human
***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: Little is known about the descriptive epidemiology of and rogen deficiency . In this study , we sought to address this issue by providing estimates of the crude and age-specific prevalence and incidence rates of and rogen deficiency in a r and omly sample d population -based cohort of middle-aged and older men . Data on and rogen deficiency ( defined using both signs/symptoms plus total and calculated free testosterone ) were available for n = 1691 ( baseline ) and n = 1087 ( follow-up ) men from the Massachusetts Male Aging Study .  Crude and age-specific prevalence and incidence rates were calculated . Based on these estimates , projections for the number of cases of and rogen deficiency in the 40- to 69-yr-old U.S. male population were computed . Estimates of the crude prevalence of and rogen deficiency at baseline and follow-up were 6.0 and 12.3 % , respectively . Prevalence increased significantly with age . From baseline age-specific prevalence data , it is estimated that there are approximately 2.4 million 40- to 69-yr-old U.S. males with and rogen deficiency . The crude incidence rate of and rogen deficiency was 12.3 per 1,000 person-years , and the rate increased significantly ( P < 0.0001 ) with age . Based on these incidence data , we can expect approximately 481,000 new cases of and rogen deficiency per year in U.S. men 40 - 69 yr old Background — The relation between endogenous testosterone concentrations and health in men is controversial . Methods and Results — We examined the prospect i ve relationship between endogenous testosterone concentrations and mortality due to all causes , cardiovascular disease , and cancer in a nested case-control study based on 11 606 men aged 40 to 79 years surveyed in 1993 to 1997 and followed up to 2003 . Among those without prevalent cancer or cardiovascular disease , 825 men who subsequently died were compared with a control group of 1489 men still alive , matched for age and date of baseline visit .  Endogenous testosterone concentrations at baseline were inversely related to mortality due to all causes ( 825 deaths ) , cardiovascular disease ( 369 deaths ) , and cancer ( 304 deaths ) . Odds ratios ( 95 % confidence intervals ) for mortality for increasing quartiles of endogenous testosterone compared with the lowest quartile were 0.75 ( 0.55 to 1.00 ) , 0.62 ( 0.45 to 0.84 ) , and 0.59 ( 0.42 to 0.85 ) , respectively ( P<0.001 for trend after adjustment for age , date of visit , body mass index , systolic blood pressure , blood cholesterol , cigarette smoking , diabetes mellitus , alcohol intake , physical activity , social class , education , dehydroepi and rosterone sulfate , and rostanediol glucuronide , and sex hormone binding globulin ) . An increase of 6 nmol/L serum testosterone ( ≈1 SD ) was associated with a 0.81 ( 95 % confidence interval 0.71 to 0.92 , P<0.01 ) multivariable-adjusted odds ratio for mortality . Inverse relationships were also observed for deaths due to cardiovascular causes and cancer and after the exclusion of deaths that occurred in the first 2 years . Conclusions — In men  , endogenous testosterone concentrations are inversely related to mortality due to cardiovascular disease and all causes . Low testosterone may be a predictive marker for those at high risk of cardiovascular disease CONTEXT Despite recognition that and rogen deficiency in men should be defined according to biochemical and clinical criteria , most prevalence estimates are based on low testosterone levels alone . OBJECTIVE The objective of this study was to examine the association between symptoms of and rogen deficiency and low total and calculated free testosterone levels and estimate the prevalence of symptomatic and rogen deficiency in men . DESIGN This study was a population -based , observational survey . PARTICIPANTS A total of 1,475 Black , Hispanic , and white men , between the ages of 30 - 79 yr , with complete data on testosterone , SHBG , and symptoms of and rogen deficiency , and who are not taking medications that impact sex steroid levels were r and omly selected from the Boston Area Community Health Survey . OUTCOME Outcomes were measured as symptomatic and rogen deficiency , defined as low total ( < 300 ng/dl ) and free ( < 5 ng/dl ) testosterone plus presence of low libido , erectile dysfunction , osteoporosis or fracture , or two or more of following symptoms : sleep disturbance , depressed mood , lethargy , or diminished physical performance . RESULTS Mean age of the sample was 47.3 + /- 12.5 yr . Approximately 24 % of subjects had total testosterone less than 300 ng/dl , and 11 % of subjects had free testosterone less than 5 ng/dl . Prevalence of symptoms were as follows : low libido ( 12 % ) , erectile dysfunction ( 16 % ) , osteoporosis/fracture ( 1 % ) , and two or more of the nonspecific symptoms ( 20 % ) . Low testosterone levels were associated with symptoms , but many men with low testosterone levels were asymptomatic ( e.g. in men 50 + yr , 47.6 % ) . Crude prevalence of symptomatic and rogen deficiency was 5.6 % ( 95 % confidence interval : 3.6 % , 8.6 % ) , and was not significantly related to race and ethnic group . Prevalence was low in men less than 70 yr ( 3.1 - 7.0 % ) and increased markedly with age to 18.4 % among 70 yr olds . Projection of these estimates to the year 2025 suggests that there will be as many as 6.5 million American men ages 30 - 79 yr with symptomatic and rogen deficiency , an increase of 38 % from 2000 population estimates . CONCLUSIONS Prevalence of symptomatic and rogen deficiency in men 30 and 79 yr of age is 5.6 % and increases substantially with age . The aging of the U.S. male population will cause a large increase in the burden of symptomatic and rogen deficiency . Future work should address the clinical significance of low testosterone levels in asymptomatic men BACKGROUND Gonadal steroid levels decline with age in men . Whether low testosterone levels affect the development of common age-related disorders , including physical functioning and falling , is unclear . METHODS This longitudinal , observational follow-up study sought to determine whether low testosterone levels are associated with physical performance and fall risk in older men . A total of 2587 community-based men aged 65 to 99 years were selected using a stratified r and om sampling scheme from a study cohort of 5995 volunteers .  Bioavailable testosterone and estradiol levels and physical performance measures were determined from baseline . Incident falls were ascertained every 4 months during 4 years of follow-up . Generalized estimating equations were used to estimate risk ratios for the relation of sex steroids to falls . RESULTS Fifty-six percent of the men reported at least 1 fall ; many fell frequently . Lower bioavailable testosterone levels were associated with increased fall risk . Men with testosterone levels in the lowest quartile had a 40 % higher fall risk than those in the highest quartile . The effect of low testosterone levels was most apparent in younger men ( 65 - 69 years ) ( relative risk , 1.8 ; 95 % confidence interval , 1.2 - 2.7 ) ; testosterone level was not associated with falls in the oldest men ( > /=80 years ) . Lower testosterone concentrations were associated with reduced physical performance . However , the association between low testosterone levels and fall risk persisted despite adjustment for performance . CONCLUSIONS Falls were common among older men . Fall risk was higher in men with lower bioavailable testosterone levels . The effect of testosterone level was independent of poorer physical performance , suggesting that the effect of testosterone on fall risk may be mediated by other and rogen actions To prospect ively compare serum hormone levels and the incidence of hormonal pathologies between men with and without erectile dysfunction , and investigate risk factors that might predict hormonal pathologies in men complaining of erectile dysfunction . The study included 262 men with erectile dysfunction and 53 healthy men with no erectile dysfunction as a control group . All men enrolled in the study were evaluated with a detailed history , physical examination ,  international index of erectile function ( IIEF-5 ) , and  serum hormone measurement .  