Gymnastik- och idrottshögskolan, GIH

Objectives: We investigated changes in weight, exercise frequency, and perceived health from the first to last health profile assessment (HPA) and between the number of tests within five years. We examined whether sociodemographic factors, or baseline values influenced these changes.

Methods: Data from 106 005 employees with ≥2 HPA (1990-2021) were included. Change between the first and last HPA within a five-year period was analyzed. Baseline age, sex, education, occupation, and baseline values of each outcome were included as predictors. XGBoost models assessed changes in the outcomes, and performance was evaluated via root mean squared error, mean absolute error, and R-squared. We employed Shapley Additive Explanations and forward marginal effects to interpret dose-response relationships and subgroup differences.

Results: Predictive performance was low, suggesting that the included variables only partially explained observed changes. Nonetheless, longer intervals between the first and last HPA correlated with greater weight gain, while a higher number of tests predicted slightly lower weight gain and modest improvements in perceived health and exercise frequency, compared to the average change. Younger participants had larger weight increases, whereas those with higher education showed smaller declines in exercise frequency.

Conclusions: Infrequent HPA alone did not appear to substantially influence the lifestyle-related factors studied. However, more frequent HPA, coupled with enhanced feedback and support, may yield small improvements in weight, perceived health, and exercise frequency compared to the average change.

OBJECTIVE: The aims were to investigate the association between youth physical activity and the risk of cardiovascular disease (CVD) later in life in men and women and whether mid-life lifestyle-associated factors, including exercise, smoking, Body Mass Index (BMI), and cardiorespiratory fitness (VO₂max), mediate this association.

METHODS: Data from 269,431 Swedish participants (52 % men) who participated in occupational health profile assessments between 1995 and 2023 were included. Youth physical activity was self-reported as overall participation in school-based physical education and physical activity outside school before age 20. CVD incidence was obtained from national registers. Mediation analyses assessed mid-life lifestyle-associated factors' influence on the association.

RESULTS: Compared to those reporting no physical education participation, participation in only physical education was associated with a 18 % lower risk for CVD later in life (HR = 0.82, 95 % CI 0.70,0.95). Participating in additional physical activity outside school yielded varying risk estimates (HR = 0.78, 95 % CI 0.67,0.90 for one to two times/week; HR = 0.84, 95 % CI 0.73,0.97 for three to five times/week). VO₂max, BMI, and smoking mediated 16 %-32 % of the association. In the single mediation model, cardiorespiratory fitness explicitly mediated the association in those who participated in physical education and at least one weekly sessions of physical activity outside school.

CONCLUSION: Youth refraining from participating in physical education class could be considered a risk group for later-life CVD. Mediation analyses suggest that engaging in only physical education or with additional physical activity outside school in youth, may confer more healthy behaviour in mid-life, which explain the lower CVD risk.

INTRODUCTION: The aim of this prospective cohort study was to investigate the associations between changes in cardiorespiratory fitness (CRF) and the risk of colorectal and prostate cancer in men.

METHODS: Data from men who completed a health assessment both in military conscription in youth and an occupational health profile assessment (HPA) later in life were used. CRF was assessed as estimated V̇O_2max, using a cycle ergometer fitness test at both time points. We linked the assessment data to national register data on colorectal and prostate cancer incidence, and hazard ratios and confidence intervals were estimated using Cox proportional hazard regression.

RESULTS: 139,764 men with a mean age of 18 (SD 0.6) at conscription and 43 (SD 8.9) at HPA were included. The average time between the two assessments was 25.9 (SD 9.0) years and mean follow-up time following HPA test was 10.0 (SD 5.6) years for prostate and colorectal cancer. Annual percentage change in relative and absolute V̇O_2max from conscription to HPA was inversely associated with the risk of colorectal cancer incidence, hazard ratio of 0.83 (95% CI [0.72-0.94]) and 0.88 (95% CI [0.79-0.99]), respectively. These associations were driven by data from individuals in the lowest and moderate level fitness tertials at conscription. Change in CRF was not associated with prostate cancer incidence risk.

