@article {6277, title = {Testosterone and dihydrotestosterone and incident ischaemic stroke in men in the Cardiovascular Health Study.}, journal = {Clin Endocrinol (Oxf)}, volume = {81}, year = {2014}, month = {2014 Nov}, pages = {746-53}, abstract = {

OBJECTIVE: Ischaemic stroke is a major cause of morbidity and mortality in elderly men. Our main objective was to examine whether testosterone (T) or dihydrotestosterone (DHT) was associated with incident ischaemic stroke in elderly men.

DESIGN: Cohort study.

PARTICIPANTS: Elderly men in the Cardiovascular Health Study who had no history of stroke, heart disease or prostate cancer as of 1994 and were followed until December 2010.

MEASUREMENTS: Adjudicated ischaemic stroke.

RESULTS: Among 1032 men (mean age 76, range 66-97), followed for a median of 10~years, 114 had an incident ischaemic stroke. Total T and free T were not significantly associated with stroke risk, while DHT had a nonlinear association with incident stroke (P~=~0{\textperiodcentered}006) in analyses adjusted for stroke risk factors. The lowest risk of stroke was at DHT levels of 50-75~ng/dl, with greater risk of stroke at DHT levels above 75~ng/dl or below 50~ng/dl. Results were unchanged when SHBG was added to the model. Calculated free DHT had an inverse linear association with incident ischaemic stroke with HR 0{\textperiodcentered}77 (95\% CI, 0{\textperiodcentered}61, 0{\textperiodcentered}98) per standard deviation in analyses adjusted for stroke risk factors.

CONCLUSIONS: Dihydrotestosterone had a nonlinear association with stroke risk in which there was an optimal DHT level associated with the lowest stroke risk. Further studies are needed to confirm these results and to clarify whether there is an optimal androgen range associated with the least risk of adverse outcomes in elderly men.

}, keywords = {Aged, Aged, 80 and over, Brain Ischemia, Cardiovascular Physiological Phenomena, Dihydrotestosterone, Health, Humans, Incidence, Longitudinal Studies, Male, Stroke, Testosterone}, issn = {1365-2265}, doi = {10.1111/cen.12452}, author = {Shores, Molly M and Arnold, Alice M and Biggs, Mary L and Longstreth, W T and Smith, Nicholas L and Kizer, Jorge R and Cappola, Anne R and Hirsch, Calvin H and Marck, Brett T and Matsumoto, Alvin M} } @article {6278, title = {Testosterone, dihydrotestosterone, and incident cardiovascular disease and mortality in the cardiovascular health study.}, journal = {J Clin Endocrinol Metab}, volume = {99}, year = {2014}, month = {2014 Jun}, pages = {2061-8}, abstract = {

CONTEXT: Low testosterone (T) is associated with prevalent cardiovascular disease (CVD) and mortality. DHT, a more potent androgen, may also be associated with CVD and mortality, but few studies have examined this.

OBJECTIVE: The study objective was to examine whether T and DHT are risk factors for incident CVD and mortality.

DESIGN: In a longitudinal cohort study, we evaluated whether total T, calculated free T (cFT), DHT, and calculated free DHT were associated with incident CVD and mortality in men in the Cardiovascular Health Study (mean age 76, range 66-97 years) who were free of CVD at the time of blood collection.

MAIN OUTCOME: The main outcomes were incident CVD and all-cause mortality.

RESULTS: Among 1032 men followed for a median of 9 years, 436 incident CVD events and 777 deaths occurred. In models adjusted for cardiovascular risk factors, total T and cFT were not associated with incident CVD or all-cause mortality, whereas DHT and calculated free DHT had curvilinear associations with incident CVD (P < .002 and P = .04, respectively) and all-cause mortality (P < .001 for both).

CONCLUSIONS: In a cohort of elderly men, DHT and calculated free DHT were associated with incident CVD and all-cause mortality. Further studies are needed to confirm these results and to clarify the underlying physiologic mechanisms.

