A Growing Social Divide in Body Mass Index, Strength, and Fitness of Swedish Male Conscripts

Poor stress resilience in adolescence predicts higher risk of severe COVID-19 and other respiratory infections: A prospective cohort study of 1.4 million Swedish men

OBJECTIVES

To investigate the associations between stress resilience in late adolescence and later risk of severe COVID-19 and other lower respiratory infections. A secondary aim was to examine potential confounding between low cardiorespiratory fitness (CRF) and stress resilience in relation to respiratory infection.

METHODS

We conducted a registry-based cohort study of 1.4 million Swedish men, undergoing military conscription between 1968 and 2005. All were assessed by a psychologist for stress resilience, receiving a score between 1 and 9. The outcomes were hospitalization or death due to COVID-19 from March 2020 to September 2021 and hospitalization due to bacterial or viral pneumonia from conscription until January 2020. A secondary aim was to examine potential confounding between low cardiorespiratory fitness (CRF) and stress resilience in relation to respiratory infection.

RESULTS

Poor stress resilience in late adolescence is associated with later risk of severe lower respiratory infections. Using a high resilience score as the reference, the hazard ratio (95 % CI) for death due to COVID-19 for the lowest scores was 1.49 (1.01-2.18) adjusted for CRF and other confounders. The corresponding adjusted hazard ratios for hospitalization due to bacterial pneumonia were 2.28 (2.03-2.57) and for viral pneumonia 1.92 (1.33-2.79). No significant interaction was seen between stress resilience and CRF in the analysis.

CONCLUSIONS

Poor stress resilience is a prospective factor for severe COVID-19 as well as for bacterial and viral respiratory pneumonia endpoints, independent of CRF. These findings imply an effect of late adolescent stress resilience on the immune system later in life.

Temporal trends and educational inequalities in obesity, overweight and underweight in pre-pregnant women and their male partners: a decade (2010-2019) with no progress in Sweden

BACKGROUND

Trends in overweight and obesity among expectant parents can provide useful information about the family environment in which children will grow up and about possible social inequalities that may be passed on to them. Therefore, we aimed to assess whether the prevalence of underweight, overweight and obesity changed over time in pre-pregnant women and their male partners in northern Sweden, and if there were any educational inequalities.

METHODS

This study is based on cross-sectional data from a repeated survey of the population in Västerbotten, Sweden. The study population included 18,568 pregnant women and 18,110 male partners during the period 2010-2019. Multinomial logistic regression models were fitted separately for pregnant women and male partners to assess whether the prevalence of age-adjusted underweight, normal weight, overweight and obesity had evolved between 2010 and 2019, and whether trends differed by educational level.

RESULTS

Among women, obesity prevalence increased from 9.4% in 2010 to 11.7% in 2019. Among men, it went from 8.9 to 12.8%. Educational inequalities were sustained across the study period. In 2019, the prevalence of obesity was 7.8 percentage points (pp) (CI = 4.4-11.3) higher among women with low compared to high education. The corresponding figure for men was 6.4 pp (CI = 3.3-9.6).

CONCLUSIONS

It is not obvious that the prevalence of obesity among parents-to-be will decrease under current dispositions. Public health policies and practice should therefore be strengthened.

Occupation-specific risk estimates for suicide and non-fatal self-harm from a Swedish cohort of male construction workers followed 1987-2018

OBJECTIVES

While suicidal behaviour has become less prevalent in non-manual workers in recent decades, rates have increased in manual workers. We aimed to identify occupations within the construction industry with excess risk of suicide and non-fatal self-harm.

METHODS

This cohort of Swedish construction workers comprises 389 132 individuals examined 1971-1993 and followed 1987-2018 using national hospital and cause of death registers. More than 200 job titles were merged into 22 occupational groups. For 296 891 men alive in 1987 and active in the construction sector, survival was calculated from baseline to first event of non-fatal self-harm or suicide and censored for emigration, long-term unemployment, disability pension, retirement, death from other causes or end of follow-up. HRs with 95% CIs were obtained from multiple Cox proportional hazard regression.

