it vary by gender or race/ethnicity among young adults aged 20-39 years?

BACKGROUND

To examine the relationship between major depression and insulin resistance by gender and race/ethnicity among young adults without diabetes mellitus.

METHODS

Secondary analyses of cross-sectional data from the National Health and Nutrition Examination Survey 1999-2008 were performed (n = 2265). Major depression was measured by the Composite International Diagnostic Interview and the Patient Health Questionnaire 9. Insulin resistance was measured by the homeostasis model assessment of insulin resistance. Multivariate logistic regression analyses adjusted for risk factors of insulin resistance were conducted.

RESULTS

There was a significant negative association between major depression and insulin resistance among men. For women, no significant association was found. There was no significant interaction between race/ethnicity and major depression on insulin resistance (Wald χ(2) = 4.2927, P = 0.2315). Body mass index (BMI) and waist circumference (WC) were significantly associated with insulin resistance among both men (odds ratio [OR] 1.255, 95% confidence interval [CI] 1.195-1.318 for BMI; OR 1.095, 95% CI 1.076-1.115 for WC) and women (OR 1.220, 95% CI 1.182-1.260 for BMI; OR 1.084, 95% CI 1.064-1.105 for WC).

CONCLUSIONS

There are gender differences in the relationship between major depression and insulin resistance among adults aged 20-39 years. No evidence was found to support the role of race/ethnicity in this relationship. Health care professionals should be aware of risk factors for insulin resistance and develop interventions to help prevent the progression of insulin resistance to type 2 diabetes mellitus.

Age at menarche and risk of colorectal cancer: a meta-analysis

Background

Various observational studies have focused on the relationship between menarcheal age and the risk of colorectal cancer (CRC). However, the association is still controversial because of inconsistent results. Therefore, we performed a meta-analysis to assess this issue from epidemiological studies.

Methods

After a literature search in MEDLINE, EMBASE, and Web of Science for studies of menarcheal age and CRC risk published through the end of January 2013, we pooled the relative risks (RRs) from included studies using a fixed- or random-effects model and performed heterogeneity and publication bias analyses. All statistical tests were two-sided.

Results

Eleven case-control and 11 cohort studies were eligible for inclusion in our analysis. The random-effects pooled RR for oldest versus youngest menarcheal age was 0.95 [95% confidence intervals (CIs) = 0.85–1.06], with significant heterogeneity (Q = 61.03, P<0.001, I² = 65.6%). When separately analyzed, case-control (RR = 0.95, 95% CI = 0.75–1.21) and cohort studies (RR = 0.97, 95% CI = 0.90–1.04) yielded similar results. Moreover, similar results were also observed among the subgroup analyses by study quality, population, exposure assessment, anatomic cancer site, subsite of colon cancer, and several potential important confounders and risk factors. There was no evidence of publication bias and significant heterogeneity between subgroups detected by meta-regression analyses.

Conclusions

Findings from this meta-analysis demonstrated that menarcheal age was not associated with the risk of CRC in humans. Further studies are warranted to stratify results by the subsite of colon cancer and menopause status in the future.

Childhood serum fatty acid quality is associated with adult carotid artery intima media thickness in women but not in men

Childhood nutrition may play a role in the development of cardiovascular disease risk in adulthood. We examined the links between childhood dietary fatty acid quality and adult subclinical atherosclerosis in a cohort of 374 males and 449 females, aged 3-18 y at baseline in 1980, followed for 27 y. Serum cholesterol ester fatty acid (CEFA) percentages were analyzed as markers of dietary fatty acid intake. Adulthood carotid artery intima media thickness (cIMT, μm), adjusted for childhood and adulthood lipid and nonlipid risk markers, was used as the outcome. In women, after adjustment for age and childhood nonlipid risk markers, the childhood saturated CEFA (B = 11.3; P = 0.011), monounsaturated CEFA (B = 2.5; P = 0.025), and n3 (ω3) polyunsaturated CEFA (B = 16.2; P = 0.035) percentages were directly associated with adult cIMT. In contrast, the n6 (ω6) polyunsaturated CEFA percentage was negatively associated with cIMT (B = -2.3; P = 0.008). Similar relationships were observed between childhood dietary intake data and adult cIMT. In men, these associations were generally weak and nonsignificant (P > 0.05) after controlling for confounders. These longitudinal data suggest that fat quality as reflected in the serum cholesterol ester fraction in childhood is associated with adult cIMT in women.

Metformin in obese children and adolescents: the MOCA trial

CONTEXT

Childhood obesity is increasingly associated with type 2 diabetes (T2D). Metformin reduces the risk for T2D in adult obese nondiabetic patients, but the evidence in obese children and young people is inconclusive.

OBJECTIVE

The objective of the study was to assess the effect of metformin on body mass index sd score (BMI-SDS), metabolic risk factors, and adipokines.

DESIGN

This was a prospective, randomized, double-blind, placebo-controlled trial.

SETTING

The study was conducted at six pediatric endocrine centers in the United Kingdom.

PARTICIPANTS

One hundred fifty-one obese children and young people with hyperinsulinemia and/or impaired fasting glucose or impaired glucose tolerance (metformin: 74, placebo: 77). The study was comprised of 67.5% females, 65.6% postpubertal individuals, and 23.8% British Asian or Afro-Caribbean participants. The age range was 8-18 yr, the mean age was 13.7 (SD 2.3) yr, and the mean BMI-SDS was +3.4 (SD 0.5).

INTERVENTIONS

The intervention included metformin 1 g in the morning and 500 mg in the evening vs. placebo for 6 months.

MAIN OUTCOME MEASURE

The main outcome measure was a reduction in BMI-SDS at 6 months. Secondary outcomes included insulin and glucose levels from oral glucose tolerance tests, alanine aminotransferase (ALT), and adiponectin to leptin ratio (ALR) at 3 and 6 months.

RESULTS

Metformin was associated with a significant reduction in BMI-SDS compared with placebo at 6 months [mean difference -0.1 SD (95% confidence interval -0.18 to -0.02), P = 0.02]. Significant improvements at 3 months were found in the metformin group: fasting glucose, -0.16 mmol/liter (-0.31 to -0.00), P = 0.047; ALT, 19% (5-36%), P = 0.008; and ALR, 32% (4-67%), P = 0.02.

CONCLUSIONS

Metformin therapy has a beneficial treatment effect over placebo for BMI-SDS, fasting glucose, ALT, and ALR ratio at 3 months, with changes in BMI-SDS sustained at 6 months.

Assessment and management of obesity in childhood and adolescence

The increased prevalence of obesity in childhood and adolescence highlights the need for effective treatment approaches. Initial assessments of these patients should include taking a careful history (investigating comorbidities, family history and potentially modifiable behaviors) and physical examination with BMI plotted on a BMI-for-age chart. The degree of investigation is dependent on the patient's age and severity of obesity, the findings on history and physical examination, and associated familial risk factors. There are several broad principles of conventional management: management of comorbidities; family involvement; taking a developmentally appropriate approach; the use of a range of behavior change techniques; long-term dietary change; increased physical activity; and decreased sedentary behaviors. Orlistat can be useful as an adjunct to lifestyle changes in severely obese adolescents and metformin can be used in older children and adolescents with clinical insulin resistance. Bariatric surgery should be considered in those who are severely obese, with recognition of the need for management in centers with multidisciplinary weight management teams and for surgery to be performed in tertiary institutions experienced in bariatric surgery. Finally, given the high prevalence and chronic nature of obesity, coordinated models of care for health-service delivery for the management of pediatric obesity are needed.

