Ola Thorsson’s research while affiliated with Lund University and other places

The longitudinal and multidisciplinary research project Malmö Youth Sport Study measured the sports results achieved by two cohorts of pupils using a variable named ACHIEVE, dividing the pupils into three categories (an elite group competing at the national or international level, a group competing at the district level, and a third group either not competing at all or below district level). This was assessed three and six years after baseline at age 13. An additional hypothetical measure, based on information from the athletes’ trainers, predicted the category the pupils were expected to belong to after twelve years (age 25). Social variables related to the ACHIEVE variable are sex, socio-economic position of the parents, ethnicity, completed secondary sports school, sports capital, and quartile of birth. After three years, 28% of the pupils belonged to the elite group and after six years, 26%. Thirty-two and 48%, respectively, had abandoned their elite efforts. The elite group remained fairly stable over time but fewer girls than boys advanced to the elite group. The pupils at the school have a homogenous middle-class background. We found little evidence that socio-economic factors affected ACHIEVE. Nearly all parents had been engaged in sports, either competing or as coaches. On admission to the school, there was a pronounced relative age effect (RAE). This remained after three years as the age was significantly different between the three groups but was reduced after six years. According to the prognosis made by the coaches, the elite group would be considerably smaller when the subjects reached the age of 25. The RAE was again significant in the prognosis. A further follow-up when the subjects are 25 years old will reveal not only what proportion of subjects are actively competing, but also if they are engaged in recreational sports, to what extent the RAE is present, and how accurately coaches can predict success.

Investigating physical activity (PA) patterns as a detailed intensity spectrum instead of crude intensity categories has improved the ability to analyze the relationship between measured PA and health variables. The aim of this methodological study was to introduce and investigate the utility of using detailed PA intensity spectrum compared to crude PA intensity categories for comparison of PA between groups and between repeated measures. The study sample consisted of two groups of children, where one group was scheduled for extended physical education by daily classes while the other group followed usual physical education schedule. Accelerometer data was processed into traditional crude PA intensity categories and into detailed PA intensity spectrum. Multivariate partial lest squares regression for discriminant analysis (PLS‐DA) was applied for PA intensity spectrum group comparison and compared to traditional univariate statistical analysis. Repeated measures were investigated using independent PLS‐DA as well as multilevel PLS‐DA for paired analysis. While traditional analysis of crude PA intensity categories was unable to find any group differences, multivariate analysis of the PA intensity spectrum identified statistically significant differences. By the extension of multilevel PLS‐DA for paired comparison, a clear difference in the PA intensity spectrum was demonstrated between repeated measures. In conclusion, analysis of detailed PA intensity spectrum demonstrates utility for comparing detailed PA data between groups and between repeated measures in interventional and observational research.

Background Tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) is a cytokine with inflammatory and apoptotic properties. A complex relationship exists between TRAIL and the lung where both elevated TRAIL and TRAIL deficiency are associated with lung impairment. In neonatal mice, TRAIL is thought to translate respiratory infections into chronic lung disease but the association between TRAIL and lung function in childhood has not been assessed. Aim To assess the cross-sectional relationship between TRAIL levels and lung function in school-aged children. Methods The study cohort consisted of 170 school-aged children attending four schools in Malmö, Sweden. Lung volumes, impulse oscillometry (IOS) and serum TRAIL were measured for all children. Linear regression was used to assess changes in lung function per 1-SD increase in TRAIL. General linear models were used to assess mean lung function by tertiles (T) of TRAIL. Results Mean age was 9.9 years (±0.6). A 1-SD increase in TRAIL was associated with lower values of FEV1 and FEV1/VC (change in FEV1 (L) and FEV1/VC ratio: −0.047, p-value 0.002, and −0.011, p-value 0.020, respectively) and higher values of lung resistance (change in R5 and R20 (kPa/(L/s)): 0.035, p-value <0.001 and 0.027, p-value 0.004, respectively). These associations remained significant after excluding children with pre-existing lung disease. Higher TRAIL levels were associated with more negative values for X5 in general linear models (Mean X5 (kPa/(L/s)) in T1 (low TRAIL): −0.193 vs T3 (high TRAIL): −0.216, p-value 0.026). Conclusions High TRAIL levels are significantly associated with markers of pulmonary airflow obstruction in school-aged children.

