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: We examined the relation between self-reported physical activity  and  large bowel cancer  in a prospect i ve cohort of men and women who participated in the Framingham Study .  Self- assessment s of physical activity were available from the fourth biennial examination on a total of 1906 men and 2308 women aged 30 to 62 yr in 1954 . The cohort was followed for up to 28 yr and yielded 152 cases ( 73 men , 79 women ) of large bowel cancer . Inactivity was associated with an increased risk of large bowel cancer among men but not among women . The relative risk estimates for large bowel cancer among men in the middle and lowest tertiles of a physical activity index ( compared with the highest tertile ) were 1.4 ( 95 % confidence intervals , 0.8 - 2.6 ) and 1.8 ( 1.0 - 3.2 ) , respectively . Among women the comparable estimates were 1.2 ( 0.7 - 2.1 ) and 1.1 ( 0.6 - 1.8 ) , respectively . These findings were unchanged after adjustment for body mass index , serum cholesterol , alcohol , and other potentially confounding variables . The narrow range of physical activity and the minimal heavy activity reported by women in this cohort may have limited our ability to detect an association between physical activity  and large bowel cancer among women A sedentary lifestyle , obesity , and a Westernized diet have been implicated in the aetiology of both colorectal cancer and non-insulin dependent diabetes mellitus , leading to the hypothesis that hyperinsulinaemia may promote colorectal cancer . We prospect ively examined the association between colorectal cancer risk and factors related to insulin resistance and hyperinsulinaemia , including BMI , physical activity , diabetes mellitus , and blood glucose , in a cohort of 75 219 Norwegian men and women . Information on incident cases of colorectal cancer was made available from the Norwegian Cancer Registry . ReportedPvalues are two-sided . During 12 years of follow up , 730 cases of colorectal cancer were registered . In men , but not in women , we found a negative association with leisure-time physical activity ( Pfor trend = 0.002 ) , with an age-adjusted RR for the highest versus the lowest category of activity of 0.54 ( 95 % CI = 0.37–0.79 ) . Women , but not men , with a history of diabetes were at increased risk of colorectal cancer ( age-adjusted RR = 1.55 ; 95 % CI = 1.04–2.31 ) , as were women with non-fasting blood glucose ≥8.0 mmol l–1(age-adjusted RR = 1.98 ; 95 % CI = 1.31–2.98 ) compared with glucose < 8.0 mmol l–1 . Overall , we found no association between BMI and risk of colorectal cancer . Additional adjustment including each of the main variables , marital status , and educational attainment did not material ly change the results . We conclude that the inverse association between leisure-time physical activity and colorectal cancer in men , and the positive association between diabetes , blood glucose , and colorectal cancer in women , at least in part , support the hypothesis that insulin may act as a tumour promoter in colorectal carcinogenesis . © 2001 Cancer Research Campaign BACKGROUND Several studies of male colon cancer have found positive associations with body size and composition . It is uncertain whether this relationship is due to non-adipose mass , adipose mass , distribution of adipose mass such as central adiposity , or all three . METHODS In a prospect i ve cohort study of men aged 27 - 75 at recruitment in 1990 - 1994 , body measurements were taken by interviewers .  Fat mass and fat-free mass ( FFM ) were estimated from bioelectrical impedance analysis . Waist circumference and waist-to-hips ratio ( WHR ) estimated central adiposity . Incident colon cancers were ascertained via the population cancer registry . Altogether , 16,556 men contributed 145,433 person-years and 153 colon cancers . RESULTS Rate ratios ( RRs ) comparing men in the fourth quartile with those in the first quartile were as follows : FFM 2.3 [ 95 % confidence interval ( CI ) 1.4 - 3.7 ] ; height 1.9 ( 95 % CI 1.1 - 3.1 ) ; waist circumference 2.1 ( 95 % CI 1.3 - 3.5 ) ; WHR 2.1 ( 95 % CI 1.3 - 3.4 ) ; fat mass 1.8 ( 95 % CI 1.1 - 3.0 ) ; and body mass index 1.7 ( 95 % CI 1.1 - 2.8 ) . When continuous measures of FFM and WHR were modeled together , the RR for FFM per 10 kg was 1.37 ( 95 % CI 1.04 - 1.80 ) and the RR for WHR per 0.1 unit was 1.65 ( 95 % CI 1.28 - 2.13 ) . After adjustment for FFM and WHR , the RRs for fat mass and body mass index were no longer statistically significant . CONCLUSION Male colon cancer appears to be related to body size and composition by two different pathways , via central adiposity and via non-adipose mass BACKGROUND Physical inactivity and high body mass index ( weight in kilograms divided by height in square meters ) have been linked to increased risk of  colon cancer .  