Temporal association between obesity and hyperinsulinemia in children, adolescents, and young adults: the Bogalusa Heart Study

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.

Utility of waist-to-height ratio, waist circumference and body mass index in predicting clustered cardiometabolic risk factors and subclinical vascular phenotypes in children and adolescents: A pooled analysis of individual data from 14 countries

AIMS

The clinical utility of waist-to-height ratio (WHtR) in predicting cardiometabolic risk factors (CMRFs) and subclinical markers of cardiovascular disease remains controversial. We aimed to compare the utility of WHtR with waist circumference (WC) and body mass index (BMI) in identifying children and adolescents (youths) at risk for cardiometabolic outcomes, including clustered CMRFs, high carotid intima-media thickness (cIMT), and arterial stiffness (assessed as high pulse wave velocity, PWV).

METHODS

We analyzed data from 34,224 youths (51.0 % boys, aged 6-18 years) with CMRFs, 5004 (49.5 % boys, aged 6-18 years) with cIMT measurement, and 3100 (56.4 % boys, aged 6-17 years) with PWV measurement from 20 pediatric samples across 14 countries.

RESULTS

WHtR, WC, and BMI z-scores had similar performance in discriminating youths with ≥3 CMRFs, with the area under the curve (AUC) (95 % confidence interval, CI)) ranging from 0.77 (0.75-0.78) to 0.78 (0.76-0.80) using the modified National Cholesterol Education Program (NCEP) definition, and from 0.77 (0.74-0.79) to 0.77 (0.74-0.80) using the International Diabetes Federation (IDF) definition. Similarly, all three measures showed similar performance in discriminating youths with subclinical vascular outcomes, with AUC (95 % CI) ranging from 0.67 (0.64-0.71) to 0.70 (0.66-0.73) for high cIMT (≥P95 values) and from 0.60 (0.58-0.66) to 0.62 (0.58-0.66) for high PWV (≥P95 values).

CONCLUSIONS

Our findings suggest that WHtR, WC, and BMI are equally effective in identifying at-risk youths across diverse pediatric populations worldwide. Given its simplicity and ease of use, WHtR could be a preferable option for quickly screening youths with increased cardiometabolic risk in clinical settings.

Establishing international optimal cut-offs of waist-to-height ratio for predicting cardiometabolic risk in children and adolescents aged 6-18 years

BACKGROUND

Waist-to-height ratio (WHtR) has been proposed as a simple and effective screening tool for assessing central obesity and cardiometabolic risk in both adult and pediatric populations. However, evidence suggests that the use of a uniform WHtR cut-off of 0.50 may not be universally optimal for pediatric populations globally. We aimed to determine the optimal cut-offs of WHtR in children and adolescents with increased cardiometabolic risk across different countries worldwide.

METHODS

We used ten population-based cross-sectional data on 24,605 children and adolescents aged 6-18 years from Brazil, China, Greece, Iran, Italy, Korea, South Africa, Spain, the UK, and the USA for establishing optimal WHtR cut-offs. We performed an external independent test (9,619 children and adolescents aged 6-18 years who came from other six countries) to validate the optimal WHtR cut-offs based on the predicting performance for at least two or three cardiometabolic risk factors.

RESULTS

Based on receiver operator characteristic curve analyses of various WHtR cut-offs to discriminate those with ≥ 2 cardiometabolic risk factors, the relatively optimal percentile cut-offs of WHtR in the normal weight subsample population in each country did not always coincide with a single fixed percentile, but varied from the 75th to 95th percentiles across the ten countries. However, these relatively optimal percentile values tended to cluster irrespective of sex, metabolic syndrome (MetS) criteria used, and WC measurement position. In general, using ≥ 2 cardiometabolic risk factors as the predictive outcome, the relatively optimal WHtR cut-off was around 0.50 in European and the US youths but was lower, around 0.46, in Asian, African, and South American youths. Secondary analyses that directly tested WHtR values ranging from 0.42 to 0.56 at 0.01 increments largely confirmed the results of the main analyses. In addition, the proposed cut-offs of 0.50 and 0.46 for two specific pediatric populations, respectively, showed a good performance in predicting ≥ 2 or ≥ 3 cardiometabolic risk factors in external independent test populations from six countries (Brazil, China, Germany, Italy, Korea, and the USA).

CONCLUSIONS

The proposed international WHtR cut-offs are easy and useful to identify central obesity and cardiometabolic risk in children and adolescents globally, thus allowing international comparison across populations.

Association of large for gestational age with cardiovascular metabolic risks: a systematic review and meta-analysis

OBJECTIVE

The aim of this study was to clarify the relationships among large for gestational age (LGA) and cardiometabolic risk factors.

METHODS

PubMed, Web of Science, and the Cochrane Library databases were searched to identify studies on LGA and outcomes of interest, including BMI, blood pressure, glucose metabolism, and lipid profiles. Data were independently extracted by two reviewers. A meta-analysis was performed using a random-effects model. The Newcastle-Ottawa Scale and funnel graph were used to assess the quality and publication bias, respectively.

RESULTS

Overall, 42 studies involving 841,325 individuals were included. Compared with individuals born appropriate for gestational age, individuals born LGA had higher odds of overweight and obesity (odds ratios [OR] = 1.44, 95% CI: 1.31-1.59), type 1 diabetes (OR = 1.28, 95% CI: 1.15-1.43), hypertension (OR = 1.23, 95% CI: 1.01-1.51), and metabolic syndrome (OR = 1.43, 95%; CI: 1.05-1.96). No significant difference was found in hypertriglyceridemia and hypercholesterolemia. Stratified analyses showed that, compared with individuals born appropriate for gestational age, individuals born LGA had higher odds for overweight and obesity from toddler age to puberty age (toddler age: OR = 2.12, 95% CI: 1.22-3.70; preschool: OR = 1.81, 95% CI: 1.55-2.12; school age: OR = 1.53, 95% CI: 1.09-2.14; puberty: OR = 1.40, 95% CI: 1.11-1.77).

CONCLUSIONS

LGA is associated with increased odds of obesity and metabolic syndrome later in life. Future studies should focus on elucidating the potential mechanisms and identifying risk factors.

Influence of Waist Circumference Measurement Site on Visceral Fat and Metabolic Risk in Youth

Although the rate of childhood obesity seems to have plateaued in recent years, the prevalence of obesity among children and adolescents remains high. Childhood obesity is a major public health concern as overweight and obese youth suffer from many co-morbid conditions once considered exclusive to adults. It is now well demonstrated that abdominal obesity as measured by waist circumference (WC) is an independent risk factor for cardiovascular disease and metabolic dysfunction in youth. Despite the strong associations between WC and cardiometabolic risk factors, there is no consensus regarding the optimal WC measurement sites to assess abdominal obesity and obesity-related health risk in children and adolescents. Currently, the WC measurement site that provides the best reflections of visceral fat and the best correlations with cardiometabolic risk factors is unclear. The purpose of this review is to explore whether WC measurement sites influence the relationships between WC, visceral fat, and cardiometabolic risk factors in children and adolescents.

Consumption of “Diabetes Risk Reduction Diet” and Odds of Breast Cancer Among Women in a Middle Eastern Country

Background:

Given the role of insulin resistance in several cancers, we hypothesized that consumption of a diet that reduces insulin resistance might lower the risk of breast cancer.

Objective

The present study was designed to assess the association between consumption of “diabetes risk reduction diet” (DRRD) and odds of breast cancer among a large group of women in a Middle Eastern country.

