Cross-sectional associations between accelerometer-measured physical activity and hip bone mineral density: the Tromsø Study 2015-2016.

Positive associations between physical activity and bone health have been found in population-based studies, however, mostly based on self-reported physical activity. Therefore, we investigated the association between accelerometer-measured physical activity, measured in steps per day and minutes of moderate to vigorous physical activity (MVPA) per day, and total hip areal BMD (aBMD) measured by DXA in a general population, utilizing multiple regression models. The study participants, 1560 women and 1177 men aged 40-84 yr, were part of the seventh survey of the Tromsø Study (2015-2016). In both genders, we found a positive association between the number of daily steps and aBMD adjusted for age, BMI, and smoking status (P < .001). In women, an increase of 1000 steps per day was associated with 0.005 g/cm2 higher aBMD. For men, a polynomial curve indicated a positive association with aBMD up to 5000 steps per day, plateauing between 5000 and 14 000 steps, and then increasing again. Additionally, MVPA duration was positively associated with aBMD in both women (P < .001) and men (P = .004) when adjusted for age, BMI, and smoking status. Specifically, each 60-min increase in daily MVPA was associated with 0.028 and 0.023 g/cm2 higher aBMD in women and men, respectively. Despite positive associations, the clinical impact of physical activity on aBMD in this general population of adults and older adults was relatively small, and a large increase in daily MVPA might not be achievable for most individuals. Therefore, further longitudinal population-based studies incorporating device-based measures of physical activity could add more clarity to these relationships.

Menstrual Cycle Phase Has No Influence on Performance-Determining Variables in Endurance-Trained Athletes: The FENDURA Project.

PURPOSE: This study aimed to investigate the effect of the MC and endogenous sex hormone concentrations on performance-determining variables in three distinct MC phases in endurance-trained females. METHODS: Twenty-one eumenorrheic trained/highly trained endurance athletes completed a standardized test battery during the early follicular phase (EFP), ovulatory phase (OP), and midluteal phase (MLP) for either one ( n = 7) or two test cycles ( n = 14). MC phases were determined using calendar-based counting, urinary ovulation testing, and verified with serum hormone analysis. MCs were retrospectively classified as eumenorrheic or disturbed. Disturbed MCs were excluded from analysis. The test battery consisted of 4-6 × 5-min submaximal stages with stepwise speed increases, a 30-s all-out double-poling ski ergometer test, and a maximal incremental treadmill running test. RESULTS: At a group level, there was no effect of MC phase or the serum concentrations of estrogen and progesterone on peak oxygen uptake (V̇O 2peak ), oxygen uptake at 4 mmol·L -1 blood lactate concentration, time to exhaustion, running economy, or mean 30-s power output (MPO 30s ). Serum testosterone concentration was positively associated with MPO 30s ( P = 0.016). Changes in V̇O 2peak from EFP to MLP were inconsistent between individuals and across cycles. CONCLUSIONS: None of the measured performance-determining variables were influenced by MC phase or serum estrogen or progesterone concentrations. Although some individual patterns could be observed, there was no indication that any single MC phase is consistently associated with improved or impaired V̇O 2peak on a group level.

Females Display Lower Risk of Myocardial Infarction From Higher Estimated Cardiorespiratory Fitness Than Males: The Tromsø Study 1994-2014.

Objective: To examine the dose-response association between estimated cardiorespiratory fitness (eCRF) and risk of myocardial infarction (MI). Patients and Methods: Adults who attended Tromsø Study surveys 4-6 (Janurary 1,1994-December 20, 2008) with no previous cardiovascular disease were followed up through December 31, 2014 for incident MI. Associations were examined using restricted cubic splines Fine and Gray regressions, adjusted for education, smoking, alcohol, diet, sex, adiposity, physical activity, study survey, and age (timescale) in the total cohort and subsamples with hyperlipidemia (n=2956), hypertension (n=8290), obesity (n=5784), metabolic syndrome (n=1410), smokers (n=3823), and poor diet (n=3463) and in those who were physically inactive (n=6255). Results: Of 14,285 participants (mean age ± SD, 53.7±11.4 years), 979 (6.9%) experienced MI during follow-up (median, 7.2 years; 25th-75th, 5.3-14.6 years). Females with median eCRF (32 mL/kg/min) had 43% lower MI risk (subdistributed hazard ratio [SHR], 0.57; 95% CI, 0.48-0.68) than those at the 10th percentile (25 mL/kg/min) as reference. The lowest MI risk was observed at 47 mL/kg/min (SHR, 0.02; 95% CI, 0.01-0.11). Males had 26% lower MI risk at median eCRF (40 mL/kg/min; SHR, 0.74; 95% CI, 0.63-0.86) than those at the 10th percentile (32 mL/kg/min), and the lowest risk was 69% (SHR, 0.31; 95% CI, 0.14-0.71) at 60 mL/kg/min. The associations were similar in subsamples with cardiovascular disease risk factors. Conclusion: Higher eCRF associated with lower MI risk in females and males, but associations were more pronounced among females than those in males. This suggest eCRF as a vital estimate to implement in medical care to identify individuals at high risk of future MI, especially for females.

