Adiponectin diminishes platelet aggregation and sCD40L release. Potential role in the metabolic syndrome

The proinflammatory and proatherogenic mediator, soluble CD40 ligand (CD40L), is increased in the metabolic syndrome (MS) and released from platelets. We hypothesized that adiponectin modulates platelet function, and we sought to evaluate the association of adiponectin and sCD40L levels with platelet aggregation in MS and the effects of adiponectin on platelet aggregation and activation. Platelet aggregation and circulating adiponectin, sCD40L and P-selectin were determined in 30 controls and 30 patients with MS. Also, in vitro studies were performed in platelet-rich plasma from nine healthy volunteers. Adiponectin receptors were demonstrated by Western blotting and flow cytometry. ADP and epinephrine platelet aggregation was measured after preincubation with adiponectin. sCD40L and P-selectin secretion was measured in the supernatants by ELISA. Patients with MS had higher sCD40L and P-selectin than controls (5.96 +/- 0.50 vs. 4.28 +/- 0.41 ng/ml, P < 0.05, and 151 +/- 8 vs. 122 +/- 9 ng/ml, P < 0.05). By contrast, adiponectin was lower in patients with MS than in controls (5.25 +/- 0.30 vs. 7.35 +/- 0.34 microg/ml, P < 0.001). Higher platelet aggregation was found in MS. Adiponectin inversely correlated with P-selectin (R = -0.35, P = 0.009), sCD40L (r = -0.24, P = 0.05) and epinephrine and collagen induced aggregation (r = -0.80, P = 0.005; r = -0.70, P = 0.011). Platelets express the receptors for adiponectin. Platelet aggregatory response to epinephrine and ADP significantly decreased following preincubation with adiponectin (96 +/- 4 vs. 23 +/- 3%, P < 0.001, and 102 +/- 9 vs. 85 +/- 9%, P = 0.004). Adiponectin prevented platelet sCD40L release (1.63 +/- 0.15 vs. 2.04 +/- 0.20 ng/ml, P < 0.001). Enhanced platelet aggregation and activation markers are found in MS associated with low adiponectin concentrations. Novel evidence is provided demonstrating that adiponectin has antithrombotic properties, since it inhibits platelet aggregation and platelet activation

Distribution and determinants of sedentary lifestyles in the European Union

Background Many studies have shown the health burden of a sedentary lifestyle. The main goal of this study was to determine the prevalence of sedentary lifestyles in the 15 Member States of the European Union (EU) and to identify the main correlates of a sedentary lifestyle. Methods Nationally representative samples (n ≈ 1000 subjects in each country; >15 years) completed a questionnaire concerning attitudes to physical activity, body weight, and health; in total 15 239 subjects. Sedentary people were defined in two ways: (1) those expending less than 10% of their leisure time expenditure in activities involving ≥4 metabolic equivalents (MET). (2) Those who did not practice any leisure-time physical activity and who also were above the median in the number of hours spent sitting down during leisure time. Logistic regression models were fitted to analyse the association between sedentary lifestyles and gender, age, body mass index (BMI), educational level, weight change in the last 6 months, and marital and smoking status. Results Percentages of sedentary lifestyles across European countries ranged between 43.3% (Sweden) and 87.8% (Portugal) according to the first definition. According to both definitions, a lower prevalence of sedentary lifestyle was found in Northern countries (especially Scandinavian countries) as compared with Mediterranean countries, whereas the prevalence was higher among older, obese, less educated, widowed/divorced individuals, and current smokers. Similar relative differences between countries and socio-demographic groups were found independently of the method used to define a sedentary lifestyle. Conclusion Prevalence of sedentary lifestyle in the EU is high, especially among inhabitants of some Mediterranean countries, obese subjects, less-educated people, and current smokers. This high prevalence involves important public health burdens and preventive strategies are urgently needed