Assessment and management of obesity in childhood and adolescence

The increased prevalence of obesity in childhood and adolescence highlights the need for effective treatment approaches. Initial assessments of these patients should include taking a careful history (investigating comorbidities, family history and potentially modifiable behaviors) and physical examination with BMI plotted on a BMI-for-age chart. The degree of investigation is dependent on the patient's age and severity of obesity, the findings on history and physical examination, and associated familial risk factors. There are several broad principles of conventional management: management of comorbidities; family involvement; taking a developmentally appropriate approach; the use of a range of behavior change techniques; long-term dietary change; increased physical activity; and decreased sedentary behaviors. Orlistat can be useful as an adjunct to lifestyle changes in severely obese adolescents and metformin can be used in older children and adolescents with clinical insulin resistance. Bariatric surgery should be considered in those who are severely obese, with recognition of the need for management in centers with multidisciplinary weight management teams and for surgery to be performed in tertiary institutions experienced in bariatric surgery. Finally, given the high prevalence and chronic nature of obesity, coordinated models of care for health-service delivery for the management of pediatric obesity are needed.

Effects of resistance training and aerobic exercise on insulin sensitivity in overweight korean adolescents: a controlled randomized trial

BACKGROUND

Data on the impact of resistance training on insulin resistance in overweight or obese children are inconclusive.

METHODS

Thirty overweight South Korean adolescents (mean age of 13.10 years) were divided by sex, and then randomly assigned to one of three treatment groups, which were the diet only (DO), diet with aerobic exercise (AE), or diet with resistance training (RT) group. Physiologic and metabolic parameters were assessed at baseline and after 12 weeks of exercise training and diet modification.

RESULTS

Both exercise groups (aerobic and resistance) showed significant improvements in their insulin area under the curve and insulin sensitivity index values when compared to their baseline values while the DO group showed no significant changes in these variables. Age-, sex-, and body mass index (BMI)-adjusted intergroup comparison analyses showed a marked reduction in BMI and a significant reduction in muscle mass in the AE group when compared to the RT group and the DO group, respectively.

CONCLUSION

A 12-week exercise training program of either resistance or aerobic activity improved insulin sensitivity in overweight adolescents, although it failed to show superiority over a DO program. Aerobic exercise decreased both body weight and BMI, and it was noted that this group also had a significant reduction in muscle mass when compared to the DO group.

Hyperinsulinemia and metabolic syndrome at mean age of 10 years in black and white schoolgirls and development of impaired fasting glucose and type 2 diabetes mellitus by mean age of 24 years

The objective of the study was to evaluate preteen insulin and metabolic syndrome (MS) as independent predictors of impaired fasting glucose (IFG) and type 2 diabetes mellitus (T2DM) in black and white females by mean age of 24 years. This was a prospective cohort study. There were 8 measures of fasting glucose and insulin from mean age of 10 years through mean age of 24 years, and insulin also at mean age of 25 years. Childhood MS was defined by at least 3 abnormal values among waist circumference, triglyceride, high-density lipoprotein cholesterol, blood pressure, and glucose. Hyperinsulinemia was defined by insulin greater than or equal to race-specific 75th percentile. Patients with type 1 diabetes mellitus were excluded. The study was held in schools and in an outpatient clinical center. Participants were schoolgirls (260 white, 296 black). There was no intervention. The outcome measures were IFG (fasting glucose of at least 100 to 125 mg/dL) and T2DM (fasting glucose of at least 126 mg/dL). By the age of 24 years, there were 11 cases of T2DM (2%) and 108 cases of IFG (19%). By the age of 24 years, IFG + T2DM was present in 18% of women (73/412) who had normal insulin-no MS at the age of 10 years vs 28% (34/122) of those with high insulin-no MS at the age of 10 years (P = .014) and 67% (10/15) of those with high insulin + MS at the age of 10 years (P < .0001). By stepwise logistic regression, significant, independent, positive predictors of IFG + T2DM were first insulin measure in childhood, age at last sampling, childhood MS, change in body mass index over 15 years, and, separately, initial glucose of at least 100 mg/dL and average of all insulin quartile ranks over 15 years. The correlation between childhood insulin z score and insulin z score 15 years later was r = .30, P < .0001. Insulin and MS at a mean age of 10 years plus change in body mass index over 15 years, and 15-year average insulin rank independently predict IFG + T2DM by mean age of 24 years, suggesting avenues for primary prevention.

Defining accelerometer thresholds for physical activity in girls using ROC analysis

BACKGROUND

Receiver operating characteristic (ROC) analysis is a common method used in diagnostic and screening tests to define thresholds levels of a factor that discriminates between 2 levels of another factor. The purpose of this analysis was to use ROC analysis to determine the optimal accelerometer-measured physical activity (PA) thresholds for predicting selective cardiovascular disease (CVD) risk factors.

METHODS

ROC was performed using data from Stanford Girls Health Enrichment Multisite Studies trial. PA was assessed for multiple days using accelerometers. CVD variables were overweight, elevated triglyceride, reduced HDL-C, hypertension, impaired fasting glucose, fasting insulin, and clustering of multiple CVD risk factors.

RESULTS

A sample of 261 girls participated, of which 208 had complete CVD risk measures (mean +/- SD age = 9.4 +/- 0.9yrs, BMI = 20.7 +/- 4.8kg/m2). An average of > or =11.1 minutes/day at > or =2,600 counts/min was the maximally sensitive and specific threshold for discriminating girls who were overweight, > or =16.6 minutes/day at > or =2,000 counts/min for hyperinsulinemia or with > or =2 CVD risk factors. The Area Under the Curve for overweight, hyperinsulinemia, and > or =2 CVD risk factors was of 0.66, 0.58, and 0.60, respectively. The sensitivity and specificity associated with overweight, hyperinsulinemia, and > or =2 CVD risk factors were 60.3% and 72.9%, 53.3% and 83.9%, 44.0% and 84.7%, respectively.

CONCLUSION

Empirically-derived thresholds of PA to optimally discriminate between girls with and without CVD risk were lower in this sample than generally recommended. This ROC approach should be repeated in other populations to determine optimal PA thresholds with clinical validity for research, surveillance and program evaluation.

Impaired glucose tolerance and insulin resistance in survivors of childhood acute lymphoblastic leukemia: prevalence and risk factors

AIM/PURPOSE

Survivors of acute lymphoblastic leukemia (ALL) are at increased risks of impaired glucose metabolism, insulin resistance, and metabolic syndrome. The aim of our study was to determine the prevalence of alterations in glucose metabolism and the predisposing factors of these disturbances in survivors of childhood ALL.

PATIENTS AND METHODS

In 131 ALL survivors, an oral glucose tolerance test was conducted to determine beta-cell function/insulin sensitivity. The particular risk factors were analyzed and 6 single nucleotide polymorphisms of diabetic predisposing genes: PAX4 and TCF7L2 were genotyped to evaluate the association between these factors and beta-cell function/insulin sensitivity.

RESULTS

Ten out of 131 survivors (7.6%) had impaired glucose tolerance (IGT) whereas 40 out of 131 (30.5%) had insulin resistance (IR) and showed characteristics of the metabolic syndrome (hyperinsulinemia, hypertriglyceridemia, and low HDL-C). In the logistic regression analysis, the most important factor predicting IGT and IR was older age of survivors (P=0.014 and P<0.001, respectively) whereas the PAX4 R192H mutation (rs2233580) was significantly associated with IGT after adjustment for age (P=0.043) (adjusted OR 5.28, 95% CI 1.06-26.40).

CONCLUSIONS

Existing evidence suggests that older age is an independent risk factor for developing IGT and IR in childhood ALL survivors, emphasizing the need for life-long metabolic screening. The PAX4 variant might impact individual susceptibility against IGT and diabetes. However, an identification of underlying risk(s) is the rational for future studies.

