Trends of physical fitness related to weight status: An analysis including over 412,000 Swiss young male conscripts from 2007 to 2022.

Objective: The high prevalence of obesity among young adults in the civilian population pose challenges in recruiting physically fit soldiers. We assessed the trend of physical fitness related to weight status among Swiss male conscripts. Methods: Cross-sectional data of medical examination data during mandatory conscription for the Swiss Armed Forces, 2007-2022 (N = 412,186). The conscription physical test (CPT) assessed five aspects of physical fitness, each aspect scoring 0-25, one component being an endurance test (ET). CPT and ET categories were defined as per military guidelines: "Insufficient", "Sufficient", "Good", "Very Good" and "Excellent". Weight status was based on body mass index (BMI). Results: Conscripts with obesity (BMI ≥ 30 kg/m2) and overweight (BMI 25-29.99) had significantly (p < 0.001) lower CPT and ET scores compared to normal weight [multivariable-adjusted mean: 54.7 ± 0.1 and 66.5 ± 0.1, vs. 73.6 ± 0.1 for CPT; 8.8 ± 0.1 and 12.5 ± 0.1, vs. 15.3 ± 0.1 for ET] and a higher likelihood to be categorized as "Insufficient" [weighted relative-risk ratio and (95 %CI): 70.4 (63.7-77.7) and 2.35 (2.16-2.55) for CPT; 77.1 (71.0-83.7) and 3.05 (2.91-3.20) for ET] or "Sufficient" [7.67 (7.38-7.97) and 2.02 (1.99-2.06) for CPT; 8.93 (8.37-9.52) and 2.02 (1.98-2.06) for ET]. Compared to normal weight conscripts, the CPT and ET scores decreased over the conscription years for conscripts with obesity (multivariable-adjusted mean yearly change: -0.11 ± 0.02 for CPT; -0.032 ± 0.007 for ET) and overweight (-0.16 ± 0.01 for CPT and -0.044 ± 0.004 for ET). Conclusion: Male Swiss conscripts with overweight and obesity have lower physical fitness than normal weight conscripts, and this condition tends to worsen over the conscription years.

Comparison of different software for processing physical activity measurements with accelerometry.

Several raw-data processing software for accelerometer-measured physical activity (PA) exist, but whether results agree has not been assessed. We examined the agreement between three different software for raw accelerometer data, and associated their results with cardiovascular risk. A cross-sectional analysis conducted between 2014 and 2017 in 2693 adults (53.4% female, 45-86 years) living in Lausanne, Switzerland was used. Participants wore the wrist-worn GENEActive accelerometer for 14 days. Data was processed with the GENEActiv manufacturer software, the Pampro package in Python and the GGIR package in R. For the latter, two sets of thresholds "White" and "MRC" defining levels of PA and two versions (1.5-9 and 1.11-1) for the "MRC" threshold were used. Cardiovascular risk was assessed using the SCORE risk score. Time spent (mins/day) in stationary, light, moderate and vigorous PA ranged from 633 (GGIR-MRC) to 1147 (Pampro); 93 (GGIR-White) to 196 (GGIR-MRC); 19 (GGIR-White) to 161 (GENEActiv) and 1 (GENEActiv) to 26 (Pampro), respectively. Spearman correlations between results ranged between 0.317 and 0.995, while concordance coefficients ranged between 0.035 and 0.968. With some exceptions, the line of perfect agreement was not in the 95% confidence interval of the Bland-Altman plots. Compliance to PA guidelines varied considerably: 99.8%, 98.7%, 76.3%, 72.6% and 50.2% for Pampro, GENEActiv, GGIR-MRC v.1.11-1, GGIR-MRC v.1.4-9 and GGIR-White, respectively. Cardiovascular risk decreased with increasing time spent in PA across most software packages. We found large differences in PA estimation between software and thresholds used, which makes comparability between studies challenging.

Effect of acute iron infusion on insulin secretion: A randomized, double-blind, placebo-controlled trial.