Hypotestosteronemia was considered as serum total testosterone value of <3 ng/mL , and hyperprolactinemia was considered as serum prolactin level of > 18 ng/mL. Serum hormone levels and the incidence of hormonal abnormalities were compared between the two groups . In addition , risk factors for hormonal abnormalities were investigated . There were no significant differences in the mean serum FSH ( p = 0.212 ) , LH ( p = 0.623 ) , testosterone ( p = 0.332 ) and prolactin values ( p = 0.351 ) between the men with and without erectile dysfunction . Hypotestosteronemia was detected in 29 ( 11 % ) of the erectile dysfunction group and in 2 ( 3.7 % ) of the control group , revealing no significant difference ( p = 0.104 ) . Hyperprolactinemia was detected in 25 ( 9.5 % ) of the erectile dysfunction group and in 2 ( 3.7 % ) of the control group , revealing no significant difference ( p = 0.171 ) . To investigate risk factors that might predict hormonal pathologies , there were no significant differences in the patient age , duration of the sexual dysfunction , smoking history and duration , the presence of chronic disease and the type of erectile dysfunction . Our findings suggest that hormonal measurement should not be routinely performed in the initial evaluation of men presenting with erectile dysfunction , and may be necessary based only on the findings obtained with a careful history and physical examination BACKGROUND The association between aging-related testosterone deficiency and late-onset hypogonadism in men remains a controversial concept . We sought evidence -based criteria for identifying late-onset hypogonadism in the general population on the basis of an association between symptoms and a low testosterone level . METHODS We surveyed a r and om population sample of 3369 men between the ages of 40 and 79 years at eight European centers . Using question naires , we collected data with regard to the subjects ' general , sexual , physical , and psychological health . Levels of total testosterone  were measured in morning blood sample s by mass spectrometry , and  free testosterone levels  were calculated with the use of Vermeulen 's formula . Data were r and omly split into separate training and validation sets for confirmatory analyses . RESULTS In the training set , symptoms of poor morning erection , low sexual desire , erectile dysfunction , inability to perform vigorous activity , depression , and fatigue were significantly related to the testosterone level . Increased probabilities of the three sexual symptoms and limited physical vigor were discernible with decreased testosterone levels ( ranges , 8.0 to 13.0 nmol per liter [ 2.3 to 3.7 ng per milliliter ] for total testosterone and 160 to 280 pmol per liter [ 46 to 81 pg per milliliter ] for free testosterone ) . However , only the three sexual symptoms had a syndromic association with decreased testosterone levels . An inverse relationship between an increasing number of sexual symptoms and a decreasing testosterone level was observed . These relationships were independently confirmed in the validation set , in which the strengths of the association between symptoms and low testosterone levels determined the minimum criteria necessary to identify late-onset hypogonadism . CONCLUSIONS Late-onset hypogonadism can be defined by the presence of at least three sexual symptoms associated with a total testosterone level of less than 11 nmol per liter ( 3.2 ng per milliliter ) and a free testosterone level of less than 220 pmol per liter ( 64 pg per milliliter ) OBJECTIVES To determine the relationship between the ADAM question naire and the sexual hormonal levels in a male population older than 50 yr , and to know the predictive capacity of this question naire with regard to biochemical hypogonadism in the ageing male . METHODS A prospect i ve study was carried out on 230 Spanish men . Patients were evaluated by clinical history . The ADAM question naire and the Yesavage 's Geriatric Depression Scale were completed by each patient . Blood tests were performed including total testosterone , SHBG , free testosterone ( FT ) , dehidroepi and rosterone sulfate ( DHEA-S ) , and rostenedione , 17-beta-estradiol , FSH , LH , and prolactin . The relationship between positive ADAM question naire and age , clinical and sociodemographic background s , and hormone levels was analysed by means of uni- and multivariate tests . The capacity of the ADAM question naire to predict biochemical hypogonadism was determined with a chi-square test . RESULTS ADAM question naire ( excluding men with positive Yesavage 's Scale ) was positive in 140 patients ( 67.9 % ) . With respect to clinical background s , diabetes mellitus and 
    Output:
    
agent
INTERPRETATION We found weak correlation between signs , symptoms and testosterone levels , uncertainty about what threshold testosterone levels should be considered low for aging men and wide variation in estimated prevalence of the condition .
