Age of study population and year of publication modified the relationship between testosterone and CVD .
Results were largely confirmed by separate analyses of free- and bioavailable testosterone .
The systematic review displayed no association between endogenous testosterone and risk for CVD in middle-aged men .
In elderly men , testosterone may weakly protect against CVD .
Alternatively , low testosterone may indicate a poor general health
CONTEXT The literature provides no clear answer as to whether low endogenous testosterone increases risk of cardiovascular disease ( CVD ) in healthy men .
OBJECTIVE Our purpose was to estimate the predictive value of testosterone for CVD and to identify study features explaining conflicting results .
Low serum testosterone and mortality in male veterans.
BACKGROUND Low serum testosterone is a common condition in aging associated with decreased muscle mass and insulin resistance . This study evaluated whether low testosterone levels are a risk factor for mortality in male veterans . METHODS We used a clinical data base to identify men older than 40 years with repeated testosterone levels obtained from October 1 , 1994 , to December 31 , 1999 , and without diagnosed prostate cancer . A low testosterone level was a total testosterone level of less than 250 ng/dL ( < 8.7 nmol/L ) or a free testosterone level of less than 0.75 ng/dL ( < 0.03 nmol/L ) . Men were classified as having a low testosterone level ( 166 [ 19.3 % ] ) , an equivocal testosterone level ( equal number of low and normal levels ) ( 240 [ 28.0 % ] ) , or a normal testosterone level ( 452 [ 52.7 % ] ) . The risk for all-cause mortality was estimated using Cox proportional hazards regression models , adjusting for demographic and clinical covariates over a follow-up of up to 8 years . RESULTS Mortality in men with normal testosterone levels was 20.1 % ( 95 % confidence interval [ CI ] , 16.2%-24.1 % ) vs 24.6 % ( 95 % CI , 19.2%-30.0 % ) in men with equivocal testosterone levels and 34.9 % ( 95 % CI , 28.5%-41.4 % ) in men with low testosterone levels . After adjusting for age , medical morbidity , and other clinical covariates , low testosterone levels continued to be associated with increased mortality ( hazard ratio , 1.88 ; 95 % CI , 1.34 - 2.63 ; P<.001 ) while equivocal testosterone levels were not significantly different from normal testosterone levels ( hazard ratio , 1.38 ; 95 % CI , 0.99%-1.92 % ; P=.06 ) . In a sensitivity analysis , men who died within the first year ( 50 [ 5.8 % ] ) were excluded to minimize the effect of acute illness , and low testosterone levels continued to be associated with elevated mortality . CONCLUSIONS Low testosterone levels were associated with increased mortality in male veterans . Further prospect i ve studies are needed to examine the association between low testosterone levels and mortality
Age of study population and year of publication modified the relationship between testosterone and CVD .
Results were largely confirmed by separate analyses of free- and bioavailable testosterone .
The systematic review displayed no association between endogenous testosterone and risk for CVD in middle-aged men .
In elderly men , testosterone may weakly protect against CVD .
Alternatively , low testosterone may indicate a poor general health
CONTEXT The literature provides no clear answer as to whether low endogenous testosterone increases risk of cardiovascular disease ( CVD ) in healthy men .
OBJECTIVE Our purpose was to estimate the predictive value of testosterone for CVD and to identify study features explaining conflicting results .