Markers of insulin resistance are associated with fatness and fitness in school-aged children: the European Youth Heart Study

Aims/hypothesis Our aim was to examine the association between markers of insulin resistance and: (1) body fat and waist circumference, taking into account cardiorespiratory fitness in school-aged children; and (2) cardiorespiratory fitness at differing levels of body fat and waist circumference. Subjects and methods This was a cross-sectional study of 873 children aged 9.6 ± 0.4 years from Estonia and Sweden. Weight, height and waist circumference were measured. Body fat was expressed as the sum of five skinfold thicknesses. Cardiorespiratory fitness was estimated by a maximal cycle-ergometer test. The studied markers of insulin resistance were fasting insulin and glucose, and homeostasis model assessment (HOMA). Results HOMA and fasting insulin were positively associated with body fat and waist circumference after adjusting for cardiorespiratory fitness, age, pubertal status and study location. HOMA and fasting insulin were negatively associated with cardiorespiratory fitness in children in the third (highest) tertile of body fat and waist circumference after controlling for sex, age, pubertal status and study location. Fasting glucose was negatively associated with cardiorespiratory fitness in children in the third (highest) tertile of waist circumference, but it was not associated when body fat was taken into account. Conclusions/interpretation In school-aged children, HOMA and fasting insulin are significantly associated with body fat and waist circumference. In addition, cardiorespiratory fitness explains a significant proportion of the HOMA and fasting insulin variance in those children with high levels of body fat and waist circumference. The findings suggest that the deleterious consequences ascribed to high fatness could be counteracted by having high levels of cardiorespiratory fitness.     

Factors associated with hospital admission in adult patients with asthma exacerbations: A systematic review

Objectives: A variable proportion of patients presenting to the emergency department (ED) with acute asthma require admission to hospital. Previous studies have identified select factors associated with admission following ED presentation; however, no review has synthesized the evidence in this regard. This systematic review summarizes the evidence regarding factors associated with hospital admission following ED presentation. Methods: Searches were conducted in seven electronic databases and common sources of grey literature. Studies reporting disposition for adults after ED presentation were included. Admission proportions and factors associated with hospitalization that remained statistically significant in multivariable analyses (p < 0.05) were reported. Results: Out of an initial 5865 identified articles, 15 articles met full inclusion criteria and 11 were included in the analyses. Female sex (n = 2) and older age (n = 2) were individual factors associated with admission. Patient vital signs and severity followed by patient attributes were the two most frequent domains associated with admission. Admission proportions were analyzed in 10 studies at an median of ～20% with no clear change between 1996 and 2012. Conclusions: Factors such as patient demographics (e.g., female sex, older age), patient vital signs/severity, and history are associated with admission following ED presentation for acute asthma. These can be employed by ED clinicians to effectively discern patients at high risk for admission and lead to more evidence-based decision-making.     

Factors associated with development of excessive fatness in children and adolescents: a review of prospective studies

The purpose of this review was to examine the factors that predict the development of excessive fatness in children and adolescents. Medline, Web of Science and PubMed were searched to identify prospective cohort studies that evaluated the association between several variables (e.g. physical activity, sedentary behaviour, dietary intake and genetic, physiological, social cognitive, family and peer, school and community factors) and the development of excessive fatness in children and adolescents (5–18 years). Sixty‐one studies met the eligibility criteria and were included. There is evidence to support the association between genetic factors and low physical activity with excessive fatness in children and adolescents. Current studies yielded mixed evidence for the contribution of sedentary behaviour, dietary intake, physiological biomarkers, family factors and the community physical activity environment. No conclusions could be drawn about social cognitive factors, peer factors, school nutrition and physical activity environments, and the community nutrition environment. There is a dearth of longitudinal evidence that examines specific factors contributing to the development of excessive fatness in childhood and adolescence. Given that childhood obesity is a worldwide public health concern, the field can benefit from large‐scale, long‐term prospective studies that use state‐of‐the‐art measures in a diverse sample of children and adolescents.     