Prevalence of physical activity during leisure time in the European Union

PURPOSE: To estimate the prevalence of physical activity during leisure time in adults from the 15 member states of the European Union and the relationship with sociodemographic variables. METHODS: A representative sample, with approximately 1000 adults, aged 15 and upward, was selected from each member state to complete a questionnaire on attitudes to physical activity, body weight, and health by a face-to-face interview, summing a total of 15,239 subjects. The amount of leisure-time physical activity was quantified by assigning metabolic equivalents (METs) to each activity. Multiple linear regression models with MET-h.wk(-1) as the dependent variable were fitted. RESULTS: Northern European countries showed higher levels of physical activity than southern ones. The highest prevalence (91.9%) was found in Finland, and the lowest (40.7%) in Portugal. A higher percentage of men practiced any leisure-time physical activity and also showed higher mean of MET-h.wk(-1). In both genders, the multivariate models showed a significant trend to higher leisure time activity in participants with higher educational levels and in nonsmokers. Also, an inverse association between body mass index and leisure-time physical activity was found. CONCLUSION: The prevalence of any physical activity during leisure time in the adult European population was similar to the U.S. estimates. Nevertheless, the amount of activity is low, and a wide disparity between countries exists. To our knowledge, this is the first study determining the prevalence and amount of leisure-time physical activity, which is the first step to define strategies to persuade populations to increase their physical activity

Validation of the Spanish version of the physical activity questionnaire used in the Nurses’ Health Study and the Health Professionals’ Follow-up Study

Objective: The objective of this analysis was to test the validity of the estimates of energy expenditure and sedentary lifestyle obtained through a self-administered questionnaire of physical activity for Spanish-speaking people adapted from US questionnaires (Nurses’ Health Study and Health Professionals’ Follow-up Study) using a triaxial accelerometer (RT3 Triaxial Research Tracker) as the reference. Design and setting: Validation study, calculating the non-parametric correlation coefficients between the level of physical activity and sedentary lifestyle collected by the self-administered questionnaire and the triaxial accelerometer measurements. Percentage of misclassification and kappa coefficients were also calculated. Subjects: The study population consisted of a sample of 40 obese women who were participants of the SUN (Seguimiento Universidad de Navarra) project (a prospective cohort study among Spanish university alumni). They were selected because of their peculiar metabolic characteristics, in the search for a sub-optimal scenario for validity. Results: Physical activity during leisure time (estimated as MET-h week21) derived from the self-administered questionnaire moderately correlated with kcal day21 assessed through the accelerometer (Spearman’s r ¼ 0.507, 95% confidence interval (CI) 0.232, 0.707). The Spearman correlation between the ratio of sedentary lifestyle to physical activity obtained through the questionnaire and the direct estimation (RT3) was 20.578 (95% CI 20.754, 20.325). The kappa index was 0.25 (P ¼ 0.002) when assessing the cross-classification into quintiles and 0.41 for the dichotomous estimation of a sedentary lifestyle. Only 2.5% of participants were misclassified by the questionnaire more than two quintiles apart from the estimates of the RT3. Conclusions: The moderate values obtained for correlation in a sub-optimal scenario for validity and the low percentage of extreme misclassification suggest the validity of the questionnaire to assess physical activity in Spanish-speaking women aged 20–50 years

Prevalencia de obesidad en Europa

La prevalencia de obesidad está aumentando de forma alarmante, mientras que la de otros factores de riesgo (hiperlipemia, hipertensión arterial...) tiende a disminuir. De todos los factores implicados en su desarrollo destacan dos por su potencial modificabilidad: la ingesta calórica excesiva y el estilo de vida sedentario, a pesar de las recomendaciones a favor de la práctica regular de ejercicio físico. El principal problema en el estudio de la prevalencia de obesidad es la escasez de estudios que la analicen de forma global. En 1989 se publicaron los primeros resultados del proyecto MONICA de la OMS, en el que se observó que la prevalencia de obesidad era mayor entre los varones que entre las mujeres, así como también era mayor en los países mediterráneos y del este de Europa, en comparación con los del norte y centro-oeste. En 1997 se llevó a cabo un estudio del Institute of European Food Studies (IEFS) en el que participaron 15.239 individuos a partir de muestras representativas de los 15 Estados Miembros de la Unión Europea. Sus resultados mostraron que la mayor prevalencia de obesidad se daba en el Reino Unido (12%) seguido de España (11%), siendo la menor en Italia, Francia y Suecia (7%). Por sexo, la prevalencia de obesidad es algo mayor entre las mujeres, siendo la de sobrepeso mayor entre los hombres. En España la distribución de sobrepeso y obesidad entre los diferentes grupos sociodemográficos es similar a la de otras regiones, siendo mayor el porcentaje de obesidad en los ancianos, los sujetos de menor nivel socioeconómico y los habitantes de las regiones del norte y noroeste de España