Occupational physical activity and risk of mortality in women and men: the Tromsø Study 1986-2021.

OBJECTIVE: Associations between occupational physical activity (OPA) and mortality risks are inconclusive. We aimed to examine associations between (1) OPA separately and (2) jointly with leisure time physical activity (LTPA), and risk of all-cause, cardiovascular disease (CVD) and cancer mortality, over four decades with updated exposure and covariates every 6-8 years. METHODS: Adults aged 20-65 years from the Tromsø Study surveys Tromsø3-Tromsø7 (1986-2016) were included. We categorised OPA as low (sedentary), moderate (walking work), high (walking+lifting work) or very high (heavy manual labour) and LTPA as inactive, moderate and vigorous. We used Cox/Fine and Gray regressions to examine associations, adjusted for age, body mass index, smoking, education, diet, alcohol and LTPA (aim 1 only). RESULTS: Of 29 605 participants with 44 140 total observations, 4131 (14.0%) died, 1057 (25.6%) from CVD and 1660 (40.4%) from cancer, during follow-up (median: 29.1 years, 25th-75th: 16.5.1-35.3). In men, compared with low OPA, high OPA was associated with lower all-cause (HR 0.83, 95% CI 0.74 to 0.92) and CVD (subdistributed HR (SHR) 0.68, 95% CI 0.54 to 0.84) but not cancer mortality (SHR 0.99, 95% CI 0.84 to 1.19), while no association was observed for moderate or very high OPA. In joint analyses using inactive LTPA and low OPA as reference, vigorous LTPA was associated with lower all-cause mortality combined with low (HR 0.75, 95% CI 0.64 to 0.89), high (HR 0.67, 95% CI 0.54 to 0.82) and very high OPA (HR 0.74, 95% CI 0.58 to 0.94), but not with moderate OPA. In women, there were no associations between OPA, or combined OPA and LTPA, with mortality. CONCLUSION: High OPA, but not moderate and very high OPA, was associated with lower all-cause and CVD mortality risk in men but not in women. Vigorous LTPA was associated with lower mortality risk in men with low, high and very high OPA, but not moderate OPA.

Device-measured physical activity, sedentary time, and risk of all-cause mortality: an individual participant data analysis of four prospective cohort studies.

OBJECTIVES: To examine whether moderate-to-vigorous physical activity (MVPA) modifies the association between sedentary time and mortality and vice versa, and estimate the joint associations of MVPA and sedentary time on mortality risk. METHODS: This study involved individual participant data analysis of four prospective cohort studies (Norway, Sweden, USA, baseline: 2003-2016, 11 989 participants ≥50 years, 50.5% women) with hip-accelerometry-measured physical activity and sedentary time. Associations were examined using restricted cubic splines and fractional polynomials in Cox regressions adjusted for sex, education, body mass index, smoking, alcohol, study cohort, cardiovascular disease, cancer, and/or diabetes, accelerometry wear time and age. RESULTS: 6.7% (n=805) died during follow-up (median 5.2 years, IQR 4.2 years). More than 12 daily sedentary hours (reference 8 hours) was associated with mortality risk only among those accumulating <22 min of MVPA per day (HR 1.38, 95% CI 1.10 to 1.74). Higher MVPA levels were associated with lower mortality risk irrespective of sedentary time, for example, HR for 10 versus 0 daily min of MVPA was 0.85 (95% CI 0.74 to 0.96) in those accumulating <10.5 daily sedentary hours and 0.65 (95% CI 0.53 to 0.79) in those accumulating ≥10.5 daily sedentary hours. Joint association analyses confirmed that higher MVPA was superior to lower sedentary time in lowering mortality risk, for example, 10 versus 0 daily min of MVPA was associated with 28-55% lower mortality risk across the sedentary time spectrum (lowest risk, 10 daily sedentary hours: HR 0.45, 95% CI 0.31 to 0.65). CONCLUSIONS: Sedentary time was associated with higher mortality risk but only in individuals accumulating less than 22 min of MVPA per day. Higher MVPA levels were associated with lower mortality risk irrespective of the amount of sedentary time.

