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: CONTEXT Physical activity can reduce the risk of  hip fractures in older women , although the required type and duration of activity have not been determined . Walking is the most common activity among older adults , and evidence suggests that it can increase femoral bone density and reduce fracture risk . OBJECTIVE To assess the relationship of walking , leisure-time activity , and risk of hip fracture among postmenopausal women . DESIGN , SETTING , AND PARTICIPANTS Prospect i ve analysis begun in 1986 with 12 years of follow-up in the Nurses ' Health Study cohort of registered nurses within 11 US states . A total of 61,200 postmenopausal women ( aged 40 - 77 years and 98 % white ) without diagnosis of cancer , heart disease , stroke , or osteoporosis at baseline . MAIN OUTCOME MEASURES Incident hip fracture result ing from low or moderate trauma , analyzed by intensity and duration of leisure-time activity  and by  time spent walking , sitting , and st and ing  , measured at baseline and up date d throughout follow-up . RESULTS From 1986 to 1998 , 415 incident hip fracture cases were identified . After controlling for age , body mass index , use of postmenopausal hormones , smoking , and dietary intakes in proportional hazards models , risk of hip fracture was lowered by 6 % ( 95 % confidence interval [ CI ] , 4%-9 % ; P<.001 ) for each increase of 3 metabolic equivalent (MET)-hours per week of activity ( equivalent to 1 h/wk of walking at an average pace ) . Active women with at least 24 MET-h/wk had a 55 % lower risk of hip fracture ( relative risk [ RR ] , 0.45 ; 95 % CI , 0.32 - 0.63 ) compared with sedentary women with less than 3 MET-h/wk . Even women with a lower risk of hip fracture due to higher body weight experienced a further reduction in risk with higher levels of activity . Risk of hip fracture decreased linearly with increasing level of activity among women not taking postmenopausal hormones ( P<.001 ) , but not among women taking hormones ( P = .24 ) . Among women who did no other exercise , walking for at least 4 h/wk was associated with a 41 % lower risk of hip fracture ( RR , 0.59 ; 95 % CI , 0.37 - 0.94 ) compared with less than 1 h/wk . More time spent st and ing was also independently associated with lower risks . CONCLUSION Moderate levels of activity , including walking , are associated with substantially lower risk of hip fracture in postmenopausal women Background : Existing data suggest that physical activity reduces colon cancer risk , but the association is not consistently observed in women . One potential explanation for this inconsistency is that hormone therapy , which is associated with lower colon cancer risk , acts as a modifier of the physical activity/colon cancer relationship . Methods : Participants in the California Teachers Study ( N = 120,147 ) , a prospect i ve cohort of female teachers and administrators residing in California , ages 22 to 84 years at baseline and with no prior history of colon cancer were eligible for study . Between 1996 and 2002 , 395 patients were diagnosed with invasive colon cancer . The relative risks ( RR ) associated with lifetime ( high school through age 54 years or current age ) and recent ( past 3 years ) strenuous and moderate recreational physical activity were estimated using Cox proportional hazards regression models . Results : Combined lifetime moderate and strenuous recreational physical activity was only modestly associated with colon cancer risk in the cohort [ ≥4 versus ≤0.5 h/wk/y : RR , 0.75 ; 95 % confidence interval , 0.57 - 1.00 ; Ptrend = 0.23 ] . Lifetime physical activity reduced colon cancer risk among postmenopausal women who had never taken hormone therapy ( ≥4 versus ≤0.5 h/wk/y : RR , 0.51 ; 95 % confidence interval , 0.31 - 0.85 ; Ptrend = 0.02 ) . Postmenopausal women with histories of hormone therapy use had lower colon cancer risk , but their risk was not associated with physical activity . The likelihood ratio test for interaction between hormone use and lifetime moderate plus strenuous physical activity was of borderline statistical significance ( P = 0.05 ) . We observed no effect modification by age , body mass index , smoking status , menopausal status , or folate intake . Conclusions : Lifetime recreational physical activity may protect against colon cancer among postmenopausal women