Adiponectin diminishes platelet aggregation and sCD40L release. Potential role in the metabolic syndrome

The proinflammatory and proatherogenic mediator, soluble CD40 ligand (CD40L), is increased in the metabolic syndrome (MS) and released from platelets. We hypothesized that adiponectin modulates platelet function, and we sought to evaluate the association of adiponectin and sCD40L levels with platelet aggregation in MS and the effects of adiponectin on platelet aggregation and activation. Platelet aggregation and circulating adiponectin, sCD40L and P-selectin were determined in 30 controls and 30 patients with MS. Also, in vitro studies were performed in platelet-rich plasma from nine healthy volunteers. Adiponectin receptors were demonstrated by Western blotting and flow cytometry. ADP and epinephrine platelet aggregation was measured after preincubation with adiponectin. sCD40L and P-selectin secretion was measured in the supernatants by ELISA. Patients with MS had higher sCD40L and P-selectin than controls (5.96 +/- 0.50 vs. 4.28 +/- 0.41 ng/ml, P < 0.05, and 151 +/- 8 vs. 122 +/- 9 ng/ml, P < 0.05). By contrast, adiponectin was lower in patients with MS than in controls (5.25 +/- 0.30 vs. 7.35 +/- 0.34 microg/ml, P < 0.001). Higher platelet aggregation was found in MS. Adiponectin inversely correlated with P-selectin (R = -0.35, P = 0.009), sCD40L (r = -0.24, P = 0.05) and epinephrine and collagen induced aggregation (r = -0.80, P = 0.005; r = -0.70, P = 0.011). Platelets express the receptors for adiponectin. Platelet aggregatory response to epinephrine and ADP significantly decreased following preincubation with adiponectin (96 +/- 4 vs. 23 +/- 3%, P < 0.001, and 102 +/- 9 vs. 85 +/- 9%, P = 0.004). Adiponectin prevented platelet sCD40L release (1.63 +/- 0.15 vs. 2.04 +/- 0.20 ng/ml, P < 0.001). Enhanced platelet aggregation and activation markers are found in MS associated with low adiponectin concentrations. Novel evidence is provided demonstrating that adiponectin has antithrombotic properties, since it inhibits platelet aggregation and platelet activation

Validation of the Spanish version of the physical activity questionnaire used in the Nurses’ Health Study and the Health Professionals’ Follow-up Study

Objective: The objective of this analysis was to test the validity of the estimates of energy expenditure and sedentary lifestyle obtained through a self-administered questionnaire of physical activity for Spanish-speaking people adapted from US questionnaires (Nurses’ Health Study and Health Professionals’ Follow-up Study) using a triaxial accelerometer (RT3 Triaxial Research Tracker) as the reference. Design and setting: Validation study, calculating the non-parametric correlation coefficients between the level of physical activity and sedentary lifestyle collected by the self-administered questionnaire and the triaxial accelerometer measurements. Percentage of misclassification and kappa coefficients were also calculated. Subjects: The study population consisted of a sample of 40 obese women who were participants of the SUN (Seguimiento Universidad de Navarra) project (a prospective cohort study among Spanish university alumni). They were selected because of their peculiar metabolic characteristics, in the search for a sub-optimal scenario for validity. Results: Physical activity during leisure time (estimated as MET-h week21) derived from the self-administered questionnaire moderately correlated with kcal day21 assessed through the accelerometer (Spearman’s r ¼ 0.507, 95% confidence interval (CI) 0.232, 0.707). The Spearman correlation between the ratio of sedentary lifestyle to physical activity obtained through the questionnaire and the direct estimation (RT3) was 20.578 (95% CI 20.754, 20.325). The kappa index was 0.25 (P ¼ 0.002) when assessing the cross-classification into quintiles and 0.41 for the dichotomous estimation of a sedentary lifestyle. Only 2.5% of participants were misclassified by the questionnaire more than two quintiles apart from the estimates of the RT3. Conclusions: The moderate values obtained for correlation in a sub-optimal scenario for validity and the low percentage of extreme misclassification suggest the validity of the questionnaire to assess physical activity in Spanish-speaking women aged 20–50 years