Background: Chronic exposure to high iron levels increases diabetes risk partly by inducing oxidative stress, but the consequences of acute iron administration on beta cells are unknown. We tested whether the acute administration of iron for the correction of iron deficiency influenced insulin secretion and the production of reactive oxygen species. Methods: Single-center, double-blinded, randomized controlled trial conducted between June 2017 and March 2020. 32 women aged 18 to 47 years, displaying symptomatic iron deficiency without anaemia, were recruited from a community setting and randomly allocated (1:1) to a single infusion of 1000 mg intravenous ferric carboxymaltose (iron) or saline (placebo). The primary outcome was the between group mean difference from baseline to day 28 in first and second phase insulin secretion, assessed by a two-step hyperglycaemic clamp. All analyses were performed by intention to treat. This trial was registered in ClinicalTrials.gov NCT03191201. Findings: Iron infusion did not affect first and second phase insulin release. For first phase, the between group mean difference from baseline to day 28 was 0 µU × 10 min/mL [95% CI, -22 to 22, P = 0.99]. For second phase, it was -5 µUx10min/mL [95% CI, -161 to 151; P = 0.95] at the first plateau of the clamp and -249 µUx10min/mL [95% CI, -635 to 137; P = 0.20] at the second plateau. Iron infusion increased serum ascorbyl/ascorbate ratio, a marker of plasma oxidative stress, at day 14, with restoration of normal ratio at day 28 relative to placebo. Finally, high-sensitive C-reactive protein levels remained similar among groups. Interpretation: In iron deficient women without anaemia, intravenous administration of 1000 mg of iron in a single sitting did not impair glucose-induced insulin secretion despite a transient increase in the levels of circulating reactive oxygen species. Funding: The Swiss National Science Foundation, University of Lausanne and Leenaards, Raymond-Berger and Placide Nicod Foundations.

Geographic clusters of objectively measured physical activity and the characteristics of their built environment in a Swiss urban area.

INTRODUCTION: Evidence suggests that the built environment can influence the intensity of physical activity. However, despite the importance of the geographic context, most of the studies do not consider the spatial framework of this association. We aimed to assess individual spatial dependence of objectively measured moderate and vigorous physical activity (MVPA) and describe the characteristics of the built environment among spatial clusters of MVPA. METHODS: Cross-sectional data from the second follow-up (2014-2017) of CoLaus|PsyCoLaus, a longitudinal population-based study of the Lausanne area (Switzerland), was used to objectively measure MVPA using accelerometers. Local Moran's I was used to assess the spatial dependence of MVPA and detect geographic clusters of low and high MVPA. Additionally, the characteristics of the built environment observed in the clusters based on raw MVPA and MVPA adjusted for socioeconomic and demographic factors were compared. RESULTS: Data from 1,889 participants (median age 63, 55% women) were used. The geographic distribution of MVPA and the characteristics of the built environment among clusters were similar for raw and adjusted MVPA. In the adjusted model, we found a low concentration of individuals within spatial clusters of high MVPA (median: 38.5mins; 3% of the studied population) and low MVPA (median: 10.9 mins; 2% of the studied population). Yet, clear differences were found in both models between clusters regarding the built environment; high MVPA clusters were located in areas where specific compositions of the built environment favor physical activity. CONCLUSIONS: Our results suggest the built environment may influence local spatial patterns of MVPA independently of socioeconomic and demographic factors. Interventions in the built environment should be considered to promote physically active behaviors in urban areas.

Comparison of the Physical Activity Frequency Questionnaire (PAFQ) with accelerometry in a middle-aged and elderly population: The CoLaus study.

OBJECTIVE: The Physical Activity Frequency Questionnaire (PAFQ) has been used in several studies, but its validation dates from 1998. We compared the PAFQ with accelerometry data for measuring levels of physical activity (PA) in a middle-aged and elderly population. DESIGN: Cross-sectional analysis was conducted with a sample of 1752 adults from the general population (50.7% female, age range 45.2-87.1 years) living in Switzerland. Participants completed the PAFQ and wore a wrist-worn accelerometer for 14 consecutive days. Spearman correlation, Lin's concordance coefficient and Bland-Altman plots were performed to compare PAFQ and accelerometry data. RESULTS: Compared with the accelerometer, the PAFQ overestimated total, light, moderate and vigorous activity by a median [interquartile range] of 143 [34.5; 249], 72 [12; 141], 23 [-46; 100] and 13 [-1; 41] minutes/day, respectively, and underestimated sedentary behaviour by 123 [14; 238] minutes/day. Spearman's correlation coefficients ranged from 0.171 for vigorous PA and 0.387 for total PA and sedentary behaviour. Lin's concordance coefficients ranged from 0.044 for vigorous PA and 0.254 for moderate to vigorous PA. The difference between PAFQ and accelerometer results increased with increasing time spent at each activity level. CONCLUSION: There is limited agreement between estimates of activity obtained by PAFQ and those obtained from accelerometers, suggesting that these tools measure activity differently. Although there is some degree of comparability, they should be considered as complementary tools to obtain comprehensive information on both individual and population activity levels.

