Moderating Role of Physical Fitness in the Association Between TV Time and Adiposity Parameters in Adolescents.

PURPOSE: To identify whether physical fitness (PF) components play a moderating role in the relationship between TV time and adiposity levels. DESIGN: Cross-sectional study. SETTING: Few studies have examined if different PF levels modify the association between TV time and adiposity in adolescents. Studies often focus on the isolated relationships between obesity and TV time, or obesity and PF levels. SUBJECTS: 1071 adolescents (617 girls), aged 12 to 17 years. MEASURES: Cardiorespiratory fitness (CRF), abdominal muscular endurance, and lower limb strength were evaluated using the protocols of the Projeto Esporte Brasil fitness testing battery. TV time was obtained using a self-reported questionnaire. Body mass index (BMI) and waist circumference (WC) were also assessed. Moderation analyses were conducted through multiple linear regression models with the following associations tested in different models: PF components, TV time, and interaction (PF component x TV time) with adiposity parameters (BMI and WC). RESULTS: A significant interaction term was found for CRF and TV time in the association with both WC (ß: -.005; 95% CI: -.009; -.001; P = .012) and BMI (ß: -.002; 95% CI: -.004; -.001; P = .009). CONCLUSION: CRF moderates the relationship between TV time and adiposity measures in this cross-sectional analysis. These data support strategies looking at increasing physical activity levels to improve CRF and avoid the development of excess abdominal obesity and excess weight.

The Effect of Atorvastatin (and Subsequent Metformin) on Adipose Tissue Acylation-Stimulatory-Protein Concentration and Inflammatory Biomarkers in Overweight/Obese Women With Polycystic Ovary Syndrome.

Background: Atorvastatin has been shown to improve cardiovascular risk (CVR) indices in women with polycystic ovary syndrome (PCOS). Low-grade chronic inflammation of adipose tissue may link PCOS and adverse CVR. In pro-inflammatory states such as PCOS, spontaneous activation of the alternative pathway of complement results in increased generation of acylation stimulating protein (ASP) from adipocytes irrespective of body mass index. Methods: The objective of this study was to determine the effect of atorvastatin on markers of adipose tissue dysfunction and inflammation; acylation-stimulating-protein (ASP), interleukin-6 (IL-6), and monocyte-chemoattractant-protein-1 (MCP-1) in PCOS. This was a randomized, double-blind, placebo-controlled study where 40 medication-naive women with PCOS and biochemical hyperandrogenaemia were randomized to either atorvastatin 20 mg daily or placebo for 12 weeks. Following the 12 week randomization; both group of women with PCOS were subsequently started on metformin 1,500 mg daily for further 12 weeks to assess whether pre-treatment with atorvastatin potentiates the effects of metformin on markers of adipose tissue function We conducted a post-hoc review to detect plasma ASP and the pro-inflammatory cytokines IL6 and MCP-1 before and after 12 and 24 weeks of treatment. Results: There was significant reduction in ASP (156.7 ± 16.2 vs. 124.4 ± 14.8 ng/ml p <0.01), IL-6 (1.48 ± 0.29 vs.0.73 ± 0.34 pg/ml p = 0.01) and MCP-1 (30.4 ± 4.2 vs. 23.0 ± 4.5 pg/ml p = 0.02) after 12 weeks of atorvastatin that was maintained subsequently with 12 weeks treatment with metformin. There was a significant positive correlation between ASP levels with CRP (p < 0.01), testosterone (p < 0.01) and HOMA-IR (p < 0.01); IL-6 levels with CRP (p <0.01) and testosterone (p < 0.01) and MCP-1 with CRP (p < 0.01); testosterone (p < 0.01) and HOMA-IR (p < 0.02). Conclusions: This post-hoc analysis revealed that 12 weeks of atorvastatin treatment significantly decreased the markers of adipose tissue dysfunction and inflammation, namely ASP, IL-6 and MCP-1 in obese women with PCOS. Changes in adipose tissue markers were significantly associative with substantial improvements in HOMA-IR, testosterone and hs-CRP levels. ISRCTN Number: ISRCTN24474824.

Low-density lipoprotein sub-fraction profiles in obese children before and after attending a residential weight loss intervention.

AIM: Small dense LDL particles are associated with an increased risk of coronary heart disease and are prevalent in obesity related dyslipidaemia. This study evaluated the effect of weight loss in nine children (BMI 33.4 +/- 8.4 kg.m(-2) and age 15.1 +/- 2.9 years) on LDL peak particle size, and cholesterol concentrations within particular LDL sub-fractions. METHODS: Each child undertook fun based physical activity, dietary restriction and modification and lifestyle education classes in a residential summer weight loss intervention. Blood was drawn before and after intervention and LDL heterogeneity measured by ultracentrifugation. RESULTS: The mean change in body weight were -6.8 +/- 4.9 kg, BMI units -2.5 +/- 1.4 kg.m(-2), and waist circumference -6.3 +/- 6.3 cm (all p < 0.01). Absolute LDL-c concentration reduced from 106.2 mg/dL to 88.3 mg/dL (p < 0.01). The cholesterol contained within the small dense LDL sub-fraction (LDL-c III) reduced from 54.1 mg/dL to 40.4 mg/dL (p < 0.01). Peak particle density decreased from 1.041g/mL to 1.035g/mL (p < 0.01). At pre intervention 50.9% of absolute cholesterol was within LDL-c III particles, changing to 46.2%. CONCLUSION: Mean weight loss of -6.8 +/- 4.9 kg lowers absolute LDL-c and the cholesterol specifically within LDL-c III particles. LDL peak particle size increased and a degree of LDL particle remodelling occurred. These favourable adaptations, accrued in a matter of 4 weeks, maybe associated with a reduction in CHD risk.