Methods

This population-based case-control study enrolled 350 newly diagnosed cases of stage I-IV breast cancer and 700 age-matched apparently healthy individuals as controls. We collected dietary data via a validated 106-item Willett-format semi-quantitative dish-based food frequency questionnaire. A DRRD score was included based on 9 dietary factors (cereal fiber, coffee, nuts, whole fruits, ratio of polyunsaturated to saturated, trans fat, sugar-sweetened beverages, red and processed meat, and lower glycemic index). For food and nutrient items with a protective association with diabetes in earlier studies, participants were given the score as the quintile of that food item, but for food groups with unfavorable association with diabetes, we did vice versa. Total DRRD score ranged from 5 to 45.

Results

Mean age of cases and controls was 65.28 and 61.04 years. Mean BMI of patients with breast cancer and controls was 25.5 and 21.0. We found that individuals with the greatest adherence to the DRRD were 0.41 times less likely to have breast cancer than those with the lowest adherence (OR: 0.59; 95% CI: 0.38, 0.90, and P-trend = 0.002). Stratified analysis by menopausal status indicated a significant inverse relationship in postmenopausal women (OR: 0.57; 95% CI: 0.36–0.90), but not in premenopausal women (OR: 0.76; 95% CI: 0.19–2.96). Moreover, by BMI status, we found statistically significant inverse association between adherence to the DRRD and odds of breast cancer among normal-weight women (OR: 0.59; 95% CI: 0.36, 0.98) but not in overweight women (OR: 0.66; 95% CI: 0.31, 1.40). Conclusions: Significant inverse associations were found between adherence to DRRD and breast cancer, especially among postmenopausal and normal-weight women.

The role of purslane in modulating diverse effects of high fat diet on biochemical, histological, and molecular parameters of rats' liver

Consuming a high-fat diet causes a harmful accumulation of fat in the liver, which may not reverse even after switching to a healthier diet. Different reports dealt with the role of purslane as an extract against high-fat diet; meanwhile, it was necessary to study the potential role of fresh purslane as a hypolipidemic agent. This study is supposed to investigate further the potential mechanism in the hypolipidemic effect of fresh purslane, by measuring cholesterol 7a-hydroxylase (CYP7A1) and low-density lipoprotein receptor (Ldlr). Rats were divided into two main groups: the first one is the normal control group (n=7 rats) and the second group (n=28 rats) received a high fat diet for 28 weeks to induce obesity. Then the high fat diet group was divided into equal four subgroups. As, the positive control group still fed on a high fat diet only. Meanwhile, the other three groups were received high-fat diet supplemented with a different percent of fresh purslane (25, 50 and 75%) respectively. At the end of the experiment, rats were sacrificed and samples were collected for molecular, biochemical, and histological studies. Current study reported that, supplementation of fresh purslane especially at a concentration of 75% play an important role against harmful effects of high-fat diet at both cellular and organ level, by increasing CYP7A1 as well as Ldlr mRNA expression. Also, there were an improvement on the tested liver functions, thyroid hormones, and lipid profile. Fresh purslane plays the potential role as a hypolipidemic agent via modulation of both Ldlr and Cyp7A, which will point to use fresh purslane against harmful effects of obesity.

Childhood BMI and Fasting Glucose and Insulin Predict Adult Type 2 Diabetes: The International Childhood Cardiovascular Cohort (i3C) Consortium

OBJECTIVE

To examine childhood BMI, fasting glucose, and insulin in relation to incident adult type 2 diabetes mellitus (T2DM).

RESEARCH DESIGN AND METHODS

We used data from the International Childhood Cardiovascular Cohort (i3C) Consortium. Data included childhood (age 3-19 years) measurements obtained during the 1970s-1990s; a health questionnaire, including self-report of adult T2DM (occurrence age, medication use) obtained at mean age 40 years; and a medical diagnosis registry (Finland).

RESULTS

The sample included 6,738 participants. Of these, 436 (6.5%) reported onset of T2DM between ages 20 and 59 (mean 40.8) years, and 86% of them reported use of a confirmed antidiabetic medication. BMI and glucose (age and sex standardized) were associated with incident T2DM after adjustment for cohort, country, sex, race, age, and calendar year of measurement. Increasing levels of childhood BMI and glucose were related to an incrementally increased risk of T2DM beginning at age 30 years, beginning at cut points <95th percentile for BMI and <100 mg/dL for glucose. Insulin was positively associated with adult T2DM after adjustment for BMI and glucose and added to T2DM discrimination.

CONCLUSIONS

Childhood BMI and glucose are predictors of adult T2DM at levels previously considered to be within the normal range. These easy-to-apply measurements are appealing from a clinical perspective. Fasting insulin has the potential to be an additional predictor.

Adiposity and attained height in adolescents: a longitudinal analysis from the LabMed Physical Activity Study

Background To investigate the associations between adiposity and attained height over a 2-year period in healthy adolescents. Methods One thousand and seventeen adolescents aged 12-18 years participated in this cohort study; 893 (87.8%) were reevaluated 1 year later (T2) and 734 (72.2%) subjects 2 years later (T3). Body fat and anthropometry were measured according to standardized procedures. Socioeconomic status, pubertal stage and lifestyles determinants were gathered and used as confounders. Prospective associations between adiposity and height were examined using generalized linear models. Results Greater adiposity at T1 was significantly associated with a lower attained height over time, when adjusting for confounders, which varied between 0.03 and 1 cm in T2 and 0.1 and 1 cm in T3. Conclusions Excess of adiposity in early adolescence may exert an effect on attained height in late adolescence. This study supports future lifestyles intervention studies aiming at preventing overweight and obesity and improving attained height.

Impact of cigarette smoking on the relationship between body mass index and insulin: Longitudinal observation from the Bogalusa Heart Study

OBJECTIVES

Despite the inverse association between cigarette smoking and body mass index (BMI), it is unknown whether the effect of smoking on insulin is mediated through decreased BMI. This study aims to examine the temporal relationship between BMI and insulin, the impact of smoking on this relationship and the mediation effect of BMI on the association between smoking and insulin levels.

METHODS

The longitudinal cohort consisted of 1121 adults (807 white and 314 black participants, mean age, 42.0 years at follow-up) for whom BMI and fasting insulin were measured twice, with an average follow-up period of 17.1 years. Cross-lagged panel and mediation analysis models were used to examine the temporal relationship between BMI and insulin, and the mediation effect of BMI on the smoking-insulin association.

RESULTS

Smoking was inversely associated with insulin (regression coefficient, -0.073; P = .015 at baseline and -0.121; P < .001 at follow-up), adjusting for age, race and gender. After additional adjustment for follow-up periods, the cross-lagged path coefficient from BMI to insulin (β, 0.226; P < .001) was significantly greater than that from insulin to BMI (β, -0.029; P = .208), with P < .001 for the difference. The path coefficient from BMI to insulin was significantly greater in non-smokers (β, 0.273; P < .001) than in smokers (β, 0.122; P = .046), with P = .013 for the difference. The mediation effect of BMI on the smoking-insulin association was estimated at 53.4% (P = .030) at baseline and 58.7% (P < .001) at follow-up.

CONCLUSIONS

These findings suggest that cigarette smoking has a significant impact on the one-directional relationship from BMI to insulin. The insulin-lowering effect of smoking is predominantly mediated through decreased BMI as the result of smoking.

The Impact of Adolescent Obesity on Adult Height

BACKGROUND

Childhood obesity is a major health concern. Excess adiposity during childhood affects growth and puberty. Our aim was to assess whether genetic adult height is compromised in adolescents with obesity.

METHODS

In a retrospective study of 190 obese patients followed at our Pediatric Endocrinology Institute, adult height and delta height (the difference between adult height and mid-parental height) were compared to those of 150 healthy age-matched normal-weight controls. Review of medical files yielded the relevant clinical and anthropometric data of patients, controls, and parents.