Association of activity behaviours and patterns with cardiovascular risk factors in Swiss middle-aged adults: The CoLaus study.

The impact of the combination between physical activity (PA) and sedentary (SE) levels on cardiovascular health is poorly known. We assessed the association of activity behaviours and patterns with cardiovascular risk factors in the general population (The CoLaus study, Switzerland, 2014-2017). 2605 adults (54.4% women, age range 45-86 years) had PA and SE levels measured for 14 days using wrist-worn accelerometry. Four activity behaviours: "Couch potato": low PA & high SE; "Light mover": low PA & low SE; "Sedentary exerciser": high PA & high SE, and "Busy bee": high PA & low SE; and three activity patterns: "Inactive", "Weekend warrior", and "Regularly active" were defined. Smoking, obesity, hypertension, dyslipidemia and diabetes were assessed. Relative to 'Couch potatoes', 'Sedentary exercisers' and 'Busy bees' had a lower likelihood of smoking: Odds Ratio (95% confidence interval): 0.40 (0.27-0.61) and 0.62 (0.47-0.81), obesity: 0.43 (0.29-0.63) and 0.41 (0.31-0.54), and diabetes: 0.53 (0.30-0.95) and 0.62 (0.42-0.89), respectively. Relative to 'Inactives', 'Weekend warriors' and 'Regularly actives' had a lower likelihood of smoking: 0.58 (0.43-0.78) and 0.56 (0.44-0.72), obesity: 0.41 (0.30-0.56) and 0.41 (0.32-0.53), hypertension: 0.66 (0.51-0.85) and 0.72 (0.59-0.89), and diabetes: 0.61 (0.38-0.98) and 0.60 (0.42-0.86), respectively. High PA is associated with a favourable cardiovascular risk profile, even when concomitant with high SE or when PA is concentrated on weekends. These findings suggest that being "Sedentary exerciser" or "Weekend warrior" might be sufficient to prevent cardiovascular disease.

Association of activity status and patterns with salivary cortisol: the population-based CoLaus study.

PURPOSE: Physical activity (PA) has been shown to influence salivary cortisol concentrations in small studies conducted among athletes. We assessed the association of activity status and patterns with salivary cortisol in the general population. METHODS: Cross-sectional study including 1948 adults (54.9% women, 45-86 years). PA and sedentary behaviour (SB) were measured for 14 days by accelerometry. Low PA and high SB status were defined, respectively, as the lowest and highest tertile of each behaviour. 'Inactive', 'Weekend warrior', and 'Regularly active' patterns were also defined. Four salivary cortisol samples were collected over a single day and the following parameters were calculated: area under the curve to ground (AUCg), awakening response (CAR) and diurnal slope. RESULTS: After multivariable adjustment, low SB remained associated to steeper slopes relative to high SB (- 1.54 ± 0.03 vs. - 1.44 ± 0.04 nmol/l per hour). Non-significant trends were found for high PA relative to low PA with steeper slopes (- 1.54 ± 0.03 vs. - 1.45 ± 0.04) and lower AUCg (208.7 ± 2.0 vs. 215.9 ± 2.9 nmol.h/l). Relative to 'Inactives', 'Regularly actives' had lower AUCg (205.4 ± 2.4 vs. 215.5 ± 2.9) and 'Weekend warriors' had steeper slopes (- 1.61 ± 0.05 vs. - 1.44 ± 0.04). No associations were found for CAR. CONCLUSION: Low SB and high PA are related to lower cortisol secretion as measured by different parameters of salivary cortisol, but the effects were only modest.

Physical activity is associated with higher sleep efficiency in the general population: the CoLaus study.

