Associations between Fatness, Fitness, IGF and IMT among Obese Korean Male Adolescents

Relationship between insulin-like growth factor-1, insulin resistance and metabolic profile with pre-obesity and obesity in children

OBJECTIVES

Childhood obesity is a serious medical condition with alarmingly high rates worldwide. There is controversy regarding the relationship between insulin-like growth factor-1 (IGF-1) and pediatric obesity. We investigated the relationship between IGF-1, insulin resistance and metabolic profile with childhood pre-obesity/obesity.

METHODS

The study involved 201 children aged 7-15 years, divided in three groups according to their nutritional status (International Obesity Task Force criteria): normal-weight (n=84), pre-obese (n=82), obese (n=35). Laboratory IGF-1, insulin, fasting blood glucose (FBG), lipid profile, alanine-aminotransferase (ALT), uric acid (UA), anthropometric and body composition parameters were analyzed. Body mass index and IGF-1 standard deviation score (SDS), waist-to-height ratio (WtHR) and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) score were calculated.

RESULTS

Pre-obese/obese children had significantly higher IGF-1 SDS, FBG, insulin, HOMA-IR, UA, ALT, triglycerides, and lower high-density lipoprotein cholesterol (HDL-c); obese group had higher WtHR and low-density lipoprotein cholesterol (LDL-c) compared to controls (p<0.05). In obese group, IGF-1 SDS was positively correlated with fat free/muscle mass, total body water (p<0.05) and negatively correlated with LDL-c (p<0.05). In pre-obese/obese HOMA-IR and insulin were positively correlated with age, total body fat (TBF) (p<0.05) and negatively correlated with HDL-c (pre-obese) (p<0.05). Multivariate ordinal logistic regression analyses showed that IGF-1 SDS (OR=1.94; 95%CI: 1.21-3.11), TBF (OR=1.37; 95%CI: 1.21-1.54) were predictors of nutritional status (p<0.001). FBG (OR=42.39; 95%CI: 2.31-77.2) and UA (OR=1.03; 95%CI: 1.01-1.05) were predictors of IR (p<0.001).

CONCLUSIONS

IGF-1 SDS and TBF were predictors of nutritional status. Further studies are required to clarify the role of IGF-1 in pathophysiology of obesity and its comorbidities.

Oxidative Stress and Inflammation, Key Targets of Atherosclerotic Plaque Progression and Vulnerability: Potential Impact of Physical Activity

Atherosclerosis, a complex cardiovascular disease, is a leading cause of mortality and morbidity worldwide. Oxidative stress and inflammation are both involved in the development of atherosclerotic plaque as they increase the biological processes associated with this pathology, such as endothelial dysfunction and macrophage recruitment and adhesion. Atherosclerotic plaque rupture leading to major ischemic events is the result of vulnerable plaque progression, which is a result of the detrimental effect of oxidative stress and inflammation on risk factors for atherosclerotic plaque rupture, such as intraplaque hemorrhage, neovascularization, and fibrous cap thickness. Thus, both are key targets for primary and secondary interventions. It is well recognized that chronic physical activity attenuates oxidative stress in healthy subjects via the improvement of antioxidant enzyme capacities and inflammation via the enhancement of anti-inflammatory molecules. Moreover, it was recently shown that chronic physical activity could decrease oxidative stress and inflammation in atherosclerotic patients. The aim of this review is to summarize the role of oxidative stress and inflammation in atherosclerosis and the results of therapeutic interventions targeting them in both preclinical and clinical studies. The effects of chronic physical activity on these two key processes are then reviewed in vulnerable atherosclerotic plaques in both coronary and carotid arteries.

Carotid Intima-Media Thickness but Not Carotid Artery Plaque in Healthy Individuals Is Linked to Lean Body Mass

