***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: Flaws in the design , conduct , analysis , and reporting of r and omised trials can cause the effect of an intervention to be underestimated or overestimated . The Cochrane Collaboration ’s tool for assessing risk of bias aims to make the process clearer and more Objective : To evaluate the contribution to peak bone mass of exercise , smoking , and calcium intake in adolescents and young adults . Design : Prospect i ve cohort study with end point measurement ( bone mineral density ) after 11 years'20follow up for lifestyle . Setting : Five university hospital clinics . Subjects : 264 ( 153 females , 111 males ) subjects aged 9 to 18 years at the beginning of the follow up20 and 20 to 29 years at the time of measurement of bone mineral density . Main outcome measure : Bone mineral density of lumbar spine and femoral neck by  dual energy x ray absorptiometry ; measures of physical activity and 20smoking and estimates of calcium intake  repeated three times during follow up . Results : In the groups with the lowest and highest20levels of exercise the femoral bone mineral densities ( adjusted for age and weight ) were 0.918 and 0.988 g/cm2 for women ( P=0.015 ) , analysis of covariance ) and 0.943 and 1.042 g/cm2 for men ( P=0.005 ) , respectively ; at the lumbar spine the respective20values were 1.045 and 1.131 ( P=0.005 ) for men . In men the femoral bone mineral densities ( adjusted for age , weight , and exercise ) were 1.022 and 0.923 g/cm2 for the groups with the lowest and highest values of smoking index ( P=0.054 , analysis of covariance ) . In women the adjusted femoral bone mineral density increased by 4.7 % together with increasing calcium intake ( P=0.089 , analysis of covariance ) . In multiple regression analysis on bone mineral density of the femoral neck , weight , exercise , age , and smoking were independent predictors for men ; with weight , exercise , and age for women . These predictors together explained 38 % of the variance in bone mineral density in women and 46 % in men . At the lumbar spine , weight , smoking , and exercise were predictors for men ; and only weight for women . Conclusions : Regular exercise and not smoking is important in achieving maximal peak bone mass in adolescents and young adults Adequate nutrition is needed for the accrual of bone mass during the pre- and postpubertal growth periods . This study aim ed to examine the associations between dietary calcium , vitamin D ( calciferol ) , and milk intakes and 25-hydroxyvitamin D [ 25(OH)D ] status and bone mineral content ( BMC ) and bone mineral density ( BMD ) in Spanish adolescents , aged 12.5 - 17.5 years , participating in the Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study ( HELENA-CSS ) .  Bone mass was measured with dual-energy X-ray absorptiometry and diet via 2 nonconsecutive 24-h dietary recalls ( n=227 ; 48 % males ) . A r and om sub sample of 101 adolescents ( 46 % males ) had available measures of 25(OH)D. Multiple linear regression was applied . Significant adjusted associations were observed in males , among milk intakes and BMC and BMD . Also in males , whole-body , head , and right arm BMD were positively related to calcium intakes . In females , 25(OH)D was positively related among others to whole-body , subtotal , and left and right arm BMC and BMD . It could be speculated that diet is not a limiting factor of bone mass development in this group of healthy adolescents , and further research on the effect of other factors in addition to diet in a larger sample should be undertaken CONTEXT It is widely believed that fractures result ing from high trauma are not osteoporotic ; however , this assumption has not been studied prospect ively . OBJECTIVE To examine the association between bone mineral density ( BMD ) and high-trauma fracture and between high-trauma fracture and  subsequent fracture in older women and men . DESIGN , SETTING , AND PARTICIPANTS Two prospect i ve US cohort studies in community-dwelling adults 65 years or older from geographically diverse sites . The Study of Osteoporotic Fractures followed up 8022 women for 9.1 years ( 1988 - 2006 ) . The Osteoporotic Fractures in Men Study followed up 5995 men for 5.1 years ( 2000 - 2007 ) . MAIN OUTCOME MEASURES Hip and spine BMD were assessed by dual-energy x-ray absorptiometry . Incident nonspine fractures were confirmed by radiographic report . Fractures were classified , without knowledge of BMD , as high trauma ( due to motor vehicle crashes and falls from greater than st and ing height ) or as low trauma ( due to falls from st and ing height and less severe trauma ) . RESULTS Overall , 264 women and 94 men sustained an initial high-trauma fracture and 3211 women and 346 men sustained an initial low-trauma fracture . For women , each 1-SD reduction in total hip BMD was similarly associated with an increased risk of high-trauma fracture ( multivariate relative hazard [ RH ] , 1.45 ; 95 % confidence interval [ CI ] , 1.23 - 1.72 ) and low-trauma fracture ( RH , 1.49 ; 95 % CI , 1.42 - 1.57 ) . Results were consistent in men ( high-trauma fracture RH , 1.54 ; 95 % CI , 1.20 - 1.96 ; low-trauma fracture RH , 1.69 ; 95 % CI , 1.49 - 1.91 ) . Risk of subsequent fracture was 34 % ( 95 % CI , 7%-67 % ) greater among women with an initial high-trauma fracture and 31 % ( 95 % CI , 20%-43 % ) greater among women with an initial low-trauma fracture , compared with women having no high- or low-trauma fracture , respectively . Risk of subsequent fracture was not modeled for men . CONCLUSIONS Similar to low-trauma nonspine fractures , high-trauma nonspine fractures are associated with low BMD and increased risk of subsequent fracture  in older adults . High-trauma nonspine fractures should be included as outcomes in osteoporosis trials and observational studies The purpose of this study was to examine the relationship between  bone mineral density ( BMD )  and survival in both sexes and to compare BMD with other established risk factors such as blood pressure and cholesterol . A population -based prospect i ve study of 1924 individuals ( 850 men , 1074 women ) was performed in Göteborg from 1980 to 1983 .  Measurements of  BMD  were obtained in 1468 ( 76 % ) of the participants ( 653 men , 815 women ) . This selection of individuals generated 10,965 person years , and death was registered for 289 men and 197 women in the 7-year period ( 2661 days ) after bone mineral measurement . Later information on date of death was obtained from the official population register . This information covers 7 years from the time of survey of the last examined participant ( in Dec. 1983 ) . At the beginning of the study , BMD was measured in the calcaneus by dual photon absorptiometry ( DPA ) , and blood pressure , serum cholesterol , serum triglycerides , and body mass index ( BMI ) were also recorded . The study was coordinated with the National Register of Causes of Death and the National Cancer Register . A modified version of the Cox proportional hazards model was used to calculate and determine the age-adjusted relations between nontrauma mortality and BMD . When the various quartiles of BMD were compared prospect ively from 70 , 75 , and 79 years of age with survival figures during the 2661-day follow-up period , the first and the second quartiles with the lowest BMD at entry showed the lowest survival rate in both men ( P= 0.01 ) and women ( P= 0.01 ) . A decrease of 1 SD of BMD in a univariate analysis was associated with a 1.39-fold increase in mortality in both men ( 95 % confidence interval 1.25–1.56 , P < 0.001 ) and women ( 95 % confidence interval 1.22–1.58 , P < 0.001 ) , and a multivariate analysis demonstrated a relative risk of 1.23 ( 95 % confidence interval 1.10–1.41 , P < 0.001 ) in men and 1.19 ( 95 % confidence interval 1.02 to 1.39 , P= 0.019 ) in women . All relations were adjusted for sex , age , and follow-up . This study indicates that BMD is a predictor of survival , especially for subjects over 70 . Bone mineral density was found to be a better predictor of death than blood pressure and cholesterol . This study indicates that , after adjustments have been made for diseases , low bone mass is an independent predictor of mortality and might be a marker of general health or functional aging . Its measurement might therefore be a valuable tool in general health investigations 
    Output:
    
Young adult swimmers  present similar BMD values than CG and lower values than HIGH