Vertebral Fractures Assessed by Dual-Energy X-Ray Absorptiometry and All-Cause Mortality: The Tromsø Study, 2007-2020.

Vertebral fractures have been associated with increased mortality, but findings are inconclusive, and many vertebral fractures avoid clinical attention. We investigated this association in a general population of 2,476 older adults aged ≥55 years from Tromsø, Norway, who were followed over 2007-2020, using dual-energy x-ray absorptiometry (DXA) at baseline to evaluate vertebral fractures (mild, moderate, or severe). We used multiple Cox regression models to estimate hazard ratios (HRs) for all-cause mortality, adjusted for age, sex, body mass index, education, smoking, alcohol intake, cardiovascular disease, and respiratory disease. Mean follow-up in the cohort was 11.2 (standard deviation, 2.7) years; 341 participants (13.8%) had ≥1 vertebral fracture at baseline, and 636 participants (25.7%) died between baseline and follow-up. Full-adjustment models showed a nonsignificant association between vertebral fracture status (yes/no) and mortality. Participants with ≥3 vertebral fractures (HR = 2.43, 95% confidence interval: 1.57, 3.78) or ≥1 severe vertebral fracture (HR = 1.65, 95% confidence interval: 1.26, 2.15) had increased mortality compared with those with no vertebral fractures. Dual-energy x-ray absorptiometry-based screening could be a potent and feasible tool in detecting vertebral fractures that are often clinically silent yet independently associated with premature death. Our data indicated that detailed vertebral assessment could be warranted for a more accurate survival estimation.

Consistent pattern between physical activity measures and chronic pain levels: the Tromsø Study 2015 to 2016.

ABSTRACT: Epidemiological literature on the relationship between physical activity and chronic pain is scarce and inconsistent. Hence, our aim was to assess the relationship applying comprehensive methodology, including self-reported and accelerometer measures of physical activity and different severity levels of chronic pain. We used data from the Tromsø Study (2015-2016). All residents in the municipality, aged 40 years and older were invited to participate (n = 32,591, 51% women). A total of 21,083 (53%) women reported on questionnaires. Additionally, 6778 participants (54% women) were invited to wear accelerometers (6125 with complete measurements). Our exposure measures were self-reported leisure time physical activity, exercise frequency, duration, and intensity and 2 accelerometer measures (steps per day and minutes of moderate to vigorous physical activity per day). Outcome measurements were chronic pain and moderate-to-severe chronic pain. We used Poisson regression to estimate chronic pain prevalence and prevalence ratios for each physical activity measure, with adjustments for sex, age, education level, smoking history, and occupational physical activity. Our main analyses showed an inverse dose-response relationship between all physical activity measures and both severity measures of chronic pain, except that the dose-response relationship with exercise duration was only found for moderate-to-severe pain. All findings were stronger for the moderate-to-severe pain outcomes than for chronic pain. Robustness analyses gave similar results as the main analyses. We conclude that an inverse dose-response association between physical activity and chronic pain is consistent across measures. To summarize, higher levels of physical activity is associated with less chronic pain and moderate-to-severe chronic pain.

Diagnostic efficacy of radiomorphometric indices for predicting osteoporosis in a Norwegian population in the Tromsø Study: Tromsø7.

OBJECTIVE: The aim of this study was to investigate the diagnostic efficacy of the radiomorphometric indices of mandibular cortical width (MCW) and mandibular cortical index (MCI) of cortical erosion for osteoporosis screening in adults (≥40 years) and older adults (≥65 years) to determine whether adding a fracture risk assessment tool (FRAX) would improve efficacy. STUDY DESIGN: One observer measured MCW and assessed MCI on dental panoramic radiographs acquired for patients in the Tromsø study. These indices, alone and with FRAX scores, were evaluated for efficacy in predicting osteoporosis, which was diagnosed by bone density measurement at the femoral necks with dual-energy X-ray absorptiometry. RESULTS: MCW ≤3 mm and MCI indicating heavily eroded cortices (C3) had accuracies of 68.8% and 83.6%, respectively, in identifying osteoporosis. In females >65 years, MCW ≤3 mm and C3 produced higher sensitivities but lower specificities, with slightly lower accuracies (61.4% and 79.8%, respectively) compared with all females. The addition of FRAX scores >15% improved the accuracy of MCW ≤3 mm (81.7%) and C3 (87.9%), resulting in high specificity (86.6% and 95.4%). Combining MCW ≤3 mm or C3 with FRAX >15% increased the probabilities of detecting osteoporosis by increasing positive likelihood ratios. CONCLUSIONS: MCW ≤3 mm or MCI C3, when combined with FRAX >15%, showed superior diagnostic efficacy, with high specificity in detecting females without osteoporosis.