Background Lean body mass has been identified as a key determinant of left ventricular mass and wall thickness. However, the importance of lean body mass or other body-size measures as normative determinants of carotid intima-media thickness (cIMT), a widely used early indicator of atherosclerosis, has not been well established. Methods and Results Carotid artery ultrasound measurements of cIMT and carotid artery plaque burden (derived from plaque number and maximum size) and measurements of body size, including height, body mass index, weight, body fat proportion, and lean body mass ([1-body fat proportion]×weight), were recorded in 25 020 participants from 10 regions of China. Analyses were restricted to a healthy younger subset (n=6617) defined as never or long-term ex-regular smokers aged <60 years (mean age, 50) without previous ischemic heart disease, stroke, diabetes mellitus, or hypertension and with plasma non-high-density lipoprotein cholesterol <4 mmol/L. Among these 6617 participants, 86% were women (because most men smoked) and 9% had carotid artery plaque. In both women and men separately, lean body mass was strongly positively associated with cIMT, but was not associated with plaque burden: overall, each 10 kg higher lean body mass was associated with a 0.03 (95% CI, 0.03-0.04) mm higher cIMT (P=5×10-33). Fat mass, height, and other body-size measures were more weakly associated with cIMT. Conclusions The strong association of lean body mass with cIMT, but not with plaque burden, in healthy adults suggests a normative relationship rather than reflecting atherosclerotic pathology. Common mechanisms may underlie the associations of lean body mass with cIMT and with nonatherosclerotic vascular traits.

Protein intake in infancy and carotid intima media thickness at 5 years--a secondary analysis from a randomized trial

BACKGROUND

Nutrition in childhood has an influence on the cardiovascular function later on in life. European Childhood Obesity Project is a multicenter, randomized clinical intervention trial examining the effect of early protein intake on later health outcomes, particularly adiposity and related disorders. The aim of the study was to examine the effect of nutritional intervention--different protein intake in infancy on carotid intima-media thickness (cIMT) at 5 years. The association of cardiovascular risk factors with cIMT was also assessed.

METHODS

Healthy term formula-fed infants in five European countries were enrolled either to the higher (HP) or to the lower (LP) protein group. Observational group consisted of breastfed infants. Plasma insulin, glucose, lipid profile, IGF-1, apolipoprotein A1 and B were measured as well as anthropometric parameters of parents and a child, blood pressure and physical activity.

RESULTS

No difference in cIMT between HP and LP group was observed. Insulin, HOMA-IR index and total IGF-1 were positively associated with cIMT but after adjustment for confounders only an inverse association between ApoA1 and positive between ApoB/ApoA1 and cIMT were significant.

CONCLUSION

High versus low protein intake in infancy does not influence cIMT at 5 years. cIMT in healthy children at 5 years is associated with their apolipoprotein profile.

High prevalence of cardiometabolic risk factors in Hispanic adolescents: correlations with adipocytokines and markers of inflammation

This study assessed the association of cardiometabolic risk factors with systemic inflammation, insulin resistance, and adypocytokines in a Hispanic adolescent subgroup. A clinic-based sample of 101 Puerto Rican adolescents, 48 of whom were overweight or obese based on body mass index percentiles for age and sex, was recruited during 2010. Data were collected through interviews, blood pressure and anthropometric measurements, and blood drawing. Overall prevalence of the metabolic syndrome was 16.8 % and increased to 37.5 % among overweight/obese youth. The overweight/obese group exhibited significantly (p < 0.05) higher values for abdominal obesity measures, systolic blood pressure, triglycerides, insulin resistance, C peptide, high-sensitivity C reactive protein, fibrinogen, leptin, and IL-6 and lower levels of high density lipoprotein cholesterol, adiponectin, and IGF-1. Total adiponectin significantly correlated with most cardiovascular risk factors independent of sex, Tanner stage, and adiposity. Altered cardiometabolic and adipocytokine profiles were present in this Hispanic subgroup, reinforcing the need to strengthen strategies addressing childhood obesity.

Cross-sectional and longitudinal relation of IGF1 and IGF-binding protein 3 with lipid metabolism

BACKGROUND

Previous intervention studies in patients with GH disorders suggested an impact of IGF1 and IGF-binding protein 3 (IGFBP3) on lipid metabolism, whereas population-based studies revealed conflicting results. Therefore, we aimed to assess the cross-sectional and longitudinal associations between IGF1 or IGFBP3 serum levels and lipids (total, LDL, or HDL cholesterol and triglycerides) in a large-scale study.

METHODS

Data of 2935 subjects (1356 women) from the population-based Study of Health in Pomerania (SHIP) were used. ANOVA, quantile regression, and logistic regression models adjusted for age, waist circumference, physical activity, and alcohol consumption were performed.

