title: Age-associated changes in hypothalamic-pituitary-testicular function in middle-aged and older men are modified by weight change and lifestyle factors: longitudinal results from the European Male Ageing Study.
abstract: OBJECTIVE
  Health and lifestyle factors are associated with variations in serum testosterone levels in ageing men. However, it remains unclear how age-related changes in testosterone may be attenuated by lifestyle modifications. The objective was to investigate the longitudinal relationships between changes in health and lifestyle factors with changes in hormones of the reproductive endocrine axis in ageing men.
  
  
  METHODS
  A longitudinal survey of 2736 community-dwelling men aged 40-79 years at baseline recruited from eight centres across Europe. Follow-up assessment occurred mean (±S.D.) 4.4±0.3 years later.
  
  
  RESULTS
  Paired testosterone results were available for 2395 men. Mean (±S.D.) annualised hormone changes were as follows: testosterone -0.1±0.95  nmol/l; free testosterone (FT) -3.83±16.8  pmol/l; sex hormone-binding globulin (SHBG) 0.56±2.5  nmol/l and LH 0.08±0.57  U/l. Weight loss was associated with a proportional increase, and weight gain a proportional decrease, in testosterone and SHBG. FT showed a curvilinear relationship to weight change; only those who gained or lost ≥15% of weight showed a significant change (in the same direction as testosterone). Smoking cessation was associated with a greater decline in testosterone than being a non-smoker, which was unrelated to weight change. Changes in number of comorbid conditions or physical activity were not associated with significant alterations in hypothalamic-pituitary-testicular (HPT) axis function.
  
  
  CONCLUSIONS
  Body weight and lifestyle factors influence HPT axis function in ageing. Weight loss was associated with a rise, and weight gain a fall, in testosterone, FT and SHBG. Weight management appears to be important in maintaining circulating testosterone in ageing men, and obesity-associated changes in HPT axis hormones are reversible following weight reduction.
authors: Andrology Research Unit, Institute of Human Development, Centre for Endocrinology and Diabetes, University of Manchester, Old St Mary's Building, Hathersage Road, Manchester M13 9WL, UK.
authors: E M
authors: EM
authors: Camacho
authors: I T
authors: IT
authors: Huhtaniemi
authors: T W
authors: TW
authors: O'Neill
authors: J D
authors: JD
authors: Finn
authors: S R
authors: SR
authors: Pye
authors: D M
authors: DM
authors: Lee
authors: A
authors: A
authors: Tajar
authors: G
authors: G
authors: Bartfai
authors: S
authors: S
authors: Boonen
authors: F F
authors: FF
authors: Casanueva
authors: G
authors: G
authors: Forti
authors: A
authors: A
authors: Giwercman
authors: T S
authors: TS
authors: Han
authors: K
authors: K
authors: Kula
authors: B
authors: B
authors: Keevil
authors: M E
authors: ME
authors: Lean
authors: N
authors: N
authors: Pendleton
authors: M
authors: M
authors: Punab
authors: D
authors: D
authors: Vanderschueren
authors: F C W
authors: FC
authors: Wu
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000097:blood / Q000502:physiology*; D015331:Cohort Studies; D005060:Europe; D005500:Follow-Up Studies; D006801:Humans; D007030:Hypothalamo-Hypophyseal System / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D008019:Life Style; D008137:Longitudinal Studies; D007986:Luteinizing Hormone / Q000097:blood / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012738:Sex Hormone-Binding Globulin / Q000032:analysis / Q000378:metabolism; D016540:Smoking Cessation; D013737:Testis / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D013739:Testosterone / Q000097:blood / Q000378:metabolism; D015430:Weight Gain; D015431:Weight Loss
chemical_list: D012738:Sex Hormone-Binding Globulin; D013739:Testosterone; D007986:Luteinizing Hormone