Study Objectives: To evaluate the association of objective physical activity (PA) and sedentary behavior (SB) with sleep duration and quality. Methods: Cross-sectional study including 2649 adults (53.5% women, 45-86 years) from the general population. Proportions of time spent in PA and SB were measured using 14 day accelerometry. Low PA and high SB statuses were defined as the lowest and highest tertile of each behavior. "Inactive," "Weekend warrior," and "Regularly active" weekly patterns were also defined. Sleep parameters were derived from the accelerometer and validated questionnaires. Results: High PA, relative to low PA, was associated with higher sleep efficiency (76.6 vs. 73.8%, p < 0.01) and lower likelihood of evening chronotype [relative-risk ratio (RR) and 95% CI: 0.71 (0.52; 0.97)]. Similar associations were found for low SB relative to high SB. "Weekend warriors" relative to "Inactives," had higher sleep efficiency [76.4 vs. 73.9%, p < 0.01] and lower likelihood of evening chronotype [RR: 0.63 (0.43; 0.93)]. "Regularly actives," relative to "Inactives," had higher sleep efficiency [76.7 vs. 73.9%, p < 0.01] and tended to have less frequently an evening chronotype [RR: 0.75 (0.54; 1.04), p = 0.09]. No associations were found for PA and SB with sleep duration, daytime sleepiness, insomnia, and risk of sleep apnea (after adjustment for body mass index). Conclusions: High PA and low SB individuals, even if they do not sleep longer, have higher sleep efficiency and have less frequently an evening chronotype.

Correlates of weekday compliance to physical activity recommendations in Swiss youth non-compliant in weekend days.

Some children are inactive on weekends but active on weekdays. Correlates of such behavior remain to be clarified. We assessed school, out-of-school and family correlates of compliance with physical activity (PA) recommendations during weekdays among weekend non-compliant youth in Switzerland. Cross-sectional data collected in 2013-2015 from the SOPHYA study. PA was objectively measured during one week using waist-worn accelerometers. Compliance with PA recommendations (≥ 60 min/day of moderate-to-vigorous PA) was assessed separately for weekend and weekdays. Data on school sport, transport to school, sports club participation, household income, parent's PA and education were collected by phone interview and questionnaires. Data from 540 youth (316 girls) aged 6-16 years were available for analysis. Participants who were compliant to recommendations during weekdays were more frequently boys (50.3% vs. 31.4%, p < 0.001), more often participated in sports club (73.3% vs. 64.3%, p = 0.024), and were more prone to adopt active transport to school (75.8% vs. 62.0%, p = 0.001) than non-compliers. Multivariable adjustment showed male gender [odds ratio and (95% confidence interval): 4.30 (2.71-6.81)], sports club participation [1.91 (1.21-3.02)], and PA-active parent [1.98 (1.20-3.28)] were significantly associated with weekday compliance. Being a male, a sports club participant and having a physically active parent significantly increase compliance with PA recommendations during weekdays among Swiss youth who are inactive on weekends.

Of weekend warriors and couch potatoes: Socio-economic determinants of physical activity in Swiss middle-aged adults.

Determinants of the interplay between physical activity (PA) and sedentary (SE) status are poorly known. We assessed the socio-economic determinants of PA and SE behaviours and patterns in a population-based study (The CoLaus study, Lausanne, Switzerland, 2014-2017). 2229 adults (51.8% women, age range 45-86 years) had PA and SE levels measured for 14 days using a wrist-worn accelerometer. Four activity behaviours: (1) 'Couch potato': low PA & high SE; (2) 'Light mover': low PA & low SE; (3) 'Sedentary exerciser': high PA & high SE, and (4) 'Busy bee': high PA & low SE; and three activity patterns: (1) 'Inactive', (2) 'Weekend warrior', and (3) 'Regularly active' were defined. Employment, household income and educational level were collected by questionnaire. For activity behaviours, relative to 'Couch potatoes', multivariate analysis showed that being employed and having a low educational level were positively associated with 'Light movers': relative risk ratios and (95% confidence interval): 1.54 (1.00-2.37) and 1.73 (1.11-2.69), respectively, and also with 'Busy bees': 1.49 (1.09-2.04) and 1.71 (1.26-2.32), respectively. High household income was negatively associated with 'Light movers': 0.58 (0.34-0.97) and positively with 'Sedentary exercisers': 1.85 (1.10-3.10). For activity patterns, relative to 'Inactives', being employed and having a high household income were positively associated with 'Weekend warriors': 1.78 (1.26-2.50) and 1.59 (1.07-2.36), respectively, while having a low educational level was positively associated with 'Regularly actives': 1.76 (1.32-2.34). Employment, educational level and household income are significantly but differently associated with activity behaviours and patterns.