Distribution and determinants of sedentary lifestyles in the European Union

Background Many studies have shown the health burden of a sedentary lifestyle. The main goal of this study was to determine the prevalence of sedentary lifestyles in the 15 Member States of the European Union (EU) and to identify the main correlates of a sedentary lifestyle. Methods Nationally representative samples (n ≈ 1000 subjects in each country; >15 years) completed a questionnaire concerning attitudes to physical activity, body weight, and health; in total 15 239 subjects. Sedentary people were defined in two ways: (1) those expending less than 10% of their leisure time expenditure in activities involving ≥4 metabolic equivalents (MET). (2) Those who did not practice any leisure-time physical activity and who also were above the median in the number of hours spent sitting down during leisure time. Logistic regression models were fitted to analyse the association between sedentary lifestyles and gender, age, body mass index (BMI), educational level, weight change in the last 6 months, and marital and smoking status. Results Percentages of sedentary lifestyles across European countries ranged between 43.3% (Sweden) and 87.8% (Portugal) according to the first definition. According to both definitions, a lower prevalence of sedentary lifestyle was found in Northern countries (especially Scandinavian countries) as compared with Mediterranean countries, whereas the prevalence was higher among older, obese, less educated, widowed/divorced individuals, and current smokers. Similar relative differences between countries and socio-demographic groups were found independently of the method used to define a sedentary lifestyle. Conclusion Prevalence of sedentary lifestyle in the EU is high, especially among inhabitants of some Mediterranean countries, obese subjects, less-educated people, and current smokers. This high prevalence involves important public health burdens and preventive strategies are urgently needed

Prevalence of physical activity during leisure time in the European Union

PURPOSE: To estimate the prevalence of physical activity during leisure time in adults from the 15 member states of the European Union and the relationship with sociodemographic variables. METHODS: A representative sample, with approximately 1000 adults, aged 15 and upward, was selected from each member state to complete a questionnaire on attitudes to physical activity, body weight, and health by a face-to-face interview, summing a total of 15,239 subjects. The amount of leisure-time physical activity was quantified by assigning metabolic equivalents (METs) to each activity. Multiple linear regression models with MET-h.wk(-1) as the dependent variable were fitted. RESULTS: Northern European countries showed higher levels of physical activity than southern ones. The highest prevalence (91.9%) was found in Finland, and the lowest (40.7%) in Portugal. A higher percentage of men practiced any leisure-time physical activity and also showed higher mean of MET-h.wk(-1). In both genders, the multivariate models showed a significant trend to higher leisure time activity in participants with higher educational levels and in nonsmokers. Also, an inverse association between body mass index and leisure-time physical activity was found. CONCLUSION: The prevalence of any physical activity during leisure time in the adult European population was similar to the U.S. estimates. Nevertheless, the amount of activity is low, and a wide disparity between countries exists. To our knowledge, this is the first study determining the prevalence and amount of leisure-time physical activity, which is the first step to define strategies to persuade populations to increase their physical activity

The influence of obesity on the assessment of carotid intima-media thickness

BACKGROUND.: The assessment of carotid intima-media thickness (CIMT) may improve cardiovascular risk prediction. The optimal protocol for CIMT measurement is unclear. CIMT may be measured in the common carotid artery (CCA), carotid bifurcation (CB), and internal carotid artery (ICA), but measurements from CB and ICA are more difficult to obtain. We studied the influence of body mass index (BMI) and atheroma plaques on the capacity to obtain CIMT measurements at different carotid sites. METHODS.: Using an automatic system, CIMT was measured in 700 subjects aged 45-75, in the near and far walls of CCA, CB, and ICA bilaterally. The presence of atheroma plaques, BMI and vascular risk factors were recorded. RESULTS.: CIMT measurements in CCA were possible in all except one subject. It was not possible to obtain CIMT measurements at CB or ICA in 24.1% of normal weight and 58.8% of obese subjects. The likelihood of obtaining CIMT measurement at all carotid sites decreased as the BMI increased. Atheroma plaques in a carotid segment did not preclude CIMT measurement at this site. CONCLUSIONS.: CIMT measurements in distal carotid segments are more challenging in obese subjects. Measuring CIMT at CCA remains feasible in obese subjects and should be the primary endpoint in these subjects. Nevertheless, CB and ICA measurements, when feasible, would improve risk classification