It is therefore difficult to extrapolate the method of diagnosing pathologic hypogonadism in younger men to clinical decisions regarding age-related testosterone decline in aging men
***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: Little is known about the descriptive epidemiology of and rogen deficiency . In this study , we sought to address this issue by providing estimates of the crude and age-specific prevalence and incidence rates of and rogen deficiency in a r and omly sample d population -based cohort of middle-aged and older men . Data on and rogen deficiency ( defined using both signs/symptoms plus total and calculated free testosterone ) were available for n = 1691 ( baseline ) and n = 1087 ( follow-up ) men from the Massachusetts Male Aging Study .  Crude and age-specific prevalence and incidence rates were calculated . Based on these estimates , projections for the number of cases of and rogen deficiency in the 40- to 69-yr-old U.S. male population were computed . Estimates of the crude prevalence of and rogen deficiency at baseline and follow-up were 6.0 and 12.3 % , respectively . Prevalence increased significantly with age . From baseline age-specific prevalence data , it is estimated that there are approximately 2.4 million 40- to 69-yr-old U.S. males with and rogen deficiency . The crude incidence rate of and rogen deficiency was 12.3 per 1,000 person-years , and the rate increased significantly ( P < 0.0001 ) with age . Based on these incidence data , we can expect approximately 481,000 new cases of and rogen deficiency per year in U.S. men 40 - 69 yr old Background — The relation between endogenous testosterone concentrations and health in men is controversial . Methods and Results — We examined the prospect i ve relationship between endogenous testosterone concentrations and mortality due to all causes , cardiovascular disease , and cancer in a nested case-control study based on 11 606 men aged 40 to 79 years surveyed in 1993 to 1997 and followed up to 2003 . Among those without prevalent cancer or cardiovascular disease , 825 men who subsequently died were compared with a control group of 1489 men still alive , matched for age and date of baseline visit .  Endogenous testosterone concentrations at baseline were inversely related to mortality due to all causes ( 825 deaths ) , cardiovascular disease ( 369 deaths ) , and cancer ( 304 deaths ) . Odds ratios ( 95 % confidence intervals ) for mortality for increasing quartiles of endogenous testosterone compared with the lowest quartile were 0.75 ( 0.55 to 1.00 ) , 0.62 ( 0.45 to 0.84 ) , and 0.59 ( 0.42 to 0.85 ) , respectively ( P<0.001 for trend after adjustment for age , date of visit , body mass index , systolic blood pressure , blood cholesterol , cigarette smoking , diabetes mellitus , alcohol intake , physical activity , social class , education , dehydroepi and rosterone sulfate , and rostanediol glucuronide , and sex hormone binding globulin ) . An increase of 6 nmol/L serum testosterone ( ≈1 SD ) was associated with a 0.81 ( 95 % confidence interval 0.71 to 0.92 , P<0.01 ) multivariable-adjusted odds ratio for mortality . Inverse relationships were also observed for deaths due to cardiovascular causes and cancer and after the exclusion of deaths that occurred in the first 2 years . Conclusions — In men  , endogenous testosterone concentrations are inversely related to mortality due to cardiovascular disease and all causes . Low testosterone may be a predictive marker for those at high risk of cardiovascular disease CONTEXT Despite recognition that and rogen deficiency in men should be defined according to biochemical and clinical criteria , most prevalence estimates are based on low testosterone levels alone . OBJECTIVE The objective of this study was to examine the association between symptoms of and rogen deficiency and low total and calculated free testosterone levels and estimate the prevalence of symptomatic and rogen deficiency in men . DESIGN This study was a population -based , observational survey . PARTICIPANTS A total of 1,475 Black , Hispanic , and white men , between the ages of 30 - 79 yr , with complete data on testosterone , SHBG , and symptoms of and rogen deficiency , and who are not taking medications that impact sex steroid levels were r and omly selected from the Boston Area Community Health Survey . OUTCOME Outcomes were measured as symptomatic and rogen