Reference values for estimated VO2max by two submaximal cycle tests: the Åstrand-test and the Ekblom-Bak test.

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.

Lifestyle-related habits and factors before and after cardiovascular diagnosis: a case control study among 2,548 Swedish individuals.

BACKGROUND: Healthy lifestyle habits are recommended in prevention of cardiovascular disease (CVD). However, there is limited knowledge concerning the change in lifestyle-related factors from before to after a CVD event. Thus, this study aimed to explore if and how lifestyle habits and other lifestyle-related factors changed between two health assessments in individuals experiencing a CVD event between the assessments, and if changes varied between subgroups of sex, age, educational level, duration from CVD event to second assessment and type of CVD event. METHODS: Among 115,504 Swedish employees with data from two assessments of occupational health screenings between 1992 and 2020, a total of 637 individuals (74% men, mean age 47 ± SD 9 years) were identified having had a CVD event (ischemic heart disease, cardiac arrythmia or stroke) between the assessments. Cases were matched with controls without an event between assessments from the same database (ratio 1:3, matching with replacement) by sex, age, and time between assessment (n = 1911 controls). Lifestyle habits included smoking, active commuting, exercise, diet, alcohol intake, and were self-rated. Lifestyle-related factors included overall stress, overall health (both self-rated), physical capacity (estimated by submaximal cycling), body mass index and resting blood pressure. Differences in lifestyle habits and lifestyle-related factors between cases and controls, and changes over time, were analysed with parametric and non-parametric tests. Multiple logistic regression, OR (95% CI) was used to analyse differences in change between subgroups. RESULTS: Cases had, in general, a higher prevalence of unhealthy lifestyle habits as well as negative life-style related factors prior to the event compared to controls. Nevertheless, cases improved their lifestyle habits and lifestyle factors to a higher degree than controls, especially their amount of active commuting (p = 0.025), exercise (p = 0.009) and non-smoking (p < 0.001). However, BMI and overall health deteriorated to a greater extent (p < 0.001) among cases, while physical capacity (p < 0.001) decreased in both groups. CONCLUSION: The results indicate that a CVD event may increase motivation to improve lifestyle habits. Nonetheless, the prevalence of unhealthy lifestyle habits was still high, emphasizing the need to improve implementation of primary and secondary CVD prevention.

Mediation of lifestyle-associated variables on the association between occupation and incident cardiovascular disease.

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 the 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.

Change in cardiorespiratory fitness on self-rated health: prospective cohort study in 98 718 Swedish adults.

Aim: To study how change in cardiorespiratory fitness over time is associated with the development of poor self-rated health in healthy Swedish adults, and whether this association varies with sex, age, body mass index and cardiorespiratory fitness at baseline. A secondary aim was to study the influence of other predictors of self-rated health. Methods: A total of 98,718 participants (45% women, mean age 42.2 years) with two assessments from occupational health service screenings between 1988 and 2019 (mean duration 4.3 years), with good self-rated health at baseline were included. Cardiorespiratory fitness was assessed as estimated maximal oxygen consumption using submaximal cycle testing. Change in cardiorespiratory fitness was expressed as percentage annual change. Poor self-rated health at follow-up was defined as percieving self-rated health as 'poor' or 'very poor'. Results: A large decrease in cardiorespiratory fitness (⩾-3%) was associated with a 34% higher risk of poor self-rated health compared to maintainers (-1 to +1%) after multi-adjustment including change in body mass index, back/neck pain, stress, exercise habits and sleep quality or sleep problems. The associations for decreasers were stronger with longer follow-up time (>10 years). Preserving, or changing to, risk level for body mass index, back/neck pain, stress, exercise and sleep quality/problems were associated with a higher risk of poor self-rated health. Conclusions: Preserving or increasing cardiorespiratory fitness is associated with a lower risk of poor self-rated health, independently of change in other health-related variables, which may act as a protection against future poor self-rated health. This is of high clinical value, and strategies for maintaining or improving cardiorespiratory fitness have the potential to influence both disease and mortality.

Disparities in Coronavirus Disease 2019 Mortality by Country of Birth in Stockholm, Sweden: A Total-Population-Based Cohort Study.