Utility of childhood glucose homeostasis variables in predicting adult diabetes and related cardiometabolic risk factors: the Bogalusa Heart Study

OBJECTIVE This study examines the usefulness of childhood glucose homeostasis variables (glucose, insulin, and insulin resistance index [homeostasis model assessment of insulin resistance {HOMA-IR}]) in predicting pre-diabetes and type 2 diabetes and related cardiometabolic risk factors in adulthood. RESEARCH DESIGN AND METHODS This retrospective cohort study consisted of normoglycemic (n = 1,058), pre-diabetic (n = 37), and type 2 diabetic (n = 25) adults aged 19-39 years who were followed on average for 17 years since childhood. RESULTS At least 50% of the individuals who ranked highest (top quintile) in childhood for glucose homeostasis variables maintained their high rank by being above the 60th percentile in adulthood. In a multivariate model, the best predictors of adulthood glucose homeostasis variables were the change in BMI Z score from childhood to adulthood and childhood BMI Z score, followed by the corresponding childhood levels of glucose, insulin, and HOMA-IR. Further, children in the top decile versus the rest for insulin and HOMA-IR were 2.85 and 2.55 times, respectively, more likely to develop pre-diabetes; children in the top decile versus the rest for glucose, insulin, and HOMA-IR were 3.28, 5.54, and 5.84 times, respectively, more likely to develop diabetes, independent of change in BMI Z score, baseline BMI Z score, and total-to-HDL cholesterol ratio. In addition, children with adverse levels (top quintile versus the rest) of glucose homeostasis variables displayed significantly higher prevalences of, among others, hyperglycemia, hypertriglyceridemia, and metabolic syndrome. CONCLUSIONS Adverse levels of glucose homeostasis variables in childhood not only persist into adulthood but also predict adult pre-diabetes and type 2 diabetes and relate to cardiometabolic risk factors.

Obesity and metabolic changes are common in young childhood brain tumor survivors

BACKGROUND

A population based cross-sectional study was used to examine the prevalence of metabolic syndrome and its components in childhood brain tumor survivors.

PROCEDURE

Fifty-two survivors were examined at a mean age of 14.4 years (range 3.8-28.7). Lipid and glucose metabolism, thyroid function, and plasma uric acid were evaluated. Fat mass and fat percentage were assessed by dual-energy X-ray absorptiometry (DXA). Metabolic syndrome was defined on International Diabetes Federation criteria.

RESULTS

Ten (19%) patients were overweight and four (8%) were obese. According to DXA, 16/46 (35%) patients were obese. Central obesity was found in 11 (21%) patients. Cranial irradiation, hypothalamic/hypophyseal damage, growth hormone (GH) deficiency and impaired mobility were associated with overweight/obesity and central obesity. Thirteen (25%) subjects had hypercholesterolemia, 14 (27%) had raised low-density lipoprotein cholesterol (LDL-C), 12 (23%) had raised blood pressure, four (8%) had metabolic syndrome, two (4%) had hyperinsulinemia and five (10%) had hyperuricemia. Cranial irradiation was associated with hypercholesterolemia (P = 0.019), raised LDL-C (P = 0.028), raised blood pressure (P = 0.040), and metabolic syndrome (P = 0.018). Impaired mobility was associated with hypercholesterolemia (P = 0.034). Hypothalamic/hypophyseal damage was associated with metabolic syndrome (P = 0.003) and hyperuricemia (P = 0.011) as was GH deficiency (P = 0.034 and P = 0.008). GH supplementation alleviated adverse metabolic outcomes among brain tumor survivors with GH deficiency.

CONCLUSIONS

Obesity/overweight, dyslipidemia, hypertension, metabolic syndrome, and hyperuricemia were common in young childhood brain tumor survivors. Cranial irradiation, hypothalamic/hypophyseal damage, growth hormone deficiency, and/or impaired mobility were associated with higher risk for obesity and metabolic changes among these patients.

Distribution of fasting plasma glucose and prevalence of impaired fasting glucose, impaired glucose tolerance and type 2 diabetes in the Mexican paediatric population

Published data on the distribution of fasting plasma glucose (FPG) in children are scarce. We therefore set out to examine the distribution of FPG and determine the prevalence of impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and type 2 diabetes (T2-DM) in Mexican children aged 6-18 years in a community-based cross-sectional study. A total of 1534 apparently healthy children were randomly enrolled and underwent an oral glucose tolerance test. IFG was defined by an FPG value between >or=100 and <126 mg/dL, IGT by glucose concentration 2-h post-load between >or=140 and <200 mg/dL, and T2-DM by glucose concentration 2-h post-load >or=200 mg/dL. The FPG level at the 75(th) percentile of distribution was 98.0, 100.0 and 99.0 mg/dL for children aged 6-9, 10-14 and 15-18 years, respectively; the 95(th) percentile of FPG was greater than 100 mg/dL for all the age strata. In the population overall, the prevalences of IFG, IGT, and T2-DM were 18.3%, 5.2% and 0.6%, respectively. Among obese children and adolescents, the prevalences of IFG, IGT, IFG + IGT and T2-DM were 19.1%, 5.7%, 2.5% and 1.3%. Our study shows a high prevalence of prediabetes and is the first that reports the distribution of FPG in Mexican children and adolescents.

Evidence of metabolic syndrome in lean children with premature pubarche at diagnosis

We investigated for evidence of early metabolic syndrome irrespective of body mass index (BMI) in subjects with premature pubarche (PP). Ten children with PP were compared with controls matched for age, sex, ethnicity, and BMI. Congenital adrenal hyperplasia and other known causes of PP were excluded by standard methods. Anthropometry, blood pressure (BP), dual-energy x-ray absorptiometry body scan, fasting blood lipid profile, and cytokines were obtained. The children were divided into 2 groups: (1) the total group of children with PP, and their age-, sex-, ethnicity-, and BMI-matched controls and (2) those with PP and normal BMI (<19 kg/m(2)) and their matched controls selected from the original groups. The PP subjects with normal BMI (S(1)) showed significantly higher systolic BP (P = .028), diastolic BP (P = .028), and mean arterial pressure (P = .018) compared with matched controls (C(1)). Nevertheless, for both groups, all the above parameters were statistically not significant when corrected for height. Fat distribution in PP subjects indicated significantly higher android (P = .047) and android-gynoid ratio (P = .013). Normal-BMI PP children had significantly higher android-gynoid ratio fat distribution compared with their matched controls (P = .037). Trunk fat percentage (p: 0.04) and trunk fat (grams) (P = .007) were significantly elevated in PP children compared with matched controls. Again, for both groups, all the above parameters were not statistically significant when corrected for height. The PP subjects had significantly higher tumor necrosis factor (TNF)-alpha (P = .038) and interleukin-8 (picograms per milliliter) (P = .05) compared with matched controls. Normal-BMI PP children also had higher TNF-alpha (P = .028) compared with matched controls. When corrected for height, TNF-alpha was higher in the total (P = .037) and normal-BMI (P = .043) PP children. Premature pubarche can be linked to markers of the metabolic syndrome in lean children.

Coronary endothelial dysfunction and impaired microcirculation response to atrial natriuretic peptide in hyperinsulinemia

Endothelial dysfunction occurs in hyperinsulinemia (HI). Coronary microcirculation responses to vasoactive agents are examined in 57 patients with angiographically normal coronary arteries. Patients were divided into 2 groups, 37 with normoinsulinemia (NI) and 20 with HI based on results of a 75-g oral glucose tolerance test. Epicardial artery vasoactivity in response to acetylcholine chloride is measured to assess endothelial function. Coronary microcirculation function is evaluated by intracoronary administration of 50 microg of adenosine triphosphate, 1 mg of isosorbide dinitrate, and 0.05 mg/kg of atrial natriuretic peptide. Epicardial artery vasoconstriction in response to 100 microg of acetylcholine is mildly reduced in HI (P = .04). Coronary flow reserve in response to adenosine triphosphate in NI is similar to that in HI. In NI, the resting mean (SD) peak velocity in response to isosorbide dinitrate (40.7 [10.9] cm/s) vs atrial natriuretic peptide (39.6 [10.9] cm/s) is similar. In contrast, the resting mean (SD) peak velocity in response to atrial natriuretic peptide (31.3 [9.3] cm/s) vs isosorbide dinitrate (43.5 [10.0] cm/s) in HI is statistically significantly blunted (P < .001). Atrial natriuretic peptide may have a pathologic effect on coronary microcirculation even in mild endothelial dysfunction among patients with HI.

Adolescents with metabolic syndrome have a history of low aerobic fitness and physical activity levels

Purpose

Metabolic syndrome (MS) is a clustering of cardiovascular disease risk factors that identifies individuals with the highest risk for heart disease. Two factors that may influence the MS are physical activity and aerobic fitness. This study determined if adolescent with the MS had low levels of aerobic fitness and physical activity as children.