RESULTS

In cross-sectional analyses, we detected that IGF1 and IGFBP3 levels were positively related to total and LDL cholesterol and inversely related to HDL cholesterol in both sexes. Furthermore, IGFBP3 levels showed a positive relationship to triglycerides. In total, IGFBP3 levels were more strongly associated to lipids than IGF1. In longitudinal analysis, we found no influence of baseline IGF1 or IGFBP3 serum concentration on incidentally elevated or reduced lipid levels. However, the positive relationship between IGFBP3 and incidentally elevated triglycerides barely missed statistical significance in women.

CONCLUSION

The present study showed strong cross-sectional associations between IGF1 or IGFBP3 and lipids, whereas no longitudinal relationships were revealed. Therefore, our findings suggest IGF1 and IGFBP3 as a risk marker rather than a risk factor for alterations in lipid metabolism. Further studies are needed to elucidate the mechanisms underlying the association between the GH/IGF axis and lipid metabolism.

Prevalence and trend of dyslipidaemia from 1996 to 2006 among normal and overweight adolescents in Taiwan

OBJECTIVES

To evaluate the trend of dyslipidaemia from 1996 to 2006 and examine its relationship with weight status among adolescents in Taiwan.

DESIGN

2 cross-sectional surveys were conducted in 1996 and 2006.

SETTING

The junior high schools in Taipei.

PARTICIPANTS

After multistage sampling, total of 1500 and 1283 junior high school students were chosen in 1996 and 2006. After excluding missing data, a total of 1353 (676 boys and 677 girls) and 1203 (585 boys and 618 girls) children were included in the final analyses in 1996 and 2006.

OUTCOME MEASURES

Anthropometric measures as body height and weight were measured, and body mass index (BMI) was calculated. Blood lipid profiles as total cholesterol, triglyceride, high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol were measured.

RESULTS

From 1996 to 2006, the prevalence of dyslipidaemia and hypercholesterolaemia significantly increased from 13% (95% CI 11.3% to 15.0%) to 22.3% (95% CI 20.0% to 24.7%) and 6.2% (95% CI 5.0% to 7.6%) to 13.8% (95% CI 11.9% to 15.9%), respectively. The prevalence of hypertriglyceridaemia and low HDL-C dyslipidaemia increased from 3% (95% CI 1.8% to 4.5%) to 4.3% (95% CI 2.8% to 6.2%) and 6.5% (95% CI 4.8% to 8.6%) to 11.6% (95% CI 9.1% to 14.5%), with significance seen only in boys. When compared with normal weight participants, overweight boys and girls faced a 2-fold and 1.6-fold increased risk of dyslipidaemia, respectively, in the 2006 study. The increased risk of low HDL-C dyslipidaemia for overweight participants was 2.6-fold and 7.2-fold in boys and girls, respectively. In 2006, each unit increment of BMI was associated with 28%, 13% and 13% risk of hypertriglyceridaemia, low HDL-C and dyslipidaemia for boys, and 25% risk of low HDL-C dyslipidaemia in girls.

CONCLUSIONS

The prevalence of dyslipidaemia had increased significantly for boys and girls in normal weight and overweight adolescents. Early screening of dyslipidaemia and weight intervention programmes in adolescents will be the key to prevent dyslipidaemia and cardiovascular-related comorbidities.

Endothelial wall thickness, cardiorespiratory fitness and inflammatory markers in obese and non-obese adolescents

BACKGROUND

Increased carotid intima-media thickness (c-IMT) is considered a marker of early-onset atherosclerosis and it has been found in obese children and adolescents, but the risk factors associated with this population remain to be elucidated.

OBJECTIVE

To compare and verify the relationship between c-IMT, metabolic profile, inflammatory markers, and cardiorespiratory fitness in obese and non-obese children and adolescents.

METHOD

Thirty-five obese subjects (19 boys) and 18 non-obese subjects (9 boys), aged 10-16 years, were included. Anthropometry, body composition, blood pressure, maximal oxygen consumption (VO2max), and basal metabolic rate were evaluated. Serum glucose, insulin, homeostasis model assessment of insulin resistance (HOMA-IR), blood lipids, C-reactive protein (CRP), and adiponectin were assessed. c-IMT was measured by ultrasound.

RESULTS

The results showed that c-IMT, triglycerides, insulin, HOMA-IR, and CRP values were significantly higher in the obese group than in the non-obese group, and high-density lipoprotein cholesterol (HDL-c), adiponectin, and VO2max values were significantly lower in the obese group than in the non-obese group. The c-IMT was directly correlated with body weight, waist circumference, % body fat, and HOMA-IR and inversely correlated with % free fat mass, HDL-c, and VO2max.

