During early adulthood, a phase in which the central nervous system displays considerable plasticity and in which important cognitive traits are shaped, the effects of exercise on cognition remain ...poorly understood. We performed a cohort study of all Swedish men born in 1950 through 1976 who were enlisted for military service at age 18 (N = 1,221,727). Of these, 268,496 were full-sibling pairs, 3,147 twin pairs, and 1,432 monozygotic twin pairs. Physical fitness and intelligence performance data were collected during conscription examinations and linked with other national databases for information on school achievement, socioeconomic status, and sibship. Relationships between cardiovascular fitness and intelligence at age 18 were evaluated by linear models in the total cohort and in subgroups of full-sibling pairs and twin pairs. Cardiovascular fitness, as measured by ergometer cycling, positively associated with intelligence after adjusting for relevant confounders (regression coefficient b = 0.172; 95% CI, 0.168-0.176). Similar results were obtained within monozygotic twin pairs. In contrast, muscle strength was not associated with cognitive performance. Cross-twin cross-trait analyses showed that the associations were primarily explained by individual specific, non-shared environmental influences (greater-than-or-equal80%), whereas heritability explained <15% of covariation. Cardiovascular fitness changes between age 15 and 18 y predicted cognitive performance at 18 y. Cox proportional-hazards models showed that cardiovascular fitness at age 18 y predicted educational achievements later in life. These data substantiate that physical exercise could be an important instrument for public health initiatives to optimize educational achievements, cognitive performance, as well as disease prevention at the society level.
Studies suggest a role for cardiovascular fitness in the prevention of affective disorders.
To determine whether cardiovascular fitness at age 18 is associated with future risk of serious affective ...illness.
Population-based Swedish cohort study of male conscripts (n = 1 117 292) born in 1950-1987 with no history of mental illness who were followed for 3-40 years. Data on cardiovascular fitness at conscription were linked with national hospital registers to calculate future risk of depression (requiring in-patient care) and bipolar disorder.
In fully adjusted models low cardiovascular fitness was associated with increased risk for serious depression (hazard ratios (HR) = 1.96, 95%, CI 1.71-2.23). No such association could be shown for bipolar disorder (HR = 1.11, 95% CI 0.84-1.47).
Lower cardiovascular fitness at age 18 was associated with increased risk of serious depression in adulthood. These results strengthen the theory of a cardiovascular contribution to the aetiology of depression.
BACKGROUND AND PURPOSE—Low cardiovascular fitness (fitness) in mid- and late life is a risk factor for stroke. However, the respective effects on long-term stroke risk of fitness and muscle strength ...in early adulthood are unknown. Therefore, we analyzed these in a large cohort of young men.
METHOD—We performed a population-based longitudinal cohort study of Swedish male conscripts registered in 1968 to 2005. Data on fitness (by the cycle ergometric test; n=1 166 035) and muscle strength (n=1 563 750) were trichotomized (low, medium, and high). During a 42-year follow-up, risk of stroke (subarachnoidal hemorrhage, intracerebral hemorrhage, and ischemic stroke) and fatality were calculated with Cox proportional hazards models. To identify cases, we used the International Classification of Diseases-Eighth to Tenth Revision in the Hospital Discharge Register and the Cause of Death Register.
RESULTS—First-time stroke events were identified (subarachnoidal hemorrhage, n=895; intracerebral hemorrhage, n=2904; ischemic stroke, n=7767). For all stroke and fatality analysis any type of first-time stroke was recorded (n=10 917). There were inverse relationships in a dose–response fashion between fitness and muscle strength with any stroke (adjusted hazard ratios for the lowest, compared with the highest, tertile of each 1.70 1.50–1.93 and 1.39 1.27–1.53, respectively). There were stronger associations for fatal stroke. All 3 stroke types displayed similar associations. Associations between fitness and stroke remained when adjusted for muscle strength, whereas associations between muscle strength and stroke weakened/disappeared when adjusted for fitness.
CONCLUSIONS—At the age of 18 years, low fitness and to a lesser degree low muscle strength were independently associated with an increased future stroke risk.
Deficits in cognitive performance are reported in patients with anxiety disorders, but research is limited and inconsistent. We aimed to investigate cross-sectional associations between cognitive ...function, with focus on executive function, and anxiety severity in primary care patients diagnosed with anxiety disorders.
189 Swedish patients aged 18-65 years (31% men) with anxiety disorders diagnosed according to Mini International Neuropsychiatric Interview were included. Severity of anxiety was assessed using Beck Anxiety Inventory self-assessment scale. Digit span, block design and matrix reasoning tests from the Wechsler Adult Intelligence Scale IV, and the design fluency test from the Delis-Kaplan Executive Function System were used. Multivariable linear regression models were applied to investigate the relationship of anxiety severity and cognitive functioning. Comparisons were also performed to a normed non-clinical population, using the Wilcoxon signed rank test.
