***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND Data regarding the relationship between physical activity and  cognitive impairment  are limited and controversial . We examined whether physical activity is associated with incident cognitive impairment during follow-up . METHODS As part of a community-based prospect i ve cohort study in southern Bavaria , Germany , 3903 participants older than 55 years were enrolled between 2001 and 2003 and followed up for 2 years .  Physical activity ( classified as no activity , moderate activity [ <3 times/wk ] , and high activity [ > or =3 times/wk ] ) , cognitive function ( assessed by the 6-Item Cognitive Impairment Test )  , and potential confounders were evaluated . The main outcome measure was incident cognitive impairment after 2 years of follow-up . RESULTS At baseline , 418 participants ( 10.7 % ) had cognitive impairment . After a 2-year follow-up , 207 of 3485 initially unimpaired subjects ( 5.9 % ) developed incident cognitive impairment . Compared with participants without physical activity , fully adjusted multiple logistic regression analysis showed a significantly reduced risk of incident cognitive impairment after 2 years for participants with moderate or high physical activity at baseline ( odds ratio [ OR ] , 0.57 ; 95 % confidence interval [ CI ] , 0.37 - 0.87 [ P = .01 ] ; and OR , 0.54 ; 95 % CI , 0.35 - 0.83 [ P = .005 ] ; respectively ) . Further sub analysis including participants ( n = 2029 ) without functional impairment and without prodromal phase of dementia result ed in an even higher reduction of risk of incident cognitive impairment for participants with moderate or high physical activity ( OR , 0.44 ; 95 % CI , 0.24 - 0.83 [ P = .01 ] ; and OR , 0.46 ; 95 % CI , 0.25 - 0.85 [ P = .01 ] ; respectively ) compared with no activity . CONCLUSION Moderate or high physical activity is associated with a reduced incidence of cognitive impairment after 2 years in a large population -based cohort of elderly subjects Two studies investigated the association between cortisol levels and memory performance in healthy adults . In a first study , 13 subjects were exposed to a brief psychosocial laboratory stress ( " Trier Social Stress Test " ) with a subsequent test of declarative memory performance . Results indicated a significant negative relationship between stress-induced cortisol levels and performance in the memory task , i.e. subjects with high cortisol response to the stressor showed poorer memory performance . In a second experiment it was investigated if cortisol , alone , i.e. independent of psychological stress , would also impair memory function . In this study , 40 healthy subjects received either 10 mg cortisol or placebo orally . One hour later they were tested for procedural and declarative memory and spatial thinking . Subjects who received cortisol showed impaired performance in the declarative memory and spatial thinking tasks but not in the procedural memory task . From these results we conclude that in healthy adults elevated free cortisol levels are associated with impaired memory function BACKGROUND The present study examined whether aerobic fitness training of older humans can increase brain volume in regions associated with age-related decline in both brain structure and cognition . METHODS Fifty-nine healthy but sedentary community-dwelling volunteers , aged 60 - 79 years , participated in the 6-month r and omized clinical trial . Half of the older adults served in the aerobic training group , the other half of the older adults participated in the toning and stretching control group .  Twenty young adults served as controls for the magnetic resonance imaging ( MRI ) , and did not participate in the exercise intervention . High spatial resolution estimates of gray and white matter volume , derived from 3D spoiled gradient recalled acquisition MRI images , were collected before and after the 6-month fitness intervention . Estimates of maximal oxygen uptake ( VO2 ) were also obtained . RESULTS Significant increases in brain volume , in both gray and white matter regions , were found as a function of fitness training for the older adults who participated in the aerobic fitness training but not for the older adults who participated in the stretching and toning ( nonaerobic ) control group . As predicted , no significant changes in either gray or white matter volume were detected for our younger participants . CONCLUSIONS These results suggest that cardiovascular fitness is associated with the sparing of brain tissue in aging humans . Furthermore , these results suggest a strong biological basis for the role of aerobic fitness in maintaining and enhancing