CONCLUSIONS

Our findings show that c-IMT correlates not only with body composition, lipids, insulin resistance, and inflammation but also with low VO2max values in children and adolescents.

Association between insulin-like growth factor-1, measures of overnutrition and undernutrition and insulin resistance in black adolescents living in the North-West Province, South Africa

OBJECTIVE

To determine if insulin-like growth factor-1 (IGF-1) is a significant predictor of body fat percentage (%BF), lean body mass, and insulin resistance (IR) in black adolescents presenting with overnutrition and undernutrition.

METHODS

A cross-sectional study was undertaken in 181 adolescents (111 girls, 70 boys, 13-20 years old) from a low socio-economic population in the North-West Province, South Africa. Anthropometric measurements were performed, and %BF and lean mass were assessed by air displacement plethysmography. Serum glucose, leptin, insulin, IGF-1 and IGF-binding protein-3 (IGFBP-3) were measured and homeostasis model assessment of IR (HOMA-IR) was calculated. Predictors of body composition and HOMA-IR were determined in multivariate linear regressions.

RESULTS

Of the boys, 31% had a %BF >20%, whereas 42% of girls had a %BF >30%. Furthermore, 17.1% male and 18.9% female adolescents were stunted, indicating overnutrition and undernutrition in the same group. IGF-1 showed a negative association with %BF in both sexes, and a positive correlation with height-for-age z-score (HAZ) and lean mass, respectively, in the boys. IGF-1 correlated positively and physical activity correlated negatively with fasting insulin and HOMA-IR in the girls. In both sexes, leptin had the strongest association with %BF in multiple regressions. Leptin and Tanner stage were significant predictors of HOMA-IR in girls, but not in boys.

CONCLUSIONS

IGF-1 was positively associated with lean mass and HAZ in boys, indicating a beneficial relationship with linear growth, but with IR in the girls, indicating possible adverse metabolic effects in the presence of high %BF and physical inactivity.

Relationship of serum insulin-like growth factor I (IGF-I) with nutritional status in pediatric patients with malignant diseases--a single Romanian center experience

The aim of this study was to analyze insulin-like growth factor I (IGF-I) serum level in pediatric patients with cancer compared with pediatric patients with nononcological diseases and to assess the relationship between IGF-I and nutritional status of oncological patients. From January 2009 to July 2012, we assessed 151 consecutively hospitalized patients in a tertiary emergency pediatric hospital. The patients were divided into two groups: group I, consisting of patients with malignant diseases (64 patients), and group II, the control group, consisting of 87 age- and gender-matched patients with different pediatric diseases. The anthropometric parameters (weight, height, body mass index, middle upper arm circumference (MUAC), and tricipital skinfold thickness (TST) and biochemical parameters (proteins, albumin, and total IGF-I) were comparatively evaluated at the diagnosis and after intensive chemotherapy in the malignant group. Anthropometric and biochemical parameters in group I were significantly different from those in group II for height, MUAC, TST, total proteins, and albumin (p < 0.05). Twenty-five out of 64 patients with malignant diseases and 5 out of 87 patients in the control group had malnutrition. IGF-I in patients with cancer was much lower than in the control group (median 48.3 ng/ml, range 25.00-662.00 ng/ml vs 129.00 ng/ml, range 25.00-745.00 ng/ml) (p = 0.014). We found a positive correlation between IGF-I, MUAC, and TST at the diagnosis of the malignant disease. Also, we identified positive correlations between IGF-I, protein, and albumin. Serum IGF-I levels in cancer patients were significantly lower at diagnosis than after chemotherapy (48.3 ng/ml, range 25.00-662.00 ng/ml vs 110.0 ng/ml, range 25.00-573.00 ng/ml; p = 0.04).

CONCLUSION

IGF-I seems to be an accurate biochemical parameter used in malnutrition assessment of children with cancer. IGF-I correlated with the anthropometric parameters of the arm, serum protein, and albumin. These parameters most accurately characterize the nutritional status.

Gene x environment interactions impact endometrial function and the menstrual cycle: PROGINS, life history, anthropometry, and physical activity

OBJECTIVES

We assessed the impact of a high frequency, functionally significant allelic variant of the progesterone receptor gene (PROGINS) on endometrial function and menstrual cycle characteristics. Further we asked whether PROGINS moderates the impact of life history characteristics, anthropometric measures, and physical activity on endometrial function.