Macular Layer Thickness and Effect of BMI, Body Fat, and Traditional Cardiovascular Risk Factors: The Tromsø Study.

Purpose: The purpose of this study was to investigate associations between cardiovascular risk factors and the thickness of retinal nerve fiber layer (RNFL), ganglion cell-inner plexiform layer (GCIPL), and outer retina layers (ORL). Methods: In this population-based study, we included participants from the Tromsø Study: Tromsø6 (2007 to 2008) and Tromsø7 (2015 to 2016). Persons with diabetes and/or diagnosed glaucoma were excluded from this study. Retinal thickness was measured on optical coherence tomography (Cirrus HD-OCT) macula-scans, segmented on RNFL, GCIPL, and ORL and associations were analyzed cross-sectionally (N = 8288) and longitudinally (N = 2595). We used directed acyclic graphs (DAGs) for model selection, and linear regression to adjust for confounders and mediators in models assessing direct effects. Factors examined were age, sex, blood pressure, daily smoking, serum lipids, glycated hemoglobin, body mass index (BMI), total body fat percentage (BFP), and the adjustment variables refraction and height. Results: The explained variance of cardiovascular risk factors was highest in GCIPL (0.126). GCIPL had a strong negative association with age. Women had thicker GCIPL than men at higher age and thinner ORL at all ages (P < 0.001). Systolic blood pressure was negatively associated with RNFL/GCIPL (P = 0.001/0.004), with indication of a U-shaped relationship with GCIPL in women. The negative association with BMI was strongest in men, with significant effect for RNFL/GCIPL/ORL (P = 0.001/<0.001/0.019) and in women for GCIPL/ORL (P = 0.030/0.037). BFP was negatively associated with GCIPL (P = 0.01). Higher baseline BMI was associated with a reduction in GCIPL over 8 years (P = 0.03). Conclusions: Cardiovascular risk factors explained 12.6% of the variance in GCIPL, with weight and blood pressure the most important modifiable factors.

Treatment target achievement after myocardial infarction and ischaemic stroke: cardiovascular risk factors, medication use, and lifestyle: the Tromsø Study 2015-16.

AIMS: To investigate European guideline treatment target achievement in cardiovascular risk factors, medication use, and lifestyle, after myocardial infarction (MI) or ischaemic stroke, in women and men living in Norway. METHODS AND RESULTS: In the population-based Tromsø Study 2015-16 (attendance 65%), 904 participants had previous validated MI and/or stroke. Cross-sectionally, we investigated target achievement for blood pressure (<140/90 mmHg, <130/80 mmHg if diabetes), LDL cholesterol (<1.8 mmol/L), HbA1c (<7.0% if diabetes), overweight (body mass index (BMI) <25 kg/m2, waist circumference women <80 cm, men <94 cm), smoking (non-smoking), physical activity (self-reported >sedentary, accelerometer-measured moderate-to-vigorous ≥150 min/week), diet (intake of fruits ≥200 g/day, vegetables ≥200 g/day, fish ≥200 g/week, saturated fat <10E%, fibre ≥30 g/day, alcohol women ≤10 g/day, men ≤20 g/day), and medication use (antihypertensives, lipid-lowering drugs, antithrombotics, and antidiabetics), using regression models. Proportion of target achievement was for blood pressure 55.2%, LDL cholesterol 9.0%, HbA1c 42.5%, BMI 21.1%, waist circumference 15.7%, non-smoking 86.7%, self-reported physical activity 79%, objectively measured physical activity 11.8%, intake of fruit 64.4%, vegetables 40.7%, fish 96.7%, saturated fat 24.3%, fibre 29.9%, and alcohol 78.5%, use of antidiabetics 83.6%, lipid-lowering drugs 81.0%, antihypertensives 75.9%, and antithrombotics 74.6%. Only 0.7% achieved all cardiovascular risk factor targets combined. Largely, there was little difference between the sexes, and in characteristics, medication use, and lifestyle among target achievers compared to non-achievers. CONCLUSION: Secondary prevention of cardiovascular disease was suboptimal. A negligible proportion achieved the treatment target for all risk factors. Improvement in follow-up care and treatment after MI and stroke is needed.

Age-specific atrial fibrillation incidence, attributable risk factors and risk of stroke and mortality: results from the MORGAM Consortium.