}, keywords = {Aged, Aged, 80 and over, Cardiovascular Diseases, Cause of Death, Dihydrotestosterone, Humans, Incidence, Longitudinal Studies, Male, Mortality, Residence Characteristics, Risk Factors, Testosterone}, issn = {1945-7197}, doi = {10.1210/jc.2013-3576}, author = {Shores, Molly M and Biggs, Mary L and Arnold, Alice M and Smith, Nicholas L and Longstreth, W T and Kizer, Jorge R and Hirsch, Calvin H and Cappola, Anne R and Matsumoto, Alvin M} } @article {7249, title = {Testosterone, Dihydrotestosterone, Sex Hormone Binding Globulin and Incident Diabetes among Older Men: the Cardiovascular Health Study.}, journal = {J Clin Endocrinol Metab}, year = {2016}, month = {2016 Oct 12}, pages = {jc20162623}, abstract = {

CONTEXT: Although sex hormone binding globulin (SHBG) and testosterone (T) have been inversely associated with risk of diabetes, few studies have examined dihydrotestosterone (DHT), a more potent androgen than T, or older adults, whose glycemic pathophysiology differs from younger adults.

OBJECTIVE: To determine the associations of SHBG, T, and DHT with insulin resistance and incident diabetes in older adult men.

DESIGN: In a prospective cohort study, we evaluated baseline levels of SHBG, T, and DHT using liquid chromatography-tandem mass spectrometry among 852 men in the Cardiovascular Health Study free of diabetes and cardiovascular disease in 1994.

MAIN OUTCOME: Insulin resistance estimated by HOMA-IR and insulin sensitivity estimated by the Gutt index in 1996, and incident diabetes (n=112) ascertained over a mean follow-up of 9.8 years.

RESULTS: In linear regression models adjusted for demographics, alcohol consumption, current smoking, body-mass index, and other androgens, SHBG (HOMA-IR 0.30 units lower per doubling; 95\% confidence interval [CI], 0.08-0.52; p=0.01) and total DHT (HOMA-IR 0.18 units lower per doubling; 95\% CI 0.06-0.30; p=0.01), but not free T (p=0.33) were inversely associated with insulin resistance. In corresponding Cox proportional hazards models, total DHT was again inversely associated with risk of diabetes (adjusted hazard ratio per doubling 0.69; 95\% CI, 0.52-0.92; p=0.01), but SHBG (hazard ratio 1.09; 95\% CI, 0.74-1.59; p=0.66) and free T (hazard ratio 1.15; 95\% CI, 0.92-1.43; p=0.23) were not.

CONCLUSIONS: Among older men, higher levels of DHT are inversely associated with insulin resistance and risk of diabetes over the ensuing 10 years, while levels of T are not. Future studies are still needed to clarify the role of SHBG in risk of diabetes in this population.

}, issn = {1945-7197}, doi = {10.1210/jc.2016-2623}, author = {Joyce, Katherine E and Biggs, Mary L and Djouss{\'e}, Luc and Ix, Joachim H and Kizer, Jorge R and Siscovick, David S and Shores, Molly M and Matsumoto, Alvin M and Mukamal, Kenneth J} } @article {7670, title = {Serum Androgens and Risk of Atrial Fibrillation in Older Men: The Cardiovascular Health Study.}, journal = {Clin Cardiol}, year = {2018}, month = {2018 Apr 19}, abstract = {

BACKGROUND: Decline in serum androgens is common among older men and has been associated with cardiovascular disease, although its role in risk of atrial fibrillation (AF) has not been well defined.

HYPOTHESIS: Low serum androgens are associated with an increased risk of AF.

METHODS: We examined the prospective associations between testosterone, its more active metabolite dihydrotestosterone (DHT), and sex-hormone binding globulin (SHBG) with risk of AF among 1019 otherwise healthy men of average age 76.3{\textpm}4.9 years in the Cardiovascular Health Study.

RESULTS: After median follow-up of 9.5 years, 304 (30\%) men developed AF. We detected a nonlinear association with risk of incident AF in both free and total DHT, in which subjects with the lowest levels had a higher risk of incident AF. After adjustment for demographics, clinical risk factors, left atrial diameter, and serum NT-proBNP levels, men with free DHT less than 0.16 ng/dL were at increased risk compared with men with higher levels (HR 1.48, CI 1.01-2.17, p<0.05). Sensitivity analyses confirmed that the increased risk was not cutpoint-specific, with a significant association noted up to cutpoints less than ~0.2 ng/dL. We also detected a complex nonlinear association between SHBG and incident AF, in which subjects in the middle quintile (52.9 - 65.3 nmol/L) had increased risk.