Preliminary evidence points to higher morbidity and mortality from coronavirus disease 2019 (COVID-19) in certain racial and ethnic groups, but population-based studies using microlevel data are lacking so far. We used register-based cohort data including all adults living in Stockholm, Sweden, between January 31, 2020 (the date of the first confirmed case of COVID-19) and May 4, 2020 (n = 1,778,670) to conduct Poisson regression analyses with region/country of birth as the exposure and underlying cause of COVID-19 death as the outcome, estimating relative risks and 95% confidence intervals. Migrants from Middle Eastern countries (relative risk (RR) = 3.2, 95% confidence interval (CI): 2.6, 3.8), Africa (RR = 3.0, 95% CI: 2.2, 4.3), and non-Sweden Nordic countries (RR = 1.5, 95% CI: 1.2, 1.8) had higher mortality from COVID-19 than persons born in Sweden. Especially high mortality risks from COVID-19 were found among persons born in Somalia, Lebanon, Syria, Turkey, Iran, and Iraq. Socioeconomic status, number of working-age household members, and neighborhood population density attenuated up to half of the increased COVID-19 mortality risks among the foreign-born. Disadvantaged socioeconomic and living conditions may increase infection rates in migrants and contribute to their higher risk of COVID-19 mortality.

Cardiorespiratory fitness and lifestyle on severe COVID-19 risk in 279,455 adults: a case control study.

BACKGROUND: The impact of cardiorespiratory fitness (CRF) and other lifestyle-related factors on severe COVID-19 risk is understudied. The present study aims to investigate lifestyle-related and socioeconomic factors as possible predictors of COVID-19, with special focus on CRF, and to further study whether these factors may attenuate obesity- and hypertension-related risks, as well as mediate associations between socioeconomic factors and severe COVID-19 risk. METHODS: Out of initially 407,131 participants who participated in nationwide occupational health service screening between 1992 and 2020, n = 857 cases (70% men, mean age 49.9 years) of severe COVID-19 were identified. CRF was estimated using a sub-maximum cycle test, and other lifestyle variables were self-reported. Analyses were performed including both unmatched, n = 278,598, and sex-and age-matched, n = 3426, controls. Severe COVID-19 included hospitalization, intensive care or death due to COVID-19. RESULTS: Patients with more severe COVID-19 had significantly lower CRF, higher BMI, a greater presence of comorbidities and were more often daily smokers. In matched analyses, there was a graded decrease in odds for severe COVID-19 with each ml in CRF (OR = 0.98, 95% CI 0.970 to 0.998), and a two-fold increase in odds between the lowest and highest (< 32 vs. ≥ 46 ml·min-1·kg-1) CRF group. Higher BMI (per unit increase, OR = 1.09, 1.06 to 1.12), larger waist circumference (per cm, OR = 1.04, 1.02 to 1.06), daily smoking (OR = 0.60, 0.41 to 0.89) and high overall stress (OR = 1.36, 1.001 to 1.84) also remained significantly associated with severe COVID-19 risk. Obesity- and blood pressure-related risks were attenuated by adjustment for CRF and lifestyle variables. Mediation through CRF, BMI and smoking accounted for 9% to 54% of the associations between low education, low income and blue collar/low skilled occupations and severe COVID-19 risk. The results were consistent using either matched or unmatched controls. CONCLUSIONS: Both lifestyle-related and socioeconomic factors were associated with risk of severe COVID-19. However, higher CRF attenuated the risk associated with obesity and high blood pressure, and mediated the risk associated with various socioeconomic factors. This emphasises the importance of interventions to maintain or increase CRF in the general population to strengthen the resilience to severe COVID-19, especially in high-risk individuals.

The Fertility of Immigrants From Low-Fertility Settings: Adaptation in the Quantum and Tempo of Childbearing?

Immigrant women who have lived longer in a destination often have relatively low levels of fertility, which is sometimes taken as evidence of the adaptation of behavior. This evidence is almost exclusively based on studies of immigrants from high-fertility settings, while the fertility of immigrants from low-fertility settings has been largely overlooked. Research has also rarely studied the fertility of immigrants who migrated as children, despite the methodological advantages of applying such an approach. This study focuses on women who grew up in Sweden with a migration background from low-fertility origins. We expect that Sweden's welfare regime makes it easier for women to combine childbearing and working life, regardless of migration background, thereby facilitating an adaptation of fertility behavior toward that prevailing in Sweden. We find evidence of adaptation in terms of birth timing for at least half of the country-origin groups that we study, but very little evidence of adaptation in terms of completed fertility. Further, we find that, in comparison with ancestral Swedes, completed fertility differentials are larger for second-generation individuals than for immigrants who arrived during childhood. This is evidence against the notion of "straight-line" adaptation for immigrants and the children of immigrants who are born in Sweden.