CONCLUSIONS: Changes in, not only level of, CRF from youth to adulthood are related to colorectal cancer incidence risk and therefore, improving CRF should be considered as an important colorectal cancer risk reduction strategy.

OBJECTIVES: This study aimed to investigate the reach of a large-scale health assessment delivered by the occupational health service in Sweden for almost 30 years.

METHODS: A total of 418 286 individuals who participated in a health assessment (Health Profile Assessment, HPA) between 1995-2021 were included. A comparative sample was obtained from Statistics Sweden, comprising the entire working population for each year (4 962 127-6 011 829 unique individuals per time period). Sociodemographic and work organization characteristics were compared between the HPA and comparative population for six different periods. Under- and overrepresented groups in the private and public sectors were identified using the most recent data (2015-2021).

RESULTS: With negative per cent indicating underrepresentation, the most notable changes over time in representation in the HPA population compared to the comparative were observed for women (-1.2% to -12.8%), private sector employees (-9.4% to 14.9%), individuals with ≥3 years of employment (14.5% to 0.9%), in personal care (0.8% to -8.8%) and manufacturing (0.7% to 6.4%) occupations. Consistently overrepresented groups (median representation across periods) included individuals who had a single income source (6.3%) and were middle-aged (10.8%), born in Sweden (5.9%), associate professionals (8.7%), and employed in companies with high operating profit (17.9%) and low staff turnover (14.3%). Conversely, individuals with low income (-34.0%) and employed in small companies/organizations (-10.9%) were consistently underrepresented. Middle-aged women in education occupations were most underrepresented in the public sector, while in the private sector, it was young women in service and shop sales occupations.

CONCLUSIONS: This health assessment has reached many professionals, including hard-to-reach groups, but did not fully represents the Swedish workforce throughout the years.

AIMS: Submaximal tests estimating VO₂max have inherent biases; hence, using VO₂max estimations from the same test is essential for reducing this bias. This study aimed to establish sex- and age-specific reference values for estimated VO₂max using the Åstrand-test (Å-test) and the Ekblom-Bak test (EB-test). We also assessed the effects of age, exercise level, and BMI on VO₂max estimations.

METHODS: We included men and women (20-69 years) from the Swedish working population participating in Health Profile Assessments between 2010 and 2020. Excluding those on heart rate-affecting medicines and smokers, n = 263,374 for the Å-test and n = 95,043 for the EB-test were included. VO₂max reference values were based on percentiles 10, 25, 40, 60, 75, and 90 for both sexes across 5-year age groups.

RESULTS: Estimated absolute and relative VO₂max were for men 3.11 L/min and 36.9 mL/min/kg using the Å-test, and 3.58 L/min and 42.4 mL/min/kg using the EB-test. For women, estimated absolute and relative VO₂max were 2.48 L/min and 36.6 mL/min/kg using the Å-test, and 2.41 L/min and 35.5 mL/min/kg using the EB-test. Higher age (negative), higher exercise level (positive), and higher BMI (negative) were associated with estimated VO₂max using both tests. However, explained variance by exercise on estimated VO₂max was low, 10% for the Å-test and 8% for the EB-test, and moderate for BMI, 23% and 29%.

CONCLUSION: We present reference values for estimated VO₂max from two submaximal cycle tests. Age, exercise, and BMI influenced estimated VO₂max. These references can be valuable in clinical evaluations using the same submaximal tests.

The main aim of this thesis was to study cardiorespiratory fitness, physical workload, and lifestyle-related factors, with a special emphasis on cardiorespiratory fitness in an occupational context and the associations with cardiovascular disease and sickness absence across a wide range of occupations. A secondary aim was to study trends in cardiorespiratory fitness in different occupational groups over the last decades.