However , none of the few prospect i ve studies in women has shown a statistically significant reduction in colon cancer incidence or mortality associated with increased leisure-time physical activity . PURPOSE In this prospect i ve study , we asked whether leisure-time physical activity , body mass index , or body fat distribution could significantly influence the risk of colon cancer in women . METHODS The participants in this study were enrolled in the Nurses ' Health Study , which began in 1976 . Every 2 years , the women provided additional personal information and information on medical risk factors and major medical events . The time spent per week at a variety of leisure-time physical activities was determined , and the time spent at each activity was multiplied by its typical energy expenditure , expressed in terms of metabolic equivalents or METs . The result ing values for each woman were added to yield an MET-hours-per-week score . Reported diagnoses of colon cancer were confirmed by review of hospital records and pathology reports . Relative risks and associated 95 % confidence intervals were calculated . RESULTS In multivariate analyses that included body mass index , women who expended more than 21 MET-hours per week on leisure-time physical activity had a relative risk of colon cancer of 0.54 ( 95 % confidence interval [ CI ] = 0.33 - 0.90 ) in comparison with women who expended less than 2 MET-hours per week . Women who had a body mass index greater than 29 kg/m2 had a relative risk of colon cancer of 1.45 ( 95 % CI = 1.02 - 2.07 ) in comparison with women who had a body mass index less than 21 kg/m2 . A tendency toward higher colon cancer risk was observed for increasing waist-to-hip ratio ( relative risk = 1.48 [ 95 % CI = 0.88 - 2.49 ] for comparison of the highest quintile ratio [ > 0.833 ] to the lowest [ < 0.728 ] ) . CONCLUSIONS AND IMPLICATION S The significant inverse association between  leisure-time physical activity  and incidence of colon cancer in women in this study is consistent with what has been found in men . Recommendations to increase physical activity and maintain lean body weight should receive greater emphasis as part of a feasible approach to the prevention of colon cancer Westernization or industrialization leads to an increase in rates of colon cancer , which is the second leading cause of malignant death in the United States [ 1 ] . Although the precise causes of colon cancer remain unclear , a diet high in red meat or animal fat and low in fruits and vegetables appears to increase the risk for this malignancy [ 2 , 3 ] . It is perhaps less well recognized that an inverse association between physical activity and risk for colon cancer has been seen in studies of occupational activity only [ 4 - 12 ] and of both job-related and recreational activity [ 13 - 23 ] . In addition , many studies have found an association between body mass and elevated risk for colon cancer in men ; this association is weaker in women [ 24 - 33 ] . The fact that the association is stronger in men suggests that the abdominal distribution of adiposity typical in men may be an important component of enhanced risk . More limited evidence suggests that height , which may be a proxy for a person 's net energy intake during childhood and adolescence , is related to a higher risk for colon cancer [ 33 - 35 ] . We examine the association between physical activity , obesity , and attained height in relation to risk for colon cancers and their precursory adenomas in a large cohort of male health professionals in the United States . Waist and hip circumferences were available for a subcohort of the study population . We address the hypotheses that physical inactivity , obesity , and height increase the risk for colon cancer and adenoma independently of each other and of diet , and that the abdominal pattern of obesity is an additional independent risk factor . Methods Study Population The Health Professionals Follow-up