Prevalence and time trends of overweight, obesity and severe obesity in 447,925 Swedish adults, 1995-2017.

Aims: The purpose of this research was to describe the current prevalence and historic trends in overweight, obesity and severe obesity in Sweden. Methods: Data on BMI, age, gender, education and geographic region were obtained in n=447,925 Swedish adults through a nationwide screening test (1995-2017). To account for sampling variations, we quantified prevalence estimates and time trends using standardized values (direct method) to all 18-74-year-old Swedes, using nationwide databases. Rates of overweight (BMI ⩾25 kg/m2), obesity (BMI ⩾30 kg/m2) and severe obesity (BMI ⩾35 kg/m2) were calculated across gender, age, education and geographic categories. Years were grouped into two-year sampling periods (except the first period where we used three years) for increased power. We used multivariable logistic regression to quantify independent associations between age, gender, education and region with obesity development and current prevalence rates. Results: In 2016/17 the unstandardized prevalence of overweight, obesity and severe obesity were 55.1%, 16.6% and 4.2%, respectively. Factors associated with a higher obesity prevalence were male gender, older age, lower education and residing in a rural region (all P<0.001). Between 1995 and 2017 the prevalence of severe obesity increased by 153%, compared to obesity (+86%) and overweight (+23%). While there were similar increases in obesity across gender and age groups, people with low education (vs high) and rural areas (vs urban) had a higher prevalence increase (both P<0.001). Conclusions: Rates of overweight, obesity and severe obesity have increased markedly in Swedish adults since 1995. Priority groups for prevention efforts include individuals with low education and those living in rural areas.

Workplace sitting is associated with self-reported general health and back/neck pain: a cross-sectional analysis in 44,978 employees.

BACKGROUND: Total sitting time is associated with a higher risk for cardio metabolic disease and mortality, while breaks in prolonged sitting attenuate these effects. However, less is known about associations of different specific domains and breaks of sitting on general health, back/neck pain and if physical activity could influence these associations. The aim was to investigate how workplace sitting and frequency of breaking up workplace sitting is associated with self-reported general health and self-reported back/neck pain. METHODS: 44,978 participants (42% women) from the Swedish working population, who participated in a nationwide occupational health service screening 2014-2019, were included in this cross-sectional study. Self-reported sitting duration and frequency of breaks from sitting at work, general health, back/neck pain, exercise, leisure time sitting, diet, smoking, stress and body mass index were assessed. Occupation was classified as requiring higher education qualifications or not. Logistic regression modelling was used to assess the association between workplace sitting/frequency of breaks in workplace sitting and poor general health and back/neck pain, respectively. RESULTS: Compared to sitting all the time at work, sitting ≤75% of the time showed significantly lower risks for poor general health (OR range 0.50-0.65), and sitting between 25 and 75% of the time showed significantly lower risks (OR 0.82-0.87) for often reported back/neck pain. For participants reporting sitting half of their working time or more, breaking up workplace sitting occasionally or more often showed significantly lower OR than seldom breaking up workplace sitting; OR ranged 0.40-0.50 for poor health and 0.74-0.81 for back/neck pain. CONCLUSIONS: Sitting almost all the time at work and not taking breaks is associated with an increased risk for self-reported poor general health and back/neck pain. People sitting almost all their time at work are recommended to take breaks from prolonged sitting, exercise regularly and decrease their leisure time sitting to reduce the risk for poor health.

Associations of sedentary behavior in leisure and occupational contexts with symptoms of depression and anxiety.