More severe anxiety was associated with lower digit span test scores (R
= 0.109, B = -0.040, p = 0.018), but not with block design, matrix reasoning or design fluency tests scores, after adjustment for comorbid major depression in a multivariable model. When compared to a normed population, patients with anxiety performed significantly lower on the block design, digit span forward, digit span sequencing and matrix reasoning tests.
Severity of anxiety among patients with anxiety disorder was associated with executive functions related to working memory, independently of comorbid major depression, but not with lower fluid intelligence. A further understanding of the executive behavioral control in patients with anxiety could allow for more tailored treatment strategies including medication, therapy and interventions targeted to improve specific cognitive domains.
Aims
To investigate the association between cardiorespiratory fitness (CRF) and muscle strength in late adolescence and the long-term risk of heart failure (HF).
Methods
A cohort was created of ...Swedish men enrolled in compulsory military service between 1968 and 2005 with measurements for CRF and muscle strength (n = 1,226,623; mean age 18.3 years). They were followed until 31 December 2014 for HF hospitalization as recorded in the Swedish national inpatient registry.
Results
During the follow-up period (median (interquartile range) 28.4 (22.0–37.0) years), 7656 cases of first HF hospitalization were observed (mean ± SD age at diagnosis 50.1 ± 7.9 years). CRF and muscle strength were estimated by maximum capacity cycle ergometer testing and strength exercises (knee extension, elbow flexion and hand grip). Inverse dose–response relationships were found between CRF and muscle strength with HF as a primary or contributory diagnosis with an adjusted hazards ratio (95% confidence interval) of 1.60 (1.44–1.77) for low CRF and 1.45 (1.32–1.58) for low muscle strength categories. The associations of incident HF with CRF and muscle strength persisted, regardless of adjustments for the other potential confounders. The highest risk was observed for HF associated with coronary heart disease, diabetes or hypertension.
Conclusions
In this longitudinal study of young men, we found inverse and mutually independent associations between CRF and muscle strength with risk of hospitalization for HF. If causal, these results may emphasize the importance of the promotion of CRF and muscle strength in younger populations.
•A randomized controlled trial to assess the effects of different exercise intensities in the treatment of anxiety syndromes in primary health care.•Results support an exercise intensity trend for ...reduced anxiety symptoms, but effect sizes were rather similar in low and higher intensities.•These effects were independent of depressive symptoms.•Structured physical activity represents an effective treatment and should be more frequently made available for persons with anxiety issues within primary health care.
There is a need for high-quality research regarding exercise interventions for persons with anxiety disorders. We investigate whether a 12-week exercise intervention, with different intensities, could reduce anxiety symptoms in patients with anxiety disorders.
286 patients were recruited from primary care in Sweden. Severity of symptoms was self-assessed using the Beck Anxiety Inventory (BAI) and the Montgomery Åsberg Depression Rating Scale (MADRS-S). Participants were randomly assigned to one of two group exercise programs with cardiorespiratory and resistance training and one control/standard treatment non-exercise group, with 1:1:1 allocation.
Patients in both exercise groups showed larger improvements in both anxiety and depressive symptoms compared to the control group. No differences in effect sizes were found between the two groups. To study a clinically relevant improvement, BAI and MADRS-S were dichotomized with the mean change in the control group as reference. In adjusted models the odds ratio for improved symptoms of anxiety after low-intensity training was 3.62 (CI 1.34–9.76) and after moderate/high intensity 4.88 (CI 1.66–14.39), for depressive symptoms 4.96 (CI 1.81–13.6) and 4.36 (CI 1.57–12.08) respectively. There was a significant intensity trend for improvement in anxiety symptoms.
The use of self-rating measures which bears the risk of an under- or overestimation of symptoms.
A 12-week group exercise program proved effective for patients with anxiety syndromes in primary care. These findings strengthen the view of physical exercise as an effective treatment and could be more frequently made available in clinical practice for persons with anxiety issues.
Progenitor cells in the subgranular zone of the hippocampus may be of significance for functional recovery after various injuries because they have a regenerative potential to form new neuronal ...cells. The hippocampus has been shown to express the GH secretagogue (GHS) receptor 1a, and recent studies suggest GHS to both promote neurogenesis and have neuroprotective effects. The aim of the present study was to investigate whether GHS could stimulate cellular proliferation and exert cell protective effects in adult rat hippocampal progenitor (AHP) cells. Both hexarelin and ghrelin stimulated increased incorporation of 3H-thymidine, indicating an increased cell proliferation. Furthermore, hexarelin, but not ghrelin, showed protection against growth factor deprivation-induced apoptosis, as measured by annexin V binding and caspase-3 activity and also against necrosis, as measured by lactate dehydrogenase release. Hexarelin activated the MAPK and the phosphatidylinositol 3-kinase/Akt pathways, whereas ghrelin activated only the MAPK pathway. AHP cells did not express the GHS receptor 1a, but binding studies could show specific binding of both hexarelin and ghrelin, suggesting effects to be mediated by an alternative GHS receptor subtype. In conclusion, our results suggest a differential effect of hexarelin and ghrelin in AHP cells. We have demonstrated stimulation of 3H-thymidine incorporation with both hexarelin and ghrelin. Hexarelin, but not ghrelin, also showed a significant inhibition of apoptosis and necrosis. These results suggest a novel cell protective and proliferative role for GHS in the central nervous system.