who have never used hormone therapy . Among hormone therapy users , who have lower risk of colon cancer , recreational physical activity does not seem to provide any additional benefit . With declining rates of hormone therapy use , physical activity offers one possible means for reducing women 's colon cancer risk . ( Cancer Epidemiol Biomarkers Prev 2007;16(3):517–25 Background Lifestyle is a well-established risk factor for colorectal cancer ( CRC ) and is also found to be associated with occurrence of adenomas . In the present study we evaluated risk factors for both low-risk adenomas and advanced neoplasia  in asymptomatic individuals using a single-paged question naire . Aim ing to see if the question naire was a useful tool in picking up high-risk individuals . Methods A cross-sectional study was carried out within a r and omised controlled colorectal cancer screening trial ( n = 6961 ) . The population comprised men and women born between 1946 and 1950 . Before screening in year 2001 they were asked to fill in a question naire about their present lifestyle . Cases were categorised according to the most severe findings at screening . Analyses were then conducted to find risk factors associated with the presence of either low-risk adenomas or advanced neoplasia . Results The response rate among attendees was 97 % ( 3998/4111 ) . Among these , 3447 ( 86 % ) had no neoplasia , 443 ( 11 % ) had low-risk adenomas , and 108 ( 3 % ) had advanced neoplasia . Low-risk adenomas were significantly associated with current smoking , and obesity .  Participants with advanced neoplasia had a two-fold increased risk of not adhering to any of the selected lifestyle recommendations compared to controls . However , current smoking was the only variable that reached statistical significance in the multivariate analysis for these lesions . A dose-response relationship to the consumption of cigarettes per day was shown , where OR was 2.04 ( CI 1.07–3.89 ) for the lowest consumption category . Conclusion The present findings indicate that a short question naire may be adequate in picking up the most consistent associations between lifestyle risk factors and colorectal neoplasia . Smoking and BMI were found to be the most significant risk factors for neoplasia , but adhering to recommendations on diet , and physical activity seems also to be of importance BACKGROUND In older people , it is unclear whether obesity relates to mortality , which calls into question its etiologic role in disease and its public health relevance . This apparent lack of relationship in older people could be an artifactual result of their diverse health states . METHODS We used Cox regression analysis to determine whether the effect of body mass index ( BMI ) ( calculated as weight in kilograms divided by the square of height in meters ) or physical activity on mortality varied with health status in a prospect i ve cohort study of Chinese people 65 years or older enrolled from 1998 to 2000 at all of the 18 Elderly Health Centers of the Hong Kong Government Department of Health . Health status was categorized into 5 morbidity groups using a 12-item index covering illnesses , medications , frailty , and smoking . RESULTS After a mean follow-up of 4.1 years , there were 3819 deaths in 54 088 subjects ( 96.5 % successful follow-up ) . The effect of BMI on mortality varied with baseline health status ( P<.001 ) . In the healthiest group , obese people ( BMI > /=25 ) had higher mortality ( adjusted hazard ratio [ HR ] , 1.54 ; 95 % confidence interval [ CI ] , 1.02 - 2.33 ) , but in the unhealthiest group they had lower mortality ( HR , 0.55 ; 95 % CI , 0.49 - 0.63 ) compared with subjects of normal weight . Daily physical activity was associated with lower mortality compared with inactivity in the unhealthiest group ( HR , 0.70 ; 95 % CI , 0.61- 0.81 ) but not in the healthiest group . CONCLUSIONS In the elderly , the relationship between obesity and mortality varies according to the underlying health status . In those with poor health status , obesity is associated with better outcome , whereas in those with initially good health status , obesity is associated with worse outcome Background and Purpose — The role of physical activity , especially that of occupational and commuting physical activity , in the prediction of stroke risk is not properly established . We assessed the relationship of different types of physical activity with total and type-specific stroke risk . Methods — We prospect ively followed 47 721 Finnish subjects 25 to 64 years of age without a history of coronary heart disease , stroke , or cancer at baseline .  