Methods

This longitudinal, exploratory study had 389 participants: 51% girls, 84% Caucasian, 12% African American, 1% Hispanic, and 3% other races, from the State of North Carolina. Habitual physical activity (PA survey), aerobic fitness (VO₂max), body mass index (BMI), blood pressure, and lipids obtained at 7–10 y of age were compared to their results obtained 7 y later at ages 14–17 y.

Results

Eighteen adolescents (4.6%) developed 3 or more characteristics of the MS. Logistic regression, adjusting for BMI percentile, blood pressure, and cholesterol levels, found that adolescents with the MS were 6.08 (95%CI = 1.18–60.08) times more likely to have low aerobic fitness as children and 5.16 (95%CI = 1.06–49.66) times more likely to have low PA levels.

Conclusion

Low levels of childhood physical activity and aerobic fitness are associated with the presence of the metabolic syndrome in adolescents. Thus, efforts need to begin early in childhood to increase exercise.

Childhood predictors of the metabolic syndrome in adulthood. The Cardiovascular Risk in Young Finns Study

BACKGROUND

Obese youths may be susceptible to develop the metabolic syndrome (MS) later in life.

AIM

To study childhood predictors of MS in adulthood.

METHOD

Prospective cohort study including 2,195 subjects, aged 3-18 years at base-line in 1980, who were re-examined in 1983, 1986, and 2001.

RESULTS

In adults (aged 24-39 years) in 2001, the prevalence of MS (using the International Diabetes Federation criteria) was 19% in men and 12% in women. Multivariable logistic regression model selected obesity, male sex, high triglycerides, high insulin, high C-reactive protein (CRP), and family history of hypertension and type 2 diabetes, as independent predictors of adult MS. Youth obesity (body mass index (BMI)>80th age- and sex-specific percentile) was the strongest risk factor for MS. During the 21-year follow-up, there was an increasing trend in BMI, insulin, systolic blood pressure, and triglycerides, and a decreasing trend in high-density lipoprotein cholesterol in obese subjects who developed MS in adulthood compared to those obese subjects who did not develop MS.

CONCLUSIONS

Youth determinants of adult MS included obesity, high triglycerides, high insulin, high CRP, and family history of hypertension and type 2 diabetes. Identifying these risk factors at an early stage could help identifying children and adolescence at greater risk of developing MS later in life.

Epidemiology of paediatric metabolic syndrome and type 2 diabetes mellitus

The epidemic in childhood obesity is a driving force behind the increase in paediatric metabolic syndrome, a collection of abnormalities that is associated in adults with increased risk for cardiovascular disease and type 2 diabetes mellitus. Although there is no clear consensus about the paediatric definition for metabolic syndrome, the prevalence of this syndrome is clearly rising. Children with metabolic syndrome are at increased risk for metabolic syndrome in adulthood. A late consequence of metabolic syndrome is type 2 diabetes, which increasingly affects adolescents. The rise in metabolic syndrome and type 2 diabetes in children is almost sure to lead to an increase in associated complications in young adulthood, including early cardiovascular disease. This epidemic will bear fruit in forthcoming decades, putting further stress on the healthcare system and probably leading to increased morbidity and a shorter lifespan for future generations.

Exercise alone reduces insulin resistance in obese children independently of changes in body composition

CONTEXT

The number of obese children with insulin resistance and type 2 diabetes is increasing, but the best management strategy is not clear.

OBJECTIVE

The objective of this study was to assess the effect of a structured 8-wk exercise training program on insulin resistance and changes in body composition in obese children.

DESIGN

The study was 8 wk of structured supervised exercise intervention with outcome measures before and after the exercise period.

SUBJECTS

Fourteen obese children (12.70 +/- 2.32 yr; eight male, six female) with high fasting insulin levels were enrolled into the study.

INTERVENTION

INTERVENTION consisted of 8 wk of supervised circuit-based exercise training, composed of three fully supervised 1-h sessions per week.

OUTCOME MEASURES

Outcome measures were assessed pretraining program and posttraining program and included insulin sensitivity (euglycemic-hyperinsulinemic clamp studies), fasting insulin and glucose levels, body composition using dual energy x-ray absorptiometry scan, lipid profile, and liver function tests.

RESULTS

Insulin sensitivity improved significantly after 8 wk of training (M(lbm) 8.20 +/- 3.44 to 10.03 +/- 4.33 mg/kg.min, P < 0.05). Submaximal exercise heart rate responses were significantly lower following the training (P < 0.05), indicating an improvement in cardiorespiratory fitness. Dual energy x-ray absorptiometry scans revealed no differences in lean body mass or abdominal fat mass.

CONCLUSION

An 8-wk exercise training program increases insulin sensitivity in obese children, and this improvement occurred in the presence of increased cardiorespiratory fitness but is independent of measurable changes in body composition.

Insufficient growth hormone secretion is associated with metabolic syndrome after allogeneic stem cell transplantation in childhood

The aim was to evaluate whether the metabolic syndrome associates with other endocrinopathies observed after allogeneic stem cell transplantation (SCT) in childhood. Thirty-one SCT long-term survivors, transplanted for leukemia (n=26) or nonmalignant hematologic diseases (n=5) were evaluated by oral glucose tolerance test and assessment of serum lipids at a median age of 15 (range 7 to 34) years. Hyperinsulinemia, hypertriglyceridemia, and abdominal obesity were required for the diagnosis of metabolic syndrome. Growth hormone (GH) secretion was evaluated either with GH releasing hormone and arginine (n=14), clonidine (n=15), or insulin-tolerance (n=2) test. A GH peak level of <20 mU/L was considered insufficient. The thyroid and gonadal functions were assessed. Twelve patients (39%) had metabolic syndrome. Nine out of 12 (75%) patients with metabolic syndrome had insufficient GH response in provocative testing as opposed to 6/19 (31%) of those without it (P=0.02). No difference was observed in thyroid or gonadal function between patients with versus without metabolic syndrome. In conclusion, metabolic syndrome is frequently associated with insufficient GH secretion in the SCT long-term survivors. This should implicate a close follow-up of the metabolic parameters in SCT patients with either frank GH insufficiency or signs of inadequate GH response in provocative testing.

Obesity and the metabolic syndrome in Korean adolescents

This study evaluated the prevalence of metabolic syndrome and investigated its association with being overweight in Korean adolescents. Data were obtained from 1,393 students between 12 and 13 yr of age in a cross-sectional survey. We defined the metabolic syndrome using criteria analogous to the Third Report of the Adult Treatment Panel (ATP III) as having at least three of the following: fasting triglycerides > or =100 mg/dL; HDL <50 mg/dL; fasting glucose > or =110 mg/dL; waist circumference >75th percentile for age and gender; and systolic blood pressure >90th percentile for age, gender, and height. Weight status was assessed using the age- and gender-specific body mass index (BMI), and a BMI > or =85th percentile was classified as overweight. Of the adolescents, 5.5% met the criteria for the metabolic syndrome, and the prevalence increased with weight status; it was 1.6% for normal weight and 22.3% in overweight (p<0.001). In multivariate logistic regression analyses among adolescents, overweight status was independently associated with the metabolic syndrome (odds ratio, 17.7; 95% confidence interval, 10.0-31.2). Since childhood metabolic syndrome and obesity likely persist into adulthood, early identification helps target interventions to improve future cardiovascular health.

The prevalence of the metabolic syndrome in young adults. The Cardiovascular Risk in Young Finns Study

OBJECTIVES

The prevalence of the metabolic syndrome is increasing worldwide. We studied its prevalence in Finnish young adults. Three definitions were applied: National Cholesterol Education Program (NCEP), European Group for the Study of Insulin Resistance (EGIR) and International Diabetes Federation (IDF) criteria. We also investigated the secular trend in the metabolic syndrome amongst 24-year-old adults from 1986 to 2001.

DESIGN

Population-based follow-up study.