Increasing overall physical activity and aerobic fitness is associated with improvements in metabolic risk: cohort analysis of the ProActive trial

Aims/hypothesis Our aim was to examine the association between change in physical activity energy expenditure (PAEE), total body movement (counts per day) and aerobic fitness (maximum oxygen consumption []) over 1 year and metabolic risk among individuals with a family history of diabetes. Methods Three hundred and sixty-five offspring of people with type 2 diabetes underwent measurement of energy expenditure (PAEE measured using the flex heart rate method), total body movement (daily activity counts from accelerometry data), predicted from a submaximal graded treadmill exercise test and anthropometric and metabolic status at baseline and 1 year (n = 321) in the ProActive trial. Clustered metabolic risk was calculated by summing standardised values for waist circumference, fasting triacylglycerol, insulin and glucose, blood pressure and the inverse of HDL-cholesterol. Linear regression was used to quantify the association between changes in PAEE, total body movement and fitness and clustered metabolic risk at follow-up. Results Participants increased their activity by 0.01 units PAEE kJ kg⁻¹ day⁻¹ over 1 year. Total body movement increased by an average of 9,848 counts per day. Change in total body movement (β = −0.066, p = 0.004) and fitness (β = −0.056, p = 0.003) was associated with clustered metabolic risk at follow-up, independently of age, sex, smoking status, socioeconomic status and baseline metabolic score. Conclusions/interpretation Small increases in activity and fitness were associated with a reduction in clustered metabolic risk in this cohort of carefully characterised at-risk individuals. Further research to quantify the reduction in risk of type 2 diabetes associated with feasible changes in these variables should inform preventive interventions. Clinical trial registration number: ISRCTN61323766. The other members of the ProActive research team, besides the authors, are listed in Acknowledgements.     

Factors associated with fasting plasma ghrelin levels in children and adolescents

AIM： To measure plasma ghrelin levels in children and adolescents, analyze the associated factors, and investigate the role of ghrelin in obesity, insulin resistance and reproductive physiology.
METHODS： A total of 283 subjects aged 4.8-15.8 year were enrolled. Fasting blood samples were collected and plasma ghrelin levels were measured by radioimmunoassay. Fasting glucose （FG）, fasting insulin （FI）, baseline testosterone （T）, estradiol （E2）, prolactin （PRL）, luteinizing hormone （LH）, follicle-stimulating hormone （FSH）, serum total cholesterol （TC）, triglyceride （TG）, alanine aminotransferase （ALT） and uric acid （UA） were measured. Body mass index （BMI）, insulin resistance by homeostasis model （HOMA-IR） and beta cell function by homeostasis model （HOMA-β） were calculated.
RESULTS： The median ghrelin level was 290 ng/L （15.0-1325.0 ng/L）. Bivariate correlation analysis showed that ghrelin levels were inversely correlated with BMI, ALT, TG, UA, LH, FI and HOMA-IR （all P 〈 0.05）. No other significant correlation was found between ghrelin levels and age, gender, TC, E2, FSH, PRL, FG and HOMA-β. Stepwise multiple regression analysis showed that only BMI and FI were independent determinants of plasma ghrelin levels in these children and adolescents （P = 0.018 and P = 0.046, respectively）, which explained 25.4% of the variance.
CONCLUSION： These data suggest that the lower ghrelin levels in obese subjects may be the result of obesity and hyperinsulinemia, which is very common in obese subjects. Moreover, ghrelin may regulate human reproductive physiology indirectly.     

Truncal Adiposity and Lung Function in Older Black Women

The increase in adiposity associated with aging is a concern in older adults, especially as it relates to the risk for ventilatory complications. Therefore, the specific aim of this study was to determine the association of various measures of abdominal adiposity with lung function in a sample of older healthy Black women. Participants (n = 27) had no history of diabetes or respiratory disease. The mean age was 67 years. Lung function was measured by spirometry using percent of predicted values for forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV₁). Body fat was measured using a three-dimensional photonic scanner and dual energy X-ray absorptiometry (DXA). Correlation analyses show that percent body fat in the trunk (%TF) is significantly associated with percent predicted FVC (r = −0.38; p < 0.05). No association was observed between anthropometric indices of truncal adiposity and lung function. Results of this study show that truncal fat mass measured by DXA is more strongly associated with lung function than anthropometric indices of truncal adiposity in this sample of women.     