Hazard ratios ( HRs ) for incident stroke were estimated for different levels of leisure time , occupational , and commuting physical activity . Results — During a mean follow-up of 19.0 years , 2863 incident stroke events were ascertained . The multivariate-adjusted ( age , sex , area , study year , body mass index , systolic blood pressure , cholesterol , education , smoking , alcohol consumption , diabetes , and other 2 types of physical activity ) HRs associated with low , moderate , and high leisure time physical activity were 1.00 , 0.86 , and 0.74 ( Ptrend<0.001 ) for total stroke , 1.00 , 0.87 , and 0.46 ( Ptrend=0.011 ) for subarachnoid hemorrhage , 1.00 , 0.77 , and 0.63 ( Ptrend=0.024 ) for intracerebral hemorrhage , and 1.00 , 0.87 , and 0.80 ( Ptrend=0.001 ) for ischemic stroke , respectively . The multivariate-adjusted HRs associated with none , 1 to 29 , and ≥30 minutes of active commuting were 1.00 , 0.92 , and 0.89 ( Ptrend=0.043 ) for total stroke , and 1.00 , 0.93 , and 0.86 ( Ptrend=0.028 ) for ischemic stroke , respectively . Occupational activity had a modest association with ischemic stroke in the multivariate analysis ( Ptrend=0.046 ) . Conclusion — A high level of leisure time physical activity  reduces the risk of all subtypes of stroke . Daily active commuting also reduces the risk of ischemic stroke OBJECTIVES The association between the risk of breast cancer and the physical load of work was studied because physical activity may reduce breast cancer risk via hormonal mechanisms . METHODS Occupational physical activity was estimated from a self-determined rating [ scale 1 (low)-5 ( high ) ] of occupational physical load for 1800 r and omly selected women born in 1930 - 1969 . The medians of the ratings were used as occupation-specific indices of occupational physical activity . All 65 occupations with at least 5 ratings , covering 75 % of the economically active female population in Finl and , were included in further analyses . The occupation-specific numbers of observed and expected cases of breast cancer during 1971 - 1995 among women born in 1906 - 1945 ( 17,986 cases ) were grouped according to the index for occupational physical activity . Expected rates were calculated with the social-class-specific population and the entire Finnish female population as reference population s. The relative risks ( RR ) of breast cancer for categories 3 - 5 , in comparison with categories 1 - 2 were calculated using Poisson regression models . The occupation-specific mean number of children and mean age at first childbirth were adjusted for . RESULTS The RR was lower for occupations in category 5 than for those in categories 1 - 4 , especially in the youngest ( 25 - 39 years ) age group ( RR 0.51 , 95 % confidence interval 0.44 - 0.58 ) . Adjustment for social class and reproductive factors raised the RR ( 95 % confidence interval 0.56 - 0.74 ) for category 5 in different age strata , all the RR values still being statistically significant . CONCLUSIONS The results support the hypothesis that occupational physical activity , if high enough , markedly reduces breast cancer risk BACKGROUND AND PURPOSE Physical activity reduces the risk of premature death and cardiovascular disease , but the relationship to stroke is less well studied . The objective of this study was to investigate the association between leisure-time physical activity and  ischemic stroke in an urban , elderly , multiethnic population . METHODS The Northern Manhattan Stroke Study is a population -based incidence and case-control study . Case subjects had first ischemic stroke , and control subjects were derived through r and om-digit dialing with 1:2 matching for age , sex , and race/ethnicity .  Physical activity  was recorded through a st and ardized in-person interview regarding the frequency and duration of 14 activities over the 2 prior weeks . Cond 
    Output:
    
agent
Overall , the current literature supports clearly the dose-response relationship between physical activity and the seven chronic conditions identified .
Moreover , higher levels of physical activity reduce the risk for premature all-cause mortality .
