***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: The objective of this study was to investigate the relation between the peripheral concentrations of the adrenal steroid hormones cortisol and dehydroepi and rosterone sulfate ( DHEAS ) and cognitive impairment and decline . A prospect i ve study design was used . The setting was a suburb of Rotterdam , The Netherl and s. The study population consisted of a sample of 189 healthy participants from the population -based Rotterdam Study , aged 55 - 80 yr , who were invited for an additional examination . Follow-up examinations took place 1.9 yr after baseline , on the average . We determined fasting blood levels of DHEAS before dexamethasone administration and of cortisol and corticosteroid-binding globulin before and after the administration of 1 mg dexamethasone overnight . The  30-point Mini-Mental State Examination ( MMSE )  was used to assess cognition . The associations with cognitive impairment ( MMSE score of < 26 ; 6 % of the sample ) and cognitive decline ( drop in MMSE score of > 1 point/yr ; 24 % ) were estimated using logistic regression , with adjustment for age , sex , education , and depressive symptoms . An increase of 1 SD in the estimate of free cortisol ( SD = 30.3 ) was associated with cognitive impairment , although not significantly [ odds ratio ( OR ) = 1.5 ; 95 % confidence interval ( CI ) , 0.9 - 2.4 ] . A 1 SD increase in the natural logarithm of cortisol after the administration of 1 mg dexamethasone ( SD = 0.68 ) was associated with an OR for cognitive decline of 1.5 ( 95 % CI , 1.0 - 2.3 ) . A 1 SD increase in DHEAS ( SD = 2.10 micromol/L ) was inversely , but nonsignificantly , related to cognitive impairment ( OR = 0.5 ; 95 % CI , 0.2 - 1.1 ) and cognitive decline ( OR = 0.6 ; 95 % CI , 0.4 - 1.1 ) . The ratio of free cortisol over DHEAS was significantly related to cognitive impairment ( OR = 1.8 ; 95 % CI , 1.0 - 3.2 ) . This prospect i ve study among healthy elderly subjects suggested that basal free cortisol levels were positively related to cognitive impairment , and cortisol levels after dexamethasone treatment were related to cognitive decline . There was an inverse , but nonsignificant , association between DHEAS and cognitive impairment and decline BACKGROUND In humans , concentrations of the adrenal steroid hormone dehydroepi and rosterone ( DHEA ) and its sulfate ester ( DHEAS ) decline with age . Results from studies in rodents have suggested that DHEA administration can improve memory performance as well as neuronal plasticity . However , a first study from our laboratory could not demonstrate beneficial effects of DHEA substitution on cognitive performance and well-being in elderly subjects . To further evaluate whether DHEA replacement has effects on the central nervous system , an experiment using event-related potentials ( ERPs ) was conducted . METHODS In this placebo-controlled crossover study , 17 elderly men ( mean age , 71.1 + /- 1.7 yr ; range 59 - 81 yr ) took  placebo or DHEA ( 50 mg/day ) for 2 weeks ( double blind ) . After each treatment period subjects participated in an auditory oddball paradigm with three oddball blocks . In the first two blocks subjects had to count the rare tone silently , whereas , in the third block they had to press a button . In addition , memory tests assessing visual , spatial , and semantic memory as well as question naires on psychological and physical well-being were presented . RESULTS Baseline DHEAS levels were lower compared with young adults . After 2-week DHEA replacement , DHEAS levels rose 5-fold to levels observed in young men . DHEA substitution modulated the P3 component of the ERPs , which reflects information updating in short-term memory . P3 amplitude was increased after DHEA administration , and only selectively in the second oddball block . DHEA did not influence P3 latency . Moreover , DHEA did not enhance memory or mood . CONCLUSIONS A 2-week DHEA replacement in elderly men results in changes in electrophysiological indices of central nervous system stimulus processing if the task is performed repeatedly . However , these effects do not appear to be strong enough to improve memory or mood Dehydroepi and rosterone ( DHEA ) and its sulfate form ( DHEAS ) have been the focus of considerable publicity because of their demonstrated associations with a broad range of health outcomes . Yet , knowledge about the effects of endogenous DHEA(S ) on health in humans is limited and often inconclusive , largely because few of the studies have been based on prospect