Factors associated with asthma in adolescents in the city of Fortaleza,Brazil

Objective: Asthma is a chronic inflammatory airway disease. In Brazil, little is known about factors associated with this disease. This study aimed to identify factors associated with asthma in 13- to 14-year-old adolescents in Fortaleza, Ceará, Brazil. Methods: It is a cross-sectional population-based study, with a probability sample of 3015 students in 2006–2007. We used the questionnaires about asthma, rhinitis and socio-demographic/environmental factors from the International Study for Asthma and Allergies in Childhood (ISAAC) protocol. Current asthma was defined as physician-diagnosed asthma and wheezing in the previous 12 months. Bivariate analysis was performed between asthma and factors included in the study, using prevalence ratio and Chi-square test. Confidence intervals (95%) and odds ratio (OR) were also calculated. Factors associated with asthma in bivariate analysis were then assessed using logistic regression. Results: Final sample was composed by 694 adolescents, 179 with asthma. Rhinoconjunctivitis and consumption of stuffed biscuits and fried snacks three or more times per week were independently and positively associated with asthma; consumption of fruits three or more times per week was negatively associated with asthma. Conclusions: Dietary factors were the most associated with asthma in this study. Besides rhinoconjunctivitis, consumption of stuffed biscuits and fried snacks (foods with high content of saturated fat) three or more times per week were independently associated with asthma as aggravating factors, while the consumption of fruits three or more times per week was associated with asthma as protective factor. Interventions acting on these factors may decrease the occurrence of asthma in this population.     

Sedentary behavior and physical activity are independently related to functional fitness in older adults

The last decades of life have been traditionally viewed as a time of inevitable disease and frailty. Sedentary living and physical activity may influence capacity to perform activities that are needed to maintain physical independence in daily living. A total of 117 males and 195 females, aged 65–103 years, were assessed for physical activity and sedentary time with accelerometers and for functional fitness with the Senior Fitness Test battery. Based on the individual scores for each fitness item, a Z-score was created. Associations between functional fitness with sedentary time and moderate-to-vigorous physical activity (MVPA) were analyzed. A negative association was found between the composite Z-score for functional fitness and the sedentary time, even adjusting for MVPA and other confounders. On the other hand, MVPA was positively associated with the composite Z-score for functional fitness, independently of the sedentary time. In conclusion elderly who spend more time in physical activity or less time in sedentary behaviors exhibit improved functional fitness and other confounders. The results reinforce the importance of promoting both the reduction of sedentary behaviors and the increase of MVPA in this age group, as it may interfere at older ages in order to preserve functional fitness and performance of daily functioning tasks.     

Adiposity facilitates increased strength capacity in heart failure patients with reduced ejection fraction

Background

Obesity is associated with relatively improved prognosis among heart failure (HF) patients. Mechanisms explaining this so-called “obesity paradox” have been unclear. We hypothesized that increased adiposity may contribute to increased strength capacity, and may thereby facilitate clinical benefits.

Methods and results

In a controlled, cross-sectional study, adults aged ≥ 50 years with HF with reduced ejection fraction (HFREF) (LVEF ≤ 40%) were compared to age matched controls. Body composition was determined by dual-energy X-ray absorptiometry (DXA). Aerobic (cardiopulmonary exercise testing), maximum strength (one repetition maximum [1RM]), and power (submaximal resistance/time) were assessed.70 adults (31 HFREF, 39 controls; mean age 66.2 ± 9.6 years) were studied. Peak oxygen consumption (VO₂) (15.4 ± 4.2 vs. 23.4 ± 6.6 ml O₂·kg^− 1·min^− 1, p < 0.0001), 1RM (154.8 ± 52.0 vs. 195.3 ± 56.8 kg, p < 0.01) and power (226.4 ± 99.2 vs. 313.3 ± 130.6, p < 0.01) were lower in HFREF vs. controls. 1RM correlated with total fat (r = 0.56, p < 0.01), leg fat (r = 0.45, p < 0.05) and arm fat (r = 0.39, p < 0.05) in HFREF. Moreover, among HFREF patients with a high (≥ 30 kg/m²) body mass index (BMI), 1RM and fat mass were significantly greater than those with lower (< 30 kg/m²) BMIs. Correlations between 1RM and total fat (r = 0.65, p < 0.05) and leg fat (r = 0.64, p < 0.05) were particularly notable in the high BMI subgroup.

