|
Low
Testosterone Levels and Mortality
Researchers writing in the
Annals of Internal Medicine examined "whether low testosterone
levels are a risk factor for mortality in male veterans."
Shores MM, Matsumoto
AM, Sloan KL, Kivlahan DR. Low serum testosterone and
mortality in male veterans.
Arch Intern Med. 2006 Aug 14-28;166(15):1660-5.
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 database 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
prospective studies are needed to examine the
association between low testosterone levels and
mortality. |
