Age, hormones, and cognitive functioning among middle-aged and elderly men: cross-sectional evidence from the Massachusetts Male Aging Study.
BACKGROUND
This study examines interrelationships among age, hormones, and cognition for middle-aged and elderly men, and tests whether hormones predict lower cognitive functioning and mediate the age-cognition relationship.


METHODS
We analyzed Time 2 data from the Massachusetts Male Aging Study, a population-based cohort study. Selection criteria included complete information on cognition and hormones (n = 981). Cognitive measures included working memory (Backward Digit Span test), speed/attention (Digit Symbol Substitution test), and spatial ability (Figural Relations test). Hormones included free testosterone, total testosterone, dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEAS), androstanediol glucuronide (3 alpha-A-diol-gluc), luteinizing hormone (LH), follicle-stimulating hormone (FSH), sex hormone-binding globulin (alternatively known as a "binding protein") (SHBG), prolactin (PRL), estrone (E1), and cortisol (CRT). Age was measured in years. Adjusted analyses added educational attainment, health conditions and behaviors, body mass index, and depression.


RESULTS
Older age was associated with lower cognitive functioning. In unadjusted models, logged free and total testosterone, DHEA, and DHEAS related to higher functioning in at least one cognitive domain; logged FSH, SHBG, and LH related to lower functioning in at least one cognitive domain; and logged E1, CRT, and PRL were not significant. In adjusted models, logged hormones did not relate to cognitive function except for logged E1 and CRT, which had negative effects. Logged hormones did not mediate the age-cognition relationship.


CONCLUSIONS
The direct effects of hormones on cognition are not significant when salient factors are considered. Further, hormones do not mediate the age-cognition relationship; it is necessary to look to other explanatory pathways.
Fonda
Stephanie J
SJ
Harvard Medical School, Joslin Diabetes Center, One Joslin Place, Boston, Massachusetts 02215, USA. stephanie.fonda@joslin.harvard.edu
Bertrand
Rosanna
R
O'Donnell
Amy
A
Longcope
Christopher
C
McKinlay
John B
JB
D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D000728:Androgens / Q000032:analysis; D001774:Blood Chemical Analysis; D003071:Cognition / Q000502:physiology; D003072:Cognition Disorders / Q000097:blood / Q000175:diagnosis*; D015331:Cohort Studies; D003687:Dehydroepiandrosterone / Q000032:analysis*; D015577:Geriatric Assessment; D012739:Gonadal Steroid Hormones / Q000032:analysis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011336:Probability; D012042:Registries; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D013739:Testosterone / Q000032:analysis
D000728:Androgens; D012739:Gonadal Steroid Hormones; D013739:Testosterone; D003687:Dehydroepiandrosterone