RESULTS

Overall, 1618 cases of suicide and 4774 events of non-fatal self-harm were registered. Self-harm before baseline was the single largest risk factor for suicide, HR 9.3 (95% CI 7.5 to 11.6). Compared with the overall mean, labourers and rock workers had excess risk for suicide, HR 1.4 (95% CI 1.1 to 1.7) and 1.5 (95% CI 1.0 to 2.3), respectively, while electricians, clerks and foremen had reduced risk. Labourers, concrete workers, sheet metal workers, painters, glaziers and the group 'other construction workers' were at increased risk for non-fatal self-harm. Almost all categories of manual workers were at increased risk for suicidal behaviour relative to clerks and foremen.

CONCLUSIONS

Specific occupations within the construction sector were associated with excess risk for suicidal behaviour. Future studies should identify underlying risk factors to inform tailored interventions.

Do early life factors explain the educational differences in early labour market exit? A register-based cohort study

BACKGROUND

Socioeconomic inequalities in labour market participation are well established. However, we do not fully know what causes these inequalities. The present study aims to examine to what extent factors in childhood and late adolescence can explain educational differences in early labour market exit among older workers.

METHODS

All men born in 1951-1953 who underwent conscription examination for the Swedish military in 1969-1973 (n = 145 551) were followed from 50 to 64 years of age regarding early labour market exit (disability pension, long-term sickness absence, long-term unemployment and early old-age retirement with and without income). Early life factors, such as cognitive ability, stress resilience, and parental socioeconomic position, were included. Cox proportional-hazards regressions were used to estimate the association between the level of education and each early labour market exit pathway, including adjustment for early life factors.

RESULTS

The lowest educated men had a higher risk of exit through disability pension (HR: 2.72), long-term sickness absence (HR: 2.29), long-term unemployment (HR: 1.45), and early old-age retirement with (HR: 1.29) and without income (HR: 1.55) compared to the highest educated men. Factors from early life explained a large part of the educational differences in disability pension, long-term sickness absence and long-term unemployment but not for early old-age retirement. Important explanatory factors were cognitive ability and stress resilience, whilst cardiorespiratory fitness had negligible impact.

CONCLUSIONS

The association between education and early exit due to disability pension, long-term sickness absence and long-term unemployment was to a large part explained by factors from early life. However, this was not seen for early old-age retirement. These results indicate the importance of taking a life-course perspective when examining labour market participation in later working life.

Assessment of physical activity among adolescents: a guide to the literature

Purpose

The aim of this article is to systematically review articles and annual reports concerning young peoples' physical activity (PA) and linking this to considerations of the state and national defense.

Method

A systematic search of the literature included an analysis of publications accessible in global databases and other available books, student papers, and projects. The articles and reports were categorized based on year of publication, methods used, age of respondents, sample size, country, and digital object identifier (DOI).

Results

The result of this search is an overview of the extent and manner in which the worldwide scientific community is addressing the current situation and the long-term development of the physical fitness of adolescents. This publication also maps to what extent professional publications and articles are addressing PA from the perspective of the needs of armies and armed forces of various countries around the world.

Conclusions

The article provides a systematic overview of methods used to measure PA, and an overview of articles dealing with assessing PA. The examined articles indicate that from the perspective of not only national defense, but also health and overall quality of life, in particular, we need initiatives to encourage and motivate young people to increase their everyday PA. The research therefore also includes an overview of factors that may considerably influence PA. The results ascertained in this publication will be used, i.a. for investigating a longitudinal defense research project of the Ministry of Defense of the Czech Republic in which the authors are participating.

