Göran Pershagen’s research while affiliated with Karolinska Institutet and other places

Introduction Snus is suggested as a risk factor for cardiometabolic disease, but little is known about health effects in young populations, particularly in women. We aimed to investigate associations between snus and cardiometabolic health markers among young men and women. Method This study was conducted within the BAMSE birth cohort and included participants followed up around 24 years (n=2256) and 26 years (n=1011). Snus use was assessed at 24 years by questionnaires. Cardiometabolic health markers were recorded at clinical examinations at 24 and 26 years. Associations between snus use and cardiometabolic markers were assessed by multivariable linear regression. Results Snus was used by 6.4% (n=81) among women and 21.9% (n=219) among men. Compared to no tobacco use, daily exclusive snus use among women at 24 years was associated with higher body mass index (BMI) (adjusted β: 1.93 kg/m2, 95% CI: 0.54, 3.33) and waist circumference (WC) (aβ: 3.80 cm, 95% CI: 0.41, 7.18) at 24 years, and with higher BMI (aβ: 2.73 kg/m2, 95% CI: 0.53-4.93) at 26 years. Among men, using ≥4 cans/week was associated with increased BMI (aβ: 2.48 kg/m2, 95% CI: 0.73, 4.24) and a tendency toward increased body fat (aβ: 2.31%, 95% CI: -0.53, 5.14) at 26 years. Snus use was not associated with glycemic status or blood pressure. Conclusion Our results suggest that snus is associated with increased BMI, and possibly other measures of adiposity, among young women and heavy using young men. Given the cross-sectional study design, the results should be interpreted with caution. Implications We found cross-sectional associations between snus use and measures of increased adiposity in a cohort of Swedish young adults, including BMI and waist circumference among women and BMI among heavy snus using men. We did not find associations between snus use and body fat %, glycemic status or blood pressure. This is one of few studies to investigate health effect of snus among both women and men as well as cardiometabolic health markers in young adults. Given the recent trends of increased snus use among young adults, our findings highlight the need for further research on snus on cardiometabolic health.

Background Road-traffic noise may influence the development of cardiovascular events such as stroke and myocardial infarction, but etiological mechanisms remain unclear. This study aimed to assess the relationship between long-term road-traffic noise exposure and coronary atherosclerosis in Sweden. Methods In the Swedish CArdioPulmonary bioImage Study (SCAPIS) cohort, including 30,154 subjects aged 50–65 years, recruited between 2013 and 2018, coronary atherosclerosis was measured based on computer tomography (CT) scans as coronary artery calcium score, segment involvement score (SIS), and non-calcified plaques (NCP) at enrollment. Based on modified Nordic model, road-traffic noise exposure was modeled for 2000, 2013, and 2018 with interpolation for intermediate years. We investigated the association between time-weighted long-term exposure to road-traffic noise (L den ) and the prevalence of atherosclerosis using ordinal logistic regression models adjusting for potential socioeconomic, behavioral, and environmental confounders, including air pollution. Results No clear associations were found between road-traffic noise and coronary atherosclerosis. The odds ratio for coronary artery calcium score was 1.00 (95% confidence interval [CI] = 0.96, 1.04), SIS 0.99 (0.96, 1.03), and NCP 0.98 (0.90, 1.03) per interquartile range (9.4 dB L den ) for road-traffic noise exposure during 10 years before enrollment. No consistent associations were observed in site-specific analyses or using shorter exposure periods. Furthermore, exposure-response analyses revealed no clear trends, and there were no strong interactions between road-traffic noise and cardiovascular risk factors in relation to the atherosclerosis markers. Conclusions Long-term exposure to road-traffic noise was not linked to coronary atherosclerosis or calcification in relatively healthy, middle-aged populations in Sweden.