RESULTS

Of the 190 obese adolescents, 150 were morbidly obese. The median adult height of morbidly obese males was 174.3 cm, of obese males 174 cm, and of normal-weight males 176 cm (p = 0.025). Delta height of morbidly obese males was -0.5 cm, of obese males -0.8 cm, and of normal-weight males, 3 cm (p < 0.0001). The median adult height of morbidly obese females was 161.3 cm, of obese females 162.8 cm, and of normal-weight females 162 cm (p = 0.37). Delta height of morbidly obese females was -1.85 cm, of obese females -0.95 cm, and of normal-weight females 0.7 cm (p = 0.019). Impairment of potential genetic height was not associated with obesity-related comorbidities.

CONCLUSION

Adolescents with obesity showed impairment of potential genetic adult height as compared to that of normal-weight subjects.

Putative Effects of Obesity on Linear Growth and Puberty

Childhood obesity is a major public health problem that has grown to epidemic proportions throughout the world. Obesity is influenced by genetic and environmental factors. The nutritional status plays an important role in growth and body weight regulation. Excess adiposity during childhood can affect the process of growth and puberty. Obese children are frequently tall for their age, with accelerated epiphyseal growth plate maturation despite low growth hormone levels. Several regulatory hormones may affect the process of linear growth in the constellation of obesity, as high levels of insulin and leptin are observed in obese children. Leptin can act as a skeletal growth factor, with a direct effect on skeletal growth centers. The finding that overweight children, especially girls, tend to mature earlier than lean children has led to the hypothesis that the degree of body fatness may trigger the neuroendocrine events that lead to the onset of puberty. Leptin receptors have been identified in the hypothalamus, as well as in gonadotrope cells, ovarian follicular cells, and Leydig cells. The increased leptin and androgen levels seen in obese children may be implicated in their earlier onset of puberty and accelerated pubertal growth. This review is focused on the interaction between childhood obesity and growth and pubertal processes.
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Long-term Impact of Temporal Sequence from Childhood Obesity to Hyperinsulinemia on Adult Metabolic Syndrome and Diabetes: The Bogalusa Heart Study

This study aims to delineate the temporal relations between body mass index (BMI) and insulin in childhood and their impact on adult metabolic syndrome (MetS) and type 2 diabetes mellitus (T2DM).The longitudinal cohort consisted of 609 whites and 339 blacks who had BMI and fasting insulin measured twice in childhood (mean age = 10.5 years at baseline and 15.9 years at follow-up). Incident MetS and T2DM were identified in adulthood (mean age = 30.5 years). Cross-lagged panel and mediation analysis models were used. After adjusting for age, race, gender, and follow-up years, the cross-lagged path coefficient of BMI → insulin (β = 0.326, p < 0.001) was significantly greater than that of insulin → BMI (β = −0.023, p = 0.207) in childhood, with p < 0.001 for the difference in βs. The path coefficient for BMI → insulin was significantly greater in MetS than in non-MetS groups (0.510 vs 0.190, p < 0.001), and greater in hyperglycemia than in normoglycemia groups (0.503 vs 0.285, p = 0.026). The mediation effect of childhood insulin on the BMI-MetS and BMI-hyperglycemia associations was estimated at 19.2% (p < 0.001) and 18.3% (p < 0.001), respectively. These findings provide evidence that higher BMI levels precede hyperinsulinemia during childhood, and this one-directional relation plays a significant role in the development of MetS and T2DM in adult life.

Tracking weight change, insulin resistance, stress, and aerobic fitness over 4 years of college

OBJECTIVE

To determine if weight gain is accompanied by development of insulin resistance (IR) during 4 years in college.

PARTICIPANTS

Two cohorts of college students were enrolled in fall semesters 2009 and 2010 and tracked for 4 years.

METHODS

Following a 12-hour fast, subjects reported for measurement of body mass index (BMI), perceived stress (PSS), aerobic fitness, and blood glucose, insulin, and lipids.

RESULTS

In the first year, 33% of subjects were overweight or obese, and 20% were hyperinsulinemic. Year 4 had 29 remaining subjects with disproportionate attrition of overweight and obese individuals. Just over half the subjects gained weight (WI), whereas nearly 30% lost considerable amounts (WD). WD showed significant decline in fasting insulin, low-density lipoprotein (LDL) cholesterol, and PSS from year 1. WI was primarily highly fit men who did not demonstrate increased IR.

CONCLUSION

WI was not associated with IR over 4 years of college.

A longitudinal study of serum insulin and insulin resistance as predictors of weight and body fat gain in African American and Caucasian children

BACKGROUND

The influence of insulin and insulin resistance (IR) on children's weight and fat gain is unclear.

OBJECTIVE

To evaluate insulin and IR as predictors of weight and body fat gain in children at high risk for adult obesity. We hypothesized that baseline IR would be positively associated with follow-up body mass index (BMI) and fat mass.

SUBJECTS/METHODS

Two hundred and forty-nine healthy African American and Caucasian children aged 6-12 years at high risk for adult obesity because of early-onset childhood overweight and/or parental overweight were followed for up to 15 years with repeated BMI and fat mass measurements. We examined baseline serum insulin and homeostasis model of assessment-IR (HOMA-IR) as predictors of follow-up BMI Z-score and fat mass by dual-energy X-ray absorptiometry in mixed model longitudinal analyses accounting for baseline body composition, pubertal stage, sociodemographic factors and follow-up interval.

RESULTS

At baseline, 39% were obese (BMI⩾95th percentile for age/sex). Data from 1335 annual visits were examined. Children were followed for an average of 7.2±4.3 years, with a maximum follow-up of 15 years. After accounting for covariates, neither baseline insulin nor HOMA-IR was significantly associated with follow-up BMI (Ps>0.26), BMIz score (Ps>0.22), fat mass (Ps>0.78) or fat mass percentage (Ps>0.71). In all models, baseline BMI (P<0.0001), body fat mass (P<0.0001) and percentage of fat (P<0.001) were strong positive predictors for change in BMI and fat mass. In models restricted to children without obesity at baseline, some but not all models had significant interaction terms between body adiposity and insulinemia/HOMA-IR that suggested less gain in mass among those with greater insulin or IR. The opposite was found in some models restricted to children with obesity at baseline.

CONCLUSIONS

In middle childhood, BMI and fat mass, but not insulin or IR, are strong predictors of children's gains in BMI and fat mass during adolescence.

Insulin-sensitive adiposity is associated with a relatively lower risk of diabetes than insulin-resistant adiposity: the Bogalusa Heart Study

Obesity and insulin resistance are both closely associated with type 2 diabetes mellitus (T2DM). It is, however, not clear whether the role of obesity in the development of T2DM is dependent on insulin resistance. This study aims to assess the hypothesis that insulin-sensitive adiposity is associated with a relatively lower risk of T2DM than insulin-resistant adiposity, and the adiposity-T2DM association is modified by insulin resistance in middle-aged black and white adults. The longitudinal study cohort consisted of 1588 middle-aged normoglycemic black and white adults aged 18-44 years at baseline who were followed for 16 years on average. Overweight/obesity at baseline was defined as BMI ≥25, and insulin resistance was measured using the homeostasis model assessment of insulin resistance (HOMA). The prevalence of incident pre-diabetes and T2DM was compared between the insulin-sensitive and insulin-resistant adiposity groups. The prevalence of both incident pre-diabetes and T2DM was higher in the insulin-resistant adiposity than in the insulin-sensitive adiposity group (11.5 vs. 7.5 %, p = 0.023 for pre-diabetes; 16.7 vs. 2.7 %, p < 0.001 for T2DM). In multivariable logistic analyses, adjusted for baseline age, race, sex, follow-up years, and smoking, baseline insulin-resistant obesity was associated with incident pre-diabetes (odds ratio, OR = 2.07, p = 0.046) and T2DM (OR = 8.19, p < 0.001). ORs did not differ between blacks and whites. The ORs for the association of BMI with pre-diabetes and T2DM significantly increased across increasing quartiles of baseline HOMA (p for trend = 0.032 for pre-diabetes and <0.001 for T2DM). Slopes of increasing follow-up glucose with baseline BMI, measured as regression coefficients (β), were significantly greater in insulin-resistant than in insulin-sensitive individuals (β = 0.86 vs. 0.38, p = 0.009 for difference in slopes). These findings suggest that insulin resistance amplifies the obesity-diabetes association and underscore the importance of preventing both adiposity and insulin resistance in young adults.