Body Weight in Adolescent Men in Sweden and Risk of an Early Acute Coronary Event: A Prospective Population-Based Study

Background Coronary heart disease remains the dominant cause of death worldwide. To improve cardiovascular disease prevention, knowledge of early key risk factors, especially those that are modifiable, is essential. The ongoing global obesity epidemic is of particular concern. We aimed to determine whether body mass index at conscription predicts early acute coronary events among men in Sweden. Methods and Results This was a population-based Swedish cohort study of conscripts (n=1 668 921; mean age, 18.3 years; 1968-2005), with follow-up through linkage to the nationwide Swedish patient and death registries. Risk of a first acute coronary event (hospitalization for acute myocardial infarction or coronary death) during follow-up (1-48 years) was calculated with generalized additive models. Objective baseline measures of fitness and cognition were included in the models in secondary analyses. During follow-up, there were 51 779 acute coronary events, of which 6457 (12.5%) were fatal within 30 days. Compared with men at the lowest end of the normal body mass index spectrum (body mass index, 18.5 kg/m²), an increasing risk for a first acute coronary event was observed, with hazard ratios (HRs) peaking at 40 years of age. After multivariable adjustments, men with a body mass index of 35 kg/m² had an HR of 4.84 (95% CI, 4.29-5.46) for an event before the age of 40 years. Conclusions An increased risk of an early acute coronary event was detectable within normal levels of body weight at the age of 18 years, increasing to almost 5-fold in the highest weight category at 40 years of age. Given increasing levels of body weight and prevalence of overweight and obesity in young adults, the current decrease in coronary heart disease incidence in Sweden may flatten or even reverse in the near future.

Body Mass Index in Adolescence and Long-Term Risk of Early Incident Atrial Fibrillation and Subsequent Mortality, Heart Failure, and Ischemic Stroke

Background We sought to determine the role of obesity in adolescent men on development of atrial fibrillation (AF) and subsequent associated clinical outcomes in subjects diagnosed with AF. Methods and Results We conducted a nationwide, register-based, cohort study of 1 704 467 men (mean age, 18.3±0.75 years) enrolled in compulsory military service in Sweden from 1969 through 2005. Height and weight, blood pressure, fitness, muscle strength, intelligence quotient, and medical disorders were recorded at baseline. Records obtained from the National Inpatient Registry and the Cause of Death Register were used to determine incidence and clinical outcomes of AF. During a median follow-up of 32 years (interquartile range, 24-41 years), 36 693 cases (mean age at diagnosis, 52.4±10.6 years) of AF were recorded. The multivariable-adjusted hazard ratio (HR) for AF increased from 1.06 (95% CI, 1.03-1.10) in individuals with body mass index (BMI) of 20.0 to <22.5 kg/m² to 3.72 (95% CI, 2.44-5.66) among men with BMI of 40.0 to 50.0 kg/m², compared with those with BMI of 18.5 to <20.0 kg/m². During a median follow-up of ≈6 years in patients diagnosed with AF, we identified 3767 deaths, 3251 cases of incident heart failure, and 921 cases of ischemic stroke. The multivariable-adjusted HRs for all-cause mortality, incident heart failure, and ischemic stroke in AF-diagnosed men with baseline BMI >30 kg/m² compared with those with BMI <20 kg/m² were 2.86 (95% CI, 2.30-3.56), 3.42 (95% CI, 2.50-4.68), and 2.34 (95% CI, 1.52-3.61), respectively. Conclusions Increasing BMI in adolescent men is strongly associated with early AF, and with subsequent worse clinical outcomes in those diagnosed with AF with respect to all-cause mortality, incident heart failure, and ischemic stroke.

Fitness, strength and severity of COVID-19: a prospective register study of 1 559 187 Swedish conscripts

OBJECTIVE

To investigate the possible connection between cardiorespiratory fitness (CRF) and muscle strength in early adulthood and severity of COVID-19 later in life.

DESIGN

Prospective registry-based cohort study.

PARTICIPANTS

1 559 187 Swedish men, undergoing military conscription between 1968 and 2005 at a mean age of 18.3 (SD 0.73) years.

MAIN OUTCOME MEASURES

Hospitalisation, intensive care or death due to COVID-19 from March to September 2020, in relation to CRF and muscle strength.

RESULTS

High CRF in late adolescence and early adulthood had a protective association with severe COVID-19 later in life with OR (95% CI) 0.76 (0.67 to 0.85) for hospitalisation (n=2 006), 0.61 (0.48 to 0.78) for intensive care (n=445) and 0.56 (0.37 to 0.85) for mortality (n=149), compared with the lowest category of CRF. The association remains unchanged when controlled for body mass index (BMI), blood pressure, chronic diseases and parental education level at baseline, and incident cardiovascular disease before 2020. Moreover, lower muscle strength in late adolescence showed a linear association with a higher risk of all three outcomes when controlled for BMI and height.