SUBJECTS

2182 healthy young adults (1007 men; 1175 women) aged 24-39 years.

MAIN OUTCOME MEASURES

Metabolic syndrome and its components.

RESULTS

The prevalence of the metabolic syndrome was 13.0% with NCEP criteria, 9.8% with EGIR criteria and 14.3% with IDF criteria. With NCEP and IDF criteria, the prevalence increased with age in both sexes, but more dramatically in men. There was over sixfold increase in the metabolic syndrome from 4.0% to 25.2% (P < 0.0001) in men between ages 24 and 39 years using the IDF criteria. Increases in obesity and serum triglycerides accounted much for the increase in the prevalence by age. The significant secular trend was seen between years 1986 and 2001 in 24-year-old subjects. The prevalence of the metabolic syndrome increased significantly from 1.0% to 7.5% (P < 0.0001) in 15 years.

CONCLUSIONS

There is a substantial increase in the prevalence of the metabolic syndrome in healthy young adults between ages 24 and 39 driven mostly by the increase in obesity. The prevalence of the metabolic syndrome is higher amongst Finnish young adult men compared with women. The secular trend between 1986 and 2001 suggest a dramatic increase in the prevalence of the metabolic syndrome in 24-year-old young adults. Condensed abstract The prevalence of the metabolic syndrome may be increasing in young people. We studied the prevalence of the metabolic syndrome in 2182 young Finnish adults aged 24-39 years using NCEP, EGIR and IDF criteria. The prevalence of the metabolic syndrome was higher amongst Finnish men than women and increased dramatically with age. There was also a dramatic increase in the prevalence of the metabolic syndrome in 24-year-old adults between 1986 and 2001.

Increasing body mass index z-score is continuously associated with complications of overweight in children, even in the healthy weight range

CONTEXT

Overweight/obesity in children is increasing. Incidence data for medical complications use arbitrary cutoff values for categories of overweight and obesity. Continuous relationships are seldom reported.

OBJECTIVES

The objective of this study is to report relationships of child body mass index (BMI) z-score as a continuous variable with the medical complications of overweight.

DESIGN

This study is a part of the larger, prospective cohort Growth and Development Study.

SETTING

Children were recruited from the community through randomly selected primary schools. Overweight children seeking treatment were recruited through tertiary centers.

PARTICIPANTS

Children aged 6-13 yr were community-recruited normal weight (n = 73), community-recruited overweight (n = 53), and overweight treatment-seeking (n = 51). Medical history, family history, and symptoms of complications of overweight were collected by interview, and physical examination was performed. Investigations included oral glucose tolerance tests, fasting lipids, and liver function tests.

MAIN OUTCOME MEASURE

Adjusted regression was used to model each complication of obesity with age- and sex-specific child BMI z-scores entered as a continuous dependent variable.

RESULTS

Adjusted logistic regression showed the proportion of children with musculoskeletal pain, obstructive sleep apnea symptoms, headaches, depression, anxiety, bullying, and acanthosis nigricans increased with child BMI z-score. Adjusted linear regression showed BMI z-score was significantly related to systolic and diastolic blood pressure, insulin during oral glucose tolerance test, total cholesterol, high-density lipoprotein, triglycerides, and alanine aminotransferase.

CONCLUSION

Child's BMI z-score is independently related to complications of overweight and obesity in a linear or curvilinear fashion. Children's risks of most complications increase across the entire range of BMI values and are not defined by thresholds.

Age, sex, and ethnic variations in serum insulin concentrations among U.S. youth: findings from the National Health and Nutrition Examination Survey 1999-2002

OBJECTIVE

Distributions of serum concentrations of insulin among adolescents and young adults are poorly understood in the U.S. The objective of this study was to describe the distribution of serum insulin across demographic characteristics of U.S. adolescents and young adults.

RESEARCH DESIGN AND METHODS

A total of 1,791 male and female subjects aged 12-19 years who participated in the National Health and Nutrition Examination Surveys for 1999-2002 were included in the analyses.

RESULTS

Among male participants, serum concentrations of insulin increased from age 12 to 14 years before decreasing. Among female participants, concentrations were highest at age 13 years before decreasing steadily through age 19 years. Among participants aged 12-17 years but not those aged 18-19 years, females had higher mean log-transformed concentrations than males (P, Wald, F = 0.038 and 0.125, respectively) after adjusting for age and ethnicity. After adjusting for age and BMI percentile, mean log-transformed concentrations were higher in African-American females aged 12-17 years than in white or Mexican-American participants. No significant ethnic differences were found among female participants aged 18-19 years or male participants aged 12-19 years. Concentrations of insulin increased strongly with increasing levels of BMI.

CONCLUSIONS

These results provide detailed information about serum concentrations of insulin in a representative sample of U.S. adolescents and young adults and may be useful to monitor future trends of this risk factor for diabetes and cardiovascular disease.

Hyperinsulinemia, impaired glucose tolerance, and diabetes mellitus in survivors of childhood cancer: prevalence and risk factors

CONTEXT

Hyperinsulinism and its associated metabolic abnormalities, including diabetes mellitus (DM), have been reported in long-term survivors of childhood cancer, mainly after bone marrow transplant (BMT); however, the predisposing factors are unclear, and early markers have not been identified.

METHODS

The prevalence of overweight/obesity, abdominal adiposity and hyperinsulinemia (HI), impaired glucose tolerance (IGT), or DM was examined prospectively in 248 survivors of childhood cancer (36 prepubertal, 88 pubertal, and 124 adult subjects; 67 BMT) at a median of 12.9 yr (2.3-33.6) after diagnosis and compared with healthy controls. Potential risk factors for the development of HI, IGT, or DM were sought.

RESULTS

Overweight/obesity was not increased when comparing subjects with controls; however, the prevalence of abdominal adiposity in prepubertal and pubertal subjects was roughly doubled (P < or = 0.04). Fasting insulin concentrations were higher in prepubertal and pubertal subjects compared with their controls (P < 0.001) and were similar in adult and pubertal subjects. HI, IGT, or DM was detected in 39 of 212 (18%) pubertal or adult subjects (23 BMT). Ten of 88 (11%) pubertal and 14 of 124 (11%) adult subjects had IGT/DM (vs. 0 and 4.9% controls, respectively; P < 0.001). Total body irradiation, untreated hypogonadism, and abdominal adiposity emerged as independent risk factors for the development of HI, IGT, or DM in multivariate regression analysis.

CONCLUSIONS

The risk factors identified suggest the need for reconsideration of BMT protocols and regular screening of survivors. The increased prevalence of abdominal adiposity among prepubertal subjects, none of whom had developed HI/IGT/DM, suggests that a waist to height ratio greater than 0.5 has potential as a clinical screening tool.

Metabolic syndrome in children and adolescents

Metabolic syndrome is a constellation of interrelated risk factors of metabolic origin that often accompany obesity and consist of atherogenic dyslipidemia, elevated blood pressure, impaired glucose tolerance, a prothrombotic state, and a proinflammatory state. Using a modification of the criteria by the National Cholesterol Education Program Adult Treatment Panel III, metabolic syndrome in children and adolescents can be clinically diagnosed when three or more of the following are present: body mass index > or = 2 z score, systolic or diastolic blood pressure greater than 95th percentile, triglyceride level greater than 95th percentile, and/or high-density lipoprotein cholesterol less than 5th percentile and impaired glucose tolerance (fasting glucose > 110 mg/dL ). The prevalence of the metabolic syndrome in adolescents has been shown to be 4% overall, but it is 30% to 50% in overweight adolescents. In the United States, 18% to 22% of children and adolescents are overweight; the prevalence of a metabolic syndrome phenotype among US adolescents has also been increasing significantly over the past decade. All of the features of metabolic syndrome are risk factors for atherosclerosis, and metabolic syndrome has been shown to constitute risk for atherosclerotic cardiovascular disease in adults. In children and adolescents with metabolic syndrome, biomarkers of an increased risk of adverse cardiovascular outcomes are already present. Therefore, there is need for prevention and treatment of metabolic syndrome in this population. The mainstay of the treatment is dietary intervention and promotion of active lifestyle to achieve and maintain optimum weight, normal blood pressure, and normal lipid profile for the height and age. The pharmaceutical intervention is usually not required and its long-term outcome has not been studied. There is need for large studies for the management and long-term outcomes of metabolic syndrome in children and adolescents if the future tides of cardiovascular and other associated complications of metabolic syndrome are to be turned around.