deficiency , defined as low total ( < 300 ng/dl ) and free ( < 5 ng/dl ) testosterone plus presence of low libido , erectile dysfunction , osteoporosis or fracture , or two or more of following symptoms : sleep disturbance , depressed mood , lethargy , or diminished physical performance . RESULTS Mean age of the sample was 47.3 + /- 12.5 yr . Approximately 24 % of subjects had total testosterone less than 300 ng/dl , and 11 % of subjects had free testosterone less than 5 ng/dl . Prevalence of symptoms were as follows : low libido ( 12 % ) , erectile dysfunction ( 16 % ) , osteoporosis/fracture ( 1 % ) , and two or more of the nonspecific symptoms ( 20 % ) . Low testosterone levels were associated with symptoms , but many men with low testosterone levels were asymptomatic ( e.g. in men 50 + yr , 47.6 % ) . Crude prevalence of symptomatic and rogen deficiency was 5.6 % ( 95 % confidence interval : 3.6 % , 8.6 % ) , and was not significantly related to race and ethnic group . Prevalence was low in men less than 70 yr ( 3.1 - 7.0 % ) and increased markedly with age to 18.4 % among 70 yr olds . Projection of these estimates to the year 2025 suggests that there will be as many as 6.5 million American men ages 30 - 79 yr with symptomatic and rogen deficiency , an increase of 38 % from 2000 population estimates . CONCLUSIONS Prevalence of symptomatic and rogen deficiency in men 30 and 79 yr of age is 5.6 % and increases substantially with age . The aging of the U.S. male population will cause a large increase in the burden of symptomatic and rogen deficiency . Future work should address the clinical significance of low testosterone levels in asymptomatic men BACKGROUND Gonadal steroid levels decline with age in men . Whether low testosterone levels affect the development of common age-related disorders , including physical functioning and falling , is unclear . METHODS This longitudinal , observational follow-up study sought to determine whether low testosterone levels are associated with physical performance and fall risk in older men . A total of 2587 community-based men aged 65 to 99 years were selected using a stratified r and om sampling scheme from a study cohort of 5995 volunteers .  Bioavailable testosterone and estradiol levels and physical performance measures were determined from baseline . Incident falls were ascertained every 4 months during 4 years of follow-up . Generalized estimating equations were used to estimate risk ratios for the relation of sex steroids to falls . RESULTS Fifty-six percent of the men reported at least 1 fall ; many fell frequently . Lower bioavailable testosterone levels were associated with increased fall risk . Men with testosterone levels in the lowest quartile had a 40 % higher fall risk than those in the highest quartile . The effect of low testosterone levels was most apparent in younger men ( 65 - 69 years ) ( relative risk , 1.8 ; 95 % confidence interval , 1.2 - 2.7 ) ; testosterone level was not associated with falls in the oldest men ( > /=80 years ) . Lower testosterone concentrations were associated with reduced physical performance . However , the association between low testosterone levels and fall risk persisted despite adjustment for performance . CONCLUSIONS Falls were common among older men . Fall risk was higher in men with lower bioavailable testosterone levels . The effect of testosterone level was independent of poorer physical performance , suggesting that the effect of testosterone on fall risk may be mediated by other and rogen actions To prospect ively compare serum hormone levels and the incidence of hormonal pathologies between men with and without erectile dysfunction , and investigate risk factors that might predict hormonal pathologies in men complaining of erectile dysfunction . The study included 262 men with erectile dysfunction and 53 healthy men with no erectile dysfunction as a control group . All men enrolled in the study were evaluated with a detailed history , physical examination ,  international index of erectile function ( IIEF-5 ) , and  serum hormone measurement .  