| 1. |
- Ahl, Matilda, et al.
(författare)
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Physical Activity Reduces Epilepsy Incidence : a Retrospective Cohort Study in Swedish Cross-Country Skiers and an Experimental Study in Seizure-Prone Synapsin II Knockout Mice
- 2019
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Ingår i: Sports medicine - open. - : Springer. - 2199-1170 .- 2198-9761. ; 5:1
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Epilepsy patients commonly exercise less than the general population. Animal studies indicate beneficial effects of physical activity in established epilepsy, while its effect on the development is currently less known.METHODS: Here, we investigated the incidence of epilepsy during 20 years in a cohort of participants from the long-distance Swedish cross-country ski race Vasaloppet (n = 197,685) and compared it to the incidence of non-participating-matched controls included in the Swedish population register (n = 197,684). Individuals diagnosed with diseases such as stroke and epilepsy before entering the race were excluded from both groups. Experimentally, we also determined how physical activity could affect the development of epilepsy in epilepsy-prone synapsin II knockout mice (SynIIKO), with and without free access to a running wheel.RESULTS: We identified up to 40-50% lower incidence of epilepsy in the Vasaloppet participants of all ages before retirement. A lower incidence of epilepsy in Vasaloppet participants was seen regardless of gender, education and occupation level compared to controls. The participants included both elite and recreational skiers, and in a previous survey, they have reported a higher exercise rate than the general Swedish population. Sub-analyses revealed a significantly lower incidence of epilepsy in participants with a faster compared to slower finishing time. Dividing participants according to specified epilepsy diagnoses revealed 40-50% decrease in focal and unspecified epilepsy, respectively, but no differences in generalized epilepsy. Voluntary exercise in seizure-prone SynIIKO mice for 1 month before predicted epilepsy development decreased seizure manifestation from > 70 to 40%. Brain tissue analyses following 1 month of exercise showed increased hippocampal neurogenesis (DCX-positive cells), while microglial (Iba1) and astrocytic activation (GFAP), neuronal Map2, brain-derived neurotrophic factor and its receptor tyrosine receptor kinase B intensity were unaltered. Continued exercise for additionally 2 months after predicted seizure onset in SynIIKO mice resulted in a 5-fold reduction in seizure manifestation (from 90 to 20%), while 2 months of exercise initiated at the time of predicted seizure development gave no seizure relief, suggesting exercise-induced anti-epileptogenic rather than anti-convulsive effect.CONCLUSION: The clinical study and the experimental findings in mice indicate that physical activity may prevent or delay the development of epilepsy.
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| 2. |
- Andersen, Kasper, 1974-, et al.
(författare)
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Long-Distance Skiing and Incidence of Hypertension : A Cohort Study of 206,889 Participants in a Long-Distance Cross-Country Skiing Event
- 2020
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Ingår i: Circulation. - : American Heart Association. - 0009-7322 .- 1524-4539. ; 141:9, s. 743-750
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Tidskriftsartikel (refereegranskat)abstract
- Background: Hypertension is the leading risk factor for death worldwide and high levels of physical activity is associated with lower incidence of hypertension. The associations of excessive levels of exercise and incidence of hypertension is less known. We aim to compare the incidence of hypertension among 206,889 participants in a long-distance cross-country skiing event and 505,542 persons randomly sampled from the general population (matched to the skiers on age sex and place of residence). Methods: Skiers best performance (in per cent of winning time) and number of completed races during the study period were associated to incidence of hypertension after participation in Vasaloppet. Hypertension was defined as prescription of blood pressure-lowering drugs as obtained from the national drug registry. Models were adjusted for sex, age, education and income (total effect). Results: During a median time-of-risk of 8.3 years skiers had lower incidence of hypertension compared to non-skiers (HR 0.59; 95% confidence interval [CI] 0.58-0.60). Among the skiers, better performance (in % of winning time) in Vasaloppet was strongly associated with lower incidence of hypertension (Fastest fifth: HR 0.41; 95% CI 0.39-0.42. Slowest fifth: 0.78 CI 0.75-0.81). The association was near linear and did not differ between sexes. Among the skiers, a weaker association of number of completed races during the study period with incidence of hypertension (1 race: HR 0.63; 95% CI 0.62-0.65.>5 races: HR 0.51; 95% CI 0.50-0.53). A sub-analysis of 10,804 participants including adjustment for lifestyle factors showed similar results. Conclusions: Participation in a long-distance skiing event was associated with 41% lower incidence of hypertension over the next 8 years, compared to non-participation; and the better the performance, the lower the incidence of hypertension. This adds to the list of beneficial effects of intensive training, as hypertension is the leading risk factor of premature death globally.
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| 3. |
- Axfors, Cathrine, et al.