Background Owing to the large variation in treatment response among patients with high-risk prostate cancer, it would be of value to use objective tools to monitor the status of bone metastases during clinical trials. Automated Bone Scan Index (aBSI) based on artificial intelligence has been proposed as an imaging biomarker for the quantification of skeletal metastases from bone scintigraphy. Objective To investigate how an increase in aBSI during treatment may predict clinical outcome in a randomised controlled clinical trial including patients with high-risk prostate cancer. Design, setting, and participants We retrospectively selected all patients from the Zometa European Study (ZEUS)/SPCG11 study with image data of sufficient quality to allow for aBSI assessment at baseline and at 48-mo follow-up. Data on aBSI were obtained using EXINIboneBSI software, blinded for clinical data and randomisation of zoledronic acid treatment. Data on age, overall survival (OS), and prostate-specific antigen (PSA) at baseline and upon follow-up were available from the study database. Outcome measurements and statistical analysis Association between clinical parameters and aBSI increase during treatment was evaluated using Cox proportional-hazards regression models, Kaplan-Meier estimates, and log-rank test. Discrimination between prognostic variables was assessed using the concordance index (C-index). Results and limitations In this cohort, 176 patients with bone metastases and a change in aBSI from baseline to follow-up of ≤0.3 had a significantly longer median survival time than patients with an aBSI change of >0.3 (p < 0.0001). The increase in aBSI was significantly associated with OS (p < 0.01 and C-index = 0.65), while age and PSA change were not. Conclusions The aBSI used as an objective imaging biomarker predicted outcome in prostate cancer patients in the ZEUS/SPCG11 study. An analysis of the change in aBSI from baseline to 48-mo follow-up represents a valuable tool for prognostication and monitoring of prostate cancer patients with bone metastases. Patient summary The increase in the burden of skeletal metastases, as measured by the automated Bone Scan Index (aBSI), during treatment was associated with overall survival in patients from the Zometa European Study/SPCG11 study. The aBSI may be a useful tool also in monitoring prostate cancer patients with newly developed bone metastases.

Background: Nerve growth factor (NGF) and brain-derived neural factor (BDNF) are important for brain function and detectable in the blood. This study explored the longitudinal associations of physical activity and body fat with serum NGF and BDNF in children. Methods: Two waves of measurements were performed 2 years apart in 8- to 11-year-old children, including physical activity using the ActiGraph model 7164, body composition by dual-energy X-ray absorptiometry, and serum NGF and BDNF determined by multiplex immunoassay. The first wave included 248 children. Full information maximum likelihood estimation with robust standard errors was applied in structural equation modeling. Results: Vigorous physical activity showed a direct positive longitudinal relationship with NGF (standardized coefficient β = 0.30, P = .01) but not with BDNF (β = 0.04, P = .84). At the same time, body fat percentage was positively related to both NGF (β = 0.59, P < .001) and BDNF (β = 0.17, P = .04). There was an indication of an indirect relationship of vigorous physical activity with NGF (product of unstandardized coefficient β = -0.18, P = .02) and BDNF (β = -0.07, P = .05) through the negative relationship with body fat percentage (β = -0.36, P < .001). Conclusions: Vigorous physical activity is directly related to serum NGF and indirectly through the level of body fat. The relationships with serum BDNF are more complex.

Conclusion: More body fat and abdominal fat, more abdominal body fat distribution, more left ventricular mass, and increased left atrial size were all associated with higher levels of galectin-3. Increase in total body fat over 2 years was also associated with higher levels of galectin-3. What is Known: • Galectin-3 has been linked to obesity and been proposed to be a novel biomarker for cardiovascular disease in adults. • Information on this subject in children is very scarce. What is New: • The present study demonstrates a relationship between galectin-3 levels and total body fat, abdominal fat, body fat distribution, cardiac size and geometry, and increase in total body fat over 2 years in young children.

Aim: We assessed if baseline measurements of physical activity, aerobic fitness, body fat and abdominal fat were predictors of changes in body fat measurements over a two-year period. Methods: The study comprised of 204 children aged 9.8 ±0.6 years with a normal body mass distribution, who recruited from four schools in middle-class areas of Malmö, Sweden, from 2001-2004. Peak oxygen uptake and physical activity were measured at baseline. Body fat was measured by dual-energy x-ray absorptiometry at baseline and two years later. Results: Physical activity, aerobic fitness and total body fat or abdominal fat were predictors of change in total body fat or abdominal fat over a period of two years. Changes in the percentage of body fat were not related to any of the baseline measurements. Conclusion: Our two-year follow up of children with a mean age of 9.8 years at baseline showed that physical activity, aerobic fitness and body fat or abdominal fat predicted changes in total body fat or abdominal fat, but not the percentage of body fat. This article is protected by copyright. All rights reserved.

Display of sex, age, anthropometric, fitness and Tanner statistics median (interquartile range) for baseline measurements between participants who had blood samples and those who had not. (DOCX)