title: A Mendelian randomization study of testosterone and cognition in men.
abstract: Testosterone replacement for older men is increasingly common, with some observations suggesting a protective effect on cognitive function. We examined the association of endogenous testosterone with cognitive function among older men in a Mendelian randomization study using a separate-sample instrumental variable (SSIV) analysis estimator to minimize confounding and reverse causality. A genetic score predicting testosterone was developed in 289 young Chinese men from Hong Kong, based on selected testosterone-related single nucleotide polymorphisms (rs10046, rs1008805 and rs1256031). The association of genetically predicted testosterone with delayed 10-word recall score and Mini-Mental State Examination (MMSE) score was assessed at baseline and follow-up using generalized estimating equation among 4,212 older Chinese men from the Guangzhou Biobank Cohort Study. Predicted testosterone was not associated with delayed 10-word recall score (-0.02 per nmol/L testosterone, 95% confidence interval (CI) -0.06-0.02) or MMSE score (0.06, 95% CI -0.002-0.12). These estimates were similar after additional adjustment for age, education, smoking, use of alcohol, body mass index and the Framingham score. Our findings do not corroborate observed protective effects of testosterone on cognitive function among older men.
authors: School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, Hong Kong, China.
authors: Jie V
authors: JV
authors: Zhao
authors: School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, Hong Kong, China.
authors: Tai Hing
authors: TH
authors: Lam
authors: Guangzhou Number 12 Hospital, Guangzhou, China.
authors: Chaoqiang
authors: C
authors: Jiang
authors: Department of Psychiatry, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.
authors: Stacey S
authors: SS
authors: Cherny
authors: Guangzhou Number 12 Hospital, Guangzhou, China.
authors: Bin
authors: B
authors: Liu
authors: Department of Public Health and Epidemiology, University of Birmingham, Birmingham, United Kingdom.
authors: Kar Keung
authors: KK
authors: Cheng
authors: Guangzhou Number 12 Hospital, Guangzhou, China.
authors: Weisen
authors: W
authors: Zhang
authors: School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, Hong Kong, China.
authors: Gabriel M
authors: GM
authors: Leung
authors: School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, Hong Kong, China.|CUNY School of Public Health and Health Policy, New York, New York, United States of America.
authors: C Mary
authors: CM
authors: Schooling
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000428:Alcohol Drinking / Q000503:physiopathology; D044466:Asian People; D015992:Body Mass Index; D003071:Cognition / Q000502:physiology*; D000066492:Cognitive Aging; D060825:Cognitive Dysfunction / Q000097:blood* / Q000208:ethnology / Q000503:physiopathology; D015331:Cohort Studies; D004522:Educational Status; D006723:Hong Kong; D006801:Humans; D008297:Male; D011939:Mental Recall / Q000502:physiology; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide; D011897:Random Allocation; D012907:Smoking / Q000503:physiopathology; D013739:Testosterone / Q000097:blood*
chemical_list: D013739:Testosterone