Sedentary behaviors (SB) can be associated with poorer mental health, but it remains unclear whether contexts for these behaviors may be important. We assessed relationships of SB in leisure-time and occupational contexts with frequent symptoms of depression and anxiety. Data originate from the Swedish Health Profile Assessment (HPA) database, a health assessment offered to employees working for companies or organizations connected to healthcare services. Analyses are based on data from 2017 onwards (N = 23,644; 57% male, mean age = 42 years). Two self-report questions assessed proportions of time spent in SB in leisure contexts and in the occupational setting. Logistic regressions examined relationships of SB in each context with the self-reporting of frequent symptoms of depression/anxiety. A separate model for the leisure plus occupational SB was also generated. Fully-adjusted models included exercise frequency. Compared to those reporting that they were 'almost never' sedentary in leisure-time contexts, a detrimental dose-response with frequent depression/anxiety symptoms was observed with increasing proportions of sedentary time: 50% of the time (OR = 1.44; 1.23-1.70), 75% (OR = 2.95; 2.45-3.54), almost always (OR = 3.85; 2.84-5.22). For occupational SB, the only associations were among those who reported being sedentary almost always, compared to almost never (OR = 1.47; 1.25-1.73). Associations of 'overall' SB with depression/anxiety symptoms mirrored the dose-response relationship for leisure-time SB. Exercise frequency attenuated the association for leisure-time SB only, but it remained statistically significant. Adults who spend ≥50% of their leisure-time in sedentary pursuits experience more frequent symptoms of depression and anxiety, compared to those who are less sedentary in that context.

Geographical variations in the incidence of oesophageal cancer in Sweden.

Background: Geographical variations in the incidence and tumour stage distribution of oesophageal cancer in Sweden are not well characterised.Methods: Using data from the Swedish Cancer Registry over 45 years (1972-2016), we compared the age-standardised incidence rates of oesophageal cancer by histological type across all seven national areas (in five-year periods) and 21 counties (in 15-year periods) in Sweden, and assessed the geographical distribution of tumour stage at diagnosis since 2004.Results: The incidence rate of oesophageal adenocarcinoma increased in all national areas and counties and in both sexes over time, while the rate of oesophageal squamous cell carcinoma decreased from the 1980s onwards. In the latest period (2012- 2016), the incidence rate of adenocarcinoma in men ranged from 3.5/100,000 person-years in West Sweden to 6.2/100,000 person-years in North Middle Sweden. At the county level, the rate of adenocarcinoma in men was lowest in Jämtland (2.7/100,000 person-years) and highest in Gotland (6.2/100 000 person-years) in 2002-2016. The incidence rates of both adenocarcinoma and squamous cell carcinoma in women were below 2/100,000 person-years in all national areas and counties in the latest calendar periods, i.e., 2012-2016 and 2002-2016, respectively. The proportion of patents with tumour stage IV ranged from 22% in Stockholm area to 31% in Middle Norrland, while at the healthcare region level it was lowest in Stockholm healthcare region (23%) and highest in North (30%) and Uppsala-Örebro (29%) healthcare regions.Conclusion: There are considerable geographical variations in the incidence and tumour stage distribution of oesophageal cancer in Sweden.

Two Decades of Same-Sex Marriage in Sweden: A Demographic Account of Developments in Marriage, Childbearing, and Divorce.

In this study, we provide demographic insight into the still relatively new family form of same-sex marriage. We focus on period trends in same-sex marriage formation and divorce during 1995-2012 in Sweden and the role of childbearing in same-sex unions. The period begins with the introduction of registered partnership for same-sex couples and also covers the introduction of formal same-sex marriage in 2009. We use register data for the complete population of Sweden to contrast patterns in male and female same-sex marriage formation and divorce. We show that female same-sex union formation increased rapidly over the period, while trends for male same-sex unions increased less. The introduction of same-sex marriage legislation in 2009 appears to have had little effect on the pace of formation of same-sex unions. In contrast, legal changes supporting parental rights in same-sex unions may have fueled the formation of female same-sex marriages as well as parenthood in such unions. Further, we show that divorce risks in the marital unions of two women are much higher than in other types of marriages. We find some convergence of divorce risks across union types at the end of our study period: male same-sex unions have the same divorce risk levels as opposite-sex marriages, and the elevated risks of divorce in female same-sex unions appear to have stabilized at somewhat lower levels than those observed in the late 1990s.

Active commuting in Swedish workers between 1998 and 2015-Trends, characteristics, and cardiovascular disease risk.

