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BACKGROUND: Underweight, overweight, and obesity in childhood and adolescence are associated with adverse health consequences throughout the life-course. Our aim was to estimate worldwide trends in mean body-mass index (BMI) and a comprehensive set of BMI categories that cover underweight to obesity in children and adolescents, and to compare trends with those of adults.

METHODS: We pooled 2416 population-based studies with measurements of height and weight on 128·9 million participants aged 5 years and older, including 31·5 million aged 5-19 years. We used a Bayesian hierarchical model to estimate trends from 1975 to 2016 in 200 countries for mean BMI and for prevalence of BMI in the following categories for children and adolescents aged 5-19 years: more than 2 SD below the median of the WHO growth reference for children and adolescents (referred to as moderate and severe underweight hereafter), 2 SD to more than 1 SD below the median (mild underweight), 1 SD below the median to 1 SD above the median (healthy weight), more than 1 SD to 2 SD above the median (overweight but not obese), and more than 2 SD above the median (obesity).

FINDINGS: Regional change in age-standardised mean BMI in girls from 1975 to 2016 ranged from virtually no change (-0·01 kg/m(2) per decade; 95% credible interval -0·42 to 0·39, posterior probability [PP] of the observed decrease being a true decrease=0·5098) in eastern Europe to an increase of 1·00 kg/m(2) per decade (0·69-1·35, PP>0·9999) in central Latin America and an increase of 0·95 kg/m(2) per decade (0·64-1·25, PP>0·9999) in Polynesia and Micronesia. The range for boys was from a non-significant increase of 0·09 kg/m(2) per decade (-0·33 to 0·49, PP=0·6926) in eastern Europe to an increase of 0·77 kg/m(2) per decade (0·50-1·06, PP>0·9999) in Polynesia and Micronesia. Trends in mean BMI have recently flattened in northwestern Europe and the high-income English-speaking and Asia-Pacific regions for both sexes, southwestern Europe for boys, and central and Andean Latin America for girls. By contrast, the rise in BMI has accelerated in east and south Asia for both sexes, and southeast Asia for boys. Global age-standardised prevalence of obesity increased from 0·7% (0·4-1·2) in 1975 to 5·6% (4·8-6·5) in 2016 in girls, and from 0·9% (0·5-1·3) in 1975 to 7·8% (6·7-9·1) in 2016 in boys; the prevalence of moderate and severe underweight decreased from 9·2% (6·0-12·9) in 1975 to 8·4% (6·8-10·1) in 2016 in girls and from 14·8% (10·4-19·5) in 1975 to 12·4% (10·3-14·5) in 2016 in boys. Prevalence of moderate and severe underweight was highest in India, at 22·7% (16·7-29·6) among girls and 30·7% (23·5-38·0) among boys. Prevalence of obesity was more than 30% in girls in Nauru, the Cook Islands, and Palau; and boys in the Cook Islands, Nauru, Palau, Niue, and American Samoa in 2016. Prevalence of obesity was about 20% or more in several countries in Polynesia and Micronesia, the Middle East and north Africa, the Caribbean, and the USA. In 2016, 75 (44-117) million girls and 117 (70-178) million boys worldwide were moderately or severely underweight. In the same year, 50 (24-89) million girls and 74 (39-125) million boys worldwide were obese.

INTERPRETATION: The rising trends in children's and adolescents' BMI have plateaued in many high-income countries, albeit at high levels, but have accelerated in parts of Asia, with trends no longer correlated with those of adults.

CONTEXT: In recent years, an association has been noted between several abnormalities that characterize the metabolic syndrome (MetS) and primary hyperparathyroidism (pHPT). These abnormalities include dyslipidaemia, obesity, insulin resistance and hypertension. The correlations between plasma calcium, parathyroid hormone (PTH) and the variables in the MetS in a normal population are still unclear.

OBJECTIVE: To describe correlations between plasma calcium and PTH and the various abnormalities present in the MetS in a healthy population.

DESIGN: We studied 1016 healthy individuals from the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) population of 70 years old, by means of plasma analyses of calcium, PTH, creatinine, lipids, insulin and glucose, as well as by standardized blood pressure measurements. Further, body mass index (BMI) and waist circumference were determined.