BACKGROUND: The main aim was to examine age-specific risk factor associations with incident atrial fibrillation (AF) and their attributable fraction in a large European cohort. Additionally, we aimed to examine risk of stroke and mortality in relation to new-onset AF across age. METHODS: We used individual-level data (n=66 951, 49.1% men, age range 40-98 years at baseline) from five European cohorts of the MOnica Risk, Genetics, Archiving and Monograph Consortium. The participants were followed for incident AF for up to 10 years and the association with modifiable risk factors from the baseline examinations (body mass index (BMI), hypertension, diabetes, daily smoking, alcohol consumption and history of stroke and myocardial infarction (MI)) was examined. Additionally, the participants were followed up for incident stroke and all-cause mortality after new-onset AF. RESULTS: AF incidence increased from 0.9 per 1000 person-years at baseline age 40-49 years, to 17.7 at baseline age ≥70 years. Multivariable-adjusted Cox models showed that higher BMI, hypertension, high alcohol consumption and a history of stroke or MI were associated with increased risk of AF across age groups (p<0.05). Between 30% and 40% of the AF risk could be attributed to BMI, hypertension and a history of stroke or MI. New-onset AF was associated with a twofold increase in risk of stroke and death at ages≥70 years (p≤0.001). CONCLUSION: In this large European cohort aged 40 years and above, risk of AF was largely attributed to BMI, high alcohol consumption and a history MI or stroke from middle age. Thus, preventive measures for AF should target risk factors such as obesity and hypertension from early age and continue throughout life.

Moderate-to-vigorous physical activity modifies the relationship between sedentary time and sarcopenia: the Tromsø Study 2015-2016.

BACKGROUND: Sarcopenia is an age-related muscle disease primarily characterized by reductions in muscle strength that increases the risk of falls, fractures, cognitive impairment, and mortality. Exercise is currently preferred in prevention and treatment, but it is unknown how different habitual physical activity and sedentary behaviour patterns associate with sarcopenia status. The purpose of the present study was to compare associations of these patterns with probable sarcopenia in older adults. METHODS: In 3653 community-dwelling participants (51% women) aged 60-84 years from the seventh survey of the Tromsø Study, we assessed objective physical activity and sedentary behaviour collected over 8 days (ActiGraph wGT3X-BT Accelerometer), grip strength (Jamar+ Digital Dynamometer), five-repetition chair stands, and self-reported disease. We combined tertiles of sedentary (SED) time and moderate-to-vigorous physical activity (MVPA) to create nine different activity profiles (SEDHIGH , SEDMOD , and SEDLOW combined with MVPAHIGH , MVPAMOD , or MVPALOW ). Multiple logistic regression models were used to examine how these profiles associated with probable sarcopenia, defined by low handgrip strength and/or slow chair stands time according to the revised European Working Group on Sarcopenia in Older People criteria. RESULTS: Probable sarcopenia was present in 227 (6.2%) participants. Men with probable sarcopenia had on average 35.3 min more SED time and 20 min less MVPA compared with participants without sarcopenia (P < 0.01 for all), while women with probable sarcopenia only had 18 min less MVPA (P < 0.001). Compared with the SEDHIGH -MVPALOW reference activity profile (714.2 min SED/day and 10.4 min MVPA/day), the SEDHIGH -MVPAMOD profile (697.1 min SED/day and 31.5 min MVPA/day) had significantly lower odds ratio (OR) for probable sarcopenia (OR 0.17, 95% confidence interval [CI] 0.08-0.35), while the SEDLOW -MVPALOW profile (482.9 min SED/day and 11.0 min MVPA/day) did not (OR 0.72, 95% CI 0.47-1.11). These findings were not influenced by age, sex, smoking, or self-reported diseases, and higher levels of MVPA did not further decrease ORs for probable sarcopenia. CONCLUSIONS: Older adults who achieve moderate amounts of MVPA have reduced odds for probable sarcopenia, even when they have high sedentary time. Those with low sedentary time did not have reduced odds for probable sarcopenia when they also had low amounts of MVPA. These findings need confirmation in longitudinal studies but suggest that interventions for preventing sarcopenia should prioritize increasing MVPA over reducing sedentary behaviour.

The bidirectional associations between leisure time physical activity change and body mass index gain. The Tromsø Study 1974-2016.