Temporal Relationship Between Childhood Body Mass Index and Insulin and Its Impact on Adult Hypertension: The Bogalusa Heart Study

Although obesity and insulin resistance are closely correlated, their temporal sequences in early life and influence on adult hypertension are largely unknown. This study aims to delineate the temporal relationship patterns between body mass index (BMI) and insulin in childhood and their impact on adult hypertension. The longitudinal cohort consisted of 990 adults (630 whites and 360 blacks) who had BMI and fasting insulin measured twice 5.4 years apart in childhood (mean age, 10.5 years at baseline and 15.9 years at follow-up) and blood pressure measured 14.7 years later in adulthood (mean age, 30.5 years). Cross-lagged panel and mediation analysis models were used to examine the temporal relationship between childhood BMI and insulin and its impact on adult hypertension. After adjusting for age, race, sex, and follow-up years, the cross-lagged path coefficient (β=0.33; P<0.001) from baseline BMI to follow-up insulin was significantly greater than the path coefficient (β=-0.02; P>0.05) from baseline insulin to follow-up BMI in childhood with P<0.001 for the difference in βs. Blacks and whites showed similar patterns of the temporal relationship. The path coefficient (β=0.59; P<0.001) from BMI to insulin in the hypertensive group was significantly greater than that (β=0.24; P<0.001) in normotensive group, with P<0.001 for the difference in βs between these 2 groups. The mediation effect of childhood insulin on the childhood BMI-adult hypertension association was estimated at 21.1% (P<0.001). These findings provide evidence that higher BMI levels precede hyperinsulinemia during childhood, and this 1-directional relation plays a role in the development of hypertension.

Review: Obesity and cardiometabolic syndrome in children

The cardiometabolic syndrome is highly prevalent among overweight youth. The risk of developing the cardiometabolic syndrome is likely triggered or exacerbated by concurrent obesity, unhealthy lifestyle/eating habits, and hormonal changes (puberty). Current screening recommendations include measurement of blood pressure, fasting insulin and glucose, and total cholesterol. However, limiting assessments to these measures underestimates cardiometabolic risk in overweight youth, particularly minorities. Early identification of cardiometabolic risk in its incipient stages may justify early and more aggressive intervention to prevent progression and complications. This review provides rationale for additional assessments to determine cardiometabolic risk in overweight youth and recommends treatment options.

Impact of Adiposity on Incident Hypertension Is Modified by Insulin Resistance in Adults: Longitudinal Observation From the Bogalusa Heart Study

Adiposity and insulin resistance are closely associated with hypertension. This study aims to investigate whether the association between adiposity and hypertension is modified by insulin resistance. The cohort consisted of 1624 middle-aged normotensive black and white adults aged 18 to 43 years at baseline who followed for 16 years on average. Overweight/obesity at baseline was defined as body mass index (BMI) ≥25, and insulin resistance was measured using homeostasis model assessment of insulin resistance. Prevalence of incident hypertension was compared between the insulin-sensitive adiposity and insulin-resistant adiposity groups. The prevalence of incident hypertension was higher in the insulin-resistant adiposity than in the insulin-sensitive adiposity group (32.1% versus 22.1%, P<0.001). In multivariable logistic analyses, adjusted for baseline age, race, sex, follow-up years, and smoking, baseline insulin-resistant obesity was associated with incident hypertension (odds ratio, 1.9; P=0.008). Odds ratios did not differ between blacks and whites (P=0.238). Of note, the odds ratios of BMI associated with hypertension significantly increased with increasing quartiles of baseline homeostasis model assessment (odds ratio, 1.3, 1.1, 1.5, and 2.5 in quartiles I, II, III, and IV, respectively; P=0.006 for trend). Slopes of increasing follow-up blood pressure with baseline BMI, measured as regression coefficients (β), were significantly greater in insulin-resistant than in insulin-sensitive individuals (β=0.74 versus β=0.35 for systolic blood pressure, P=0.004 for difference; β=0.51 versus β=0.23 for diastolic blood pressure, P=0.001 for difference). These findings suggest that insulin resistance has a synergistic effect on the obesity-hypertension association in young adults, indicating that the role of adiposity in the development of hypertension is modified by insulin resistance.

Effect of a 1-Year Obesity Intervention (KLAKS Program) on Preexisting Autonomic Nervous Dysfunction in Childhood Obesity

Childhood obesity may involve autonomic nervous system dysfunction. Whether it improves following weight loss remains unclear. Thirty-one obese children (body mass index standard deviation scores 2.33 ± 0.47; age 11.2 ± 2.0) completed a 1-year lifestyle intervention (KLAKS: Concept Leipzig: Adiposity Therapy for School-Aged Children). Anthropometric/biochemical parameters and autonomic nervous system function (heart rate variability, quantitative pupillography) were assessed at baseline and follow-up. A multivariate model for changes in body mass index standard deviation scores considered age, gender, and changes in autonomic nervous system function. Weight status (Δ body mass index standard deviation scores: 0.16 [0.05, 0.29], P = .008), glycemic control, and free fatty acids (all P < .05) improved after the intervention. Redilation velocity increased by 0.22 mm/s [0.06, 0.38] (P = .008), and changes tended to be negatively associated with Δ body mass index standard deviation scores (P = .08 [-0.61, 0.03]). Relative reflex amplitude (23.4 vs 26.3, P = .004) and constriction velocity (4.97 mm/s vs 5.47 mm/s, P < .001) also improved. Our data provide preliminary evidence that lifestyle-intervention induced improvement of weight status/metabolic risk factors may ameliorate some parameters of autonomic nervous system dysfunction in childhood obesity.

Prevalance of obesity in children with cerebral palsy

INTRODUCTION

Obesity are epidemic among children and adolescents. There is worldwide tendency of increasing prevalence of obesity in children. Cerebral palsy (CP) is leading cause of childhood disability.studies have proposed mechanism of children with disability leading towards obesity and related health risks. So this study is aimed at determining whether such trend of obesity exists in children with CP in terms of BMI and WHR.

STUDY DESIGN

Cross -sectional study.

MATERIALS AND METHODS

PARTICIPANTS

40 children diagnosed as CP age 2-18 years, GMFCS I-IV.

PROCEDURE

BMI; kg/m(2) was calculated from height and weight. WHR was calculated by measuring waist circumference and hip circumference. BMI percentiles were reported according to sex-specific age group standards for growth set by the WHO growth charts.

RESULTS

Out of total CP subjects 40% were found to be underweight, 45%, 7.5% and 7.5% were found to be normal, overweight and obese respectively according to BMI. Whereas 20%, 20% 60% were found to be at high risk, moderate risk and high risk of obesity respectively according to WHR.