central nervous system health and cognitive functioning in older adults Background Reductions in skeletal muscle mass and increased adiposity are key elements in the aging process and in the pathophysiology of several chronic diseases . Systemic low grade inflammation associated with obesity has been shown to accelerate the age-related decline in skeletal muscle . The aim of this investigation was to determine the effects of 12 months of progressive resistance training ( PRT ) on systemic inflammation , and whether reductions in systemic inflammation were associated with changes in body composition . We hypothesized that reductions in systemic inflammation following 12 months of PRT in older adults with type 2 diabetes would be associated with reductions in adiposity and increases in skeletal muscle mass . Methods Participants ( n = 103 ) were r and omized to receive either PRT or sham-exercise , 3 days a week for 12 months . C-reactive protein ( CRP ) was used to assess systemic inflammation . Skeletal muscle mass and total fat mass were determined using bioelectrical impedance . Results Twelve months of PRT tended to reduce CRP compared to sham exercise ( β = −0.25 , p = 0.087 ) . Using linear mixed-effects models , the hypothesized relationships between body composition adaptations and CRP changes were significantly stronger for skeletal muscle mass ( p = 0.04 ) and tended to be stronger for total fat mass ( p = 0.07 ) following PRT when compared to sham-exercise . Using univariate regression models , stratified by group allocation , reductions in CRP were associated with increases in skeletal muscle mass ( p = 0.01 ) and reductions in total fat mass ( p = 0.02 ) in the PRT group , but not in the sham-exercise group ( p = 0.87 and p = 0.32 , respectively ) . Conclusions We have shown for the first time that reductions in systemic inflammation in older adults with type 2 diabetes following PRT were associated with increases in skeletal muscle mass . Furthermore , reductions in CRP were associated with reductions in adiposity , but only when associated with PRT . Lifestyle interventions aim ed at reducing systemic inflammation in older adults with type 2 diabetes should therefore incorporate anabolic exercise such as PRT to optimize the anti-inflammatory benefits of favorable body composition adaptations OBJECTIVE To examine the effects of acute hyperglycemia on cognitive function and mood in people with type 2 diabetes . RESEARCH DESIGN AND METHODS Twenty subjects with type 2 diabetes , median age 61.5 years ( range 53.1 - 72.0 ) , known duration of diabetes 5.9 years ( range 2.8 - 11.2 ) , BMI 29.8 kg/m2 ( range 22.0 - 34.6 ) , and HbA1c 7.5 % ( range 6.7 - 8.4 ) were studied . Treatment modalities varied from antidiabetic medications to insulin . A hyperinsulinemic glucose clamp was used to maintain arterialized blood glucose at either 4.5 ( euglycemia ) or 16.5 mmol/l ( hyperglycemia ) on two occasions in a r and omized and counterbalanced fashion . Tests of information processing , immediate and delayed memory , working memory , and attention were administered , along with a mood question naire , during each experimental condition . RESULTS Speed of information processing , working memory , and some aspects of attention were impaired during acute hyperglycemia . Subjects were significantly more dysphoric during hyperglycemia , with reduced energetic arousal and increased sadness and anxiety . CONCLUSIONS During acute hyperglycemia , cognitive function was impaired and mood state deteriorated in a group of people with type 2 diabetes . These findings are of practical importance because intermittent or chronic hyperglycemia is common in people with type 2 diabetes and may interfere with many daily activities through adverse effects on cognitive function and mood Background To examine the effects of a multicomponent exercise program on the cognitive function of older adults with amnestic mild cognitive impairment ( aMCI ) . Methods Design : Twelve months , r and omized controlled trial ; Setting : Community center in Japan ; Participants : Fifty older adults ( 27 men ) with aMCI ranging in age from 65 to 93 years ( mean age , 75 years ) ; Intervention : Subjects were r and omized into either a multicomponent exercise ( n = 25 ) or an education control group ( n = 25 ) . Subjects in the multicomponent exercise group exercised under the supervision of physiotherapists for 90 min/d , 2 d/wk , for a total of 80 times over 12 months . The exercises included aerobic exercises , muscle strength training , and postural balance retraining , and were conducted using multiple conditions to stimulate cognitive functions . Subjects in the