The thesis is based on data from health profile assessments performed in the Swedish working population over the last decades and consists of four studies. Paper I examines health risk factors across a diverse range of occupational groups and finds that high-skilled occupations have a more favorable health risk profile than low-skilled occupations, with some sub-major categories displaying a more unfavorable health risk profile than others. Paper III demonstrates that individuals in low-skilled and blue-collar occupations have a significantly higher risk of incident cardiovascular disease than high-skilled white-collar workers. Cardiorespiratory fitness, smoking, and body mass index partially explain this association. Paper IV shows that occupational physical workload is associated with sickness absence, where a higher physical workload is related with a higher risk of total sickness absence due to musculoskeletal and cardiorespiratory causes but a lower risk of sickness absence due to psychiatric causes. Higher cardiorespiratory fitness is associated with reduced predicted days of sickness absence, mainly for cardiorespiratory diagnoses and musculoskeletal diagnoses, with some variations between occupational groups. Paper II finds a consistent decline in cardiorespiratory fitness from 2001 to 2020. This decline is more pronounced in low-skilled occupations, regardless of their classification as white-collar or blue-collar. Forecast analyses revealed a continuing downward trend in cardiorespiratory fitness, particularly in low-skilled occupations.

In conclusion, promoting smoking cessation, reduced obesity, and physical activities to improve cardiorespiratory fitness may reduce the disparity in cardiovascular disease incidence observed across occupational groups. The decline in cardiorespiratory fitness, particularly in low-skilled occupations, is concerning and calls for targeted interventions that can reach out to those who need it most. This could be achieved through structural and individual-level changes at the workplace and in society at large.

The main aim was to examine the association between occupational groups and incident cardiovascular disease (CVD), and to which extent associations are mediated by lifestyle-associated variables (cardiorespiratory fitness, smoking, BMI, exercise, and diet). A total of 304.702 participants (mean age 42.5 yrs., 47% women), who performed a health profile assessment in Sweden between 1982 and 2019, were included in the analyses. CVD incidence was obtained from national registers. All participants were free from CVD prior to the health profile assessment. Occupational group was defined using the Swedish Standard Classification of Occupations and analyzed separately (13 different occupational groups) as well as after aggregation into four occupational groups (white-collar high-skilled, white-collar low-skilled, blue-collar high-skilled and blue-collar low-skilled). Cardiorespiratory fitness, BMI, exercise, smoking, and diet were included as mediators and analyzed separately in single models and simultaneously in one multiple mediation model. All mediation analyses were adjusted for sex, age, length of education and calendar time. White-collar high-skilled was set as reference in all analyses. Blue-collar and low-skilled occupation had a higher risk of incident CVD compared to reference. Cardiorespiratory fitness, BMI, exercise, smoking, and diet mediated 48% to 54% of the associations between reference and the other aggregated occupational groups. In the single model, the strongest mediators were cardiorespiratory fitness, smoking and BMI. In conclusion, blue-collar and low skilled occupations had a significantly higher risk for incident CVD compared to white-collar high-skilled workers, with the association mediated to a large extent by variation in lifestyle-associated variables.

Sickness absence from work has a large adverse impact on both individuals and societies in Sweden and the costs for sickness absence were calculated to 64.6 billion Swedish kronor (approx. 5.6 billion in Euros) in 2020. Although high cardiorespiratory fitness may protect against potential adverse effects of high physical workload, research on the moderating effect of respiratory fitness in the relation between having an occupation with high physical workload and sickness absence is scarce. To study the moderating effect of cardiorespiratory fitness in the association between occupation and psychiatric, musculoskeletal, and cardiorespiratory diagnoses. Data was retrieved from the HPI Health Profile Institute database (1988-2020) and Included 77,366 participants (mean age 41.8 years, 52.5% women) from the Swedish workforce. The sample was chosen based on occupational groups with a generally low education level and differences in physical workload. Hurdle models were used to account for incident sickness absence and the rate of sickness absence days. There were differences in sickness absence between occupational groups for musculoskeletal and cardiorespiratory diagnoses, but not for psychiatric diagnoses. In general, the association between occupation and musculoskeletal and cardiorespiratory diagnoses was moderated by cardiorespiratory fitness in most occupational groups with higher physical workload, whereas no moderating effect was observed for psychiatric diagnoses. The study results encourage community and workplace interventions to both consider variation in physical workload and to maintain and/or improve cardiorespiratory fitness for a lower risk of sickness absence, especially in occupations with high physical workload.