OBJECTIVES: To examine whether leisure time physical activity changes predict subsequent body mass index (BMI) changes, and conversely, whether BMI changes predict subsequent leisure time physical activity changes. METHODS: This prospective cohort study included adults attending ≥3 consecutive Tromsø Study surveys (time: T1, T2, T3) during 1974-2016 (n = 10779). If participants attended >3 surveys, we used the three most recent surveys. We computed physical activity change (assessed by the Saltin-Grimby Physical Activity Level Scale) from T1 to T2, categorized as Persistently Inactive (n = 992), Persistently Active (n = 7314), Active to Inactive (n = 1167) and Inactive to Active (n = 1306). We computed BMI change from T2 to T3, which regressed on preceding physical activity changes using analyses of covariance. The reverse association (BMI change from T1 to T2 and physical activity change from T2 to T3; n = 4385) was assessed using multinomial regression. RESULTS: Average BMI increase was 0.86 kg/m2 (95% CI: 0.82-0.90) from T2 to T3. With adjustment for sex, birth year, education, smoking and BMI at T2, there was no association between physical activity change from T1 to T2 and BMI change from T2 to T3 (Persistently Inactive: 0.89 kg/m2 (95% CI: 0.77-1.00), Persistently Active: 0.85 kg/m2 (95% CI: 0.81-0.89), Active to Inactive: 0.90 kg/m2 (95% CI: 0.79-1.00), Inactive to Active 0.85 kg/m2 (95% CI: 0.75-0.95), p = 0.84). Conversely, increasing BMI was associated with Persistently Inactive (odds ratio (OR): 1.17, 95% CI: 1.08-1.27, p < 0.001) and changing from Active to Inactive (OR: 1.16, 95% CI: 1.07-1.25, p < 0.001) compared with being Persistently Active. CONCLUSIONS: We found no association between leisure time physical activity changes and subsequent BMI changes, whereas BMI change predicted subsequent physical activity change. These findings indicate that BMI change predicts subsequent physical activity change at population level and not vice versa.

Cross-sectional associations between accelerometry-measured physical activity, left atrial size, and indices of left ventricular diastolic dysfunction: The Tromsø Study.

Whereas left atrial (LA) enlargement is an independent predictor for adverse cardiovascular events and all-cause mortality, this is regarded a physiological adaption of exercise. Paradoxically, LA size in athletes may overlap the enlargement observed in patients with cardiac pathology. Current knowledge is mainly derived from studies of athletes, and little is known about cardiac adaptations to physical activity (PA) in the general population. We explored the association between objectively measured PA and LA volume index (LAVi), and between LAVi enlargement and indices of diastolic dysfunction stratified by PA-level. Our study included 1573 participants from the population-based Tromsø Study (2015-16). PA was assessed with an ActiGraph wGT3X-BT accelerometer. Echocardiography was performed according to current guidelines. The associations between PA and LAVi, and between LAVi enlargement and indices of diastolic dysfunction were estimated by univariable and multivariable linear regression analyses, adjusted for sex, age, and cardiovascular risk factors. Our multiple adjusted analyses showed significant linear associations between PA and LAVi in ages < 70 years, and between PA and LAVi in participants with normal diastolic function. No associations were seen in ages ≥ 70 years or for participants with abnormal diastolic function. In those 40-54 years, the most active participants had larger LAVi (4.45 mL/m2, p = 0.016) than the least active. LAVi enlargement was only associated with indices of diastolic dysfunction in the most inactive participants. In conclusion, higher levels of PA associate with greater LAVi in participants < 70 years with normal diastolic function. LAVi enlargement is only associated with diastolic dysfunction in the most inactive participants.

Do declines in occupational physical activity contribute to population gains in body mass index? Tromsø Study 1974-2016.

OBJECTIVE: To examine whether occupational physical activity changes predict future body mass index (BMI) changes. METHODS: This longitudinal cohort study included adult participants attending ≥3 consecutive Tromsø Study surveys (examinations 1, 2 and 3) from 1974 to 2016 (N=11 308). If a participant attended >3 surveys, the three most recent surveys were included. Occupational physical activity change (assessed by the Saltin-Grimby Physical Activity Level Scale) was computed from the first to the second examination, categorised into persistently inactive (n=3692), persistently active (n=5560), active to inactive (n=741) and inactive to active (n=1315). BMI change was calculated from the second to the third examination (height being fixed at the second examination) and regressed on preceding occupational physical activity changes using analysis of covariance adjusted for sex, birth year, smoking, education and BMI at examination 2. RESULTS: Overall, BMI increased by 0.84 kg/m2 (95% CI 0.82 to 0.89). Following adjustments as described previously, we observed no differences in BMI increase between the occupational physical activity change groups (Persistently Inactive: 0.81 kg/m2, 95% CI 0.75 to 0.87; Persistently Active: 0.87 kg/m2, 95% CI 0.82 to 0.92; Active to Inactive: 0.81 kg/m2, 95% CI 0.67 to 0.94; Inactive to Active: 0.91 kg/m2, 95% CI 0.81 to 1.01; p=0.25). CONCLUSION: We observed no prospective association between occupational physical activity changes and subsequent BMI changes. Our findings do not support the hypothesis that occupational physical activity declines contributed to population BMI gains over the past decades. Public health initiatives aimed at weight gain prevention may have greater success if focusing on other aspects than occupational physical activity.