Conclusion

Increased adiposity correlates with relatively greater strength in HFREF patients which may explain some of the clinical benefits that result from obesity.     

Factors associated with low levels of physical activity among elderly residents in a small urban area in the interior of the Brazilian Amazon

The aim of the present study was to investigate levels of physical activity and risk factors for inactivity in older adults living in an urban area in the interior of the Amazonas state, Brazil. Data were collected between 2013 and 2015 from 274 individuals 60 years of age or older who resided in the interior of the Brazilian Amazon. Sociodemographic, general health, functional capacity and physical performance were associated with self-referred physical activity level. A multivariate analysis, after adjustment, showed that being a man, having a body mass index above 27 kg/m², never having lived in riverside communities and having less than three associated chronic diseases were independent risk factors for low levels of physical activity among elderly residing in the interior of the Brazilian Amazon. Few studies have been conducted about the characteristics that are singular to this population. Our results suggest that the physical activity level and, consequently, the aging process of the elderly is influenced by where they have resided throughout their lives. Additionally, the results showed particular risk factors associated with low physical activity level among older adults residing in the interior of the state of Amazonas.     

Reduced cardiorespiratory fitness,low physical activity and an urban environment are independently associated with increased cardiovascular risk in children

AIMS/HYPOTHESIS: To assist in the development of preventive strategies, we studied whether the neighbourhood environment or modifiable behavioural parameters, including cardiorespiratory fitness (CRF) and physical activity (PA), are independently associated with obesity and metabolic risk markers in children. METHODS: We carried out a cross-sectional analysis of 502 randomly selected first and fifth grade urban and rural Swiss schoolchildren with regard to CRF, PA and the neighbourhood (rural vs urban) environment. Outcome measures included BMI, sum of four skinfold thicknesses, homeostasis model assessment of insulin resistance (HOMA-IR) and a standardised clustered metabolic risk score. RESULTS: CRF and PA (especially total PA, but also the time spent engaged in light and in moderate and vigorous intensity PA) were inversely associated with measures of obesity, HOMA-IR and the metabolic risk score, independently of each other, and of sociodemographic and nutritional parameters, media use, sleep duration, BMI and the neighbourhood environment (all p < 0.05). Children living in a rural environment were more physically active and had higher CRF values and reduced HOMA-IR and metabolic risk scores compared with children living in an urban environment (all p < 0.05). These differences in cardiovascular risk factors persisted after adjustment for CRF, total PA and BMI. CONCLUSIONS/INTERPRETATION: Reduced CRF, low PA and an urban environment are independently associated with an increase in metabolic risk markers in children.     

Atherosclerotic risk factors associated with cardiorespiratory fitness and BMI in adolescents

Previous research has demonstrated high prevalence of atherosclerotic risk factors in adolescents; however, the associate factors related to its onset are unclear. Therefore, the objective of this study was to relate inadequate blood pressure levels, total cholesterol (TC), HDL-C, LDL-C and triglycerides (TG) with different VO2máx and BMI levels in a sample of 249 adolescents, aged between 12 to 16 years old. For VO2máx prediction, the 20 meters test was used. The BMI was calculated using the body mass/heigh(2) equation. The considerate inadequate levels were: blood pressure > or =90th percentile; total cholesterol > or =150 mg/dL; LDL-C > or = 100 mg/dL, TG > or =100 mg/dL and HDL-C <45 mg/dL. Logistic regression was used as statistical procedures, with p<0.05. For the boys, significant associations were observed between the low VO2máx with TC (OR 4.33; IC=1.23-15.20) and TG (OR=4.88; IC=1.15-20.79) and between overweight and TG (OR=4.33; IC=1.42-13.21). After BMI correction, the males subjects with low VO2máx maintained their significant associations with TC (OR=5.73; IC=1.52-21.58) and TG (OR=3.81; IC=1.86-16.94). The evidences in this study suggested an inverse relationship of the cardiorespiratory fitness with TC and TG for boys, independently of the BMI.     

