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 older men.
CONTEXT Declining testosterone levels in elderly men are thought to underlie many of the symptoms and diseases of aging ; however , studies demonstrating associations of low testosterone with clinical outcomes are few . OBJECTIVE The objective of the study was to examine the association of endogenous testosterone levels with mortality in older community-dwelling men . DESIGN , SETTING , AND PARTICIPANTS This was a prospect i ve , population -based study of 794 men , aged 50 - 91 ( median 73.6 ) yr who had serum testosterone measurements at baseline ( 1984 - 1987 ) and were followed for mortality through July 2004 . MAIN OUTCOME MEASURE All-cause mortality by serum testosterone level  was measured . RESULTS During an average 11.8-yr follow-up , 538 deaths occurred . Men whose total testosterone levels were in the lowest quartile ( < 241 ng/dl ) were 40 % [ hazards ratio ( HR ) 1.40 ; 95 % confidence interval ( CI ) 1.14 - 1.71 ] more likely to die than those with higher levels , independent of age , adiposity , and lifestyle . Additional adjustment for health status markers , lipids , lipoproteins , blood pressure , glycemia , adipocytokines , and estradiol levels had minimal effect on results . The low testosterone-mortality association was also independent of the metabolic syndrome , diabetes , and prevalent cardiovascular disease but was attenuated by adjustment for IL-6 and C-reactive protein . In cause-specific analyses , low testosterone predicted increased risk of cardiovascular ( HR 1.38 ; 95 % CI 1.02 - 1.85 ) and respiratory disease ( HR 2.29 ; 95 % CI 1.25 - 4.20 ) mortality but was not significantly related to cancer death ( HR 1.34 ; 95 % CI 0.89 - 2.00 ) . Results were similar for bioavailable testosterone . CONCLUSIONS Testosterone insufficiency in older men is associated with increased risk of death over the following 20 yr , independent of multiple risk factors and several preexisting health conditions
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 .