control group attended three education classes regarding health during the 12-month period . Measurements were administered before , after the 6-month , and after the 12-month intervention period ; Measurements : The performance measures included the mini-mental state examination , logical memory subtest of the Wechsler memory scale-revised , digit symbol coding test , letter and categorical verbal fluency test , and the Stroop color word test . Results The mean adherence to the exercise program was 79.2 % . Improvements of cognitive function following multicomponent exercise were superior at treatment end ( group × time interactions for the mini-mental state examination ( P = 0.04 ) , logical memory of immediate recall ( P = 0.03 ) , and letter verbal fluency test ( P = 0.02 ) ) . The logical memory of delayed recall , digit symbol coding , and Stroop color word test showed main effects of time , although there were no group × time interactions . Conclusions This study indicates that exercise improves or supports , at least partly , cognitive performance in older adults with aMCI Cardiovascular fitness is thought to offset declines in cognitive performance , but little is known about the cortical mechanisms that underlie these changes in humans . Research using animal models shows that aerobic training increases cortical capillary supplies , the number of synaptic connections , and the development of new neurons . The end result is a brain that is more efficient , plastic , and adaptive , which translates into better performance in aging animals . Here , in two separate experiments , we demonstrate for the first time to our knowledge , in humans that increases in cardiovascular fitness results in increased functioning of key aspects of the attentional network of the brain during a cognitively challenging task . Specifically , highly fit ( Study 1 ) or aerobically trained ( Study 2 ) persons show greater task-related activity in regions of the prefrontal and parietal cortices that are involved in spatial selection and inhibitory functioning , when compared with low-fit ( Study 1 ) or nonaerobic control ( Study 2 ) participants . Additionally , in both studies there exist groupwise differences in activation of the anterior cingulate cortex , which is thought to monitor for conflict in the attentional system , and signal the need for adaptation in the attentional network . These data suggest that increased cardiovascular fitness can affect improvements in the plasticity of the aging human brain , and may serve to reduce both biological and cognitive senescence in humans Impaired glucose regulation is a defining characteristic of type 2 diabetes mellitus ( T2DM ) pathology and has been linked to increased risk of cognitive impairment and dementia . Although the benefits of aerobic exercise for physical health are well-documented , exercise effects on cognition have not been examined for older adults with poor glucose regulation associated with prediabetes and early T2DM . Using a r and omized controlled design , twenty-eight adults ( 57 - 83 y old ) meeting 2-h tolerance test criteria for glucose intolerance completed 6 months of aerobic exercise or stretching  , which served as the control . The primary cognitive outcomes included measures of executive function ( Trails B , Task Switching , Stroop , Self-ordered Pointing Test , and Verbal Fluency ) . Other outcomes included memory performance ( Story Recall , List Learning ) , measures of cardiorespiratory fitness obtained via maximal- grade d exercise treadmill test , glucose disposal during hyperinsulinemic-euglycemic clamp , body fat , and fasting plasma levels of insulin , cortisol , brain-derived neurotrophic factor , insulin-like growth factor-1 , amyloid-β ( Aβ40 and Aβ42 ) . Six months of aerobic exercise  improved executive function ( MANCOVA , p=0.04 ) , cardiorespiratory fitness ( MANOVA , p=0.03 ) , and insulin sensitivity ( p=0.05 ) . Across all subjects , 6-month changes in cardiorespiratory fitness and insulin sensitivity were positively correlated ( p=0.01 ) . For Aβ42 , plasma levels tended to decrease for the aerobic group relative to controls ( p=0.07 ) . The results of our study using rigorous controlled methodology suggest a cognition-enhancing effect of aerobic exercise for older glucose intolerant adults . Although replication in a larger sample is needed , our findings potentially have important therapeutic implication s for a growing number of adult 
    Output:
    
Conclusions Literature does not provide evidence that physical activity or exercise interventions contribute to a better cognitive function in patients with type 2 diabetes or impaired glucose tolerance .