i ve surveys of population -representative sample s. This analysis uses a national longitudinal survey in Taiwan to investigate whether DHEAS is associated with subsequent changes ( 2000 - 2003 ) in functional limitations , cognitive impairment , depressive symptoms , and global self-rated health . Regression models based on this older Taiwanese sample show that among men , lower levels of DHEAS are related to declines in mobility and self-assessed health status and increases in depressive symptoms , while both low and very high levels of DHEAS are associated with poor cognitive function . There are no significant associations among women . These findings differ from those in a previous cross-sectional analysis based on the Taiwan study and underscore the importance of using prospect i ve data to examine the effects of DHEAS on health . The evidence based on this and other longitudinal studies suggests that endogenous DHEAS is related to health outcomes for men , but not women , in both Western and non-Western population This study explores the potential relationship between a series of cognitive abilities and  testosterone , dehydroepi and rosterone ( DHEA )  , and  rostenedione  , and body mass index ( BMI ) measurements in 5-year-old children . 60 boys and 69 girls were administered a test ( K-BIT ) which provided measurements of fluid intelligence ( Matrices subtest ) , crystallized intelligence ( Vocabulary subtest ) , and IQ composite ( the combination of the two subtests ) ; a sub- sample of 48 boys and 61 girls was also subjected to diverse tests related to theory of mind ( affective labeling , appearance-reality distinction , display rules , and false belief ) .  Testosterone , DHEA , and and rostenedione levels were measured using an enzyme immunoassay technique in saliva sample s. An analysis of variance failed to reveal any significant differences between boys and girls in any of the cognitive abilities assessed . The correlation analysis revealed a positive relationship between fluid intelligence and testosterone levels in boys , a negative relationship between crystallized intelligence and and rostenedione levels in girls , and between affective labeling and and rostenedione levels in boys . A multiple regression analysis indicated that and rostenedione and BMI were the best predictors for some of the cognitive abilities assessed The levels of dehydroepi and rosterone ( DHEA ) and its sulfate ester DHEAS decrease with age after a peak around 25 yr . Animal studies as well as the first studies in humans have generated the idea that DHEA replacement in elderly subjects may have beneficial effects on well-being and cognitive functions . In the present experiment 40 healthy elderly men and women ( mean age , 69 yr ) participated in a double blind , placebo-controlled DHEA substitution study . For 2 weeks subjects took 50 mg DHEA daily , followed by a 2-week wash-out period and a 2-week placebo period . The treatment sequence was r and omized in a cross-over design . After 2 weeks of DHEA or placebo , psychological and physical well-being as well as cognitive performance were assessed using several question naires and neuropsychological tests . All subjects had low DHEAS baseline levels .  DHEA substitution lead to a 5-fold increase in DHEAS levels in women ( from 0.67 + /- 0.1 to 4.1 + /- 0.4 micrograms/mL ; P < 0.001 ) and men ( from 0.85 + /- 0.1 to 4.5 + /- 0.4 micrograms/mL ; P < 0.001 ) . DHEA , and rostenedione , and testosterone levels also increased significantly in both sexes ( all P < 0.001 ) . No significant changes were observed in insulin-like growth factor I or insulin-like growth factor-binding protein-3 levels .  DHEA replacement had no strong beneficial effect on any of the measured psychological or cognitive parameters . Only women tended to report an increase in well-being ( P = 0.11 ) and mood ( P = 0.10 ) , as assessed with question naires . They also showed better performance in one of six cognitive tests ( picture memory ) after DHEA . However , after Bonferroni alpha adjustment , this difference was no longer significant . No such trend was observed in men ( P > 0.20 ) . Likewise , no beneficial effects of DHEA substitution could be observed in any of the other tests of the neuropsychological test battery in either sex ( all P > 0.20 ) . In conclusion , the present data do not support the idea of strong beneficial effects of a physiological DHEA substitution on well-being or cognitive performance in healthy elderly individuals BACKGROUND The observation that dehydroepi and