Inflammation and changes in metabolic syndrome abnormalities in US adolescents: findings from the 1988-1994 and 1999-2000 National Health and Nutrition Examination Surveys

BACKGROUND

Understanding of C-reactive protein (CRP) in adult metabolic syndrome is increasing; however, this relationship in children is less clear.

METHODS

We compared the prevalence of metabolic abnormalities and metabolic syndrome in fasting 12- to 19-year-olds from the 1999-2000 and 1988-1994 National Health and Nutrition Examination Survey (NHANES). In the more recent dataset we explored the relationship between metabolic abnormalities and CRP as measured by a high-sensitivity assay.

RESULTS

The prevalence of central obesity, low HDL-cholesterol, and hypertension increased between the 2 surveys. Three or more abnormalities (metabolic syndrome) were found in 12.7% [95% confidence interval (CI), 10.0%-15.4%] of fasting adolescents from the 1999-2000 survey, compared with 9.2% (95% CI, 7.8%-10.6%; P < 0.001) in the 1988-1994 dataset, with increases also seen in sex and ethnic/racial subgroups. Increases in metabolic syndrome were primarily attributable to increasing body mass index (BMI); prevalence of BMI at or above the 85th percentile increased from 25.9% to 30.5%. Metabolic syndrome was much more prevalent in overweight compared with normal-weight adolescents (38.6% vs 1.4%; P < 0.001). Median CRP increased with increasing numbers of metabolic abnormalities and was higher in adolescents with metabolic syndrome than in those without. CRP was higher in adolescents with BMI at or above the 85th percentile than those with normal BMI.

CONCLUSIONS

Metabolic abnormalities and the metabolic syndrome phenotype are increasingly prevalent in US adolescents, attributable in part to the increasing incidence of overweight. Adolescents with more metabolic abnormalities have higher CRP, which may be an indicator of greater metabolic derangement and future cardiovascular risk.

Low-saturated fat dietary counseling starting in infancy improves insulin sensitivity in 9-year-old healthy children: the Special Turku Coronary Risk Factor Intervention Project for Children (STRIP) study

OBJECTIVE

Insulin resistance is promoted already in childhood by obesity and possibly by high-saturated fat intake. We examined the effect of infancy onset biannually given dietary counseling on markers of insulin resistance in healthy 9-year-old children.

RESEARCH DESIGN AND METHODS

Healthy 7-month-old infants (n = 1,062) were randomized to the intervention (n = 540) and control (n = 522) groups. Each year, two individualized counseling sessions were organized to each intervention family. The purpose of counseling was to minimize children's exposure to known environmental atherosclerosis risk factors. Homeostasis model assessment of insulin resistance (HOMA-IR) index, serum lipids, blood pressure, and weight for height were determined in a random subgroup of 78 intervention children and 89 control children at the age of 9 years.

RESULTS

Intervention children consumed less total and saturated fat than the control children (P = 0.002 and < 0.0001, respectively). The HOMA-IR index was lower in intervention children than in control children (P = 0.020). There was a significant association between saturated fat intake and HOMA-IR. In multivariate analyses including saturated fat intake, study group, and other determinants of HOMA-IR (serum triglyceride concentration, weight for height, and systolic blood pressure), study group was, whereas saturated fat intake was not, significantly associated with HOMA-IR. This suggests that the beneficial effect of intervention on insulin sensitivity was largely, but not fully, explained by the decrease in saturated fat intake.

CONCLUSIONS

The long-term biannual dietary intervention decreases the intake of total and saturated fat and has a positive effect on insulin resistance index in 9-year-old children.

The metabolic syndrome: prevalence, CHD risk, and treatment

An increased risk of coronary heart disease (CHD) morbidity and mortality is associated with the metabolic syndrome, a condition characterized by the concomitant presence of several abnormalities, including abdominal obesity, dyslipidemia, hypertension, insulin resistance (with or without glucose intolerance or diabetes), microalbuminuria, prothrombotic, and proinflammatory states. Estimates of the prevalence of the metabolic syndrome indicate that this condition is now common and likely to increase dramatically over the coming decades, in parallel with greater rates of obesity and Type 2 diabetes. Risk factors for the metabolic syndrome are already present in obese children and adolescents. Thus, identifying and treating all affected individuals promptly and optimally are critical to ensure that this potentially challenging healthcare burden is minimized. Here, we review the prevalence of the metabolic syndrome, dyslipidemias, and CHD risk. Although changes in lifestyle are fundamental to reducing many of the CHD risk factors associated with the metabolic syndrome, pharmacologic interventions also play an important role. Retrospective subanalyses of the effects of statins on coronary event rates and lipid levels in patients with the metabolic syndrome included in clinical trials indicate that these agents are beneficial in correcting the extensive lipid abnormalities that are frequently present in these individuals. However, the optimal management of metabolic syndrome dyslipidemia will depend on the outcomes of future prospective clinical trials. This review examines the underlying causes and prevalence of the metabolic syndrome and its impact on CHD morbidity and mortality and discusses the role of statins in optimizing its management.

Risk factors for coronary heart disease in children and young adults

This review covers two ongoing studies in Finland: the Cardiovascular Risk in Young Finns study, which started in 1978, and the Special Turku Coronary Risk Factor Intervention Project for Children (STRIP), which started in 1989. In the cross-sectional Cardiovascular Risk in Young Finns study, cardiovascular risk factors were first assessed in 1980 in 3596 children and adolescents covering ages between 3 and 18 y at 3-y intervals. The latest follow-up examination was performed in 2001, when risk factors and early markers of atherosclerosis in carotid and brachial arteries were examined in 2264 subjects from the original cohorts, now covering ages from 24 to 39 y. The results clearly show that an individual's coronary heart disease (CHD) risk factor profile is regulated by early lifestyle-related factors and that exposure to risk factors in childhood induces changes in arteries that contribute to the development of atherosclerosis in adulthood. In the STRIP study, 1062 infants were randomized into an intervention group (n = 540; low-saturated-fat, low-cholesterol diet) or a control group (n = 522) at 7 mo of age. Fat, saturated fat and cholesterol intakes have been lower, while the polyunsaturated to saturated fat ratio has been higher in the intervention children than in the control children throughout the ongoing trial. During the first 7 y of life, serum cholesterol concentration was 0.2-0.3 mmol/l lower in the intervention boys than in the control boys, but the difference was negligible in girls. Neurological development of the intervention children at age 5 y was at least as good as that of the control children. Counselling had no effect on children's growth.

Prevalence of the metabolic syndrome in American adolescents: findings from the Third National Health and Nutrition Examination Survey

BACKGROUND

Metabolic syndrome (MetS) is defined by the Third Report of the Adult Treatment Panel (ATP III) using criteria easily applied by clinicians and researchers. There is no standard pediatric definition.

METHODS AND RESULTS

We defined pediatric MetS using criteria analogous to ATP III as > or =3 of the following: (1) fasting triglycerides > or =1.1 mmol/L (100 mg/dL); (2) HDL <1.3 mmol/L (50 mg/dL), except in boys aged 15 to 19 years, in whom the cutpoint was <1.2 mmol/L (45 mg/dL); (3) fasting glucose > or =6.1 mmol/L (110 mg/dL); (4) waist circumference >75th percentile for age and gender; and (5) systolic blood pressure >90th percentile for gender, age, and height. MetS prevalence in US adolescents was estimated with the Third National Health and Nutritional Survey 1988 to 1994. Among 1960 children aged > or =12 years who fasted > or =8 hours, two thirds had at least 1 metabolic abnormality, and nearly 1 in 10 had MetS. The racial/ethnic distribution was similar to adults: Mexican-Americans, followed by non-Hispanic whites, had a greater prevalence of MetS compared with non-Hispanic blacks (12.9%, [95% CI 10.4% to 15.4%]; 10.9%, [95% CI 8.4% to 13.4%]; and 2.5%, [95% CI 1.3% to 3.7%], respectively). Nearly one third (31.2% [95% CI 28.3% to 34.1%]) of overweight/obese adolescents had MetS.