(författare)
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Pre-pregnancy participation and performance in world's largest cross-country ski race as a proxy for physical exercise and fitness, and perinatal outcomes : Prospective registry-based cohort study
- 2023
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Ingår i: British Journal of Obstetrics and Gynecology. - : John Wiley & Sons. - 1470-0328 .- 1471-0528. ; 130:8, s. 891-901
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Investigate associations between pre-pregnancy participation and performance in a demanding cross-country ski race (proxy for exercise volume and fitness) and perinatal outcomes. Pre-registered protocol: osf.io/aywg2.Design: Prospective cohort study.Setting: Based on entire overlap between the Vasaloppet registry and the population-based Swedish Pregnancy Register.Sample: All female Vasaloppet participants 1991-2017 with subsequent singleton delivery (skiers), and age- and county-matched non-skiers.Methods: We calculated odds ratios (ORs) for non-skiers versus skiers (model 1) and, among skiers, by performance (model 2), in Bayesian logistic regressions adjusted for socio-demographics, lifestyle factors, and comorbidities. We repeated calculations adjusting for early pregnancy body mass index (potential mediator) and explored robustness (selection/exposure settings; multiple comparisons correction).Main outcome measures: Twenty-nine important perinatal outcomes, predefined based on existing expert consensus.Results: Non-skiers (n = 194 384) versus skiers (n = 15 377) (and slower versus faster performance, not shown) consistently had higher odds of gestational diabetes mellitus (GDM) (OR 1.70, 95% highest density interval: 1.40-2.09), excessive gestational weight gain (GWG) (1.28, 1.22-1.38), psychiatric morbidity (1.60, 1.49-1.72), any caesarean section (CS) (1.34, 1.28-1.40), elective CS (1.39, 1.29-1.49), and large-for-gestational-age babies (> 90th percentile, 1.11, 1.04-1.18); lower odds of inadequate GWG (0.83, 0.79-0.88); and no associations with fetal/neonatal complications (e.g. preterm birth [1.09, 0.98-1.20], small for gestational age [SGA] [1.23, 1.05-1.45]). Adjustment for body mass index attenuated associations with excessive (1.20, 1.14-1.30) and inadequate GWG (0.87, 0.83-0.92) and large for gestational age (1.07, 1.00-1.13).Conclusion: Non-skiers compared with skiers, and slower versus faster performance, consistently displayed higher odds of GDM, excessive GWG, psychiatric morbidity, CS and large-for-gestational-age babies; and lower odds of inadequate GWG, after adjustment for socio-demographic and lifestyle factors and comorbidities. There were no associations with fetal/neonatal complications.
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| 4. |
- Fang, Fang, et al.
(författare)
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Amyotrophic lateral sclerosis among cross-country skiers in Sweden.
- 2016
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Ingår i: European Journal of Epidemiology. - : Springer Science and Business Media LLC. - 0393-2990 .- 1573-7284. ; 31:3, s. 247-253
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Tidskriftsartikel (refereegranskat)abstract
- A highly increased risk of amyotrophic lateral sclerosis (ALS) has been suggested among professional athletes. We aimed to examine whether long distance cross-country skiers have also a higher risk of ALS and whether the increased risk was modified by skiing performance. We followed 212,246 cross-country skiers in the Swedish Vasaloppet cohort and a random selection of 508,176 general Swedes not participating in the Vasaloppet during 1989-2010. The associations between cross-country skiing as well as skiing performance (i.e., type of race, finishing time and number of races) and the consequent risk of ALS were estimated through hazard ratios (HRs) derived from Cox model. During the study, 39 cases of ALS were ascertained among the skiers. The fastest skiers (100-150 % of winner time) had more than fourfold risk of ALS (HR 4.31, 95 % confidence interval [CI] 1.78-10.4), as compared to skiers that finished at >180 % of winner time. Skiers who participated >4 races during this period had also a higher risk (HR 3.13, 95 % CI 1.37-7.17) than those participated only one race. When compared to the non-skiers, the fastest skiers still had a higher risk (HR 2.08, 95 % CI 1.12-3.84), as skiers who had >4 races (HR 1.88, 95 % CI 1.05-3.35), but those finishing at >180 % of winner time had a lower risk (HR 0.46, 95 % CI 0.24-0.87). In conclusion, long distance cross-country skiing is associated with a higher risk of ALS, but only among the best skiers; recreational skiers appear to have a largely reduced risk.
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| 5. |
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| 6. |
- Hansson, Oskar, et al.