CONCLUSION

In our patient population, analysis of BMI and WHR suggests that children with CP have a high rate of overweight and are at risk of overweight, particularly of central obesity.

The one year exercise and lifestyle intervention program KLAKS: Effects on anthropometric parameters, cardiometabolic risk factors and glycemic control in childhood obesity

OBJECTIVE

Regular physical exercise within structured lifestyle programs may improve weight status and minimize metabolic risk factors in childhood obesity. The aim of this study was to evaluate the effect of the one-year combined physical exercise/lifestyle program KLAKS on anthropometric and metabolic parameters and glycemic control in childhood obesity.

MATERIALS AND METHODS

142 overweight/obese (BMI>90th percentile) candidates (7-18years) were enrolled, 115 participants completed the program. Anthropometrics and biochemical parameters were obtained at beginning and completion. An oral glucose tolerance test (OGTT) was performed in a subgroup of participants. Course of glucose and insulin levels within OGTT was correlated with several parameters and is reported here for those who completed the program.

RESULTS

The mean standard deviation scores (SDS) decreased significantly for BMI, waist circumference, waist-to-height ratio (WHtR) and percentage body fat (all p≤0.01). Improved metabolic risk markers included mean glucose levels within an OGTT at follow-up compared to baseline (p<0.0001) and HbA1c (p=0.05) as well as indications of improvement for gamma-glutamyl-transferase and free fatty acids.

CONCLUSIONS

The one-year combined exercise/lifestyle program KLAKS significantly improves markers of obesity and glycemic control. Impaired cardiometabolic risk markers, even subclinical, are also favorably influenced by program participation.

Effect of obesity on linear growth

PURPOSE OF REVIEW

To describe our current understanding of the mechanisms involved in the regulation of linear growth in childhood obesity.

RECENT FINDINGS

The developmental origins hypothesis has focused on low birth weight individuals with subsequent obesity, identifying a cascade of neuroendocrine regulatory factors involved in the progressive increase in body fat and metabolic risk. Yet, tall stature is the common clinical outcome of childhood obesity. Recent data have expanded our understanding of environmental influences on developing systems. Here, we review the elements of neuroendocrine systems contributing to the integration of metabolic controls involved in growth regulation in the obese child with particular emphasis on growth hormone, ghrelin, insulin-like growth factors and insulin.

SUMMARY

Growth patterns of obesity during childhood are well described, documenting increased linear growth in early childhood associated with accelerated pubertal maturation resulting in normal adult height. Despite recent data suggesting that ghrelin and the growth hormone secretagogue receptor, as well as the insulin-like growth factors, their binding proteins and insulin have potential to be mediators of nutrient exposure and linear growth, it remains to be determined how these systems interrelate and determine growth. This is an area of ongoing investigation.

Relationship between Plasma Adiponectin Levels and Metabolic Risk Profiles in Taiwanese Children

OBJECTIVE

Adiponectin, a novel adipokine with antiinflammatory and insulin-sensitizing properties, has an important role in glucose metabolism and is negatively correlated with body fat amount in adults. The purpose of this study was to evaluate the association of plasma adiponectin level with metabolic risk profiles and insulin resistance status among Taiwanese children.

RESEARCH METHODS AND PROCEDURES

We enrolled 1,248 children (608 boys and 640 girls) to ascertain their demographic, anthropometric, and cardiovascular risk factors distribution in Taipei. We measured plasma insulin, adiponectin, and leptin levels by radioimmunoassay (Linco Research Inc, St. Charles, MO). We calculated an insulin resistance index (IRI) using the Homeostasis Model Assessment model and also calculated an insulin resistance syndrome (IRS) summary score for each individual by adding the quartile ranks from the distribution of systolic blood pressure, serum triglyceride, high-density lipoprotein-cholesterol (HDL-C) (inverse), and insulin levels.

RESULTS

In general, the boys had larger BMI, higher systolic blood pressure, serum total cholesterol, and triglyceride, and lower plasma leptin and adiponectin levels than girls. Plasma adiponectin levels were correlated negatively with BMI, leptin, insulin, IRI, and IRS summary score but positively correlated with HDL-C in both boys and girls. In multivariate regression analyses, adiponectin was negatively associated with insulin (girls only), IRI (girls only), and IRS score, and positively associated with HDL-C in both genders even after adjusting for age, BMI, plasma leptin level, and other potential confounders.

DISCUSSION

These data suggest that plasma adiponectin levels were negatively associated with metabolic risk profiles that may have played a protective role in the development of insulin resistance among Taiwanese school children.

Correlates of age onset of type 2 diabetes among relatively young black and white adults in a community: the Bogalusa Heart Study

OBJECTIVE

The risk factors for middle-age onset of type 2 diabetes are well known. However, information is scant regarding the age onset of type 2 diabetes and its correlates in community-based black and white relatively young adults.

RESEARCH DESIGN AND METHODS

This prospective cohort study consisted of normoglycemic (n = 2,459) and type 2 diabetic (n = 144) adults aged 18-50 years who were followed for an average of 16 years.

RESULTS

The incidence rate of the onset of type 2 diabetes was 1.6, 4.3, 3.9, and 3.4 per 1,000 person-years for age-groups 18-29, 30-39, and 40-50 and total sample, respectively. Incidences of diabetes increased with age by race and sex groups (P for trend ≤ 0.01); higher in black females versus white females and blacks versus whites in total sample (P < 0.05). In a multivariable Cox model, baseline parental diabetes (hazard ratio [HR] 5.24) and plasma insulin were significantly associated with diabetes incidence at the youngest age (18-29 years); black race, BMI, and glucose at age 30-39 years; female sex, parental diabetes (HR 2.44), BMI, ratio of triglycerides and HDL cholesterol (TG/HDL-C ratio), and glucose at age 40-50 years; and black race, parental diabetes (HR 2.44), BMI, TG/HDL-C ratio, and glucose in whole cohort. Further, patients with diabetes, regardless of age onset, displayed a significantly higher prevalence of maternal history of diabetes at baseline (P < 0.01).

CONCLUSIONS

In relatively young adults, predictability of baseline cardiometabolic risk factors along with race, sex, and parental history of diabetes for the onset of type 2 diabetes varied by age-group. These findings have implications for early prevention and intervention in relatively young adults.

Prevalence of hyperinsulinemia associated with body mass index, genetic predisposition, and lifestyle in college freshmen students

OBJECTIVE

College lifestyle places an individual at greater risk for the development of insulin resistance (IR) and disease. The aim of this study was to establish a baseline measurement of insulin, and other variables influencing IR in college freshmen.

PARTICIPANTS

Twenty-two men and women, 18 to 19 years of age, during first month of college.

METHODS

Following 12-hour fast, subjects reported to the laboratory for determination of body mass index (BMI) and completion of questionnaire determining ethnicity, family history, and patterns of diet, exercise, and stress. Blood samples were obtained and analyzed for glucose and insulin.

RESULTS

Mean insulin value for men (14.9 ± 1.86 μU/mL) was normal, and that for women (17.3 ± 1.74 μU/mL) was slightly elevated. When subjects were grouped by BMI, genetic predisposition, and summated lifestyle risk, fasting insulin values were significantly different. Eight of 22 subjects were hyperinsulinemic (insulin >19 μU/mL).

CONCLUSION

Hyperinsulinemia is prevalent in this population and merits further investigation and intervention.