Study [ 36 ] was started in 1986 ; in that year , 51 529 male dentists , optometrists , osteopaths , podiatrists , pharmacists , and veterinarians in the United States between 40 and 75 years of age responded to a mailed question naire . They reported on their leisure-time physical activity ( described below ) ; current body weight ; weight at age 21 years ; height ; history of cancer and other medical conditions ; parental history of various diseases , including colorectal cancer ; and use of aspirin and other nonsteroidal anti-inflammatory medications . They also reported dietary and alcohol intake using a vali date d [ 37 , 38 ] , semi-quantitative food-frequency question naire . We mailed an optional question naire in 1987 to assess  waist and hip circumferences . In 1988 , 1990 , and 1992 , we up date d exposure information and ascertained newly diagnosed medical conditions and history of colonoscopy or sigmoidoscopy , including the indications for endoscopy : bleeding in stool , positive results from tests for occult fecal blood , abdominal pain , diarrhea or constipation , family history of colorectal cancer , routine screening without symptoms , or follow-up [ 39 ] . Most of the deaths in the cohort were reported by family members or by the postal system in response to the follow-up question naires . We also used the National Death Index to identify deaths among nonrespondents [ 40 ] . Assessment of Physical Activity The 1986 question naire included a section about mainly recreational or leisure-time physical activity . The reliability and validity of question naires design ed to assess physical activity have been investigated [ 41 - 43 ] . A question naire such as the one used in our cohort was evaluated in a cohort of U.S. nurses and was found to provide useful information [ 44 ] , and similar results were found during a similar validation study done within the Health Professionals cohort ( Chasan-Taber S. Personal communication ) . Participants reported the average time per week spent doing each of eight moderate and vigorous activities , choosing from among 10 possible responses that ranged from 0 minutes to 11 or more hours per week . The specific activities listed were walking or hiking outdoors ( including walking during golf ) ; jogging ( slower than 10 minutes/mile ) ; running ( 10 minutes/mile or faster ) ; bicycling ( including that done on a stationary machine ) ; lap swimming ; tennis , squash , or racquetball ; and calisthenics or rowing . In addition , each respondent reported the number of flights of stairs he climbed daily and his usual walking pace . The reported time spent at each activity per week was multiplied by its typical energy expenditure requirements expressed in metabolic equivalents ( METs ) [ 45 ] to yield a MET-hour score . One MET , which is the energy expended by sitting quietly , is equivalent to 3.5 mL of oxygen uptake per kilogram of body weight per minute for a 70-kg adult . For example , 1 hour per week of running contributed 10.2 MET-hours , 1 hour of tennis contributed 6 MET-hours , and 1 hour of walking at a moderate pace contributed 3.2 MET-hours . Body weight was excluded from the derivation of energy expenditure from physical activity to avoid confounding the expenditure variable by body weight . If more than one published intensity level was available for a given activity , the moderate or general MET value was chosen . An average MET value was assigned to the categories that listed more than one activity , such as rowing or calisthenics , and squash or racquetball . Assessment of Anthropometric Variables  Each man reported his current weight and height and his weight at age 21 years on the 1986 question naire . In 1987 , we mailed an optional question naire once to obtain additional exposure information , including body circumference measurements . We instructed each participant to measure ( to the nearest quarter inch ) his waist at the umbilicus and his hips at the largest circumference between the waist and thighs while st and ing and without measuring over bulky clothing [ 46 ] . We provided a tape measure and an illustration to help st and ardize the measurements . Sixty-five percent of the cohort responded . We used the Quetelet index ( kilograms/height in meters2 ) as a measure of total adiposity , waist-to-hip ratio to measure relative distribution of fat , and waist circumference to 
    Output:
    
agent
