Cédric Gubelmann

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/m2 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.

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.

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.

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.

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.

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, parents 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.