Elevated liver function enzymes are related to the development of prediabetes and type 2 diabetes in younger adults: the Bogalusa Heart Study

OBJECTIVE

Elevations in alanine aminotransferase (ALT) and γ-glutamyl transferase (GGT), surrogate markers of liver dysfunction and nonalcoholic fatty liver, are considered as part of metabolic syndrome and related type 2 diabetes. However, information is limited regarding the long-term predictability of ALT and GGT in the development of prediabetes and type 2 diabetes.

RESEARCH DESIGN AND METHODS

In this retrospective cohort study, normoglycemic (n = 874), prediabetic (n = 101), and diabetic (n = 80) adults aged 26-50 years (average age 41.3 years) were followed over an average period of 16 years since their young adulthood (aged 18-38 years, average age 25.1 years), with measurements of cardiometabolic risk factor variables including ALT and GGT.

RESULTS

The follow-up prevalence rate of adult diabetes status by quartiles of baseline ALT and GGT levels showed an adverse trend for both prediabetes (P < 0.05) and diabetes (P < 0.01). In a longitudinal multivariate logistic regression analysis that included anthropometric, hemodynamic, and metabolic variables, as well as alcohol consumption and smoking, individuals with elevated baseline ALT and GGT levels (per 1-SD increment) were 1.16 and 1.20 times, respectively, more likely to develop diabetes (P = 0.05 for ALT and P < 0.01 for GGT); no such associations were noted for prediabetes. Regarding the predictive value of ALT and GGT, the area under the receiver operating curve analysis yielded C values ranging from 0.70 to 0.82, with values significantly higher for diabetes compared with prediabetes.

CONCLUSIONS

These findings in younger adults suggest potential clinical utility of including ALT and GGT as biomarkers in diabetes risk assessment formulations.

Thyroid function in childhood obesity and metabolic comorbidity

Childhood obesity is a worldwide health problem and its prevalence is increasing steadily and dramatically all over the world. Obese subjects have a much greater likelihood than normal-weight children of acquiring dyslipidemia, elevated blood pressure, and impaired glucose metabolism, which significantly increase their risk of cardiovascular and metabolic diseases. Elevated TSH concentrations in association with normal or slightly elevated free T4 and/or free T3 levels have been consistently found in obese subjects, but the mechanisms underlying these thyroid hormonal changes are still unclear. Whether higher TSH in childhood obesity is adaptive, increasing metabolic rate in an attempt to reduce further weight gain, or indicates subclinical hypothyroidism or resistance and thereby contributes to lipid and/or glucose dysmetabolism, remains controversial. This review highlights current evidence on thyroid involvement in obese children and discusses the current controversy regarding the relationship between thyroid hormonal derangements and obesity-related metabolic changes (hypertension, dyslipidemia, hyperglycemia and insulin resistance, nonalcoholic fatty liver disease) in such population. Moreover, the possible mechanisms linking thyroid dysfunction and pediatric obesity are reviewed. Finally, the potential role of lifestyle intervention as well as of therapy with thyroid hormone in the treatment of thyroid abnormalities in childhood obesity is discussed.

Direction of causality between body fat and insulin resistance in children--a longitudinal study (EarlyBird 51)

OBJECTIVE

To investigate the direction of causality in the association between adiposity and insulin resistance in children.

METHODS

Body composition by DEXA, and insulin resistance by HOMA-2 IR were measured annually in 238 children aged from 7-13 years. Longitudinal modelling was used to establish whether baseline and/or trends in adiposity were associated with change in IR or whether, conversely, baseline and/or trends in IR were associated with change in adiposity.

RESULTS

Baseline adiposity was associated with change in IR in the short-term (p < 0.001) but less so in the long-term (p < 0.09) in both genders. Baseline IR was not associated with short-term change in adiposity in either gender (p > 0.42). In the long-term, baseline IR appeared to be positively associated with change in adiposity in boys (p = 0.02) but inversely associated with change in adiposity (the higher the baseline IR, the lower the gain in %fat) in girls (p < 0.001).

CONCLUSIONS

The dominant direction of causality appears to be from adiposity to insulin resistance. In boys, adiposity appears to be both a cause and an effect of IR in the long term. In girls, however, higher insulin resistance appeared to limit further gain in body fat in the long term, an observation consistent with insulin desensitization as an adaptive response to weight gain.

Childhood obesity and cardiovascular disease: links and prevention strategies

The prevalence and severity of pediatric obesity have dramatically increased since the late 1980s, raising concerns about a subsequent increase in cardiovascular outcomes. Strong evidence, particularly from autopsy studies, supports the concept that precursors of adult cardiovascular disease (CVD) begin in childhood, and that pediatric obesity has an important influence on overall CVD risk. Lifestyle patterns also begin early and impact CVD risk. In addition, obesity and other CVD risk factors tend to persist over time. However, whether childhood obesity causes adult CVD directly, or does so by persisting as adult obesity, or both, is less clear. Regardless, sufficient data exist to warrant early implementation of both obesity prevention and treatment in youth and adults. In this Review, we examine the evidence supporting the impact of childhood obesity on adult obesity, surrogate markers of CVD, components of the metabolic syndrome, and the development of CVD. We also evaluate how obesity treatment strategies can improve risk factors and, ultimately, adverse clinical outcomes.

Glycemic status, metabolic syndrome, and cardiovascular risk in children

The metabolic syndrome and adult manifestation of prediabetes and diabetes are major public health problems that begin in childhood. Prevention must be considered as a serious public health issue. Health education and health promotion of school children needs incorporation as a community effort.

Adiposity, fitness and metabolic risk in children: a cross-sectional and longitudinal study

OBJECTIVE

To better understand the early development of cardiovascular disease, we examined the association of adiposity measures and cardiorespiratory fitness (CRF) with baseline values and changes in low-grade chronic inflammation and insulin resistance (IR) in school children.

METHODS

Eighty-three 1(st) and 5(th) grade children from a randomly selected control group of a physical activity intervention study (KISS) were prospectively studied during one academic year. Outcome variables included highly sensitive C-reactive protein (hs-CRP) and homeostasis assessment of IR (HOMA-IR). Adiposity measures included body mass index (BMI), waist circumference and the sum of skinfold thickness at four sites. CRF was assessed by the 20 m shuttle run test. All models were adjusted for age group, sex and pubertal group and included children who had a complete valid dataset for all variables.

RESULTS

Baseline metabolic markers correlated positively with measures of adiposity and inversely with CRF (all p ≤ 0.02). On average, longitudinal changes in hs-CRP concentration increased with high baseline BMI in boys and skinfold thickness in both genders (both p < 0.01). Increases in adiposity had an additional effect on these changes (adjusted R(2) of the models including baseline and change in adiposity 0.49-0.53, p < 0.001). On the other hand, longitudinal changes in HOMA-IR were positively related to changes in BMI and waist circumference (p ≤ 0.03). Increases in HOMA-IR, but not in hs-CRP concentrations, were associated with low baseline CRF (p = 0.01).

CONCLUSION

The relationship of baseline adiposity and CRF with increases in metabolic risk markers may have relevant implications for long-term cardiovascular risk. International Standard Randomised Controlled Trial Number (ISRCTN):

TRIAL REGISTRATION

isrctn.org 15360785.

Pediatric metabolic syndrome predicts adulthood metabolic syndrome, subclinical atherosclerosis, and type 2 diabetes mellitus but is no better than body mass index alone: the Bogalusa Heart Study and the Cardiovascular Risk in Young Finns Study

BACKGROUND

The clinical utility of identifying pediatric metabolic syndrome (MetS) is controversial. This study sought to determine the status of pediatric MetS as a risk factor for adult subclinical atherosclerosis (carotid intima-media thickness [cIMT]) and type 2 diabetes mellitus (T2DM) and compare and contrast this prediction with its individual components.

