Clinical Interventions in Aging (Aug 2021)
Effect of 5 Years of Exercise Intervention at Different Intensities on Brain Structure in Older Adults from the General Population: A Generation 100 Substudy
Abstract
Jasmine Pani,1,2 Line S Reitlo,1,2 Hallvard Røe Evensmoen,2 Stian Lydersen,3 Ulrik Wisløff,4,5 Dorthe Stensvold,4,6 Asta K Håberg1,2 1Department of Neuromedicine and Movement Science, Faculty of Medicine and Health Sciences, NTNU (Norwegian University of Science and Technology), Trondheim, Norway; 2Department of Radiology and Nuclear Medicine, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway; 3Department of Mental Health, Faculty of Medicine and Health Sciences, NTNU (Norwegian University of Science and Technology), Trondheim, Norway; 4Department of Circulation and Medical Imaging, Faculty of Medicine and Health Sciences, NTNU (Norwegian University of Science and Technology), Trondheim, Norway; 5School of Human Movement & Nutrition Sciences, University of Queensland, Queensland, Australia; 6Department of Cardiology, St. Olavs Hospital, Trondheim University Hospital, Trondheim, NorwayCorrespondence: Asta K HåbergDepartment of Neuromedicine and Movement Science, Faculty of Medicine and Health Sciences, NTNU (Norwegian University of Science and Technology), Trondheim, N-7491, NorwayTel +47 90 25 91 47Email [email protected]: The aim was to examine the effect of a 5-year exercise intervention at different intensities on brain structure in older adults from the general population partaking in the randomized controlled trial Generation 100 Study.Participants and Methods: Generation 100 Study participants were invited to a longitudinal neuroimaging study before randomization. A total of 105 participants (52 women, 70– 77 years) volunteered. Participants were randomized into supervised exercise twice a week performing high intensity interval training in 4× 4 intervals at ∼ 90% peak heart rate (HIIT, n = 33) or 50 minutes of moderate intensity continuous training at ∼ 70% of peak heart rate (MICT, n = 24). The control group (n = 48) followed the national physical activity guidelines of ≥ 30 min physical activity daily. Brain MRI at 3T, clinical and cardiorespiratory fitness (CRF), measured as peak oxygen uptake, were collected at baseline, and after 1, 3, and 5 years of intervention. Brain volumes and cortical thickness were derived from T1 weighted 3D MRI data using FreeSurfer. The effect of HIIT or MICT on brain volumes over time was investigated with linear mixed models, while linear regressions examined the effect of baseline CRF on brain volumes at later time points.Results: Adherence in each group was between 79 and 94% after 5 years. CRF increased significantly in all groups during the first year. Compared to controls, the HIIT group had significantly increased hippocampal atrophy located to CA1 and hippocampal body, though within normal range, and the MICT group greater thalamic atrophy. No other effects of intervention group were found. CRF across the intervention was not associated with brain structure, but CRF at baseline was positively associated with cortical volume at all later time points.Conclusion: Higher baseline CRF reduced 5-year cortical atrophy rate in older adults, while following physical activity guidelines was associated with the lowest hippocampal and thalamic atrophy rates.Keywords: CNS, aging, limbic, brain reserve, morphometry