(författare)
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Midlife physical activity is associated with lower incidence of vascular dementia but not Alzheimer's disease
- 2019
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Ingår i: Alzheimer's Research & Therapy. - : BMC. - 1758-9193. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Background: Physical activity might reduce the risk of developing dementia. However, it is still unclear whether the protective effect differs depending on the subtype of dementia. We aimed to investigate if midlife physical activity affects the development of vascular dementia (VaD) and Alzheimer's disease (AD) differently in two large study populations with different designs.Methods: Using a prospective observational design, we studied whether long-distance skiers of the Swedish Vasaloppet (n = 197,685) exhibited reduced incidence of VaD or AD compared to matched individuals from the general population (n = 197,684) during 21 years of follow-up (median 10, interquartile range (IQR) 5-15 years). Next, we studied the association between self-reported physical activity, stated twice 5 years apart, and incident VaD and AD in 20,639 participants in the Swedish population-based Malmo Diet and Cancer Study during 18 years of follow-up (median 15, IQR 14-17 years). Finally, we used a mouse model of AD and studied brain levels of amyloid-beta, synaptic proteins, and cognitive function following 6 months of voluntary wheel running.Results Vasaloppet skiers (median age 36.0 years [IQR 29.0-46.0], 38% women) had lower incidence of all-cause dementia (adjusted hazard ratio (HR) 0.63, 95% CI 0.52-0.75) and VaD (adjusted HR 0.49, 95% CI 0.33-0.73), but not AD, compared to non-skiers. Further, faster skiers exhibited a reduced incidence of VaD (adjusted HR 0.38, 95% CI 0.16-0.95), but not AD or all-cause dementia compared to slower skiers. In the Malmo Diet and Cancer Study (median age 57.5 years [IQR 51.0-63.8], 60% women), higher physical activity was associated with reduced incidence of VaD (adjusted HR 0.65, 95% CI 0.49-0.87), but not AD nor all-cause dementia. These findings were also independent of APOE-epsilon 4 genotype. In AD mice, voluntary running did not improve memory, amyloid-beta, or synaptic proteins.Conclusions: Our results indicate that physical activity in midlife is associated with lower incidence of VaD. Using three different study designs, we found no significant association between physical activity and subsequent development of AD.
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| 7. |
- Hållmarker, Ulf, et al.
(författare)
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Cancer incidence in participants in a long-distance ski race (Vasaloppet, Sweden) compared to the background population
- 2015
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Ingår i: European Journal of Cancer. - : Elsevier BV. - 0959-8049 .- 1879-0852. ; 51:4, s. 558-568
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Tidskriftsartikel (refereegranskat)abstract
- Background: We studied the association between taking part in a long distance ski race and cancer incidence to address the hypothesis that a lifestyle involving a high degree of physical activity (PA) lowers cancer incidence with a pattern that is different by cancer site. Methods: Cancer incidence was estimated in a large cohort of skiers (n = 185,412) participating in the Vasaloppet long distance ski race in Sweden 1989-2010 and non-participants in the ski race, randomly selected from the Swedish general population (n = 184,617). Data include race finishing times as a measurement of physical fitness. Hazard ratios (HRs) and net probability of cancer over twenty years of follow-up were estimated for all invasive cancer, and separately for prostate, breast, colo-rectal and lung cancer, and groups of cancers with presumed relation to lifestyle. Findings: Participating in Vasaloppet was associated with a relative risk reduction for all invasive cancer of 6% (95% confidence interval 2-9%) and a relative risk reduction of 32% (95% confidence interval 28-37%) of cancer sites where there is epidemiological evidence that smoking, bodyweight, regular PA and consumption of fruit and vegetables are aetiological factors. For skin cancer the risk was increased, as for prostate cancer. Skiers with shorter finishing times had lower incidence of cancer. Interpretation: This study indicates that it is unrealistic to reduce overall population cancer incidence drastically with life style. However, cancers that are epidemiologically associated with life style factors were significantly reduced by what presumably is a blend of nonsmoking, normal body weight, sound dietary habits and PA. Our data thus provide additional support for present days' recommendations about life style prevention. Higher health awareness is associated with attendance to screening, which may explain our results for prostate cancer.
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| 8. |
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| 9. |
- Hållmarker, Ulf, 1946-
(författare)
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Epidemiological Studies on Long Distance Cross-Country Skiers : Participants in the Vasaloppet 1955-2010
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The overall aim of this thesis was to study the influence of physical activity on health. Risks and benefits of physical activity is of particular interest since there is a global trend of less physical activity among youths and adults.In order to investigate this aim we used a database from a large cross country ski race, Vasaloppet, with participants with a wide age range, and with both elite athletes and ordinary people who exercise and promote their health. The most serious risk of strenuous exercise is sudden death and it is challenging to identify preventive effects of major endemic diseases.Using epidemiological methodology we studied 200 000 Vasaloppet skiers and compared them with the general population. Based on personal identification numbers we added data from Swedish national personal and health registers, clinical registers as the cancer register, Swedeheart, or Swedish stroke register, and socioeconomic information from Statistics Sweden. In the Vasaloppet database we collected data on age, gender, finish time and number of races during the period 1989 to 2010.We evaluated risk of death during the race in two papers (I,II). During 90 years of annual races, cardiac arrest occurred in 20 skiers, of which five survived. The death rate is in average two per 100 000 skiers.We also studied the association with cancer incidence (paper III). The overall reduction of cancer was modest among skiers compared with the general population, but for cancers related to lifestyle the risks were markedly lower.We investigated the risk for recurrent myocardial infarction and found a 30% reduction among skiers (paper IV). In paper V we showed that skiers with a first stroke have a lower incidence of all-cause death. The skiers had a higher frequency of atrial fibrillation but had less severe stroke and no increased risk of recurrent stroke. Thus our data suggest that a lifestyle with a high level of physical activity may work as a protection after a cardiovascular event.Summary: The short excess mortality in endurance physical activity is by far outweighed by the long term protective effect of exercise in cardiovascular diseases and cancer.
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