***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: We examined the relation between self-reported physical activity  and  large bowel cancer  in a prospect i ve cohort of men and women who participated in the Framingham Study .  Self- assessment s of physical activity were available from the fourth biennial examination on a total of 1906 men and 2308 women aged 30 to 62 yr in 1954 . The cohort was followed for up to 28 yr and yielded 152 cases ( 73 men , 79 women ) of large bowel cancer . Inactivity was associated with an increased risk of large bowel cancer among men but not among women . The relative risk estimates for large bowel cancer among men in the middle and lowest tertiles of a physical activity index ( compared with the highest tertile ) were 1.4 ( 95 % confidence intervals , 0.8 - 2.6 ) and 1.8 ( 1.0 - 3.2 ) , respectively . Among women the comparable estimates were 1.2 ( 0.7 - 2.1 ) and 1.1 ( 0.6 - 1.8 ) , respectively . These findings were unchanged after adjustment for body mass index , serum cholesterol , alcohol , and other potentially confounding variables . The narrow range of physical activity and the minimal heavy activity reported by women in this cohort may have limited our ability to detect an association between physical activity  and large bowel cancer among women A sedentary lifestyle , obesity , and a Westernized diet have been implicated in the aetiology of both colorectal cancer and non-insulin dependent diabetes mellitus , leading to the hypothesis that hyperinsulinaemia may promote colorectal cancer . We prospect ively examined the association between colorectal cancer risk and factors related to insulin resistance and hyperinsulinaemia , including BMI , physical activity , diabetes mellitus , and blood glucose , in a cohort of 75 219 Norwegian men and women . Information on incident cases of colorectal cancer was made available from the Norwegian Cancer Registry . ReportedPvalues are two-sided . During 12 years of follow up , 730 cases of colorectal cancer were registered . In men , but not in women , we found a negative association with leisure-time physical activity ( Pfor trend = 0.002 ) , with an age-adjusted RR for the highest versus the lowest category of activity of 0.54 ( 95 % CI = 0.37–0.79 ) . Women , but not men , with a history of diabetes were at increased risk of colorectal cancer ( age-adjusted RR = 1.55 ; 95 % CI = 1.04–2.31 ) , as were women with non-fasting blood glucose ≥8.0 mmol l–1(age-adjusted RR = 1.98 ; 95 % CI = 1.31–2.98 ) compared with glucose < 8.0 mmol l–1 . Overall , we found no association between BMI and risk of colorectal cancer . Additional adjustment including each of the main variables , marital status , and educational attainment did not material ly change the results . We conclude that the inverse association between leisure-time physical activity and colorectal cancer in men , and the positive association between diabetes , blood glucose , and colorectal cancer in women , at least in part , support the hypothesis that insulin may act as a tumour promoter in colorectal carcinogenesis . © 2001 Cancer Research Campaign BACKGROUND Several studies of male colon cancer have found positive associations with body size and composition . It is uncertain whether this relationship is due to non-adipose mass , adipose mass , distribution of adipose mass such as central adiposity , or all three . METHODS In a prospect i ve cohort study of men aged 27 - 75 at recruitment in 1990 - 1994 , body measurements were taken by interviewers .  Fat mass and fat-free mass ( FFM ) were estimated from bioelectrical impedance analysis . Waist circumference and waist-to-hips ratio ( WHR ) estimated central adiposity . Incident colon cancers were ascertained via the population cancer registry . Altogether , 16,556 men contributed 145,433 person-years and 153 colon cancers . RESULTS Rate ratios ( RRs ) comparing men in the fourth quartile with those in the first quartile were as follows : FFM 2.3 [ 95 % confidence interval ( CI ) 1.4 - 3.7 ] ; height 1.9 ( 95 % CI 1.1 - 3.1 ) ; waist circumference 2.1 ( 95 % CI 1.3 - 3.5 ) ; WHR 2.1 ( 95 % CI 1.3 - 3.4 ) ; fat mass 1.8 ( 95 % CI 1.1 - 3.0 ) ; and body mass index 1.7 ( 95 % CI 1.1 - 2.8 ) . When continuous measures of FFM and WHR were modeled together , the RR for FFM per 10 kg was 1.37 ( 95 % CI 1.04 - 1.80 ) and the RR for WHR per 0.1 unit was 1.65 ( 95 % CI 1.28 - 2.13 ) . After adjustment for FFM and WHR , the RRs for fat mass and body mass index were no longer statistically significant . CONCLUSION Male colon cancer appears to be related to body size and composition by two different pathways , via central adiposity and via non-adipose mass BACKGROUND Physical inactivity and high body mass index ( weight in kilograms divided by height in square meters ) have been linked to increased risk of  colon cancer .  