title: Associations between thyroid function and mortality: the influence of age.
abstract: OBJECTIVE
  The aim of this study was to investigate the influence of age on the association between thyroid function and mortality.
  
  
  METHODS
  The Nijmegen Biomedical Study is a population-based study, comprising 5816 randomly selected adults of all age groups without previously known thyroid disease.
  
  
  METHODS
  TSH, free thyroxine (FT4) and peroxidase antibodies were measured in 2002-2003. The number of deaths were established in 2012 (median follow-up time 9.4 years).
  
  
  RESULTS
  Subclinical thyrotoxicosis was associated with mortality in subjects aged <65 years (hazard ratio (HR) 2.5, 95% CI 1.1-5.7), but not in subjects aged >65 years. As for thyroid function within the normal range: in the 493 participants aged 80 years or older, an FT4 level in the high-normal range (18.5-22 pmol/l) was associated with a higher mortality in comparison with FT4 levels in the middle range (11.5-15.0 pmol/l): HR 1.7 (95% CI 1.0-2.9). In these elderly, TSH levels within the high-normal range (3.0-4.0 mIU/l) were also associated with a higher mortality in comparison with TSH levels within the middle range (1.0-2.0 mIU/l): HR 1.8 (95% CI 1.0-3.1).
  
  
  CONCLUSIONS
  The relationship between thyroid function and mortality differs according to age. This finding might (partially) explain the discrepant results of previous studies examining the relationship between thyroid function and mortality in different age groups.
authors.affiliation: Division of EndocrinologyDepartment of MedicineDepartment for Health EvidenceDepartment of Laboratory MedicineDepartment of UrologyRadboud University Medical Centre, PO Box 9101, 6500 HB Nijmegen, The NetherlandsSection of EndocrinologyDepartment of Internal Medicine, VU University Medical Center, Amsterdam, The Netherlands Annenienke.vandeVen@radboudumc.nl.
authors.forename: Annenienke C
authors.initials: AC
authors.lastname: van de Ven
authors.affiliation: Division of EndocrinologyDepartment of MedicineDepartment for Health EvidenceDepartment of Laboratory MedicineDepartment of UrologyRadboud University Medical Centre, PO Box 9101, 6500 HB Nijmegen, The NetherlandsSection of EndocrinologyDepartment of Internal Medicine, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Romana T
authors.initials: RT
authors.lastname: Netea-Maier
authors.affiliation: Division of EndocrinologyDepartment of MedicineDepartment for Health EvidenceDepartment of Laboratory MedicineDepartment of UrologyRadboud University Medical Centre, PO Box 9101, 6500 HB Nijmegen, The NetherlandsSection of EndocrinologyDepartment of Internal Medicine, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Femmie
authors.initials: F
authors.lastname: de Vegt
authors.affiliation: Division of EndocrinologyDepartment of MedicineDepartment for Health EvidenceDepartment of Laboratory MedicineDepartment of UrologyRadboud University Medical Centre, PO Box 9101, 6500 HB Nijmegen, The NetherlandsSection of EndocrinologyDepartment of Internal Medicine, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: H Alec
authors.initials: HA
authors.lastname: Ross
authors.affiliation: Division of EndocrinologyDepartment of MedicineDepartment for Health EvidenceDepartment of Laboratory MedicineDepartment of UrologyRadboud University Medical Centre, PO Box 9101, 6500 HB Nijmegen, The NetherlandsSection of EndocrinologyDepartment of Internal Medicine, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Fred C G J
authors.initials: FC
authors.lastname: Sweep
authors.affiliation: Division of EndocrinologyDepartment of MedicineDepartment for Health EvidenceDepartment of Laboratory MedicineDepartment of UrologyRadboud University Medical Centre, PO Box 9101, 6500 HB Nijmegen, The NetherlandsSection of EndocrinologyDepartment of Internal Medicine, VU University Medical Center, Amsterdam, The NetherlandsDivision of EndocrinologyDepartment of MedicineDepartment for Health EvidenceDepartment of Laboratory MedicineDepartment of UrologyRadboud University Medical Centre, PO Box 9101, 6500 HB Nijmegen, The NetherlandsSection of EndocrinologyDepartment of Internal Medicine, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Lambertus A
authors.initials: LA
authors.lastname: Kiemeney
authors.affiliation: Division of EndocrinologyDepartment of MedicineDepartment for Health EvidenceDepartment of Laboratory MedicineDepartment of UrologyRadboud University Medical Centre, PO Box 9101, 6500 HB Nijmegen, The NetherlandsSection of EndocrinologyDepartment of Internal Medicine, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Johannes W
authors.initials: JW
authors.lastname: Smit
authors.affiliation: Division of EndocrinologyDepartment of MedicineDepartment for Health EvidenceDepartment of Laboratory MedicineDepartment of UrologyRadboud University Medical Centre, PO Box 9101, 6500 HB Nijmegen, The NetherlandsSection of EndocrinologyDepartment of Internal Medicine, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Ad R
authors.initials: AR
authors.lastname: Hermus
authors.affiliation: Division of EndocrinologyDepartment of MedicineDepartment for Health EvidenceDepartment of Laboratory MedicineDepartment of UrologyRadboud University Medical Centre, PO Box 9101, 6500 HB Nijmegen, The NetherlandsSection of EndocrinologyDepartment of Internal Medicine, VU University Medical Center, Amsterdam, The NetherlandsDivision of EndocrinologyDepartment of MedicineDepartment for Health EvidenceDepartment of Laboratory MedicineDepartment of UrologyRadboud University Medical Centre, PO Box 9101, 6500 HB Nijmegen, The NetherlandsSection of EndocrinologyDepartment of Internal Medicine, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Martin
authors.initials: M
authors.lastname: den Heijer
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D053208:Kaplan-Meier Estimate; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D013960:Thyroid Function Tests; D013961:Thyroid Gland / Q000503:physiopathology*; D013971:Thyrotoxicosis / Q000401:mortality* / Q000503:physiopathology; D013972:Thyrotropin / Q000097:blood*; D013974:Thyroxine / Q000097:blood*
chemical_list: D013972:Thyrotropin; D013974:Thyroxine