Vibeke Manniche’s research while affiliated with IT University of Copenhagen and other places

Background and Objective: An unexpected batch-dependent safety signal for the BNT162b2 mRNA COVID-19 vaccine was recently identified in a nationwide study from Denmark, but the generalizability of this finding is unknown. Therefore, we compared batch-dependent rates of suspected adverse events (SAEs) reported to national authorities in Denmark and Sweden. Materials and Methods: SAE and vaccine batch data were received from national authorities in Denmark and Sweden, and analyses of heterogeneity in the relationship between numbers of vaccine doses and SAEs per batch were performed, along with comparison of SAE rates and severities for batches that were shared between the two countries. Results: Significant batch-dependent heterogeneity was found in the number of SAEs per 1000 doses for both countries, with batches associated with high SAE rates detected in the early phase of the vaccination campaign and positive correlations observed between the two countries for the severity of SAEs from vaccine batches that they shared. Mild SAEs predominated in the batches used in the early part of the vaccination roll-out, where markedly higher SAE rates per 1000 doses in Denmark for the batches that were shared between the two countries suggested that a large proportion of these SAEs were under-reported in Sweden. Conclusions: The batch-dependent safety signal observed in Denmark and now confirmed in Sweden suggests that early commercial batches of BNT162b2 may have differed from those used later on, and these preliminary and hypothesis-generating results warrant further study.

The present study examined cardiovascular adaptations in 8–10-year-old schoolchildren after a full school year (10 months) of 5 × 12 min/wk. of intense physical training, including small-sided ball games (soccer, basketball and floorball) or interval running. The study involved 8–10-year-old healthy Danish schoolchildren (n = 232), who were cluster-randomized to a small-sided games group (SSG, n = 60), an interval running group (IR, n = 57) or a control group (CON, n = 115). Comprehensive transthoracic echocardiography, resting heart rate and blood pressure measurements were performed at baseline and post intervention. For interval running, analysis of baseline-to-10-months changes showed significant (P < 0.05) between-group differences in delta scores for diastolic blood pressure (BP) and mean arterial BP (IR −3.2 ± 5.7 and − 2.2 ± 6.5 mmHg vs. CON 0.2 ± 5.3 and 0.4 ± 6.4 mmHg, respectively). Delta scores also showed a trend for reduction of mean arterial BP in SSG compared to CON (−2.1 ± 6.0 vs. 0.2 ± 5.3 mmHg, P = 0.067). Moreover, there were between-group differences in delta scores (P < 0.05) for selected echocardiographic parameters, i.e. in SSG vs. CON for interventricular septum thickness and peak transmitral flow velocity in early diastole, and in IR vs. CON for left ventricular systolic diameter. In conclusion, 10 months of 5 × 12 min/wk. of IR in 8–10-year-old children decreased diastolic BP, while both IR and SSG elicited cardiac adaptations. The results suggest that frequent low volume, intense physical training can have effects on the cardiovascular health profile in healthy children.

This study examined cardiovascular adaptations in 8‐ to 10‐year‐old schoolchildren after 10 months (a full school year) of 3 × 40 minute per week of small‐sided ball games (SSG, including football, basketball, and/or floorball) or circuit strength training (CST). The study involved 291 Danish schoolchildren, 8‐10 years old, cluster‐randomized to SSG (n = 93, 4 schools, 5 classes), CST (n = 83, 4 schools, 4 classes), or a control group (CON, n = 115, 2 schools, 5 classes). Before and after the 10‐month intervention, resting heart rate and blood pressure measurements were performed as well as comprehensive transthoracic echocardiography and peripheral arterial tonometry (PAT). Analysis of baseline‐to‐10‐months changes showed between‐group differences (P < 0.05) after both training interventions in diastolic blood pressure (delta scores: SSG −2.1 ± 6.0 mm Hg; CST −3.0 ± 7.1 mm Hg; CON 0.2 ± 5.3 mm Hg). Moreover, there were between‐group differences in delta scores (P < 0.05) in interventricular septum thickness (SSG 0.17 ± 0.87 mm; CST 0.30 ± 0.94 mm; CON −0.15 ± 0.68 mm), left‐atrial volume index (SSG 0.32 ± 5.13 mL/m²; CON 2.60 ± 5.94 mL/m²), and tricuspid annular plane systolic excursion (SSG −0.4 ± 3.3 mm; CON: 0.1 ± 3.6 mm). No significant between‐group differences were observed for the PAT‐derived reactive hyperemia index. In conclusion, 10 months of 3 × 40 minutes per week of SSG and CST in 8‐ to 10‐year‐old children decreased diastolic blood pressure and elicited discrete cardiac adaptations, suggesting that intense physical exercise in school classes can have effects on cardiovascular health in children.

We investigated whether physical fitness and body composition in 8-10-year-old Danish children are associated with sports club participation. The study included 423 schoolchildren, comprising 209 girls and 214 boys, of whom 67 and 74%, respectively, were active in sports clubs. Yo-Yo Intermittent Recovery level 1 for Children (YYIR1C), balance, jump and coordination tests, together with DXA scans, were used to determine exercise capacity and body composition. Children active in sports clubs had better (P<0.05) YYIR1C (33%, 767±26 vs. 575±29 m), 20-m sprint (3%, 4.33±0.03 vs. 4.48±0.04 s), coordination (6%, 68±1 vs. 72±1 s) and balance test performances (9%, 19.3±0.5 vs. 21.2±0.7 falls/min) and lower fat mass index (16%, 3.8±0.1 vs. 4.5±0.2 kg(fat)·m) than children not active in sports clubs. Ball game players had better (P<0.05) YYIR1C (38%, 925±39 vs. 671±28 m), 20-m sprint (4%, 4.25±0.03 vs. 4.42±0.04 s) and coordination test performances (5%, 65±1 vs. 69±1 s), along with higher (P<0.05) lean body mass (5%, 24.00±0.22 vs. 22.83±0.25 kg) and whole-body BMD (2%, 0.90±0.00 vs. 0.88±0.00 g/cm) compared to children active in other sports. The study showed that 8-10-year-old Danish children engaged in sports club activity, especially ball game players, have better exercise capacity and superior body composition compared to children not active in sports clubs.