rosterone ( DHEA ) concentrations decrease markedly with age has led to the hypothesis that declining DHEA concentrations may contribute to age-related changes in cognition . In the United States , DHEA is widely available as an over-the-counter supplement that individuals are using in an effort to ameliorate age-related cognitive and physical changes . OBJECTIVE To investigate the relationship between age-associated decreases in endogenous DHEA sulfate ( DHEA-S ) concentrations and declines in neuropsychological performance in a prospect i ve , longitudinal study . METHODS The subjects were 883 men from a community-dwelling volunteer sample in the Baltimore Longitudinal Study of Aging . The men were aged 22 to 91 years at the initial visit , and they were followed up for as long as 31 years ( mean , 11 . 55 years ) , with biennial re assessment s of multiple cognitive domains and contemporaneous measurement of serum DHEA-S concentrations . Outcome measures were the results of cognitive tests of verbal and visual memory , 2 tests of mental status , phonemic and semantic word fluency tests , and measures of visuomotor scanning and attention . Serum DHEA-S concentrations were determined by st and ard radioimmunoassay . RESULTS Neither the rates of decline in mean DHEA-S concentrations nor the mean DHEA-S concentrations within individuals were related to cognitive status or cognitive decline . A comparison between the highest and lowest DHEA-S quartiles revealed no cognitive differences , despite the fact that these groups differed in endogenous DHEA-S concentration by more than a factor of 4 for a mean duration of 12 years . CONCLUSION Our longitudinal results augment those of previous prospect i ve studies by suggesting that the decline in endogenous DHEA-S concentration is independent of cognitive status and cognitive decline in healthy aging men Dehydroepi and rosterone ( DHEA ) and its sulfate , DHEA-S , are plentiful adrenal steroid hormones that decrease with aging and may have significant neuropsychiatric effects . In this study , six middle-aged and elderly patients with major depression and low basal plasma DHEA f1p4or DHEA-S levels were openly administered DHEA ( 30 - 90 mg/d x 4 weeks ) in doses sufficient to achieve circulating plasma levels observed in younger healthy individuals . Depression ratings , as well as aspects of memory performance significantly improved . One treatment-resistant patient received extended treatment with DHEA for 6 months : her depression ratings improved 48 - 72 % and her semantic memory performance improved 63 % . These measures returned to baseline after treatment ended . In both studies , improvements in depression ratings and memory performance were directly related to increases in plasma levels of DHEA and DHEA-S and to increases in their ratios with plasma cortisol levels . These preliminary data suggest DHEA may have antidepressant and promemory effects and should encourage double-blind trials in depressed patients There are few reported data on biochemical and functional correlates of and rogen levels in African-American men . This study aim ed at reporting physical and biochemical correlates of serum total testosterone ( total T ) , bioavailable testosterone ( BT ) and dehydroepi and rosterone-sulphate ( DHEAS ) levels in community-dwelling , African-American men aged 50 - 65 years .  Home-based physical examinations and health status question naires were administered to r and omly sample d men .  Body composition ( dual-energy X-ray absorptiometry ) , lower limb and h and -grip muscle strength , and neuropsychological functions were assessed . Levels of serum total T , BT , DHEAS , oestradiol ( E2 ) , adiponectin , leptin , triglycerides and glucose were measured . Multiple linear regression models were constructed to identify factors independently associated with and rogen levels . DHEAS levels declined from age 50 to 65 years ( p < 0.0001 ) , but total T and BT levels remained constant . Independent of other associated factors , higher total T levels were associated with lower serum triglyceride levels ( beta = -0.142 , p = 0.049 ) ; higher BT was associated with better performance on the trail-making tests ( TMT-B : TMT-A ratio : beta = -0.118 , p = 0.024 ) and higher DHEAS levels were associated with lower adiponectin ( beta = -0.293 , 
    Output:
    
Other positive correlations between DHEA-S and working memory , attention and verbal fluency were found only in women .
The DHEA effect on cognition is limited to one study conducted among young men with high-doses