The current Canadian guidelines appear to be appropriate to reduce the risk for the seven chronic conditions identified above and all-cause mortality
***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: CONTEXT Physical activity can reduce the risk of  hip fractures in older women , although the required type and duration of activity have not been determined . Walking is the most common activity among older adults , and evidence suggests that it can increase femoral bone density and reduce fracture risk . OBJECTIVE To assess the relationship of walking , leisure-time activity , and risk of hip fracture among postmenopausal women . DESIGN , SETTING , AND PARTICIPANTS Prospect i ve analysis begun in 1986 with 12 years of follow-up in the Nurses ' Health Study cohort of registered nurses within 11 US states . A total of 61,200 postmenopausal women ( aged 40 - 77 years and 98 % white ) without diagnosis of cancer , heart disease , stroke , or osteoporosis at baseline . MAIN OUTCOME MEASURES Incident hip fracture result ing from low or moderate trauma , analyzed by intensity and duration of leisure-time activity  and by  time spent walking , sitting , and st and ing  , measured at baseline and up date d throughout follow-up . RESULTS From 1986 to 1998 , 415 incident hip fracture cases were identified . After controlling for age , body mass index , use of postmenopausal hormones , smoking , and dietary intakes in proportional hazards models , risk of hip fracture was lowered by 6 % ( 95 % confidence interval [ CI ] , 4%-9 % ; P<.001 ) for each increase of 3 metabolic equivalent (MET)-hours per week of activity ( equivalent to 1 h/wk of walking at an average pace ) . Active women with at least 24 MET-h/wk had a 55 % lower risk of hip fracture ( relative risk [ RR ] , 0.45 ; 95 % CI , 0.32 - 0.63 ) compared with sedentary women with less than 3 MET-h/wk . Even women with a lower risk of hip fracture due to higher body weight experienced a further reduction in risk with higher levels of activity . Risk of hip fracture decreased linearly with increasing level of activity among women not taking postmenopausal hormones ( P<.001 ) , but not among women taking hormones ( P = .24 ) . Among women who did no other exercise , walking for at least 4 h/wk was associated with a 41 % lower risk of hip fracture ( RR , 0.59 ; 95 % CI , 0.37 - 0.94 ) compared with less than 1 h/wk . More time spent st and ing was also independently associated with lower risks . CONCLUSION Moderate levels of activity , including walking , are associated with substantially lower risk of hip fracture in postmenopausal women Background : Existing data suggest that physical activity reduces colon cancer risk , but the association is not consistently observed in women . One potential explanation for this inconsistency is that hormone therapy , which is associated with lower colon cancer risk , acts as a modifier of the physical activity/colon cancer relationship . Methods : Participants in the California Teachers Study ( N = 120,147 ) , a prospect i ve cohort of female teachers and administrators residing in California , ages 22 to 84 years at baseline and with no prior history of colon cancer were eligible for study . Between 1996 and 2002 , 395 patients were diagnosed with invasive colon cancer . The relative risks ( RR ) associated with lifetime ( high school through age 54 years or current age ) and recent ( past 3 years ) strenuous and moderate recreational physical activity were estimated using Cox proportional hazards regression models . Results : Combined lifetime moderate and strenuous recreational physical activity was only modestly associated with colon cancer risk in the cohort [ ≥4 versus ≤0.5 h/wk/y : RR , 0.75 ; 95 % confidence interval , 0.57 - 1.00 ; Ptrend = 0.23 ] . Lifetime physical activity reduced colon cancer risk among postmenopausal women who had never taken hormone therapy ( ≥4 versus ≤0.5 h/wk/y : RR , 0.51 ; 95 % confidence interval , 0.31 - 0.85 ; Ptrend = 0.02 ) . Postmenopausal women with histories of hormone therapy use had lower colon cancer risk , but their risk was not associated with physical activity . The likelihood ratio test for interaction between hormone use and lifetime moderate plus strenuous physical activity was of borderline statistical significance ( P = 0.05 ) . We observed no effect modification by age , body mass index , smoking status , menopausal status , or folate intake . Conclusions : Lifetime recreational physical activity may protect against colon cancer among postmenopausal women who have never used hormone therapy . Among hormone therapy users , who have lower risk of colon cancer , recreational physical activity does not seem to provide any additional benefit . With declining rates of hormone therapy use , physical activity offers one possible means for reducing women 's colon cancer risk . ( Cancer Epidemiol Biomarkers Prev 2007;16(3):517–25 Background Lifestyle is a well-established risk factor for colorectal cancer ( CRC ) and is also found to be associated with occurrence of adenomas . In the present study we evaluated risk factors for both low-risk adenomas and advanced neoplasia  in asymptomatic individuals using a single-paged question naire . Aim ing to see if the question naire was a useful tool in picking up high-risk individuals . Methods A cross-sectional study was carried out within a r and omised controlled colorectal cancer screening trial ( n = 6961 ) . The population comprised men and women born between 1946 and 1950 . Before screening in year 2001 they were asked to fill in a question naire about their present lifestyle . Cases were categorised according to the most severe findings at screening . Analyses were then conducted to find risk factors associated with the presence of either low-risk adenomas or advanced neoplasia . Results The response rate among attendees was 97 % ( 3998/4111 ) . Among these , 3447 ( 86 % ) had no neoplasia , 443 ( 11 % ) had low-risk adenomas , and 108 ( 3 % ) had advanced neoplasia . Low-risk adenomas were significantly associated with current smoking , and obesity .  Participants with advanced neoplasia had a two-fold increased risk of not adhering to any of the selected lifestyle recommendations compared to controls . However , current smoking was the only variable that reached statistical significance in the multivariate analysis for these lesions . A dose-response relationship to the consumption of cigarettes per day was shown , where OR was 2.04 ( CI 1.07–3.89 ) for the lowest consumption category . Conclusion The present findings indicate that a short question naire may be adequate in picking up the most consistent associations between lifestyle risk factors and colorectal neoplasia . Smoking and BMI were found to be the most significant risk factors for neoplasia , but adhering to recommendations on diet , and physical activity seems also to be of importance BACKGROUND In older people , it is unclear whether obesity relates to mortality , which calls into question its etiologic role in disease and its public health relevance . This apparent lack of relationship in older people could be an artifactual result of their diverse health states . METHODS We used Cox regression analysis to determine whether the effect of body mass index ( BMI ) ( calculated as weight in kilograms divided by the square of height in meters ) or physical activity on mortality varied with health status in a prospect i ve cohort study of Chinese people 65 years or older enrolled from 1998 to 2000 at all of the 18 Elderly Health Centers of the Hong Kong Government Department of Health . Health status was categorized into 5 morbidity groups using a 12-item index covering illnesses , medications , frailty , and smoking . RESULTS After a mean follow-up of 4.1 years , there were 3819 deaths in 54 088 subjects ( 96.5 % successful follow-up ) . The effect of BMI on mortality varied with baseline health status ( P<.001 ) . In the healthiest group , obese people ( BMI > /=25 ) had higher mortality ( adjusted hazard ratio [ HR ] , 1.54 ; 95 % confidence interval [ CI ] , 1.02 - 2.33 ) , but in the unhealthiest group they had lower mortality ( HR , 0.55 ; 95 % CI , 0.49 - 0.63 ) compared with subjects of normal weight . Daily physical activity was associated with lower mortality compared with inactivity in the unhealthiest group ( HR , 0.70 ; 95 % CI , 0.61- 0.81 ) but not in the healthiest group . CONCLUSIONS In the elderly , the relationship between obesity and mortality varies according to the underlying health status . In those with poor health status , obesity is associated with better outcome , whereas in those with initially good health status , obesity is associated with worse outcome Background and Purpose — The role of physical activity , especially that of occupational and commuting physical activity , in the prediction of stroke risk is not properly established . We assessed the relationship of different types of physical activity with total and type-specific stroke risk . Methods — We prospect ively followed 47 721 Finnish subjects 25 to 64 years of age without a history of coronary heart disease , stroke , or cancer at baseline .  