Hypotestosteronemia was considered as serum total testosterone value of <3 ng/mL , and hyperprolactinemia was considered as serum prolactin level of > 18 ng/mL. Serum hormone levels and the incidence of hormonal abnormalities were compared between the two groups . In addition , risk factors for hormonal abnormalities were investigated . There were no significant differences in the mean serum FSH ( p = 0.212 ) , LH ( p = 0.623 ) , testosterone ( p = 0.332 ) and prolactin values ( p = 0.351 ) between the men with and without erectile dysfunction . Hypotestosteronemia was detected in 29 ( 11 % ) of the erectile dysfunction group and in 2 ( 3.7 % ) of the control group , revealing no significant difference ( p = 0.104 ) . Hyperprolactinemia was detected in 25 ( 9.5 % ) of the erectile dysfunction group and in 2 ( 3.7 % ) of the control group , revealing no significant difference ( p = 0.171 ) . To investigate risk factors that might predict hormonal pathologies , there were no significant differences in the patient age , duration of the sexual dysfunction , smoking history and duration , the presence of chronic disease and the type of erectile dysfunction . Our findings suggest that hormonal measurement should not be routinely performed in the initial evaluation of men presenting with erectile dysfunction , and may be necessary based only on the findings obtained with a careful history and physical examination BACKGROUND The association between aging-related testosterone deficiency and late-onset hypogonadism in men remains a controversial concept . We sought evidence -based criteria for identifying late-onset hypogonadism in the general population on the basis of an association between symptoms and a low testosterone level . METHODS We surveyed a r and om population sample of 3369 men between the ages of 40 and 79 years at eight European centers . Using question naires , we collected data with regard to the subjects ' general , sexual , physical , and psychological health . Levels of total testosterone  were measured in morning blood sample s by mass spectrometry , and  free testosterone levels  were calculated with the use of Vermeulen 's formula . Data were r and omly split into separate training and validation sets for confirmatory analyses . RESULTS In the training set , symptoms of poor morning erection , low sexual desire , erectile dysfunction , inability to perform vigorous activity , depression , and fatigue were significantly related to the testosterone level . Increased probabilities of the three sexual symptoms and limited physical vigor were discernible with decreased testosterone levels ( ranges , 8.0 to 13.0 nmol per liter [ 2.3 to 3.7 ng per milliliter ] for total testosterone and 160 to 280 pmol per liter [ 46 to 81 pg per milliliter ] for free testosterone ) . However , only the three sexual symptoms had a syndromic association with decreased testosterone levels . An inverse relationship between an increasing number of sexual symptoms and a decreasing testosterone level was observed . These relationships were independently confirmed in the validation set , in which the strengths of the association between symptoms and low testosterone levels determined the minimum criteria necessary to identify late-onset hypogonadism . CONCLUSIONS Late-onset hypogonadism can be defined by the presence of at least three sexual symptoms associated with a total testosterone level of less than 11 nmol per liter ( 3.2 ng per milliliter ) and a free testosterone level of less than 220 pmol per liter ( 64 pg per milliliter ) OBJECTIVES To determine the relationship between the ADAM question naire and the sexual hormonal levels in a male population older than 50 yr , and to know the predictive capacity of this question naire with regard to biochemical hypogonadism in the ageing male . METHODS A prospect i ve study was carried out on 230 Spanish men . Patients were evaluated by clinical history . The ADAM question naire and the Yesavage 's Geriatric Depression Scale were completed by each patient . Blood tests were performed including total testosterone , SHBG , free testosterone ( FT ) , dehidroepi and rosterone sulfate ( DHEA-S ) , and rostenedione , 17-beta-estradiol , FSH , LH , and prolactin . The relationship between positive ADAM question naire and age , clinical and sociodemographic background s , and hormone levels was analysed by means of uni- and multivariate tests . The capacity of the ADAM question naire to predict biochemical hypogonadism was determined with a chi-square test . RESULTS ADAM question naire ( excluding men with positive Yesavage 's Scale ) was positive in 140 patients ( 67.9 % ) . With respect to clinical background s , diabetes mellitus and 
    Output:
    