BACKGROUND: Trend analyses of active commuting and potential variations in trends and association with cardiovascular disease (CVD) risk within subgroups are unknown. OBJECTIVES: To (a) describe trends in active commuting between 1998 and 2015 and (b) to study the association between different amounts of active commuting and the incidence risk of CVD in a large sample of Swedish workers, and analyses of potential variations across subgroups of socio-demographics, physical activity, and BMI. METHODS: A total of 318 309 participants (47% women, 18-74 years) who participated in a nationwide occupational health service screening between 1998 and 2015 were included. Commuting habits were self-reported, and data on first-time CVD events were derived from national registers. RESULTS: Self-reported passive commuters decreased between 1998 and 2015 (64% to 56%), transferring to an increase in mainly moderate/high-dose active commuters (12% to 19%). Changes were seen in all subgroups. The characteristics and lifestyle habits of the typical passive and active commuter changed little over the study period. Low- and moderate/high-dose active commuters had significantly decreased risks for a first time CVD during follow-up. This was accentuated in men, middle-aged, and in participants with light physical work situations, irregular exercise habits, being overweight/obese, and with low fitness. CONCLUSION: Increases in active commuting were observed between 1998 and 2015, however still leaving a majority who do not actively commute. As active commuting, regardless dose, is associated with a lower CVD risk, encouraging more people to actively commute may provide an easily accessible and time-efficient possibility to increase physical activity and health in the general population.

Lifestyle-associated health risk indicators across a wide range of occupational groups: a cross-sectional analysis in 72,855 workers.

BACKGROUND: Identify and compare health risk indicators for common chronic diseases between different occupational groups. METHODS: A total of 72,855 participants (41% women) participating in an occupational health service screening in 2014-2019 were included. Occupation was defined by the Swedish Standard Classification of Occupation, and divided into nine major and additionally eight sub-major groups. These were analysed separately, as white- and blue-collar occupations and as low- and high-skilled occupations. Seven health risk indicators were self-reported: exercise, physical work situation, sitting at work and leisure, smoking, diet, and perceived health, whereas cardiorespiratory fitness, BMI and blood pressure were measured. These were further dichotomized (yes/no) and as clustering of risk indicators (≥3 vs. <3). RESULTS: The greatest variation in OR across sub-major and major occupational groups were seen for daily smoking (OR = 0.68 to OR = 5.12), physically demanding work (OR = 0.55 to OR = 45.74) and high sitting at work (OR = 0.04 to OR = 1.86). For clustering of health risk indicators, blue-collar workers had significantly higher clustering of health risks (OR: 1.80; 95% CI 1.71-1.90) compared to white-collar workers (reference). Compared to high-skilled white-collar workers, low-skilled white-collar workers had similar OR (2.00; 1.88-2.13) as high-skilled blue-collar workers (1.98; 1.86-2.12), with low-skilled blue-collar workers having the highest clustered risk (2.32; 2.17-2.48). CONCLUSION: There were large differences in health risk indicators across occupational groups, mainly between high-skilled white-collar occupations and the other occupations, with important variations also between major and sub-major occupational groups. Future health interventions should target the occupational groups identified with the highest risk for effective disease prevention.

Lumbar facet joint subchondral bone density in low back pain and asymptomatic subjects.

OBJECTIVE: To report in vivo measurements of lumbar facet joint subchondral bone mineral density used in the description of facet joint loading patterns and to interrogate if low back pain is associated with changes in subchondral bone mineral density. MATERIALS AND METHODS: In vivo measurements of lumbar facet joint subchondral bone mineral density (L1/2 to L5/S1) in Hounsfield units were performed on 89 volunteers (56 controls and 33 with low back pain) by computed tomography osteoabsorptiometry at subchondral regions between 1.5 mm and 2.5 mm below the joint surface. The facet surface was divided into five topographic zones: cranial, lateral, caudal, medial, and central. RESULTS: We analyzed 1780 facet joint surfaces. Facets were denser (p < 0.0001) both in superior facets and in low back pain subjects (p < 0.0001). For the entire cohort, the facet center zone subchondral bone mineral density was higher (p < 0.0001) than that of the peripheral zones. The analyses indicate that subchondral bone mineral density is highest in patients with low back pain, the superior facets, and the center zone of the facets. CONCLUSIONS: Subchondral bone mineral density is thought to reflect cumulative, long-term distribution of stress acting on a joint. This work shows that higher subchondral bone mineral density values in the center zone indicate predominant stress transmission through the center of the facet joints. Finally, the greater subchondral bone mineral density in patients with low back pain may reflect both increased load bearing by the facets secondary to disc degeneration and misdistribution of loading within the joint.