However , none of the few prospect i ve studies in women has shown a statistically significant reduction in colon cancer incidence or mortality associated with increased leisure-time physical activity . PURPOSE In this prospect i ve study , we asked whether leisure-time physical activity , body mass index , or body fat distribution could significantly influence the risk of colon cancer in women . METHODS The participants in this study were enrolled in the Nurses ' Health Study , which began in 1976 . Every 2 years , the women provided additional personal information and information on medical risk factors and major medical events . The time spent per week at a variety of leisure-time physical activities was determined , and the time spent at each activity was multiplied by its typical energy expenditure , expressed in terms of metabolic equivalents or METs . The result ing values for each woman were added to yield an MET-hours-per-week score . Reported diagnoses of colon cancer were confirmed by review of hospital records and pathology reports . Relative risks and associated 95 % confidence intervals were calculated . RESULTS In multivariate analyses that included body mass index , women who expended more than 21 MET-hours per week on leisure-time physical activity had a relative risk of colon cancer of 0.54 ( 95 % confidence interval [ CI ] = 0.33 - 0.90 ) in comparison with women who expended less than 2 MET-hours per week . Women who had a body mass index greater than 29 kg/m2 had a relative risk of colon cancer of 1.45 ( 95 % CI = 1.02 - 2.07 ) in comparison with women who had a body mass index less than 21 kg/m2 . A tendency toward higher colon cancer risk was observed for increasing waist-to-hip ratio ( relative risk = 1.48 [ 95 % CI = 0.88 - 2.49 ] for comparison of the highest quintile ratio [ > 0.833 ] to the lowest [ < 0.728 ] ) . CONCLUSIONS AND IMPLICATION S The significant inverse association between  leisure-time physical activity  and incidence of colon cancer in women in this study is consistent with what has been found in men . Recommendations to increase physical activity and maintain lean body weight should receive greater emphasis as part of a feasible approach to the prevention of colon cancer Westernization or industrialization leads to an increase in rates of colon cancer , which is the second leading cause of malignant death in the United States [ 1 ] . Although the precise causes of colon cancer remain unclear , a diet high in red meat or animal fat and low in fruits and vegetables appears to increase the risk for this malignancy [ 2 , 3 ] . It is perhaps less well recognized that an inverse association between physical activity and risk for colon cancer has been seen in studies of occupational activity only [ 4 - 12 ] and of both job-related and recreational activity [ 13 - 23 ] . In addition , many studies have found an association between body mass and elevated risk for colon cancer in men ; this association is weaker in women [ 24 - 33 ] . The fact that the association is stronger in men suggests that the abdominal distribution of adiposity typical in men may be an important component of enhanced risk . More limited evidence suggests that height , which may be a proxy for a person 's net energy intake during childhood and adolescence , is related to a higher risk for colon cancer [ 33 - 35 ] . We examine the association between physical activity , obesity , and attained height in relation to risk for colon cancers and their precursory adenomas in a large cohort of male health professionals in the United States . Waist and hip circumferences were available for a subcohort of the study population . We address the hypotheses that physical inactivity , obesity , and height increase the risk for colon cancer and adenoma independently of each other and of diet , and that the abdominal pattern of obesity is an additional independent risk factor . Methods Study Population The Health Professionals Follow-up