METHODS

Fifty-two women were genotyped for the PROGINS variant, provided life history information, and had anthropometric measurements made. Women monitored their menstrual bleeding for three cycles, performed mid-cycle urinary ovulation tests, and recorded physical activity. A subset of women provided daily saliva samples and had mid-luteal endometrial thickness measurements taken during the third menstrual cycle. Salivary progesterone was assayed using ELISAs. The direct impact of PROGINS on endometrial and menstrual cycle characteristics was determined via independent t-tests with Bonferroni correction. Interactions between PROGINS and covariates were assessed by moderated regression.

RESULTS

PROGINS did not directly impact any indicator of endometrial function. However, PROGINS caused an increase in menstrual cycle length with increasing mid-luteal progesterone levels; the opposite relationship was present in noncarriers (P < 0.05). Additionally, PROGINS interacted with four of six anthropometric measures (BMI, waist circumference, height, and waist-hip ratio) to impact endometrial function, however, interactions between PROGINS and life history variables, or physical activity was limited.

CONCLUSIONS

The gene x environment interactions we report suggest that PROGINS alters endometrial sensitivity to maternal energetic condition. Thus, the possibility of genetically-based variation in sensitivity to energetic stress should be considered in future adaptive models of women's reproduction.

Insulin-like growth factor-I (IGF-I) and clinical nutrition

IGF-I (insulin-like growth factor-I) is a peptide hormone, produced predominantly by the liver in response to pituitary GH (growth hormone), which is involved in a wide variety of physiological processes. It acts in an endocrine, paracrine and autocrine manner to promote growth. The production of IGF-I signals the availability of nutrients needed for its anabolic actions. Recently, there has been growing interest in its role in health and disease. IGF-I has long been known to be regulated by nutrition and dysregulated in states of under- and over-nutrition, its serum concentrations falling in malnutrition and responding promptly to refeeding. This has led to interest in its utility as a nutritional biomarker. A considerable evidence base supports utility for measurement of IGF-I in nutritional contexts. Its concentration may be valuable in providing information on nutritional status, prognosis and in monitoring nutritional support. However, it is insufficiently specific for use as a screening test for under nutrition as its serum concentration is influenced by many factors other than nutritional status, notably the APR (acute-phase response) and endocrine conditions. Concentrations should be interpreted along with clinical findings and the results of other investigations such as CRP (C-reactive protein). More recently, there has been interest in free IGF-I which holds promise as a nutritional marker. The present review covers nutritional regulation of IGF-I and its dysregulation in disease, then goes on to review recent studies supporting its utility as a nutritional marker in clinical contexts. Although not currently recommended by clinical guidelines, it is likely that, in time, measurement of IGF-I will become a routine part of nutritional assessment in a number of these contexts.

Higher body mass index leads to longer operative time in total knee arthroplasty

Obesity has been shown to be a risk factor for degenerative knee arthritis and its incidence is increasing in epidemic proportions. Obesity has also been shown to be a risk factor for surgical complications associated with total knee replacement (TKR) surgery. There have been no prior investigations examining the relationship between body mass index (BMI) and surgical time during TKR. Two hundred and seventy three patients were evaluated and stratified by BMI. There was a direct linear relationship between BMI and operative time. In addition, the higher the BMI group, the younger the age at surgery, and obese class III patients experienced a higher rate of early post-operative complication. Therefore, patients should be counseled that obesity prior to TKR surgery might lead to a longer operative time and any sequelae associated with further exposure of the operative wound, especially with regard to higher rates of prosthetic joint infection (PJI).

The insulin-like growth factor system and nutritional assessment

Over recent years there has been considerable interest in the role of the insulin-like growth factor (IGF) system in health and disease. It has long been known to be dysregulated in states of under- and overnutrition, serum IGF-I levels falling in malnourished patients and responding promptly to nutritional support. More recently, other proteins in this system have been observed to be dysregulated in both malnutrition and obesity. Currently no biochemical marker is sufficiently specific for use in screening for malnutrition, but levels may be valuable in providing information on nutritional status and in monitoring of nutritional support. All have limitations as nutritional markers in that their serum levels are influenced by factors other than nutritional status, most importantly the acute phase response (APR). Levels should be interpreted along with clinical findings and the results of other investigations such as C-reactive protein (CRP). This paper reviews data supporting the use of proteins of the IGF system as nutritional markers.