Sex- and age-specific associations between cardiorespiratory fitness, CVD morbidity and all-cause mortality in 266.109 adults.

The aim was to investigate sex- and age-specific associations between cardiorespiratory fitness, all-cause and cause-specific mortality, and cardiovascular disease (CVD) morbidity. 266.109 participants (47% women, 18-74 years) free from CVD, participating in occupational health service screenings in 1995-2015 were included. CRF was assessed as estimated maximal oxygen consumption (estVO2max) using a submaximal cycle test. Incident cases of first-time CVD event and death from any cause were ascertained through national registers. There were 4244 CVD events and 2750 cases of all-cause mortality during mean 7.6 years follow-up. Male gender, higher age and lower estVO2max were associated with higher all-cause mortality and CVD morbidity incidence rates. Risk reductions with increasing estVO2max were present in all age-groups of men and women. No obvious levelling off in risk was identified in the total cohort. However, women and older age-groups showed no further reduction in higher aggregated estVO2max levels. CVD specific mortality was more associated with estVO2max compared to tumor specific mortality. The risk for all-cause mortality and CVD morbidity decreased by 2.3% and 2.6% per increase in 1 ml·min-1·kg-1 with no significant sex-differences but more pronounced in the three lower estVO2max categories for all-cause mortality (9.1%, 3.8% and 3.3%, respectively). High compared to lower levels of estVO2max was not related to a significantly elevated mortality or morbidity. In this large cohort study, CVD morbidity and all-cause mortality were inversely related to estVO2max in both men and women of all age-groups. Increasing cardiorespiratory fitness is a clear public health priority.

Decline in cardiorespiratory fitness in the Swedish working force between 1995 and 2017.

BACKGROUND: Long-term trend analyses of cardiorespiratory fitness (VO2 max) in the general population are limited. OBJECTIVES: To describe trends in VO2 max from 1995 to 2017 in the Swedish working force and to study developments across categories of sex, age, education, and geographic regions. METHODS: A total of 354 277 participants (44% women, 18-74 years) who participated in a nationwide occupational health service screening between 1995 and 2017 were included. Changes in standardized mean values of absolute (L/min) and relative (mL/min/kg) VO2 max, and the proportion with low (<32) relative VO2 max are reported. VO2 max was estimated using a submaximal cycle test. RESULTS: Absolute VO2 max decreased by -6.7% (-0.19 L/min) in the total population. Relative VO2 max decreased by -10.8% (-4.2 mL/min/kg) with approximately one-third explained by a simultaneous increase in body mass. Decreases in absolute fitness were more pronounced in men vs women (8.7% vs 5.3%), in younger vs older (6.5% vs 2.3%), in short (11.4%) vs long (4.5%) education, and in rural vs urban regions (6.5% vs 3.5%), all P < 0.001. The proportions with low VO2 max increased from 27% to 46% (P < 0.001). CONCLUSION: Between 1995 and 2017, there was a steady and pronounced decline in mean cardiorespiratory fitness in Swedish adults. Male gender, young age, short education, and living in a rural area were predictive of greater reductions. The proportion with low cardiorespiratory fitness almost doubled. Given the strong associations between cardiorespiratory fitness and multiple morbidities and mortality, preventing further decreases is a clear public health priority, especially for vulnerable groups.

Fecundity and human birth seasonality in Sweden: a register-based study.