We investigated the exercise intensity and fitness effects of frequent school-based low-volume high-intensity training for 10 months in 8–10-year-old children. 239 Danish 3rd-grade school children from four schools were cluster-randomised into a control group (CON, n=116 ) or two training groups performing either 5×12 min/wk small-sided football plus other ball games (SSG, n=62 ) or interval running (IR, n=61 ). Whole-body DXA scans, flamingo balance, standing long-jump, 20 m sprint, and Yo-Yo IR1 children’s tests (YYIR1C) were performed before and after the intervention. Mean running velocity was higher ( p<0.05 ) in SSG than in IR ( 0.88±0.14 versus 0.63±0.20 m/s), while more time ( p<0.05 ) was spent in the highest player load zone (>2; 5.6±3.4 versus 3.7±3.4 %) and highest HR zone (>90% HRmax ; 12.4±8.9 versus 8.4±8.0 %) in IR compared to SSG. After 10 months, no significant between-group differences were observed for YYIR1C performance and HR after 2 min of YYIR1C ( HRsubmax ), but median-split analyses showed that HRsubmax was reduced ( p<0.05 ) in both training groups compared to CON for those with the lowest aerobic fitness (SSG versus CON: 3.2% HRmax [95% CI: 0.8–5.5]; IR versus CON: 2.6% HRmax [95% CI: 1.1–5.2]). After 10 months, IR had improved ( p<0.05 ) 20 m sprint performance (IR versus CON: 154 ms [95% CI: 61–241]). No between-group differences ( p>0.05 ) were observed for whole-body or leg aBMD, lean mass, postural balance, or jump length. In conclusion, frequent low-volume ball games and interval running can be conducted over a full school year with high intensity rate but has limited positive fitness effects in 8–10-year-old children.

Objectives We investigated whether musculoskeletal fitness of school children aged 8–10 years was affected by frequent intense PE sessions. Design and participants 295 Danish school children aged 8–10 years were cluster randomised to a small-sided ball game group (SSG) (n=96, four schools, five classes), a circuit strength training group (CST) (n=83, four schools, four classes) or a control group (CON, n=116, two schools, five classes). Intervention SSG or CST was performed 3×40 min/week over 10 months. Whole-body dual-energy X-ray absorptiometry (DXA) scans were used to determine areal bone mineral density (aBMD), bone mineral content (BMC) and lean body mass (LBM). Flamingo balance, standing long jump and 20-m sprint tests were used to determine muscular fitness. Results Analysis of baseline-to-10 months change scores showed between-group differences in favour of the interventions in whole-body aBMD (SSG vs CON: 8 mg/cm2, 95% CI 3 to 13; CST vs CON: 7 mg/cm2, 95% CI 2 to 13, p<0.05) and leg BMC (SSG vs CON: 11 g, 95% CI 4 to 18; CST vs CON: 11 g, 95% CI 3 to 18, p<0.05). SSG had higher change scores in leg aBMD compared with CON and CST (SSG vs CON: 19 mg/cm2, 95% CI 11 to 39, p<0.05; SSG vs CST: 12 mg/cm2, 95% CI 3 to 21, p<0.05), and CST had higher change scores in whole-body BMC compared with CON (CST vs CON: 25 g, 95% CI 10 to 39, p<0.05). Both training types resulted in higher change scores in postural balance (SSG vs CON: 2.4 fewer falls/min, 95% CI 0.3 to 4.5, CST vs CON: 3.6 fewer falls/min, 95% CI 1.3 to 5.9, p<0.05) and jump length (SSG vs CON: 10%, 95% CI 5 to 16%; CST vs CON: 9%, 95% CI 3 to 15%, p<0.05). No between-group differences were observed for sprint performance or LBM (p>0.05). Conclusions In conclusion, 3×40 min/week with SSG or CST over a full school year improves bone mineralisation and several aspects of muscular fitness of children aged 8–10 years, suggesting that well-organised intense physical education classes can contribute positively to develop musculoskeletal health in young children. Trial registration number NCT02000492, post results.

The present study investigated the cardiac effects of a 10-week football training intervention for school children aged 9-10 years using comprehensive transthoracic echocardiography as a part of a larger ongoing study. A total of 97 pupils from four school classes were cluster-randomized into a control group that maintained their usual activities (CON; two classes, n = 51, 21 boys and 30 girls) and a football training group that performed an additional 3 × 40 min of small-sided football training per week (FT; two classes, n = 46, 23 boys and 23 girls). No baseline differences were observed in age, body composition, or echocardiographic variables between FT and CON. After the 10-week intervention, left ventricular posterior wall diameter was increased in FT compared with CON [0.4 ± 0.7 vs -0.1 ± 0.6 (± SD) mm; P < 0.01] as was the interventricular septum thickness (0.2 ± 0.7 vs -0.2 ± 0.8 mm; P < 0.001). Global isovolumetric relaxation time increased more in FT than in CON (3.8 ± 10.4 vs -0.9 ± 6.6 ms, P < 0.05) while the change in ventricular systolic ejection fraction tended to be higher (1.4 ± 8.0 vs -1.1 ± 5.5%; P = 0.08). No changes were observed in resting heart rate or blood pressure. In conclusion, a short-term, school-based intervention comprising small-sided football sessions resulted in significant structural and functional cardiac adaptations in pre-adolescent children.