CONCLUSION: Among older men, low free DHT is associated with an increased risk of incident atrial fibrillation. Further studies are needed to explore mechanisms for this association.

}, issn = {1932-8737}, doi = {10.1002/clc.22965}, author = {Rosenberg, Michael A and Shores, Molly M and Matsumoto, Alvin M and B{\r u}zkov{\'a}, Petra and Lange, Leslie A and Kronmal, Richard A and Heckbert, Susan R and Mukamal, Kenneth J} } @article {9487, title = {Factors Associated With Circulating Sex Hormones in Men : Individual Participant Data Meta-analyses.}, journal = {Ann Intern Med}, year = {2023}, month = {2023 Aug 29}, abstract = {

BACKGROUND: Various factors modulate circulating testosterone in men, affecting interpretation of testosterone measurements.

PURPOSE: To clarify factors associated with variations in sex hormone concentrations.

DATA SOURCES: Systematic literature searches (to July 2019).

STUDY SELECTION: Prospective cohort studies of community-dwelling men with total testosterone measured using mass spectrometry.

DATA EXTRACTION: Individual participant data (IPD) (9 studies; ~= 21 074) and aggregate data (2 studies; ~= 4075). Sociodemographic, lifestyle, and health factors and concentrations of total testosterone, sex hormone-binding globulin (SHBG), luteinizing hormone (LH), dihydrotestosterone, and estradiol were extracted.

DATA SYNTHESIS: Two-stage random-effects IPD meta-analyses found a nonlinear association of testosterone with age, with negligible change among men aged 17 to 70 years (change per SD increase about the midpoint, -0.27 nmol/L [-7.8 ng/dL] [CI, -0.71 to 0.18 nmol/L {-20.5 to 5.2 ng/dL}]) and decreasing testosterone levels with age for men older than 70 years (-1.55 nmol/L [-44.7 ng/dL] [CI, -2.05 to -1.06 nmol/L {-59.1 to -30.6 ng/dL}]). Testosterone was inversely associated with body mass index (BMI) (change per SD increase, -2.42 nmol/L [-69.7 ng/dL] [CI, -2.70 to -2.13 nmol/L {-77.8 to -61.4 ng/dL}]). Testosterone concentrations were lower for men who were married (mean difference, -0.57 nmol/L [-16.4 ng/dL] [CI, -0.89 to -0.26 nmol/L {-25.6 to -7.5 ng/dL}]); undertook at most 75 minutes of vigorous physical activity per week (-0.51 nmol/L [-14.7 ng/dL] [CI, -0.90 to -0.13 nmol/L {-25.9 to -3.7 ng/dL}]); were former smokers (-0.34 nmol/L [-9.8 ng/dL] [CI, -0.55 to -0.12 nmol/L {-15.9 to -3.5 ng/dL}]); or had hypertension (-0.53 nmol/L [-15.3 ng/dL] [CI, -0.82 to -0.24 nmol/L {-23.6 to -6.9 ng/dL}]), cardiovascular disease (-0.35 nmol/L [-10.1 ng/dL] [CI, -0.55 to -0.15 nmol/L {-15.9 to -4.3 ng/dL}]), cancer (-1.39 nmol/L [-40.1 ng/dL] [CI, -1.79 to -0.99 nmol/L {-51.6 to -28.5 ng/dL}]), or diabetes (-1.43 nmol/L [-41.2 ng/dL] [CI, -1.65 to -1.22 nmol/L {-47.6 to -35.2 ng/dL}]). Sex hormone-binding globulin was directly associated with age and inversely associated with BMI. Luteinizing hormone was directly associated with age in men older than 70 years.

LIMITATION: Cross-sectional analysis, heterogeneity between studies and in timing of blood sampling, and imputation for missing data.

CONCLUSION: Multiple factors are associated with variation in male testosterone, SHBG, and LH concentrations. Reduced testosterone and increased LH concentrations may indicate impaired testicular function after age 70 years. Interpretation of individual testosterone measurements should account particularly for age older than 70 years, obesity, diabetes, and cancer.

PRIMARY FUNDING SOURCE: Medical Research Future Fund, Government of Western Australia, and Lawley Pharmaceuticals. (PROSPERO: CRD42019139668).