METHODS AND RESULTS

Using data from the population-based, prospective, observational Bogalusa Heart and Cardiovascular Risk in Young Finns studies, we examined the utility of 4 categorical definitions of youth MetS and their components in predicting adult high cIMT and T2DM among 1781 participants aged 9 to 18 years at baseline (1984 to 1988) who were then examined 14 to 27 years later (2001-2007) when aged 24 to 41 years. Youth with MetS were at 2 to 3 times the risk of having high cIMT and T2DM as adults compared with those free of MetS at youth. Risk estimates with the use of high body mass index were similar to those of MetS phenotypes in predicting adult outcomes. Comparisons of area under the receiver operating characteristic curve and net reclassification index suggested that prediction of adult MetS, high cIMT, and T2DM in adulthood with the use of youth MetS was either equivalent or inferior to classification based on high body mass index or overweight and obesity.

CONCLUSIONS

Youth with MetS are at increased risk of meaningful adult outcomes; however, the simplicity of screening for high BMI or overweight and obesity in the pediatric setting offers a simpler, equally accurate alternative to identifying youth at risk of developing adult MetS, high cIMT, or T2DM.

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.

Metabolic risk varies according to waist circumference measurement site in overweight boys and girls

OBJECTIVES

To compare waist circumference (WC) values measured at 4 commonly recommended sites and examine the relationships between WC sites and markers of metabolic risk in a sample of overweight boys and girls referred for weight management.

STUDY DESIGN

Overweight (mean body mass index percentile, 98.7; SD, 1.0) children and adolescents (n = 73; 41 girls, 32 boys; mean age, 12.5 years; SD, 2.6 years) had WC measured at 4 sites: iliac crest (WC1), narrowest waist (WC2), midpoint between the floating rib and iliac crest (WC3), and umbilicus (WC4). Height, weight, fasting insulin level, glucose level, cholesterol level, and systolic and diastolic blood pressure were also measured.

RESULTS

Overall, WC1 (108.5 cm; SD, 16.3 cm) was greater than WC2 (97.4 cm; SD, 13.6 cm; P < .003), and WC2 was smaller than WC3 (104.3 cm; SD, 15.3 cm; P = .02) and WC4 (108.7 cm; SD, 16.2 cm; P < .0003). With logistic regression, WC2 and WC3 were revealed to be more consistently associated with metabolic syndrome by using 3 different definitions.

CONCLUSION

In our sample, we observed differences in 4 commonly recommended WC measurement sites and found that all sites were not equivalently associated with metabolic risk. Our findings provide preliminary support suggesting that WC measured at the narrowest waist and midpoint between the floating rib and iliac crest may represent the measurement sites most closely associated with metabolic risk in overweight boys and girls.

Central obesity as a precursor to the metabolic syndrome in the AusDiab study and Mauritius

Evidence from epidemiologic studies that central obesity precedes future metabolic change and does not occur concurrently with the appearance of the blood pressure, glucose, and lipid abnormalities that characterize the metabolic syndrome (MetS) has been lacking. Longitudinal surveys were conducted in Mauritius in 1987, 1992, and 1998, and in Australia in 2000 and 2005 (AusDiab). This analysis included men and women (aged > or = 25 years) in three cohorts: AusDiab 2000-2005 (n = 5,039), Mauritius 1987-1992 (n = 2,849), and Mauritius 1987-1998 (n = 1,999). MetS components included waist circumference, systolic blood pressure, fasting and 2-h postload plasma glucose, high-density lipoprotein (HDL) cholesterol, triglycerides, and homeostasis model assessment of insulin sensitivity (HOMA-S) (representing insulin sensitivity). Linear regression was used to determine which baseline components predicted deterioration in other MetS components over 5 years in AusDiab and 5 and 11 years in Mauritius, adjusted for age, sex, and ethnic group. Baseline waist circumference predicted deterioration (P < 0.01) in four of the other six MetS variables tested in AusDiab, five of six in Mauritius 1987-1992, and four of six in Mauritius 1987-1998. In contrast, an increase in waist circumference between baseline and follow-up was only predicted by insulin sensitivity (HOMA-S) at baseline, and only in one of the three cohorts. These results suggest that central obesity plays a central role in the development of the MetS and appears to precede the appearance of the other MetS components.

Distribution and cardiovascular risk correlates of hemoglobin A(1c) in nondiabetic younger adults: the Bogalusa Heart Study

Excess glycated hemoglobin (HbA(1c)), an indicator of long-term glucose homeostasis, is recognized as a risk factor for cardiovascular (CV) disease and mortality even among persons without diabetes. However, information is scant regarding its distribution and correlates of CV risk in nondiabetic younger adults. This aspect was examined in a biracial (black-white) community-based sample of 1111 younger adults (mean age: 36.2 years; 71% white, 43% male) enrolled in the Bogalusa Heart Study. Blacks vs whites and women vs men had higher HbA(1c) values (P < .0001). In bivariate analysis adjusted for age, race, sex, and smoking status, significant adverse trends were noted for body mass index, waist circumference, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol (HDL-C), total cholesterol to HDL-C ratio, insulin, glucose, and homeostasis model assessment of insulin resistance across HbA(1c) quartiles; trends were not significant for mean arterial blood pressure, triglycerides, C-reactive protein, adiponectin, and estimated glomerular filtration rate. In multivariate analysis, besides race and sex, total cholesterol to HDL-C ratio and waist circumference were independent correlates of HbA(1c). Furthermore, the prevalence of excess (top decile) HbA(1c) was 1.6-fold (P < .05) higher among those with metabolic syndrome defined by the National Cholesterol Education Program Adult Treatment Panel III and 2.1-fold (P < .01) and 1.5-fold (P < .05) higher, respectively, among those with positive parental history of CV disease and type 2 diabetes mellitus. These findings underscore the potential value of HbA(1c) in risk assessments of CV disease and type 2 diabetes mellitus in nondiabetic, apparently "healthy" younger adults.

Evidence for association between insulin resistance and premature carotid atherosclerosis in childhood obesity

The present study was undertaken to determine the presence and predictors of the subclinical atherosclerosis in obese children. Fifty obese children [mean age: 11.7 +/- 2.5 y, mean body mass index (BMI): 28.2 +/- 4.0 kg/m] and 50 age- and sex-matched healthy nonobese controls (mean age: 11.4 +/- 3.73 y, mean BMI: 17.6 +/- 3.0 kg/m) were enrolled in the present study. Oral glucose tolerance test was performed to all obese subjects. Common carotid artery intima-media thickness (IMT) was measured by high-resolution B-mode ultrasonography. Carotid artery IMT was significantly increased (0.0476 +/- 0.007 versus 0.033 +/- 0.011 cm; p < 0.001) in the obese group. There were significant relations between carotid artery IMT and insulin sensitivity indexes derived from fasting samples (fasting glucose to insulin ratio (FGIR; p = 0.004, r = -0.404), quantitative insulin-sensitivity check index (QUICK-I; p = 0.002, r = -0.401) and homeostasis model assessment of insulin resistance (HOMA-IR; p = 0.034, r = 0.300) in the obese group. In a multivariate regression model, QUICK-I emerged as independent correlates for mean IMT in obese children with the total variance explained being 20.7% (beta = -0.58, p < 0.001). We concluded that insulin resistance is an independent risk factor for increased carotid artery IMT in obese children.

