title: Thyroid Status and Mortality Risk in Older Adults With Normal Thyrotropin: Sex Differences in the Milan Geriatrics 75+ Cohort Study.
abstract: BACKGROUND
  Thresholds of optimal thyroid status in old age are controversial. We investigated the longitudinal association between thyroid parameters and 10-year all-cause mortality risk in older outpatients with normal thyrotropin (TSH) and modification by sex and age.
  
  
  METHODS
  Baseline TSH, free thyroxine (fT4), and free triiodothyronine (fT3) were assessed in the Milan Geriatrics 75+ Cohort Study. 324 men and 609 women older than 75 years had normal TSH. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated for the associations between thyroid parameters and mortality risk using Cox regression. Sex-stratified analyses were adjusted for sociodemographic factors and comorbidities.
  
  
  RESULTS
  233 men and 367 women died during follow-up. After adjustment, each 1-mU/L higher TSH was associated with decreased mortality risk in men (HR 0.83, 95% CI 0.69-0.98), but not in women (HR 1.09, 95% CI 0.95-1.24) (p for sex interaction = .006). Each 1-ng/L higher fT4 was associated with increased mortality risk in men (HR 1.11, 95% CI 1.02-1.22), but not in women (HR 0.98, 95% CI 0.93-1.04) (p for sex interaction = .013). Each 1-pg/mL higher fT3 was associated with decreased mortality risk in women (HR 0.77, 95% CI 0.60-0.98), but not in men (HR 0.80, 95% CI 0.57-1.13). The inverse association between TSH and mortality was most pronounced in men older than 85 years.
  
  
  CONCLUSIONS
  Among older outpatients with normal TSH, higher TSH and lower fT4 were associated with decreased mortality risk in men but not in women. When assessing thyroid status, sex and age should be taken into account.
authors.affiliation: Department of Internal Medicine, Section of Gerontology and Geriatrics, Leiden University Medical Center, the Netherlands.|Department of Clinical Sciences and Community Health, University of Milan, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Ogliari
authors.affiliation: Department of Internal Medicine, Section of Gerontology and Geriatrics, Leiden University Medical Center, the Netherlands.|Department of Cardiology, Leiden University Medical Center, the Netherlands.
authors.forename: Roelof A J
authors.initials: RA
authors.lastname: Smit
authors.affiliation: Department of Internal Medicine, Section of Gerontology and Geriatrics, Leiden University Medical Center, the Netherlands.
authors.forename: Evie
authors.initials: E
authors.lastname: van der Spoel
authors.affiliation: Department of Clinical Sciences and Community Health, University of Milan, Italy.|Geriatric Unit and.
authors.forename: Daniela
authors.initials: D
authors.lastname: Mari
authors.affiliation: Clinical Chemistry and Microbiology Laboratory, Fondazione I.R.C.C.S. Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
authors.forename: Erminio
authors.initials: E
authors.lastname: Torresani
authors.affiliation: Clinical Chemistry and Microbiology Laboratory, Fondazione I.R.C.C.S. Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
authors.forename: Irene
authors.initials: I
authors.lastname: Felicetta
authors.affiliation: Geriatric Unit and.
authors.forename: Tiziano A
authors.initials: TA
authors.lastname: Lucchi
authors.affiliation: Geriatric Unit and.
authors.forename: Paolo D
authors.initials: PD
authors.lastname: Rossi
authors.affiliation: Department of Internal Medicine, Section of Gerontology and Geriatrics, Leiden University Medical Center, the Netherlands.
authors.forename: Diana
authors.initials: D
authors.lastname: van Heemst
authors.affiliation: Department of Internal Medicine, Section of Gerontology and Geriatrics, Leiden University Medical Center, the Netherlands.
authors.forename: Anton J M
authors.initials: AJ
authors.lastname: de Craen
authors.affiliation: Department of Internal Medicine, Section of Gerontology and Geriatrics, Leiden University Medical Center, the Netherlands.|Public Health and Center of Healthy Aging, University of Copenhagen, Denmark.
authors.forename: Rudi G J
authors.initials: RG
authors.lastname: Westendorp
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D009026:Mortality; D018570:Risk Assessment; D012737:Sex Factors; D013961:Thyroid Gland / Q000502:physiology; D013972:Thyrotropin / Q000097:blood*; D013974:Thyroxine / Q000097:blood*; D014284:Triiodothyronine / Q000097:blood*
chemical_list: D014284:Triiodothyronine; D013972:Thyrotropin; D013974:Thyroxine
keywords: Geriatric cohort; Longevity; Thyrotropin; Thyroxine