CONCLUSIONS

Physical fitness at a young age is associated with severity of COVID-19 many years later. This underscores the necessity to increase the general physical fitness of the population to offer protection against future viral pandemics.

Social inequalities and trends in pre-pregnancy body mass index in Swedish women

Obesity rates in adolescence and young adulthood have increased in Sweden, reflecting global trends. To which extent this occurs across different socioeconomic strata has not been clarified. The aim of the present study was to investigate trends in social inequalities in body mass index (BMI) in young/mid-adulthood Swedish women. We obtained weight and height for all women aged 20–45 years, at their first registered pregnancy (< 12 weeks of gestation) in the Swedish Medical Birth Register 1982–2013 (1,022,330, mean age = 28.8 years), documenting education and county of residence. Trends in mean BMI and in the prevalence of BMI categories between 1982 and 2013 were estimated across education levels and geographical location. Overall, mean BMI increased from 22.7 kg/m² (SD 3.2) to 24.3 kg/m² (SD 4.4) between 1982 and 2013. Simultaneously, the prevalence of overweight and obesity (BMI ≥ 25 kg/m²) increased from 18.1 to 33.4% while that of moderate obesity (BMI ≥ 30 to < 35 kg/m²) and severe obesity (BMI ≥ 35 kg/m²) increased markedly from 3.4 and 0.4% to 7.4 and 3.1%, respectively. The prevalence of moderate and severe obesity more than doubled during the study period across all educational levels. In conclusion, BMI and moderate and severe obesity increased markedly among young/mid-adulthood Swedish women regardless of education with a widening gap between those with lower and higher education. These growing social inequalities in BMI are likely to cause a rising divide in serious health problems following early and long-lasting obesity.

A randomized controlled trial comparing intensive non-surgical treatment with bariatric surgery in adolescents aged 13-16 years (AMOS2): Rationale, study design, and patient recruitment

Background

Previous non-randomized studies show similar outcomes in adolescents and adults after bariatric surgery. We describe the study protocol, recruitment, and selected baseline data of patients in a randomized multi-center study, the Adolescent Morbid Obesity Surgery 2 (AMOS2).

Methods

Three clinics in Sweden collaborated in designing the study and recruitment of patients from August 1, 2014 to June 30, 2017. Patients were selected among adolescents 13–16 years of age attending third-level obesity care for at least one year. Patients were randomized 1:1 to bariatric surgery (predominantly Roux-en-Y gastric bypass) or intensive non-surgical treatment starting with an eight-week low-calorie-diet.

Results

Fifty adolescents (37 girls) were randomized, 25 (19 girls) to bariatric surgery. Mean age was 15.7 years (range 13.3–16.9), weight 122.6 kg (range 95–183.3), Body Mass Index (BMI) 42.6 kg/m² (range 35.7–54.9) and BMI-SDS 3.45 (range 2.9–4.1). One patient had type 2 diabetes mellitus, and 12/45 (27%) had elevated liver enzymes. There were no significant differences between the groups. For the 39 eligible patients who were offered but declined inclusion, BMI was not different from included patients. However, patients who declined were younger, 15.2 years (p = 0.021). A sex difference was also noted with more of eligible girls, 37/53 (69.8%), than boys, 13/36 (36.1%), wanting to participate in the study (p = 0.002).

Conclusions

This clinical trial, randomizing adolescents with severe obesity to bariatric surgery or intensive non-surgical treatment, aims at informing about whether it is beneficial to undergo bariatric surgery in early adolescence. It will also enlighten the outcome of comprehensive non-surgical treatment. The study was registered at www.clinicalTrials.gov number NCT02378259.

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Bariatric surgery is already a treatment option for adolescents with severe obesity in many countries.

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We recruited 50 patients 13-16 years of age to a randomized controlled trial.

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We aimed at investigating the optimal time point for bariatric surgery.

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Adolescents and their families seemed to make well considered decisions to participate in the study.