AIMS: To describe time trends in combinations of cardiorespiratory fitness (CRF) and body mass index (BMI) status, and to analyse their associations with cardiovascular disease (CVD) incidence and mortality and all-cause mortality.

METHODS AND RESULTS: Prospective cohort study with data from occupational health screenings in Swedish employees, including n = 471 216 (aged 18-74 years) between 1995 and 2020, and n = 169 989 in risk analyses. Cardiorespiratory fitness was estimated from a submaximal cycle test. High CRF was defined as top quartile, and low CRF as bottom quartile. Body mass index was used to define normal weight (18.5-24.9 kg/m2), overweight (25.0-29.9 kg/m2), and obesity (≥30 kg/m2). Outcome data (CVD incidence and mortality, all-cause mortality) were obtained from national registers. From 1995 to 2020, the combination of obesity + low CRF increased from 2.1% to 5.3% (relative increase 154%) whereas the combination of normal weight + high CRF decreased from 13.2% to 9.3% (-30%) (both P < 0.001). Negative changes were more pronounced in men, younger ages, and non-university educated. At the end of the period, prevalence of obesity + low CRF were higher in men vs. women (3.1% vs. 2.2%), older vs. younger (3.7% vs. 1.7%), and in non-university vs. university educated (5.0% vs. 0.3%), all P-value <0.001. Having a high CRF attenuated the risk of all three outcomes in all BMI categories, especially in individuals with obesity (hazard ratio 3.90 vs. 6.67 for CVD mortality). Both a low BMI and a high CRF prolonged age of onset for all three outcomes.

CONCLUSIONS: The combination of obesity with low CRF has increased markedly since the mid-90s, with clear implications for increased CVD morbidity and mortality, and all-cause mortality.

Objectives: This study aimed to identify main sex-specific correlates of cardiorespiratory fitness (CRF) in a population-based, urban sample of Swedish adults.

Design: Cross-sectional.

Setting: Multi-site study at university hospitals, data from the Gothenburg site.

Participants: A total of 5308 participants (51% women, aged 50-64 years) with a valid estimated VO2max, from submaximal cycle test, in the Swedish CArdioPulmonary bioImage Study (SCAPIS), were included.

Primary and secondary outcomes: A wide range of correlates were examined including (a) sociodemographic and lifestyle behaviours, (b) perceived health, anthropometrics and chronic conditions and (c) self-reported as well as accelerometer-derived physical activity and sedentary behaviours. Both continuous levels of estimated VO2max as well as odds ratios (OR) and confidence intervals (CI)s of low VO2max (lowest sex-specific tertile) were reported.

Results: In multivariable regression analyses, higher age, being born abroad, short education, high waist circumference, poor perceived health, high accelerometer-derived time in sedentary and low in vigorous physical activity, as well as being passive commuter, correlated independently and significantly with low VO2max in both men and women (OR range 1.31-9.58). Additionally in men, financial strain and being an ex-smoker are associated with higher odds for low VO2max (OR 2.15; 95% CI 1.33 to 3.48 and OR 1.40; 95% CI 1.09 to 1.80), while constant stress with lower odds (OR 0.61; 95% CI 0.43 to 0.85). Additionally in women, being a regular smoker is associated with lower odds for low VO2max (OR 0.64; 95% CI 0.45 to 0.92).

Conclusions: The present study provides important reference material on CRF and correlates of CRF in a general middle-aged population, which can be valuable for future research, clinical practice and public health work. If relations are causal, increased knowledge about specific subgroups will aid in the development of appropriate, targeted interventions.