title: Thyroid status and 6-year mortality in elderly people living in a mildly iodine-deficient area: the aging in the Chianti Area Study.
abstract: OBJECTIVE
  To test the hypothesis that, in older adults, living in a mildly iodine-deficient area, thyroid dysfunction may be associated with mortality independent of potential confounders.
  
  
  METHODS
  Longitudinal.
  
  
  METHODS
  Community-based.
  
  
  METHODS
  Nine hundred fifty-one individuals aged 65 and older.
  
  
  METHODS
  Plasma thyrotropin, free thyroxine, and free triiodothyronine concentrations and demographic features were evaluated in participants of the Invecchiare in Chianti Study aged 65 and older. Participants were classified according to thyroid function test. Kaplan-Meier survival and Cox proportional hazards models adjusted for confounders were used in the analysis.
  
  
  RESULTS
  Eight hundred nineteen participants were euthyroid, 83 had subclinical hyperthyroidism (SHyper), and 29 had subclinical hypothyroidism (SHypo). Overt hypo- and hyperthyroidism were found in five and 15 subjects, respectively. During a median of 6 years of follow-up, 210 deaths occurred (22.1%), 98 (46.6%) of which were from cardiovascular causes. Kaplan-Meier analysis revealed higher overall mortality for SHyper (P = .04) than euthyroid subjects. After adjusting for multiple confounders, participants with SHyper (hazard ratio (HR) = 1.65, 95% confidence interval (CI) = 1.02-2.69) had significantly higher all-cause mortality than those with normal thyroid function. No significant association was found between SHyper and cardiovascular mortality. In euthyroid subjects, thyrotropin was found to be predictive of lower risk of all-cause mortality (HR = 0.76, 95% CI = 0.57-0.99).
  
