Testosterone, sex hormone-binding globulin, and frailty in older men.
OBJECTIVE
To determine whether testosterone (T) levels are associated with frailty or its components.


METHODS
Population-based cohort study conducted in three waves (T1: 1987-1989, T2: 1995-1997, T3: 2002-2004).


METHODS
Communities in the Boston, Massachusetts, area.


METHODS
Six hundred forty-six men aged 50 to 86 at T(3) with complete data on frailty components and hormone measurements.


METHODS
The frailty phenotype was defined as the presence of three or more of the following: weight loss, exhaustion, low physical activity, slowness, and weakness. Men were classified as frail (> or = 3 components), intermediate (1-2 components), and nonfrail (0 components). Whether total and free T or sex hormone-binding globulin (SHBG) levels were associated cross-sectionally with frailty and with degree of frailty was determined. Potential confounders such as age, chronic disease, lifestyle factors, diet, and physical activity were considered.


RESULTS
No association was observed between total or free T and the frailty phenotype after adjusting for confounders. Conversely, a significant association was observed between SHBG and frailty phenotype with an adjusted odds ratio of 1.25 (95% confidence interval=1.06-1.46) per 10-nM increase in SHBG levels. Associations between hormones and degree of frailty were similar to those for overall frailty. Of frailty components, grip strength and physical activity, but not exhaustion, slow walking, or weight loss, were associated with total T levels, whereas SHBG was related to weight loss, exhaustion, and physical activity.


CONCLUSIONS
Total and free T levels were not associated with frailty phenotype, but SHBG was. Furthermore, T and SHBG levels were associated with some, but not all, components of frailty. Therefore, T trials in older men should focus on men experiencing decreases in strength.
Mohr
Beth A
BA
New England Research Institutes, Watertown, Massachusetts 02472, USA.
Bhasin
Shalender
S
Kupelian
Varant
V
Araujo
Andre B
AB
O'Donnell
Amy B
AB
McKinlay
John B
JB
D000368:Aged; D000369:Aged, 80 and over; D016330:Frail Elderly / Q000706:statistics & numerical data; D015577:Geriatric Assessment / Q000379:methods*; D006801:Humans; D008019:Life Style; D008297:Male; D008404:Massachusetts / Q000453:epidemiology; D008875:Middle Aged; D011446:Prospective Studies; D012738:Sex Hormone-Binding Globulin / Q000378:metabolism*; D013739:Testosterone / Q000097:blood*; D015431:Weight Loss
D012738:Sex Hormone-Binding Globulin; D013739:Testosterone