A cross-sectional and 6-year follow-up study of associations between leisure time physical activity and vertebral fracture in adults.

INTRODUCTION: Vertebral fractures are common osteoporotic fractures, affecting 2-46% of the population, causing morbidity and increased risk of mortality. Physical activity has beneficial effects for bone health, including increased bone mineral density and reduced hip fractures. However, evidence concerning prevention of vertebral fractures is scarce. Therefore, the aim of this study was to investigate the association between leisure time physical activity and vertebral fracture risk. METHODS: The data were retrieved from the 2001 and 2007-2008 surveys of the Tromsø Study, a longitudinal population study in Norway. A total of 1904 participants (1030 women and 874 men, age 38-87 yr and 40-87 yr respectively) were included in the cross-sectional analysis (2007-2008). Prospective follow-up data (2001 to 2007) on physical activity were available for 1131 participants (636 women and 495 men, age 32-69 yr and 33-69 yr respectively). Physical activity was assessed by a questionnaire and vertebral fracture by lateral vertebral fracture assessment from dual-energy x-ray absorptiometry scans. Logistic regression was used to examine associations between physical activity and vertebral fracture. RESULTS: After controlling for confounders (age, height, weight, smoking, osteoporosis, osteoporosis medication, left hip total bone mineral density, and use of hormones in women only), no cross-sectional associations between physical activity levels and vertebral fracture were observed, OR 1.13 (95% CI: 0.59-2.13), for moderately active women and 1.44 (0.61-3.42) for highly active women, compared with sedentary women. In men, the respective ORs were 1.74 (95% CI: 0.91-3.35) and 1.64 (0.78-3.41). In the prospective analyses, OR for vertebral fracture in women with reduced physical activity was 0.81 (95% CI: 0.18-3.62), 1.24 (95% CI: 0.29-5.26) for increased physical activity and 1.54 (95% CI: 0.43-5.50) for active unchanged physical activity pattern, compared with sedentary unchanged physical activity. In men, the respective ORs were 2.05 (95% CI: 0.57-7.42), 2.23 (95% CI: 0.63-7.87), and 1.81 (95% CI: 0.54-6.02). Subanalyses of women and men ≥50 yr showed similar results. CONCLUSIONS: Our findings suggest that physical activity does not play a major role in preventing vertebral fractures in Norwegian adults. Future studies may benefit from data on incident vertebral fracture, and objectively measured physical activity.

The impact of changes in leisure time physical activity on changes in cardiovascular risk factors: results from The Finnmark 3 Study and SAMINOR 1, 1987-2003.

OBJECTIVE: The aim of this study was to examine the associations between changes in leisure time physical activity and changes in cardiovascular risk factors over 16 years and whether they differ between two ethnic groups in Norway. METHODS: Data were extracted from two population-based studies. Altogether, 3671 men and women participated in both surveys, and 30% reported being of Sami ethnicity. Leisure time physical activity was self-reported, and cardiovascular risk factors were measured. ANCOVA analysis was used to examine associations between changes in physical activity and changes in cardiovascular risk factors. RESULTS: After adjustment for age, sex, smoking, ethnicity and respective baseline values, favourable changes in body mass index (BMI) and levels of triglycerides were most pronounced in those who were active in both surveys (p < 0.05) whereas the opposite was the situation for cholesterol levels (p = 0.003). Changes in systolic blood pressure, diastolic blood pressure and resting heart rate were not significantly associated with change in physical activity. Ethnicity did not influence the associations between physical activity and cardiovascular risk factors. CONCLUSION: Traditional cardiovascular risk factors were to a small extent associated with change in leisure time physical activity. Persistent physical activity was associated with beneficial changes in BMI and triglycerides.

Secular trends and correlates of physical activity: The Tromsø Study 1979-2008.