Association of lung function with physical, mental and cognitive function in early old age

Lung function predicts mortality; whether it is associated with functional status in the general population remains unclear. This study examined the association of lung function with multiple measures of functioning in early old age. Data are drawn from the Whitehall II study; data on lung function (forced expiratory volume in 1 s, height FEV(1)), walking speed (2.44 m), cognitive function (memory and reasoning) and self-reported physical and mental functioning (SF-36) were available on 4,443 individuals, aged 50-74 years. In models adjusted for age, 1 standard deviation (SD) higher height-adjusted FEV(1) was associated with greater walking speed (beta=0.16, 95% CI: 0.13, 0.19), memory (beta=0.09, 95% CI: 0.06, 0.12), reasoning (beta=0.16, 95% CI: 0.13, 0.19) and self-reported physical functioning (beta=0.13, 95% CI: 0.10, 0.16). Socio-demographic measures, health behaviours (smoking, alcohol, physical activity, fruit/vegetable consumption), body mass index (BMI) and chronic conditions explained two-thirds of the association with walking speed and self-assessed physical functioning and over 80% of the association with cognitive function. Our results suggest that lung function is a good 'summary' measure of overall functioning in early old age.     

Elevated ACE activity is not associated with asthma, COPD, and COPD co-morbidity

The angiotensin-converting enzyme (ACE) gene is a potential candidate gene for risk of asthma, COPD, and COPD co-morbidity. In 9034 Danish adults, we determined whether individuals homozygous or heterozygous for the ACE D allele are at greater risk of asthma, COPD, or COPD co-morbidity compared with ACE II homozygous individuals. In the general population, serum ACE activity increased with the number of D alleles (Kruskal-Wallis ANOVA: II vs. ID, p < 0.001; ID vs. DD, p < 0.001); however, this did not translate into altered risk of asthma or COPD. In the general population, the odds ratio (95% confidence interval) for asthma was 1.2 (0.9–1.4) for ID individuals and 1.2 (0.9–1.5) for DD individuals compared with II individuals. In the general population, the odds ratio for COPD was 0.9 (0.8–1.1) for ID individuals and 1.0 (0.8–1.2) for DD individuals compared with II individuals. Among patients with COPD, the odds ratio for ischemic heart disease was 1.1 (0.8–1.6) for ID individuals and 1.2 (0.8–1.7) for DD individuals compared with II individuals; corresponding odds ratios for hypertension were 1.1 (0.7–1.5) and 0.8 (0.5–1.2), and for low physical activity 0.9 (0.5–1.4) and 0.7 (0.4–1.2). The results were similar upon adjustment for sex, age, smoking status, body mass index, total cholesterol, and ACE inhibitor/angiotensin II type 1 receptor blocker use. These data suggest that lifelong genetically elevated ACE activity is not a major risk factor for asthma or COPD, or for ischemic heart disease, hypertension, and low physical activity in COPD patients.     

Defining COPD exacerbations: impact on estimation of incidence and burden in primary care

Aims

To investigate the impact of definition on the incidence of chronic obstructive pulmonary disease (COPD) exacerbations in primary care.

Methods

In a one-year prospective, observational study, data from diary cards were used to determine the incidence of symptom- and healthcare-defined exacerbations. One hundred and twenty seven patients completed ≥80% of days in the diary card and were included in the analysis.

Results

Incidence of COPD exacerbation varied according to definition. Mean yearly rates were 2.3 for symptom- and 2.8 for healthcare-defined exacerbations. Although patients with FEV₁ < 50% had a higher mean yearly rate of healthcare-defined exacerbations than those with FEV₁ ≥ 50% (3.2 vs 2.3; p = 0.003), patients with less severe disease reported recurrent exacerbations. There was limited agreement between symptom- and healthcare-defined exacerbations.

Conclusion

Lung function does not appear to be a valid criterion for assigning COPD management directed at patients with recurrent exacerbation.