No association between grip strength and cardiovascular risk: The CoLaus population-based study.

BACKGROUND: Decreased grip strength (GS) is predictive of cardiovascular (CV) disease but whether it improves CV risk prediction has not been evaluated. We assessed the predictive value of low GS on incident CV events and overall mortality taking into account CV risk equations in a population-based study from Switzerland. METHODS: 2707 adults (54.8% women, age range 50-75years) were followed for a median time of 5.4years. GS was assessed using a hydraulic hand dynamometer. CV absolute risk at baseline was assessed using recalibrated SCORE, Framingham and PROCAM risk equations. Incident CV events were adjudicated by an independent committee. RESULTS: 160 deaths and 188 incident CV events occurred during follow-up. On bivariate analysis, low GS was associated with increased incident CV events: hazard ratio (HR) and (95% confidence interval) 1.76 (1.13-2.76), p<0.01 but not with overall mortality: HR=1.51 (0.94-2.45), p=0.09. The association between low GS and incident CV events disappeared after adjusting for baseline CV risk: HR=1.23 (0.79-1.94), p=0.36; 1.34 (0.86-2.10), p=0.20 and 1.47 (0.94-2.31), p=0.09 after adjusting for SCORE, Framingham and PROCAM scores, respectively. CONCLUSION: Low GS is not predictive of incident CV events when taking into account CV absolute risk.

Association of grip strength with cardiovascular risk markers.

Background Mechanisms underlying the association between grip strength and cardiovascular mortality are poorly understood. We aimed to assess the association of grip strength with a panel of cardiovascular risk markers. Design The study was based on a cross-sectional analysis of 3468 adults aged 50-75 years (1891 women) from a population-based sample in Lausanne, Switzerland. Methods Grip strength was measured using a hydraulic hand dynamometer. Cardiovascular risk markers included anthropometry, blood pressure, lipids, glucose, adiposity, inflammatory and other metabolic markers. Results In both genders, grip strength was negatively associated with fat mass (Pearson correlation coefficient: women: -0.170, men: -0.198), systolic blood pressure (women: -0.096, men: -0.074), fasting glucose (women: -0.048, men: -0.071), log-transformed leptin (women: -0.074, men: -0.065), log-transformed high-sensitivity C-reactive protein (women: -0.101, men: -0.079) and log-transformed homocysteine (women: -0.109, men: -0.060). In men, grip strength was also positively associated with diastolic blood pressure (0.068), total (0.106) and low density lipoprotein-cholesterol (0.082), and negatively associated with interleukin-6 (-0.071); in women, grip strength was negatively associated with triglycerides (-0.064) and uric acid (-0.059). After multivariate adjustment, grip strength was negatively associated with waist circumference (change per 5 kg increase in grip strength: -0.82 cm in women and -0.77 cm in men), fat mass (-0.56% in women; -0.27% in men) and high-sensitivity C-reactive protein (-6.8% in women; -3.2% in men) in both genders, and with body mass index (0.22 kg/m2) and leptin (-2.7%) in men. Conclusion Grip strength shows only moderate associations with cardiovascular risk markers. The effect of muscle strength as measured by grip strength on cardiovascular disease does not seem to be mediated by cardiovascular risk markers.

Seasonal variation of overall and cardiovascular mortality: a study in 19 countries from different geographic locations.