Background Coronary heart disease remains the dominant cause of death worldwide. To improve cardiovascular disease prevention, knowledge of early key risk factors, especially those that are ...modifiable, is essential. The ongoing global obesity epidemic is of particular concern. We aimed to determine whether body mass index at conscription predicts early acute coronary events among men in Sweden. Methods and Results This was a population-based Swedish cohort study of conscripts (n=1 668 921; mean age, 18.3 years; 1968-2005), with follow-up through linkage to the nationwide Swedish patient and death registries. Risk of a first acute coronary event (hospitalization for acute myocardial infarction or coronary death) during follow-up (1-48 years) was calculated with generalized additive models. Objective baseline measures of fitness and cognition were included in the models in secondary analyses. During follow-up, there were 51 779 acute coronary events, of which 6457 (12.5%) were fatal within 30 days. Compared with men at the lowest end of the normal body mass index spectrum (body mass index, 18.5 kg/m
), an increasing risk for a first acute coronary event was observed, with hazard ratios (HRs) peaking at 40 years of age. After multivariable adjustments, men with a body mass index of 35 kg/m
had an HR of 4.84 (95% CI, 4.29-5.46) for an event before the age of 40 years. Conclusions An increased risk of an early acute coronary event was detectable within normal levels of body weight at the age of 18 years, increasing to almost 5-fold in the highest weight category at 40 years of age. Given increasing levels of body weight and prevalence of overweight and obesity in young adults, the current decrease in coronary heart disease incidence in Sweden may flatten or even reverse in the near future.
In several species, including humans, the dentate granule cell layer (GCL) of the hippocampus exhibits neurogenesis throughout adult life. The ability to regulate adult neurogenesis pharmacologically ...may be of therapeutic value as a mechanism for replacing lost neurons. Insulin-like growth factor-I (IGF-I) is a growth-promoting peptide hormone that has been shown to have neurotrophic properties. The relationship between IGF-I and adult hippocampal neurogenesis is to date unknown. The aim of this study was to investigate the effect of the peripheral administration of IGF-I on cellular proliferation in the dentate subgranular proliferative zone, which contains neuronal progenitor cells, and on the subsequent migration and differentiation of progenitor cells within the GCL. Using bromodeoxyuridine (BrdU) labeling, we found a significant increase of BrdU-immunoreactive progenitors in the GCL after 6 d of peripheral IGF-I administration. To determine the cell fate in progenitor progeny, we characterized the colocalization of BrdU-immunolabeled cells with cell-specific markers. In animals treated with IGF-I for 20 d, BrdU-positive cells increased significantly. Furthermore, the fraction of newly generated neurons in the GCL increased, as evaluated by the neuronal markers Calbindin D(28K), microtubule-associated protein-2, and NeuN. There was no difference in the fraction of newly generated astrocytes. Thus, our results show that peripheral infusion of IGF-I increases progenitor cell proliferation and selectively induces neurogenesis in the progeny of adult neural progenitor cells. This corresponds to a 78 +/- 17% (p < 0.001) increase in the number of new neurons in IGF-I-treated animals compared with controls.
To study the relation between body mass index (BMI) in young men and risk of early hospitalization with heart failure.
In a prospective cohort study, men from the Swedish Conscript Registry ...investigated 1968-2005 (n = 1 610 437; mean age, 18.6 years were followed 5-42 years (median, 23.0 years; interquartile range, 15.0-32.0), 5492 first hospitalizations for heart failure occurred (mean age at diagnosis, 46.6 (SD 8.0) years). Compared with men with a body mass index (BMI) of 18.5-20.0 kg/m2, men with a BMI 20.0-22.5 kg/m2 had an hazard ratio (HR) of 1.22 (95% CI, 1.10-1.35), after adjustment for age, year of conscription, comorbidities at baseline, parental education, blood pressure, IQ, muscle strength, and fitness. The risk rose incrementally with increasing BMI such that men with a BMI of 30-35 kg/m2 had an adjusted HR of 6.47 (95% CI, 5.39-7.77) and those with a BMI of ≥35 kg/m2 had an HR of 9.21 (95% CI, 6.57-12.92). The multiple-adjusted risk of heart failure per 1 unit increase in BMI ranged from 1.06 (95% CI, 1.02-1.11) in heart failure associated with valvular disease to 1.20 (95% CI, 1.18-1.22) for cases associated with coronary heart disease, diabetes, or hypertension.
We found a steeply rising risk of early heart failure detectable already at a normal body weight, increasing nearly 10-fold in the highest weight category. Given the current obesity epidemic, heart failure in the young may increase substantially in the future and physicians need to be aware of this.
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