Effects of reducing inspired oxygen concentration for one hour in patients with chronic heart failure: implications for air travel.

AIMS: The objective of this study was to establish the acute effects of hypoxia on clinical, spirometric, haemodynamic, and echocardiographic variables. Reducing inspired oxygen to 15%, as experienced during commercial air travel, decreases arterial oxygen saturation, increases respiratory rate and pulmonary artery pressure in healthy subjects. The effect on patients with chronic heart failure is unknown. METHODS AND RESULTS: Seventy-two patients with chronic heart failure and an LVEF <40%, in NYHA functional class II (74%) or III (26%), on stable treatment were studied and compared with 18 age-matched controls (65 ± 11 vs. 62 ± 12 years, respectively). Clinical, spirometric, haemodynamic, and echocardiographic measurements were performed in patients and controls before and after one hour inspiring 15% oxygen. Inspired 15% oxygen for 1 h was tolerated in all subjects and caused no worsening of symptoms. Arterial oxygen saturation decreased to a similar extent in patients (from 97 ± 2% to 86 ± 4%) and controls (from 97 ± 2% to 86 ± 3%). Mean arterial pressure increased from 81 ± 13 mmHg to 87 ± 12 mmHg in patients, but did not change in controls. There was no effect on heart rate, but systolic pulmonary artery pressure rose from 30.2 ± 14.0 mmHg to 34.0 ± 15.2 mmHg in patients, and from 22.4 ± 5.5 mmHg to 24.1 ± 6.9 mmHg in controls. CONCLUSIONS: Inspiring 15% oxygen was tolerated and caused no worsening of symptoms despite reductions in arterial oxygen saturation and increases in mean arterial pressure and systolic pulmonary artery pressure.

The predictive ability of triglycerides and waist (hypertriglyceridemic waist) in assessing metabolic triad change in obese children and adolescents.

BACKGROUND: The metabolic triad [fasting insulin, apolipoprotein B, and low-density lipoporotein (LDL) peak particle density] is characteristic of increased intra-abdominal adipose tissue and insulin resistance and can be predicted by the simple and adoptable screening tool, the hypertriglyceridemic waist. The associations between hypertriglyceridemic waist components [fasting triglycerides (TG) and waist circumference cut-points derived from a child-specific metabolic syndrome definition] with the metabolic triad were examined in obese youth before and after weight loss. METHODS: A continuous metabolic triad score (MTS) was calculated as a cumulative and standardized residual score of fasting insulin, apolipoprotein B, and LDL peak particle density (z-scores of the metabolic triad variables regressed onto age and sex). The predictive ability of TG and waist in assessing metabolic triad change was undertaken in 75 clinically obese boys and girls, aged 8-18, body mass index (BMI) 34.2±6.4 kg/m(2) before and after weight loss. RESULTS: Fasting TG concentrations (r(2)=0.216, P<0.0001) and waist circumference (r(2)=0.049, P=0.019) were both significant independent predictors of the cumulative MTS, together accounting for 26.5% of its total variance. All cardiometabolic risk factors [except a reduction in high-density lipoprotein cholesterol (HDL-C)] were favorably modified following weight loss. Fasting TG change was the only significant predictor of the MTS change (r(2)=0.177, P<0.0001). Waist circumference was not a significant predictor of MTS change. CONCLUSION: The reduction in fasting TG concentration (but not waist circumference) was the only significant predictor of MTS change. Fasting TG may be the most important metabolic syndrome component to best characterize the metabolic heterogeneity in obese cohorts and the changes in metabolic risk in clinically obese youth.

Longitudinal factor analysis reveals a distinct clustering of cardiometabolic improvements during intensive, short-term dietary and exercise intervention in obese children and adolescents.

OBJECTIVE: The aim of this study was to investigate changes in cardiometabolic clustering characteristics in response to highly significant weight loss. BACKGROUND: Pre-post analysis of a lifestyle intervention for the treatment of obesity and the assessment of interrelated metabolic changes were analyzed using principal component analysis (PCA). A total of n=75 clinically obese boys and girls [standardized body mass index (sBMI) 3.07±0.59] aged 8-18 years were assessed after lifestyle intervention (30±12 days). RESULTS: There were favorable improvements in BMI waist circumference, fasting insulin, triglycerides (TGs), systolic blood pressure (SBP) and diastolic blood pressure (DBP) (all P<0.001). PCA was performed using a simple conceptual model of changes in six metabolic variables: Overall and central obesity (BMI and waist circumference), dyslipidemia [TG and high-density lipoprotein cholesterol (HDL-C)], insulin resistance [fasting insulin or homeostasis model assessment of insulin resistance (HOMA-IR)], and blood pressure [SBP or mean arterial pressure (MAP)]. PCA models consistently identified two factors underlying the changes in six cardiometabolic variables. These were labeled a "metabolic" factor, typically including waist circumference, fasting triglyceride, insulin, or HOMA-IR and HDL-C (negatively) and an "obesity/blood pressure" factor, typically loading waist, BMI, SBP or MAP, and occasionally fasting insulin/HOMA-IR). The metabolic and obesity/blood pressure factors explained 26.5%-28.4% and 30.4%-31.9%, of the variance in metabolic risk factors changes, respectively. Reductions in BMI, waist circumference, and HOMA-IR (or fasting insulin) were central underlying features of cardiometabolic changes. CONCLUSION: There were significant and favorable cardiometabolic risk factor changes to short-term weight-loss. A distinct clustering of cardiometabolic responses supports the etiological importance of both overall and central obesity and insulin resistance in the modification of cardiometabolic risk in obese youths.