RESULTS: The more National Cholesterol Education Program (NCEP) criteria for the MetS that were met, the higher the s-PTH and albumin-corrected s-calcium. Further, positive correlations between plasma calcium and BMI (P = 0.0003), waist circumference (P = 0.0009) and insulin resistance (P = 0.079) were found. PTH and BMI (P < 0.0001), waist circumference (P < 0.0001), systolic blood pressure (P = 0.0034), diastolic blood pressure (P = 0.0008), serum triglycerides (P = 0.0003) and insulin resistance (P = 0.0003) were positively correlated, whereas serum high density lipoproteins (HDL) (P = 0.036) and PTH were negatively correlated.

CONCLUSIONS: We conclude that PTH correlates with several of the metabolic factors included in the MetS within a normocalcaemic population. In addition, individuals with mild pHPT present significantly more NCEP criteria for MetS. We postulate that increased levels of PTH in pHPT may be associated with the increased cardiovascular morbidity and mortality seen in pHPT.

Background—The nature of the association between levels of physical activity and risk of heart failure is little known. We investigated nonlinear associations of total and leisure time physical activity with risk of heart failure.

Methods and Results—In 1997, 39 805 persons without heart failure completed a questionnaire of lifestyle factors and medical history. We used Cox regression models to investigate total (adjusting for education and previous myocardial infarction) and direct (multivariable-adjusted) effects of self-reported total and leisure time physical activity on risk of heart failure of any cause and heart failure of nonischemic origin. Heart failure diagnoses were obtained until December 31, 2010. Higher leisure time physical activity was associated with lower risk of heart failure of any cause; hazard ratio of the total effect of leisure time physical activity was for fifth versus first quintile 0.54; 95% confidence interval was 0.44 to 0.66. The direct effect was similar. High total daily physical activity level was associated with lower risk of heart failure, although the effect was less pronounced than for leisure time physical activity (total effect hazard ratio, 0.81; 95% confidence interval, 0.69–0.95; fifth versus first quintile). A similar direct effect observed.

Conclusions—Leisure time physical activity was inversely related to risk of developing heart failure in a dose–response fashion. This was reflected in a similar but less pronounced association of total physical activity with risk of heart failure. Only part of the effects appeared to be mediated by traditional risk factors.

AIMS:

We aimed to investigate the association of number of completed races and finishing time with risk of arrhythmias among participants of Vasaloppet, a 90 km cross-country skiing event.

METHODS AND RESULTS:

All the participants without cardiovascular disease who completed Vasaloppet during 1989-98 were followed through national registries until December 2005. Primary outcome was hospitalization for any arrhythmia and secondary outcomes were atrial fibrillation/flutter (AF), bradyarrhythmias, other supraventricular tachycardias (SVT), and ventricular tachycardia/ventricular fibrillation/cardiac arrest (VT/VF/CA). Among 52 755 participants, 919 experienced arrhythmia during follow-up. Adjusting for age, education, and occupational status, those who completed the highest number of races during the period had higher risk of any arrhythmias [hazard ratio (HR)1.30; 95% CI 1.08-1.58; for ≥5 vs. 1 completed race], AF (HR 1.29; 95% CI 1.04-1.61), and bradyarrhythmias (HR 2.10; 95% CI 1.28-3.47). Those who had the fastest relative finishing time also had higher risk of any arrhythmias (HR 1.30; 95% CI 1.04-1.62; for 100-160% vs. >240% of winning time), AF (1.20; 95% CI 0.93-1.55), and bradyarrhythmias (HR 1.85; 95% CI 0.97-3.54). SVT or VT/VF/CA was not associated with finishing time or number of completed races.

CONCLUSIONS:

Among male participants of a 90 km cross-country skiing event, a faster finishing time and a high number of completed races were associated with higher risk of arrhythmias. This was mainly driven by a higher incidence of AF and bradyarrhythmias. No association with SVT or VT/VF/CA was found.

Background:

While physical activity and exercise protects against cardiovascular disease, athletes have higher risk of atrial fibrillation and other arrhythmias. Graded independent and joint influences of exercise capacity and muscle strength on these diseases are unknown.

Methods:

All 1.26 million Swedish men who participated in mandatory military conscription between 1972 and 1995 (at a median age of 18.2 years) contributed. Multivariable-adjusted Cox proportional hazards models were used to evaluate the associations of maximal exercise capacity and muscle strength at conscription to subsequent risk of vascular disease and arrhythmias, as identified in national registries.