CONCLUSIONS

Our definition of pediatric MetS, designed to be closely analogous to ATP III, found MetS is common in adolescents and has a similar racial/ethnic distribution to adults in this representative national sample. Because childhood MetS likely tracks into adulthood, early identification may help target interventions to improve future cardiovascular health.

A prospective study of reproductive and menstrual factors and colon cancer risk in Japanese women: findings from the JACC study

The effects of reproductive factors on the etiology of colon cancer in Asian populations remain unexplored. So we examined 38,420 Japanese women aged 40-79 years who responded to a questionnaire on reproductive and other lifestyle factors from 1988 to 1990 in the Japan Collaborative Cohort Study for Evaluation of Cancer Risk. During an average 7.6 years of follow-up, we documented 207 incident colon cancers. Multivariate analysis indicated that colon cancer risk was likely to be lower among parous women than among nulliparous. Women who had two abortions or more had a 72% higher risk of developing colon cancer [relative risk (RR) 1.72; 95% confidence interval (CI) 1.16-2.55; trend P < 0.01] compared with women who never had an abortion. The RR of colon cancer among postmenopausal women significantly decreased with increasing age at menarche (trend P = 0.01). No apparent association between colon cancer and gravida, age at first birth, age at menopause, or duration of menstruation was seen. These prospective data support the hypothesis that female reproductive events modify colon cancer risk, and suggest that reproductive factors, particularly age at menarche and having an abortion, may be of importance in the etiology of colon cancer among Japanese women.

Postnatal ontogeny of glucose homeostasis and insulin action in sheep

Glucose tolerance declines with maturation and aging in several species, but the time of onset and extent of changes in insulin sensitivity and insulin secretion and their contribution to changes in glucose tolerance are unclear. We therefore determined the effect of maturation on glucose tolerance, insulin secretion, and insulin sensitivity in a longitudinal study of male and female sheep from preweaning to adulthood, and whether these measures were related across age. Glucose tolerance was assessed by intravenous glucose tolerance test (IVGTT, 0.25 g glucose/kg), insulin secretion as the integrated insulin concentration during IVGTT, and insulin sensitivity by hyperinsulinemic-euglycemic clamp (2 mU insulin.kg(-1).min(-1)). Glucose tolerance, relative insulin secretion, and insulin sensitivity each decreased with age (P < 0.001). The disposition index, the product of insulin sensitivity, and various measures of insulin secretion during fasting or IVGTT also decreased with age (P < 0.001). Glucose tolerance in young adult sheep was independently predicted by insulin sensitivity (P = 0.012) and by insulin secretion relative to integrated glucose during IVGTT (P = 0.005). Relative insulin secretion before weaning was correlated positively with that in the adult (P = 0.023), whereas glucose tolerance, insulin sensitivity, and disposition indexes in the adult did not correlate with those at earlier ages. We conclude that glucose tolerance declines between the first month of life and early adulthood in the sheep, reflecting decreasing insulin sensitivity and absence of compensatory insulin secretion. Nevertheless, the capacity for insulin secretion in the adult reflects that early in life, suggesting that it is determined genetically or by persistent influences of the perinatal environment.

Obesidade e síndrome metabólica na infância e adolescência

Nas últimas décadas a prevalência da obesidade vem apresentando um aumento em vários países ao redor do mundo. Este fato é preocupante, já que o excesso de gordura corporal, principalmente a abdominal, está diretamente relacionado com alterações do perfil lipídico, com o aumento da pressão arterial e a hiperinsulinemia, considerados fatores de risco para o desenvolvimento de doenças crônicas, como o diabetes melito tipo 2 e as doenças cardiovasculares. Níveis elevados de leptina e de ácido úrico e a alteração dos fatores fibrinolíticos também têm sido observados em indivíduos obesos. O conjunto destas alterações tem sido descrito como "síndrome metabólica" ou "síndrome da resistência à insulina", já que a hiperinsulinemia tem um papel importante no desenvolvimento dos outros componentes da síndrome metabólica. Entretanto, questiona-se se estas alterações já estão presentes em crianças e adolescentes obesos. Este artigo descreve a fisiopatologia dos componentes da síndrome metabólica e esclarece como este processo ocorre na faixa etária mais jovem.

Obesity, insulin resistance, and other clinicopathological correlates of pediatric nonalcoholic fatty liver disease

OBJECTIVE

To describe the clinical characteristics of nonalcoholic fatty liver disease (NAFLD) in children, including insulin resistance, and to test for correlation with liver pathology.

STUDY DESIGN

A retrospective review of children with biopsy-proven NAFLD at Children's Hospital San Diego from 1999 to 2002. Liver biopsy specimens were independently reviewed by two pathologists.

RESULTS

Children with NAFLD (n=43) were mostly male (70%), Hispanic American (53%) and obese (88%). The criteria for insulin resistance were met by 95% of subjects. Steatosis was predicted by the combination of quantitative insulin sensitivity check index, age, and ethnicity (P<.0001). Portal inflammation was predicted by the combination of ALT and fasting insulin (P=.0009). Perisinusoidal fibrosis was predicted by the combination of AST, fasting insulin, and BMI Z score (P<.0001). Portal fibrosis was predicted by the combination of right upper quadrant pain and homeostasis model assessment of insulin resistance (P=.0028).

CONCLUSIONS

We identified significant predictors of liver pathology in children with NAFLD. Children being evaluated for NAFLD should be screened for insulin resistance, which is nearly universal and correlates with liver histology.

Affects and autonomic cardiac reactivity during experimentally induced stress as related to precursors of insulin resistance syndrome

This study examined the association of insulin resistance syndrome (IRS) precursors with state affects and autonomic reactivity in randomly selected healthy young adults. It was asked whether IRS precursors are able to predict a person's mental and physiological coping with acute stress over an 11-year follow-up period. IRS parameters were serum insulin, high-density lipoprotein cholesterol, triglycerides, systolic blood pressure, body-mass index, and subscapular skinfold thickness. In the psychophysiological experiment, state affects and cardiac responses (heart rate, respiratory sinus arrhythmia, and pre-ejection period) were measured during different challenges. The main result was that IRS precursors predicted high levels of negative emotions during the challenges; IRS accounted for 19% of the variance in tiredness. IRS was unrelated to cardiac reactivity. Mechanisms underlying the associations found are discussed.

Fasting plasma insulin modulates lipid levels and particle sizes in 2- to 3-year-old children

OBJECTIVE

Obesity and hyperinsulinemia are associated with dyslipidemia in adults and older children, but little is known about these relationships in very young children. We examined the relation of fasting insulin to lipid levels and lipid particle size in young healthy children.

RESEARCH METHODS AND PROCEDURES

Analyses were performed on data from 491 healthy 2- and 3-year old Hispanic children enrolled in a dietary study conducted in New York City, 1992-1995. Obesity measures included BMI, ponderal index, skinfold thickness, and waist circumference. Low-density lipoprotein (LDL)- and high-density lipoprotein (HDL)-cholesterol particle size were measured by nuclear magnetic resonance.

RESULTS

Fasting insulin level was positively correlated with triglyceride levels (r = 0.24 for boys and r = 0.23 for girls; p < 0.001 for both) and inversely correlated with HDL-cholesterol level in boys (r = -0.20; p < 0.01). Higher fasting insulin level was also correlated with smaller mean HDL particle size in both boys (r = -0.21; p < 0.001) and girls (r = -0.14; p < 0.05) and smaller mean LDL particle size in boys (r = -0.13; p < 0.05). The associations of fasting insulin level with triglyceride and HDL-cholesterol levels and HDL and LDL particle size remained significant after multivariate regression adjustment for age, sex, and BMI or ponderal index.