BACKGROUND: It is well-established that couples' fecundities vary widely. Each couple has a relatively constant monthly probability of conceiving, which can vary from zero to quite high. This underlying probability is usually expressed as the time (number of menstrual cycles) the couple requires to conceive. Couples with high fecundity will, on average, need fewer cycles than couples with low fecundity. It is also well-documented that almost all human populations exhibit seasonal variation in births. Most European countries show seasonal variation that usually peak in the spring and are the lowest during the last quarter of the year. The increasingly strong pattern of depressed birth rates in November and December is likely explained by the December-January cut-off threshold for Swedish pupils' school entry and their parents increasing awareness of the negative effects on school outcomes for children who are juniors in the school-entry cohort they belong to. To actively plan births for a specific time of the year, couples need to have some knowledge of the time required for them to conceive. METHODS: We use the duration between marriage of childless couples and first birth as a proxy measure of couples' fecundity. Based on this time-to-pregnancy measure we study to what extent couples' capacity to conceive affects the seasonality of their second births. We hypothesize that in a society with highly controlled fertility and a strong norm of having at least two children, sub-fertile couples will on average show less seasonal variation in second births. Sub-fertile couples, requiring more time to conceive the first time, will be less likely to try to target a desired birth month for their second child because doing so could jeopardize fulfilling their desired family size. We apply multinomial logistic regressions on 81,998 Swedish couples who married while being childless and subsequently gave birth to at least two children between 1990 and 2012, to investigate fecundity's role in seasonal variation in second births. RESULTS: We found that seasonal variation in second births was strongly associated with couples' observed fecundity, measured as the duration between marriage formation and first birth. Our results support the hypothesis that sub-fertile couples, requiring more time to conceive the first time, show less seasonal variation in second births. The seasonal variations in second order births among couples with normal fecundity shows some similarities to traditional patterns as seen in agricultural and industrial societies of the past, with high numbers of births during the spring, and low numbers during the last quarter of the year. However, two important differences are notable. The characteristic Christmas peak in September has vanished, and the low birth rates in November and December come out much stronger than in the past. CONCLUSIONS: The birth seasonality among couples with normal fecundity are what we would expect if couples actively plan their births according to the cut-off date for Swedish pupils' school entry. We argue that our findings support the notion that scheduled childbirth is a reality in contemporary sociality.

Higher divorce risk when mates are plentiful? Evidence from Denmark.

Work from social and biological sciences has shown that adult sex ratios are associated with relationship behaviours. When partners are abundant, opportunities for mate switching may increase and relationship stability decrease. To date, most of the human literature has used regional areas at various levels of aggregation to define partner markets. But, in developed countries, many individuals of reproductive age spend a considerable amount of time outside their residential areas, and other measures may better capture the opportunities to meet a (new) partner. Here, we use Danish register data to test whether the sex ratio of the occupational sector is linked to divorce. Our data cover individuals in Denmark who married during 1981-2002 and we control for age at and duration of marriage, education and parity. Results support the prediction that a higher proportion of opposite-sex individuals in one's occupational sector is associated with higher divorce risk. This holds for both men and women, but associations are somewhat stronger for men and vary by education. Our results highlight the need to study demographic behaviours of men and women simultaneously, and to consider partner markets beyond geographical areas so that differing strategies for males and females may be examined.

Anxiety and Depression Among Sexual Minority Women and Men in Sweden: Is the Risk Equally Spread Within the Sexual Minority Population?

INTRODUCTION: Sexual minority individuals have a higher risk of anxiety and depression compared with heterosexuals. However, whether the higher risk is spread equally across the sexual minority population is not clear. AIM: To investigate the association between sexual orientation and self-reported current anxiety and a history of diagnosis of depression, paying particular attention to possible subgroup differences in risks within the sexual minority population, stratified by sex and to examine participants' history of medical care for anxiety disorders and depression. METHODS: We conducted a population-based study of 874 lesbians and gays, 841 bisexuals, and 67,980 heterosexuals recruited in 2010 in Stockholm County. Data were obtained from self-administered surveys that were linked to nationwide registers. MAIN OUTCOME MEASURES: By using logistic regression, we compared risks of current anxiety, histories of diagnosed depression, and register-based medical care for anxiety and/or depression in lesbian and gay, bisexual, and heterosexual individuals. RESULTS: Bisexual women and gay men were more likely to report anxiety compared with their heterosexual peers. Bisexual individuals and gay men also were more likely to report a past diagnosis of depression. All sexual minority groups had an increased risk of having used medical care for anxiety and depression compared with heterosexuals, with bisexual women having the highest risk. CONCLUSION: Bisexual women appear to be a particularly vulnerable sexual minority group. Advocating for non-discrimination and protections for lesbian, gay, and bisexual people is a logical extension of the effort to lower the prevalence of mental illness. Björkenstam C, Björkenstam E, Andersson G, et al. Anxiety and Depression Among Sexual Minority Women and Men in Sweden: Is the Risk Equally Spread Within the Sexual Minority Population? J Sex Med 2017;14:396-403.