Results:

During a median follow-up of 26.3 years, about 26,000 hospitalizations for vascular disease events and 17,000 for arrhythmias occurred. Exercise capacity was inversely associated with risk of vascular disease (hazard ratio [HR] 0.64; 95% confidence interval [CI] 0.61-0.67]; for 5^th vs. 1^st quintile) and so was muscle strength (HR 0.79; 0.76-0.83; for 5^th vs. 1^st quintile ). Similar associations were seen across a range of major vascular disease events. Exercise capacity was associated with incidence of arrhythmias in a U-shaped fashion (HR 0.91; 0.86-0.96; for 3^rd vs. 1^st quintile, and 0.99; 0.94-1.04; for 5^th vs. 1^st quintile). Higher muscle strength was associated with lower risk of arrhythmias (HR 0.87; 0.83-0.91; for 5^th vs. 1^st quintile). 

Conclusion:

Exercise capacity and muscle strength in late adolescence are independently and jointly associated with long-term risk of vascular disease and arrhythmias. The lower risk of vascular events with higher exercise capacity was not outweighed by higher risk of arrhythmias.

BACKGROUND:

While it is well known that physical inactivity is a major risk factor for cardiovascular disease, there is still a search for the mechanisms by which exercise exerts its positive effect. Skeletal muscle fibre type can be affected to some extent by exercise, and different fibre types possess different anti-inflammatory and glucometabolic properties that may influence cardiovascular disease risk.

DESIGN:

Population-based cohort study.

METHODS:

We investigated relations of skeletal muscle morphology to risk of cardiovascular events in a sample of 466 71-year-old men without cardiovascular disease, of which 295 were physically active (strenuous physical activity at least 3 h/week).

RESULTS:

During a median of 13.1 years of follow up, 173 major cardiovascular events occurred. Among physically active men, 10% higher proportion of type-I (slow-twitch oxidative) fibres was associated with a hazard ratio (HR) of 0.84 (95% confidence interval 0.74-0.95) for cardiovascular events, and 10% higher proportion of type-IIx (fast-twitch glycolytic) fibres was associated with a HR of 1.24 (1.06-1.45), adjusting for age. Similar results were observed in several sets of multivariable-adjusted models. No association of muscle fibre type with risk of cardiovascular events was observed among physically inactive men.

CONCLUSIONS:

Higher skeletal muscle proportion of type-I fibres was associated with lower risk of cardiovascular events and a higher proportion of type-IIx fibres was associated with higher risk of cardiovascular events. These relations were only observed in physically active men. Skeletal muscle fibre composition may be a mediator of the protective effects of exercise against cardiovascular disease.

Background: Whilst tall stature has been related to lower risk of vascular disease, it has been proposed as a risk factor for atrial fibrillation. Little is known about other anthropometric measures and their joint effects on risk of atrial fibrillation.

Objectives: We aim to investigate associations and potential joint effects of height, weight, body surface area (BSA) and body mass index (BMI) with risk of atrial fibrillation.

Methods: In a cohort covering 1 153 151 18-year-old men participating in the Swedish military conscription (1972-1995), Cox regression was used to investigate associations of height, weight, BSA and BMI with risk of atrial fibrillation.

Results: During a median of 26.3 years of follow-up, higher height was associated with higher risk of atrial fibrillation (hazard ratio [HR] 2.80; 95% CI 2.63-2.98; for 5th vs. 1st quintile) and so was larger BSA (HR 3.05; 95% CI 2.82-3.28; for 5th vs. 1st quintile). Higher weight and BMI were to a lesser extent associated with risk of atrial fibrillation (BMI: 1.42; 95% CI 1.33-1.52, for 5th vs. 1st quintile). We found a multiplicative joint effect of height and weight. Adjusting for muscle strength, exercise capacity and diseases related to atrial fibrillation attenuated these measures.

Conclusions: Higher height and weight are strongly associated with higher risk of atrial fibrillation. These associations are multiplicative and independent of each other and are summarized in a strong association of body surface area with risk of atrial fibrillation. The mechanisms remain unknown but may involve increased atrial volume load with larger body size.