Study [ 36 ] was started in 1986 ; in that year , 51 529 male dentists , optometrists , osteopaths , podiatrists , pharmacists , and veterinarians in the United States between 40 and 75 years of age responded to a mailed question naire . They reported on their leisure-time physical activity ( described below ) ; current body weight ; weight at age 21 years ; height ; history of cancer and other medical conditions ; parental history of various diseases , including colorectal cancer ; and use of aspirin and other nonsteroidal anti-inflammatory medications . They also reported dietary and alcohol intake using a vali date d [ 37 , 38 ] , semi-quantitative food-frequency question naire . We mailed an optional question naire in 1987 to assess  waist and hip circumferences . In 1988 , 1990 , and 1992 , we up date d exposure information and ascertained newly diagnosed medical conditions and history of colonoscopy or sigmoidoscopy , including the indications for endoscopy : bleeding in stool , positive results from tests for occult fecal blood , abdominal pain , diarrhea or constipation , family history of colorectal cancer , routine screening without symptoms , or follow-up [ 39 ] . Most of the deaths in the cohort were reported by family members or by the postal system in response to the follow-up question naires . We also used the National Death Index to identify deaths among nonrespondents [ 40 ] . Assessment of Physical Activity The 1986 question naire included a section about mainly recreational or leisure-time physical activity . The reliability and validity of question naires design ed to assess physical activity have been investigated [ 41 - 43 ] . A question naire such as the one used in our cohort was evaluated in a cohort of U.S. nurses and was found to provide useful information [ 44 ] , and similar results were found during a similar validation study done within the Health Professionals cohort ( Chasan-Taber S. Personal communication ) . Participants reported the average time per week spent doing each of eight moderate and vigorous activities , choosing from among 10 possible responses that ranged from 0 minutes to 11 or more hours per week . The specific activities listed were walking or hiking outdoors ( including walking during golf ) ; jogging ( slower than 10 minutes/mile ) ; running ( 10 minutes/mile or faster ) ; bicycling ( including that done on a stationary machine ) ; lap swimming ; tennis , squash , or racquetball ; and calisthenics or rowing . In addition , each respondent reported the number of flights of stairs he climbed daily and his usual walking pace . The reported time spent at each activity per week was multiplied by its typical energy expenditure requirements expressed in metabolic equivalents ( METs ) [ 45 ] to yield a MET-hour score . One MET , which is the energy expended by sitting quietly , is equivalent to 3.5 mL of oxygen uptake per kilogram of body weight per minute for a 70-kg adult . For example , 1 hour per week of running contributed 10.2 MET-hours , 1 hour of tennis contributed 6 MET-hours , and 1 hour of walking at a moderate pace contributed 3.2 MET-hours . Body weight was excluded from the derivation of energy expenditure from physical activity to avoid confounding the expenditure variable by body weight . If more than one published intensity level was available for a given activity , the moderate or general MET value was chosen . An average MET value was assigned to the categories that listed more than one activity , such as rowing or calisthenics , and squash or racquetball . Assessment of Anthropometric Variables  Each man reported his current weight and height and his weight at age 21 years on the 1986 question naire . In 1987 , we mailed an optional question naire once to obtain additional exposure information , including body circumference measurements . We instructed each participant to measure ( to the nearest quarter inch ) his waist at the umbilicus and his hips at the largest circumference between the waist and thighs while st and ing and without measuring over bulky clothing [ 46 ] . We provided a tape measure and an illustration to help st and ardize the measurements . Sixty-five percent of the cohort responded . We used the Quetelet index ( kilograms/height in meters2 ) as a measure of total adiposity , waist-to-hip ratio to measure relative distribution of fat , and waist circumference to 
    Output:
    