Hazard ratios ( HRs ) for incident stroke were estimated for different levels of leisure time , occupational , and commuting physical activity . Results — During a mean follow-up of 19.0 years , 2863 incident stroke events were ascertained . The multivariate-adjusted ( age , sex , area , study year , body mass index , systolic blood pressure , cholesterol , education , smoking , alcohol consumption , diabetes , and other 2 types of physical activity ) HRs associated with low , moderate , and high leisure time physical activity were 1.00 , 0.86 , and 0.74 ( Ptrend<0.001 ) for total stroke , 1.00 , 0.87 , and 0.46 ( Ptrend=0.011 ) for subarachnoid hemorrhage , 1.00 , 0.77 , and 0.63 ( Ptrend=0.024 ) for intracerebral hemorrhage , and 1.00 , 0.87 , and 0.80 ( Ptrend=0.001 ) for ischemic stroke , respectively . The multivariate-adjusted HRs associated with none , 1 to 29 , and ≥30 minutes of active commuting were 1.00 , 0.92 , and 0.89 ( Ptrend=0.043 ) for total stroke , and 1.00 , 0.93 , and 0.86 ( Ptrend=0.028 ) for ischemic stroke , respectively . Occupational activity had a modest association with ischemic stroke in the multivariate analysis ( Ptrend=0.046 ) . Conclusion — A high level of leisure time physical activity  reduces the risk of all subtypes of stroke . Daily active commuting also reduces the risk of ischemic stroke OBJECTIVES The association between the risk of breast cancer and the physical load of work was studied because physical activity may reduce breast cancer risk via hormonal mechanisms . METHODS Occupational physical activity was estimated from a self-determined rating [ scale 1 (low)-5 ( high ) ] of occupational physical load for 1800 r and omly selected women born in 1930 - 1969 . The medians of the ratings were used as occupation-specific indices of occupational physical activity . All 65 occupations with at least 5 ratings , covering 75 % of the economically active female population in Finl and , were included in further analyses . The occupation-specific numbers of observed and expected cases of breast cancer during 1971 - 1995 among women born in 1906 - 1945 ( 17,986 cases ) were grouped according to the index for occupational physical activity . Expected rates were calculated with the social-class-specific population and the entire Finnish female population as reference population s. The relative risks ( RR ) of breast cancer for categories 3 - 5 , in comparison with categories 1 - 2 were calculated using Poisson regression models . The occupation-specific mean number of children and mean age at first childbirth were adjusted for . RESULTS The RR was lower for occupations in category 5 than for those in categories 1 - 4 , especially in the youngest ( 25 - 39 years ) age group ( RR 0.51 , 95 % confidence interval 0.44 - 0.58 ) . Adjustment for social class and reproductive factors raised the RR ( 95 % confidence interval 0.56 - 0.74 ) for category 5 in different age strata , all the RR values still being statistically significant . CONCLUSIONS The results support the hypothesis that occupational physical activity , if high enough , markedly reduces breast cancer risk BACKGROUND AND PURPOSE Physical activity reduces the risk of premature death and cardiovascular disease , but the relationship to stroke is less well studied . The objective of this study was to investigate the association between leisure-time physical activity and  ischemic stroke in an urban , elderly , multiethnic population . METHODS The Northern Manhattan Stroke Study is a population -based incidence and case-control study . Case subjects had first ischemic stroke , and control subjects were derived through r and om-digit dialing with 1:2 matching for age , sex , and race/ethnicity .  Physical activity  was recorded through a st and ardized in-person interview regarding the frequency and duration of 14 activities over the 2 prior weeks . Cond 
    Output:
    