OBJECTIVE To investigate the associations of exercise capacity and muscle strength in late adolescence with risk of vascular disease and arrhythmia. DESIGN Cohort study. SETTING General population in Sweden. PARTICIPANTS 1.1 million men who participated in mandatory military conscription between 1 August 1972 and 31 December 1995, at a median age of 18.2 years. Participants were followed until 31 December 2010. MAIN OUTCOMES Associations between exercise capacity and muscle strength with risk of vascular disease and subgroups (ischaemic heart disease, heart failure, stroke, and cardiovascular death) and risk of arrhythmia and subgroups (atrial fibrillation or flutter, bradyarrhythmia, supraventricular tachycardia, and ventricular arrhythmia or sudden cardiac death). Maximum exercise capacity was estimated by the ergometer bicycle test, and muscle strength was measured as handgrip strength by a hand dynamometer. High exercise capacity or muscle strength was deemed as above the median level. RESULTS During a median follow-up of 26.3 years, 26 088 vascular disease events and 17 312 arrhythmia events were recorded. Exercise capacity was inversely associated with risk of vascular disease and its subgroups. Muscle strength was also inversely associated with vascular disease risk, driven by associations of higher muscle strength with lower risk of heart failure and cardiovascular death. Exercise capacity had a U shaped association with risk of arrhythmia, driven by a direct association with risk of atrial fibrillation and a U shaped association with bradyarrhythmia. Higher muscle strength was associated with lower risk of arrhythmia (specifically, lower risk of bradyarrhythmia and ventricular arrhythmia). The combination of high exercise capacity and high muscle strength was associated with a hazard ratio of 0.67 (95% confidence interval 0.65 to 0.70) for vascular events and 0.92 (0.88 to 0.97) for arrhythmia compared with the combination of low exercise capacity and low muscle strength. CONCLUSIONS Exercise capacity and muscle strength in late adolescence are independently and jointly associated with long term risk of vascular disease and arrhythmia. The health benefit of lower risk of vascular events with higher exercise capacity was not outweighed by higher risk of arrhythmia.

Objectives. The aims of this study were to evaluate the community-based prevalence of atrial fibrillation (AF) in a western society using a geographically well-defined population in the northern part of Sweden as a reference and to estimate the proportion of patients eligible for oral anticoagulation (OAC) prophylactic therapy according to the stroke risk indices CHADS2 and CHA2DS2-VASc. Bleeding risk was assessed using the HAS-BLED score.

Design. The study population was recruited from AURICULA, a Swedish national quality register for patients receiving anticoagulation treatment. All patients with the diagnosis AF in the catchment area are registered in AURICULA.

Results. Of the 65 532 inhabitants in the catchment area, 1616 were diagnosed with AF (1200 cases were characterized as chronic AF). Thus, the overall prevalence of AF was 2.5%. The prevalence increased with age from 6.3% in patients over 55 years of age to 13.8% in those over 80 years. The prevalence was higher in men than in women in all age groups. Overall, 56.3% and 85.1% of the population were at high risk of stroke (=2 points) according to CHADS2 and CHA2DS2-VASc, respectively. In addition, 26.9% had an increased bleeding risk according to HAS-BLED.

Conclusion. Within this large Caucasian population, we identified the highest community-based prevalence of AF to date. The prevalence was strongly associated with increasing age and male gender. Using CHA2DS2-VASc instead of CHADS2 widened the indication for OAC prophylactic therapy of AF in this population.

Background: Previous studies of patients with "lone" and "idiopathic" atrial fibrillation (AF) have provided conflicting evidence concerning the development, management and prognosis of this condition. Methods: In this nation-wide, retrospective, cohort study, we studied patients diagnosed with incidental AF recorded in national Swedish registries between 1995 and 2008. Controls were matched for age, sex and calendar year of the diagnosis of AF in patients. All subjects were free of any in-hospital diagnosis from 1987 and until patients were diagnosed with AF and also free of any diagnosis within one year from the time of inclusion. Follow-up continued until 2009. We identified 9519 patients (31% women) and 12,468 matched controls. Results: Relative risks (RR) versus controls for stroke or transient ischemic attack (TIA) in women were 19.6, 4.4, 3.4 and 2.5 in the age categories <55, 55-64, 65-74 and 75-85, years respectively. Corresponding figures for men were 3.4, 2.5, 1.7 and 1.9. RR for heart failure were 6.6, 6.6, 6.3 and 3.8 in women and 7.8, 4.6, 4.9 and 2.9 in men. All RR were statistically significant with p < 0.01. RR for myocardial infarction and all-cause mortality were statistically significantly increased only in the two oldest age categories in women and 65-74 years in men. Conclusions: Patients with AF and no co-morbidities at inclusion had at least a doubled risk of stroke or TIA and a tripled risk of heart failure, through all age categories, as compared to controls. Women were at higher RR of stroke or TIA than men.