Background Transportation noise has been linked with cardiometabolic outcomes, yet whether it is a risk factor for atrial fibrillation (AF) remains inconclusive. We aimed to assess whether transportation noise was associated with AF in a large, pooled Nordic cohort. Methods We pooled data from 11 Nordic cohorts, totaling 161,115 participants. Based on address history from five years before baseline until end of follow-up, road, railway, and aircraft noise was estimated at a residential level. Incident AF was ascertained via linkage to nationwide patient registries. Cox proportional hazards models were utilized to estimate associations between running 5-year time-weighted mean transportation noise (Lden) and AF after adjusting for sociodemographics, lifestyle, and air pollution. Findings We identified 18,939 incident AF cases over a median follow-up of 19.6 years. Road traffic noise was associated with AF, with a hazard ratio (HR) and 95% confidence interval (CI) of 1.02 (1.00–1.04) per 10-dB of 5-year mean time-weighted exposure, which changed to 1.03 (1.01–1.06) when implementing a 53-dB cut-off. In effect modification analyses, the association for road traffic noise and AF appeared strongest in women and overweight and obese participants. Compared to exposures ≤40 dB, aircraft noise of 40.1–50 and > 50 dB were associated with HRs of 1.04 (0.93–1.16) and 1.12 (0.98–1.27), respectively. Railway noise was not associated with AF. We found a HR of 1.19 (1.02–1.40) among people exposed to noise from road (≥45 dB), railway (>40 dB), and aircraft (>40 dB) combined. Interpretation Road traffic noise, and possibly aircraft noise, may be associated with elevated risk of AF. Funding 10.13039/501100004785NordForsk.

Background Available evidence suggests a link between exposure to transportation noise and an increased risk of obesity. We aimed to assess exposure-response functions for long-term residential exposure to road traffic, railway and aircraft noise, and markers of obesity. Methods Our cross-sectional study is based on pooled data from 11 Nordic cohorts, including up to 162,639 individuals with either measured (69.2%) or self-reported obesity data. Residential exposure to transportation noise was estimated as a time-weighted average L den 5 years before recruitment. Adjusted linear and logistic regression models were fitted to assess beta coefficients and odds ratios (OR) with 95% confidence intervals (CI) for body mass index, overweight, and obesity, as well as for waist circumference and central obesity. Furthermore, natural splines were fitted to assess the shape of the exposure-response functions. Results For road traffic noise, the OR for obesity was 1.06 (95% CI = 1.03, 1.08) and for central obesity 1.03 (95% CI = 1.01, 1.05) per 10 dB L den . Thresholds were observed at around 50–55 and 55–60 dB L den , respectively, above which there was an approximate 10% risk increase per 10 dB L den increment for both outcomes. However, linear associations only occurred in participants with measured obesity markers and were strongly influenced by the largest cohort. Similar risk estimates as for road traffic noise were found for railway noise, with no clear thresholds. For aircraft noise, results were uncertain due to the low number of exposed participants. Conclusion Our results support an association between road traffic and railway noise and obesity.

Background The benefits of improved air quality on asthma remain understudied. Therefore, our aim was to investigate associations of changes in ambient air pollution with incident asthma from school-age until young adulthood in an area with mostly low air pollution levels. Methods Participants in the BAMSE birth cohort from Stockholm without asthma before the 8-year follow-up were included (N=2371). We estimated the association of change in individual-level air pollutant exposure (particulate matter with diameter ⩽2.5 μm (PM2.5) and, ⩽10 μm (PM10), black carbon (BC) and nitrogen oxides (NOx)) from the first year of life to the 8-year follow-up with asthma incidence from the 8-year until the 24-year follow-up. Multi-pollutant trajectories were identified using Group-Based Multivariate Trajectory model. We also used parametric g-computation to quantify the asthma incidence under different hypothetical interventions regarding air pollution levels. Results Air pollution levels at residency decreased during the period, with median reductions of 5.6% for PM2.5, 3.1% for PM10, 5.9% for BC, and 26.8% for NOx. A total of 395 incident asthma cases were identified from the 8-year until the 24-year follow-up. The odds ratio for asthma was 0.89 (95%CI: 0.80, 0.99) for each interquartile range reduction in PM2.5 (equal to 8.1% reduction). Associations appeared less clear for PM10, BC and NOx. Five multi-pollutant trajectories were identified, where the largest reduction trajectory displayed the lowest odds of asthma (OR=0.55, 95%CI: 0.31, 0.98) compared with the least reduction trajectory. If the PM2.5 exposure had not declined up to the 8-year follow-up, the hypothetical asthma incidence was estimated to have been 10.9% higher (95%CI: 0.8%, 20.8%). Conclusions Decrease in PM2.5 levels during childhood was associated with lower risk of incident asthma from school-age to young adulthood in an area with relatively low air pollution levels, suggesting broad respiratory health benefits from improved air quality. This article is open access and distributed under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/).