BACKGROUND: The aim was to describe secular trends in leisure time physical activity (LTPA) and work related physical activity (WPA) from 1979 to 2008. Additionally, we explored potential cross-sectional and longitudinal correlates of LTPA and WPA. METHODS: Data are collected from 34,898 individuals (49.7% men) aged >20 years who participated in at least one Tromsø Study survey between 1979 and 2008. In each survey, the participants completed a self-administered questionnaire and underwent physical examinations. LTPA and WPA were assessed by the validated "Saltin-Grimby" 4-scale questions. Potential correlates of LTPA and WPA (sex, age, body mass index (BMI), education, smoking, self-reported cardiovascular disease, self-perceived health, and employment status) were tested using ordinal logistic regression. RESULTS: The age-adjusted prevalence of participants being inactive in leisure time remained relatively stable around 20% from 1979 to 2008 (range 19.9-23.6%). The age-adjusted prevalence of moderate-vigorous LTPA decreased from 23.2% in 1979-80 to 16.0% in 2001, thereafter the prevalence increased to 24.3% in 2007-08 (P <0.05). The age-adjusted prevalence of being mostly sedentary at work increased gradually from 35.5% in 1979-80 to 53.4% in 2007-08 (P <0.05). Sex, age, education, and smoking were identified as cross-sectional correlates of LTPA and WPA (P <0.05). Men had higher odds of engaging in LTPA than women (adjusted OR 1.52 [95% CI 1.39-1.67] in 2007-08), whereas the association between sex and WPA shifted over time. High education level, not being a smoker, and high WPA were associated with high LTPA, whereas low education level, being a smoker, and high levels of LTPA were associated with high WPA (P <0.05). In general, odds of engaging in LTPA and WPA decreased with age (P <0.05). Individuals with healthy BMI had higher odds of being in a higher LTPA level than those who were underweight and obese (P <0.05). Longitudinal analyses identified sex, age, education, smoking, WPA, and LTPA measured in 1979-80 as determinants of LTPA in 2007-08. CONCLUSIONS: In Norwegian adults, the proportion of sedentary WPA increased from 1979 to 2008, whereas the proportion of inactive LTPA remained stable. Being female, older, smoker, obese or underweight, and low education level were associated with low LTPA levels.

Leisure time physical activity and risk of non-vertebral fracture in men and women aged 55 years and older: the Tromsø Study.

Our aim was to examine associations between leisure time physical activity and risk of non-vertebral fractures in men and women aged ≥55 years, with focus on the anatomical fracture location. Self-reported physical activity was registered in 3,450 men and 4,072 women aged 55-97 years at baseline in the Tromsø Study, Norway, in 1994-1995. Non-vertebral fractures were registered through December 31, 2009. During 75,546 person-years at risk, 1,693 non-vertebral fractures were identified. Risk of any non-vertebral fracture decreased with increasing physical activity level in men (P (trend) = 0.006) and non-significantly in women (P (trend) = 0.15), after adjustment for age, body mass index, height, smoking, and previous fracture. The reduced fracture risk was due to a reduced risk in the weight-bearing skeleton, particular at the hip, whereas risk of fracture in the non-weight-bearing skeleton was not related to physical activity. At weight-bearing sites, an inverse relationship between physical activity and fracture risk was present in both sexes (P (trend) ≤ 0.013). Compared with sedentary subjects, the most active men and women had respectively 37% (HR = 0.63, 95% CI: 0.45, 0.88) and 23% (HR = 0.77, 95% CI: 0.62, 0.95) reduced fracture risk in the weight-bearing skeleton. Physical activity is associated with reduced fracture risk at weight-bearing sites, with no associations at non-weight-bearing sites, in both sexes. Habitual physical activity is an important amendable approach to prevent hip fracture.

Leisure time physical activity in adulthood is positively associated with bone mineral density 22 years later. The Tromsø study.

Although the positive association between physical activity and bone mineral density (BMD) is well established, few epidemiological studies have investigated the long-term associations between physical activity during adulthood and BMD later in life. The aim of this prospective, population-based study was to examine the association between leisure time physical activity in adulthood and areal BMD (aBMD) later in life. We examined 1,766 women and 1,451 men aged 20-54 years at baseline who were followed up 22 years later, as part of a population-based study in Norway. Leisure time physical activity was assessed by questionnaire at baseline and follow-up. aBMD was measured at the hip and forearm at follow-up, using X-ray absorptiometry. The association between aBMD and physical activity was analyzed using general linear models. We observed a positive linear trend in aBMD across physical activity levels in both women and men, after adjustments for baseline age, height, weight, and smoking status (P < 0.05). The relationship between aBMD and leisure time physical activity was consistent over different sites of the hip (total hip, femoral neck and trochanter area) and forearm (distal and ultradistal area). In a subsample of 2,436 men and women under 70 years of age, those who where sedentary at both baseline and follow-up (6%) had lower aBMD than those who were moderately active or active at both baseline and follow-up (71%) (P