Metabolic syndrome in a multiethnic sample of school children: implications for the pediatric nurse

There is lack of translational work that may assist the pediatric nurse in identifying the child who is at risk for metabolic syndrome. Early identification of the syndrome could assist pediatric health care providers in intervening and in lowering child health risks. Fasting serum insulin, metabolic syndrome criteria, and dietary intake were examined in a multiethnic sample of children aged 9-15 years. Forty-seven percent had two or more risk factors for metabolic syndrome, and 28% had three or more risk factors. Insulin levels were negatively correlated with the recommended dietary allowance. A regression model, including gender, age, race, body mass index, serum glucose, high-density lipoprotein cholesterol, triglycerides, and blood pressure, explained 48% of insulin variance.

Obesity—A Critical Issue in Preventive Cardiology: The Bogalusa Heart Study

Obesity has become a major public health problem in the United States, with a marked upward trend occurring over the past three decades. It plays a critical role in the development of cardiovascular risk factors that mediate the evolution of asymptomatic cardiovascular disease. Longitudinal observations of children, adolescents, and young adults enrolled in the Bogalusa Heart Study show that obesity persists over time and is linked to the clustering of components of metabolic syndrome including hyperinsulinemia/insulin resistance, dyslipidemia, and hypertension, thereby creating a long-term burden of cardiovascular risk beginning in childhood. This burden is associated with subclinical and adverse structural and functional changes of the cardiovascular system in youth. Ultimately, these changes can result in morbidity from disease, as exemplified in the Framingham Heart Study. Obesity is governed by the interplay of both genetic and environmental factors. Unlike genetic factors, lifestyle behaviors are amenable to modification. Since obesity is so widespread and underlying cardiovascular disease is so prevalent, health education beginning in childhood is suggested as an approach to prevention.

Childhood overweight and cardiovascular disease risk factors: the National Heart, Lung, and Blood Institute Growth and Health Study

OBJECTIVE

To estimate the prevalence and incidence of overweight in African-American and Caucasian girls, and to examine associations between adolescent overweight and cardiovascular disease (CVD) risk factors.

STUDY DESIGN

In the National Heart, Lung and Blood Institute Growth and Health Study (NGHS), annual measurements were obtained from girls followed longitudinally between age 9 or 10 and 18 years; self-reported measures were obtained at age 21 to 23 years. A total of 1166 Caucasian girls and 1213 African-American girls participated in the study. Childhood overweight as defined by the Centers for Disease Control and Prevention (CDC) was the independent variable of primary interest. Measured outcomes included blood pressure and lipid levels.

RESULTS

Rates of overweight increased through adolescence from 7% to 10% in the Caucasian girls and from 17% to 24% in the African-American girls. The incidence of overweight was greater at age 9 to 12 than in later adolescence. Girls who were overweight during childhood were 11 to 30 times more likely to be obese in young adulthood. Overweight was significantly associated with increased percent body fat, sum of skinfolds and waist circumference measurements, and unhealthful systolic and diastolic blood pressure, high-density lipoprotein cholesterol, and triglyceride levels.

CONCLUSION

A relationship between CVD risk factors and CDC-defined overweight is present at age 9.

The entero-insular axis and adipose tissue-related factors in the prediction of weight gain in humans

Obesity has now reached epidemic proportions. Epidemiological studies in the past decades have shown that adults gain weight and adiposity from the early twenties until their sixties. In the paediatric population, growing numbers of children and adolescents put on unhealthy weight. Many environmental, socio-economical and biological determinants that predispose to weight gain have been identified thus far. The aim of the present review is to summarize the current knowledge on the role of the circulating levels of adipokines and other entero-insular hormones and biological markers of obesity to predict weight gain in humans. The review focuses on relationship between hormonal and biochemical markers (insulin, insulin-like growth factors, gastrointestinal hormones, leptin, adiponectin, resistin, inflammatory proteins and cytokines) and weight gain in prospective studies. The complex relationships displayed by these hormonal factors with future weight gain in humans are critically reviewed and integrative models are proposed. Overall, most of the studies reported to date made adjustments for baseline body mass index but failed to consider dietary intake and physical activity as confounding factors. Outstanding questions are raised and new directions for future prospective studies are proposed in order to improve our understanding of the role of biological determinants of energy balance and development of obesity in humans.

Changes in Metabolic Syndrome Variables Since Childhood in Prehypertensive and Hypertensive Subjects

That essential hypertension is associated with metabolic syndrome is known. However, information is scant regarding the course of development of adverse levels of blood pressure and other risk variables of metabolic syndrome in youth at risk for developing hypertension. This aspect was studied, retrospectively, in a community-based cohort of normotensive (n=2206), prehypertensive (n=721), and hypertensive (n=328) subjects examined serially during childhood (4 to 11 years), adolescence (12 to 18 years), and adulthood (19 to 42 years). Prehypertensive subjects versus normotensive subjects had significantly higher body mass index and subscapular skinfold, systolic (SBP) and diastolic (DBP) blood pressures, and triglycerides beginning in childhood; higher glucose in adolescence; and higher low-density lipoprotein cholesterol, fasting insulin, and insulin resistance index in adulthood. Hypertensive subjects versus normotensive subjects had higher adiposity measures, SBP and DBP, glucose, and triglycerides beginning in childhood; higher insulin and insulin resistant index in childhood and adulthood; and lower high-density lipoprotein, cholesterol in adulthood. Most of these variables progressed adversely at an increased rate in prehypertensive and hypertensive subjects. In a multivariate analysis, adverse changes in adiposity, SBP, and DBP were independently associated with prehypertensive status; and adverse changes in adiposity, SBP and DBP, insulin resistant index, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglycerides with hypertension status. As young adults, prehypertensive and hypertensive subjects showed significantly higher prevalence of obesity, hyperinsulinemia, hyperglycemia, and dyslipidemias. Thus, excess adiposity and blood pressure beginning in childhood and accelerated adverse longitudinal changes in risk variables of metabolic syndrome through young adulthood characterize the early natural history of hypertension.

Distribution and metabolic syndrome correlates of plasma C-reactive protein in biracial (black-white) younger adults: the Bogalusa Heart Study

The association between plasma C-reactive protein (CRP), a marker of systemic inflammation, and the metabolic syndrome is well recognized. However, information is scant regarding the component of metabolic syndrome that is critical in modulating CRP levels in younger adults. This aspect was examined in a biracial (black-white) community-based sample of 1083 younger adults (mean age, 36.1 years; 71% white, 45% male) enrolled in the Bogalusa Heart Study. Plasma CRP along with metabolic syndrome variables were measured. CRP levels showed a significant race (black>white, P=.01) and sex (female>male, P=.0001) differences, and related to measures of obesity (body mass index [BMI], waist circumference, and sagittal diameter), blood pressure (systolic, diastolic, and mean arterial blood pressure), lipoproteins (low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, total cholesterol-high-density lipoprotein cholesterol ratio), glucose homeostasis (insulin, glucose, homeostasis model assessment of insulin resistance), and uric acid, after adjusting for age, race, sex, and cigarette smoking. Furthermore, CRP levels increased with increasing number of metabolic syndrome risk factors, as defined by the National Cholesterol Education Program Adult Treatment Panel III, regardless of race and sex (P for trend<0001). In multivariate analysis, using 3 separate models for different obesity measures, obesity was the major contributor to the explained variance in each model with BMI, waist, and sagittal diameter contributing 17.0%, 13.4%, and 17.1% of the variance, respectively. In contrast, homeostasis model assessment of insulin resistance contributed 1.2%, 0.3%, and 0% to the explained variance in the models with BMI, waist, and sagittal diameter, respectively. In conclusion, CRP levels differ among race and sex groups and correlate to metabolic syndrome variables in younger adults. In addition, these findings strongly suggest that although obesity and insulin resistance are the main underlying features of the metabolic syndrome, the former appears to be the major mediator of CRP levels, which has important health implications.