}, issn = {1539-3704}, doi = {10.7326/M23-0342}, author = {Marriott, Ross J and Murray, Kevin and Adams, Robert J and Antonio, Leen and Ballantyne, Christie M and Bauer, Douglas C and Bhasin, Shalender and Biggs, Mary L and Cawthon, Peggy M and Couper, David J and Dobs, Adrian S and Flicker, Leon and Handelsman, David J and Hankey, Graeme J and Hannemann, Anke and Haring, Robin and Hsu, Benjumin and Karlsson, Magnus and Martin, Sean A and Matsumoto, Alvin M and Mellstr{\"o}m, Dan and Ohlsson, Claes and O{\textquoteright}Neill, Terence W and Orwoll, Eric S and Quartagno, Matteo and Shores, Molly M and Steveling, Antje and Tivesten, {\r A}sa and Travison, Thomas G and Vanderschueren, Dirk and Wittert, Gary A and Wu, Frederick C W and Yeap, Bu B} } @article {9804, title = {Sociodemographic, lifestyle, and medical factors associated with calculated free testosterone concentrations in men: individual participant data meta-analyses.}, journal = {Eur J Endocrinol}, volume = {191}, year = {2024}, month = {2024 Oct 29}, pages = {523-534}, abstract = {

OBJECTIVE: Sociodemographic, lifestyle, and medical variables influence total testosterone (T) and sex hormone-binding globulin (SHBG) concentrations. The relationship between these factors and "free" T remains unclear. We examined 21 sociodemographic, lifestyle, and medical predictors influencing calculated free T (cFT) in community-dwelling men across ages.

DESIGN: This is a cross-sectional analysis in 20 631 participants in the Androgens in Men Study.

METHODS: Individual participant data (IPD) were provided by 9 cohorts. Total T was determined using mass spectrometry, SHBG using immunoassays, and cFT using the Vermeulen formula. Associations were analyzed using 2-stage random effects IPD meta-analyses.

RESULTS: Cohort median ages ranged from 40 to 76 years and median cFT concentrations from 174.3 to 422.8 pmol/L. In men aged 17-99 years, there was a linear inverse association of cFT with age (-57.2 pmol/L [95\% confidence interval, -69.4, -44.9] per 1 SD increase in age). Calculated free T increased with increasing baseline body mass index (BMI) among men with BMI < 23.6 kg/m2, but decreased among men with BMI > 23.6 kg/m2 (-24.7 pmol/L [-29.1, -20.3] per 1 SD increase in the 25.4-29.6 kg/m2 BMI range). Calculated free T was lower in younger men, who were married or in a de facto relationship (-18.4 pmol/L [-27.6, -9.3]) and in men who formerly smoked (-5.7 pmol/L [-8.9, -2.6]), were in poor general health (-14.0 pmol/L [-20.1, -7.8]), and had diabetes (-19.6 pmol/L [-23.0, -16.3]), cardiovascular disease (-5.8 pmol/L [-8.3, -3.2]), or cancer (-19.2 pmol/L [-24.4, -14.1]).

CONCLUSIONS: Calculated free T was most prominently associated with age and BMI. The linear, inverse association with age, nonlinear association with BMI, and presence of diabetes, cancer, and sociodemographic factors should be considered when interpreting cFT values.

}, keywords = {Adolescent, Adult, Age Factors, Aged, Aged, 80 and over, Body Mass Index, Cohort Studies, Cross-Sectional Studies, Humans, Life Style, Male, Middle Aged, Sex Hormone-Binding Globulin, Sociodemographic Factors, Socioeconomic Factors, Testosterone, Young Adult}, issn = {1479-683X}, doi = {10.1093/ejendo/lvae133}, author = {Narinx, Nick and Marriott, Ross J and Murray, Kevin and Adams, Robert J and Ballantyne, Christie M and Bauer, Douglas C and Bhasin, Shalender and Biggs, Mary L and Cawthon, Peggy M and Couper, David J and Dobs, Adrian S and Flicker, Leon and Hankey, Graeme J and Hannemann, Anke and Wilkening, Robin and Martin, Sean A and Matsumoto, Alvin M and Ohlsson, Claes and O{\textquoteright}Neill, Terence W and Orwoll, Eric S and Shores, Molly M and Steveling, Antje and Travison, Thomas G and Wittert, Gary A and Wu, Frederick C W and Antonio, Leen and Vanderschueren, Dirk and Yeap, Bu B} }