DISCUSSION

Fasting insulin level is associated with relative dyslipidemia in healthy 2- and 3-year-old Hispanic children.

Distribution of fasting plasma insulin, free fatty acids, and glucose concentrations and of homeostasis model assessment of insulin resistance in a representative sample of Quebec children and adolescents

BACKGROUND

Plasma fasting insulin and the homeostasis model assessment of insulin resistance (HOMA-IR) are markers of IR, which, at least in part, mediates the relation of obesity to increased cardiovascular risk. Increased free fatty acids (FFAs) may be involved in the pathogenesis of IR. Our objectives were to describe the distributions of fasting plasma insulin, glucose, and FFAs and HOMA-IR in youth and to assess the relationship between FFAs and markers of IR.

METHODS

Fasting plasma insulin, glucose, and FFAs were measured in a representative sample of Quebec youth comprising 2244 individuals 9, 13, and 16 years of age.

RESULTS

In all age and sex groups, glucose exhibited remarkably tight distributions (median CV, 7.1%) in contrast to insulin, HOMA-IR, and FFAs (median CVs, 52%, 54% and 45%, respectively). For every percentile examined, 9-year-olds had lower insulin concentrations and HOMA-IR values than 13- and 16-year-olds. We observed strong correlations between insulin concentrations and HOMA-IR values, as well as close similarity in their rankings of individuals. The mean concentrations of glucose were higher in our population than in other Caucasian pediatric populations. No positive correlations were detected between FFAs and markers of IR.

CONCLUSIONS

We report some of the first data on the distributions of fasting plasma insulin, HOMA-IR, and FFAs from a representative sample of youth. HOMA-IR does not appear more informative than fasting insulin as a marker of IR. Our findings on higher mean glucose concentrations in this population require confirmation in other representative samples of youth to assess whether the North American distribution of glucose concentrations is shifting positively.

Childhood obesity in Canada: a review of prevalence estimates and risk factors for cardiovascular diseases and type 2 diabetes

Childhood obesity in Canada has become increasingly prevalent over the past 2 decades. Despite inconsistencies regarding different anthropometric indicators, cut-offs, and reference populations, both regional and national investigations have revealed high numbers of overweight and obese children and adolescents. A number of risk factors and health consequences have been associated with increased levels of body fatness in youth. Specifically, risk factors for cardiovascular diseases (CVD) and type 2 diabetes are known to develop early in life and tend to emerge in clusters among overweight youngsters. Unhealthy lifestyle behaviours (i.e., physical inactivity), a genetic disposition, and a centralized body fat distribution, all contribute to increased risk. In order to prevent future generations of children from experiencing increased morbidity and mortality as overweight and obese adults, coordinated efforts at all levels (family, school, community, and government) must be established with a long-term commitment to promote healthy nutrition and physical activity behaviours in our youth.

Obesity, fasting plasma insulin, and C-reactive protein levels in healthy children

OBJECTIVE

Obesity is associated with hyperinsulinemia and increased level of C-reactive protein in older children and adults, but little is known about these relationships in very young children. We examined these relationships in healthy 2- to 3-year-old children.

RESEARCH METHODS AND PROCEDURES

Analyses were performed on data from 491 healthy 2- to 3-year-old Hispanic children enrolled in a dietary study conducted in New York City, 1992 to 1995.

RESULTS

Body mass index (BMI), ponderal index, and sum of four skinfolds were highly correlated (r > 0.75) in both boys and girls. Fasting insulin and glucose levels were only modestly correlated (r = 0.37 for boys and r = 0.28 for girls; p < 0.001 for both), but essentially all of the variability in a calculated index of insulin resistance was attributable to variability in fasting insulin level. The correlations of BMI with fasting insulin level were r = 0.16 (p < 0.05) in boys and r = 0.14 (p < 0.05) in girls. In separate multivariate regression analyses adjusting for age and sex, BMI and ponderal index were associated with fasting plasma insulin level (p < 0.001 for both obesity measures). In multivariate regression analyses adjusting simultaneously for age, sex, and either BMI or ponderal index, fasting insulin level, but not these obesity measures, was associated with C-reactive protein level.

DISCUSSION

Obesity is associated with higher fasting insulin level, and fasting insulin is associated with C-reactive protein level, in healthy 2- to 3-year-old children.

Persistent hypercholesterolemia is associated with the development of obesity among girls: the Bogalusa Heart Study

BACKGROUND

Obesity is associated with cardiovascular disease (CVD) risk factors. Cross-sectional data suggest that hypercholesterolemia is associated with the development of childhood obesity.

OBJECTIVE

The objective was to assess age-related changes in relative weight and the association between relative weight and CVD risk factors in hypercholesterolemic and nonhypercholesterolemic children who were nonobese at baseline.

DESIGN

Data on relative weight and CVD risk factors were extracted from the Bogalusa Heart Study for nonobese 5-6-y-old black and white hypercholesterolemic (LDL cholesterol > 75th percentile; n = 58) and nonhypercholesterolemic (LDL cholesterol < 60th percentile; n = 215) children (41% black, 52% girls) who were also assessed 3 and 6 y later. Changes in body mass index (BMI) and CVD risk factors were assessed as a function of age, sex, race, and cholesterol concentration.

RESULTS

BMI increased more in the hypercholesterolemic (n = 31) than in the nonhypercholesterolemic (n = 111) girls during the 6 y of follow-up but was not significantly different between hypercholesterolemic (n = 27) and nonhypercholesterolemic (n = 104) boys aged 5-12 y. Associations between BMI and the risk factors blood pressure, insulin, and blood lipids were observed to be stronger with increasing age and, in some cases, stronger in hypercholesterolemic children and girls.

CONCLUSIONS

Hypercholesterolemia is associated with increased relative weight in girls. The increased relative weight, even at an early age, is associated with a deleterious effect on blood lipids and other CVD risk factors in hypercholesterolemic children, although the strength of these associations is sex dependent.

Childhood and adolescent obesity. Prevalence and significance

The prevalence of children and adolescents with body mass index (BMI) of greater than 95th percentile has doubled in the last 2 decades (present prevalence is 10.9%) and there is a 50% increase in the prevalence of those with a BMI greater than 85th percentile (present prevalence is 22.0%) in the US. There are substantial risks for morbidity in obese children even before they reach adulthood. Further, if obesity in childhood persists into the adult years, the morbidity and mortality is greater than if the obesity developed in the adult. Screening using appropriate historical and physical data will reveal those children most in need of modification of weight gain.

Defining health-related obesity in prepubertal children

OBJECTIVE

The purpose of this study was to develop percentage of fat and waist circumference cut-points in prepubertal children with the intention of defining obesity associated with cardiovascular disease (CVD) risk.

RESEARCH METHODS AND PROCEDURES

A cross-sectional analysis of 87 prepubertal children aged 4 to 11 years was used. Percentage of body fat was determined by DXA. Waist circumference was measured to the nearest millimeter. Receiver Operating Characteristic analyses of percentage of fat and waist circumference were used to develop cut-points for individuals with adverse levels of CVD risk factors.

RESULTS

The risk factors selected for analyses (i.e., fasting insulin, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, and total cholesterol/high-density lipoprotein cholesterol) were significantly related to percentage of body fat and waist circumference. Likelihood ratios were used to identify percentage of fat and waist circumference cut-points associated with adverse cardiovascular risk profiles. Two cut-points, an upper cut-point of 33% body fat and a lower cut-point of 20% body fat, were derived. Waist circumference cut-points indicative of adverse and normal risk-factor profiles were 71 cm and 61 cm, respectively.

DISCUSSION

The data indicate that children with > or =33% body fat and children with a waist circumference > or =71 cm were more likely to possess an adverse CVD risk-factor profile than a normal risk-factor profile. The likelihood of children with < 20% body fat or a waist circumference < 61 cm possessing an adverse CVD risk-factor profile as opposed to a normal risk-factor profile was small. The cut-points describe an adequate health-related definition of childhood obesity.