BACKGROUND: Cardiovascular diseases (CVD) mortality has been shown to follow a seasonal pattern. Several studies suggested several possible determinants of this pattern, including misclassification of causes of deaths. We aimed at assessing seasonality in overall, CVD, cancer and non-CVD/non-cancer mortality using data from 19 countries from different latitudes. METHODS AND FINDINGS: Monthly mortality data were compiled from 19 countries, amounting to over 54 million deaths. We calculated ratios of the observed to the expected numbers of deaths in the absence of a seasonal pattern. Seasonal variation (peak to nadir difference) for overall and cause-specific (CVD, cancer or non-CVD/non-cancer) mortality was analyzed using the cosinor function model. Mortality from overall, CVD and non-CVD/non-cancer showed a consistent seasonal pattern. In both hemispheres, the number of deaths was higher than expected in winter. In countries close to the Equator the seasonal pattern was considerably lower for mortality from any cause. For CVD mortality, the peak to nadir differences ranged from 0.185 to 0.466 in the Northern Hemisphere, from 0.087 to 0.108 near the Equator, and from 0.219 to 0.409 in the Southern Hemisphere. For cancer mortality, the seasonal variation was nonexistent in most countries. CONCLUSIONS: In countries with seasonal variation, mortality from overall, CVD and non-CVD/non-cancer show a seasonal pattern with mortality being higher in winter than in summer. Conversely, cancer mortality shows no substantial seasonality.

Trends and determinants of time in bed in Geneva, Switzerland.

STUDY OBJECTIVES: There is limited information regarding sleep duration and determinants in Switzerland. We aimed to assess the trends and determinants of time in bed as a proxy for sleep duration in the Swiss canton of Geneva. METHODS: Data from repeated, independent cross-sectional representative samples of adults (≥ 18 years) of the Geneva population were collected between 2005 and 2011. Self-reported time in bed, education, monthly income, and nationality were assessed by questionnaire. RESULTS: Data from 3,853 participants (50% women, 51.7 ± 10.9 years) were analyzed. No significant trend was observed between 2005 and 2011 regarding time in bed or the prevalence of short (≤ 6 h/day) and long (> 9 h/day) time in bed. Elderly participants reported a longer time in bed (year-adjusted mean ± standard error: 7.67 ± 0.02, 7.82 ± 0.03, and 8.41 ± 0.04 h/day for 35-50, 50-65, and 65+ years, respectively, p < 0.001), while shorter time in bed was reported by non-Swiss participants (7.77 ± 0.03 vs. 7.92 ± 0.03 h/day for Swiss nationals, p < 0.001), participants with higher education (7.92 ± 0.02 for non-university vs. 7.74 ± 0.03 h/day for university, p < 0.001) or higher income (8.10 ± 0.04, 7.84 ± 0.03, and 7.70 ± 0.03 h/day for < 5,000 SFr; 5,000-9,500 SFr, and > 9,500 SFr, respectively, p < 0.001). Multivariable-adjusted polytomous logistic regression showed short and long time in bed to be positively associated with obesity and negatively associated with income. CONCLUSION: In a Swiss adult population, sleep duration as assessed by time in bed did not change significantly between 2005 and 2011. Both clinical and socioeconomic factors influence time in bed.

Seasonality of cardiovascular risk factors: an analysis including over 230†000 participants in 15 countries.

OBJECTIVE: To assess the seasonality of cardiovascular risk factors (CVRF) in a large set of population-based studies. METHODS: Cross-sectional data from 24 population-based studies from 15 countries, with a total sample size of 237 979 subjects. CVRFs included Body Mass Index (BMI) and waist circumference; systolic (SBP) and diastolic (DBP) blood pressure; total, high (HDL) and low (LDL) density lipoprotein cholesterol; triglycerides and glucose levels. Within each study, all data were adjusted for age, gender and current smoking. For blood pressure, lipids and glucose levels, further adjustments on BMI and drug treatment were performed. RESULTS: In the Northern and Southern Hemispheres, CVRFs levels tended to be higher in winter and lower in summer months. These patterns were observed for most studies. In the Northern Hemisphere, the estimated seasonal variations were 0.26 kg/m(2) for BMI, 0.6 cm for waist circumference, 2.9 mm Hg for SBP, 1.4 mm Hg for DBP, 0.02 mmol/L for triglycerides, 0.10 mmol/L for total cholesterol, 0.01 mmol/L for HDL cholesterol, 0.11 mmol/L for LDL cholesterol, and 0.07 mmol/L for glycaemia. Similar results were obtained when the analysis was restricted to studies collecting fasting blood samples. Similar seasonal variations were found for most CVRFs in the Southern Hemisphere, with the exception of waist circumference, HDL, and LDL cholesterol. CONCLUSIONS: CVRFs show a seasonal pattern characterised by higher levels in winter, and lower levels in summer. This pattern could contribute to the seasonality of CV mortality.