  
  CONCLUSIONS
  SHyper is an independent risk factor for all-cause mortality in older adults. Low to normal circulating thyrotropin should be carefully monitored in elderly euthyroid individuals.
authors: Department Clinical and Experimental Medicine, Geriatric Endocrine Unit, University Hospital of Parma, Parma, Italy.
authors: Graziano
authors: G
authors: Ceresini
authors: Department Clinical and Experimental Medicine, Geriatric Endocrine Unit, University Hospital of Parma, Parma, Italy.
authors: Gian Paolo
authors: GP
authors: Ceda
authors: Geriatric Unit, University Hospital of Parma, Parma, Italy.
authors: Fulvio
authors: F
authors: Lauretani
authors: Department Clinical and Experimental Medicine, Geriatric Endocrine Unit, University Hospital of Parma, Parma, Italy.
authors: Marcello
authors: M
authors: Maggio
authors: Department Clinical and Experimental Medicine, Geriatric Endocrine Unit, University Hospital of Parma, Parma, Italy.
authors: Elisa
authors: E
authors: Usberti
authors: Department Clinical and Experimental Medicine, Geriatric Endocrine Unit, University Hospital of Parma, Parma, Italy.
authors: Michela
authors: M
authors: Marina
authors: Geriatric Unit, Azienda Sanitaria di Firenze Toscana, Florence, Italy.
authors: Stefania
authors: S
authors: Bandinelli
authors: Laboratory of Epidemiology, Demography, and Biometry, National Institute on Aging, Baltimore, Maryland.
authors: Jack M
authors: JM
authors: Guralnik
authors: Department Clinical and Experimental Medicine, Geriatric Endocrine Unit, University Hospital of Parma, Parma, Italy.
authors: Giorgio
authors: G
authors: Valenti
authors: National Institute on Aging, Baltimore, Maryland.
authors: Luigi
authors: L
authors: Ferrucci
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D002423:Cause of Death / Q000639:trends; D016001:Confidence Intervals; D005260:Female; D005500:Follow-Up Studies; D006043:Goiter, Endemic / Q000097:blood* / Q000401:mortality; D006801:Humans; D007455:Iodine / Q000097:blood* / Q000172:deficiency; D007558:Italy / Q000453:epidemiology; D053208:Kaplan-Meier Estimate; D008297:Male; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate / Q000639:trends; D013960:Thyroid Function Tests; D013961:Thyroid Gland / Q000378:metabolism*; D013997:Time Factors
chemical_list: D007455:Iodine
references: Eur J Endocrinol. 2010 Mar;162(3):587-9
references: 20064895
references: J Psychiatr Res. 1975 Nov;12(3):189-98
references: 1202204
references: Eur J Endocrinol. 2010 Mar;162(3):569-77
references: 19966035
references: Am J Med. 1990 Nov;89(5):602-8
references: 2239979
references: Eur J Endocrinol. 2008 Sep;159(3):329-41
references: 18511471
references: J Clin Endocrinol Metab. 2010 Apr;95(4):1734-40
references: 20150579
references: J Clin Endocrinol Metab. 2012 Mar;97(3):862-70
references: 22238396
references: J Clin Endocrinol Metab. 1999 Feb;84(2):561-6
references: 10022416
references: Ann Intern Med. 2008 Jun 3;148(11):832-45
references: 18490668
references: Eur J Endocrinol. 2008 Sep;159(3):343-5
references: 18647822
references: Endocrine. 2003 Jul;21(2):133-6
references: 12897375
references: Eur J Endocrinol. 2012 Sep;167(3):295-9
references: 22802423
references: Ann Intern Med. 2000 Feb 15;132(4):270-8
references: 10681281
references: Aging Male. 2011 Dec;14(4):213-9
references: 21875391
references: Endocr Rev. 1995 Dec;16(6):686-715
references: 8747831
references: Eur J Endocrinol. 2011 Oct;165(4):545-54
references: 21768248
references: J Endocrinol Invest. 1995 Jan;18(1):57-62
references: 7759786
references: Arch Intern Med. 2012 May 28;172(10):799-809
references: 22529182
references: Clin Endocrinol (Oxf). 2000 Dec;53(6):733-7
references: 11155096
references: JAMA. 2010 Sep 22;304(12):1365-74
references: 20858880
references: J Am Geriatr Soc. 2000 Dec;48(12):1618-25
references: 11129752
references: J Am Geriatr Soc. 2008 Apr;56(4):615-20
references: 18312314
references: Am J Psychiatry. 1980 Sep;137(9):1081-4
references: 7425160
references: Lancet. 2001 Sep 15;358(9285):861-5
references: 11567699
references: Med Sci Sports Exerc. 1993 Jan;25(1):71-80
references: 8292105
references: J Clin Endocrinol Metab. 2005 Dec;90(12):6403-9
references: 16174720
references: J Am Geriatr Soc. 2009 Jan;57(1):89-93
references: 19054181
references: N Engl J Med. 1994 Nov 10;331(19):1249-52
references: 7935681
references: J Clin Endocrinol Metab. 2012 Nov;97(11):3944-50
references: 22879629
references: Int J Epidemiol. 1997;26 Suppl 1:S152-60
references: 9126543
references: JAMA. 2006 Mar 1;295(9):1033-41
references: 16507804
references: Arch Intern Med. 2005 Nov 28;165(21):2460-6
references: 16314541
references: Am J Med. 2002 Oct 1;113(5):359-64
references: 12401529
references: Endocr Rev. 2008 Feb;29(1):76-131
references: 17991805
references: Thyroid. 2011 Aug;21(8):837-43
references: 21745107
references: Evid Based Med. 2011 Feb;16(1):31-2
references: 21169625
references: J Am Geriatr Soc. 2010 Sep;58(9):1825-7
references: 20863360
references: JAMA. 2004 Dec 1;292(21):2591-9
references: 15572717
references: Ann Intern Med. 2006 Oct 17;145(8):573-81
references: 17043339
references: J Clin Endocrinol Metab. 2005 Dec;90(12):6735-7
references: 16330808
references: J Clin Endocrinol Metab. 2004 Jul;89(7):3365-70
references: 15240616
references: Arch Intern Med. 2005 Nov 28;165(21):2467-72
references: 16314542