Article

Spontaneous subclinical hypothyroidism in patients older than 55 years: An analysis of natural course and risk factors for the development of overt thyroid failure

Hospital General De Segovia, Segovia, Castille and León, Spain
Journal of Clinical Endocrinology &amp Metabolism (Impact Factor: 6.31). 11/2004; 89(10):4890-7. DOI: 10.1210/jc.2003-032061
Source: PubMed

ABSTRACT We aimed to analyze the natural course of subclinical hypothyroidism, quantify the incidence rate of overt hypothyroidism, and evaluate the risk factors for the development of definitive thyroid failure in elderly patients. One hundred seven patients (93 women and 14 men) over age 55 yr with subclinical hypothyroidism and no previous history of thyroid disease were prospectively studied. Subjects were followed up for 6-72 months (mean, 31.7 months) with repeated determinations of TSH and free T(4). Twenty-eight patients (26.8%) developed overt hypothyroidism, and 40 (37.4%) showed normalization of their TSH values. The incidence rate of overt hypothyroidism was 9.91 cases per 100 patient-years in the whole population, and 1.76, 19.67, and 73.47 cases per 100 patient-years in subjects with initial TSH values between 5.0-9.9, 10.0-14.9, and 15.0-19.9 mU/liter, respectively. Kaplan-Meier analysis showed that the development of definitive thyroid hypofunction was significantly related to the presence of symptoms of hypothyroidism, goiter, positive thyroid antibodies (P < 0.05), and mainly low normal free T(4) (P < 0.01) and high TSH (P < 0.0001) concentrations at baseline. A stepwise multivariate Cox regression analysis showed that the only significant factor for progression to overt hypothyroidism was serum TSH concentration (P < 0.0001). In conclusion, TSH concentration is the most powerful predictor for the outcome of spontaneous subclinical hypothyroidism in patients over age 55 yr. Subjects with mildly elevated TSH have a low incidence rate of overt hypothyroidism. We recommend follow-up with clinical and biochemical monitoring in these patients.

Download full-text

Full-text

Available from: Pedro Iglesias, Dec 21, 2013
0 Followers
 · 
125 Views
  • Source
    • "Simonsick et al. documented that individuals aged between 70 and 79 years and with mild TSH elevation (4.5-7 mIU/L) had a faster usual and rapid gait speed and better cardiorespiratory fitness than euthyroid controls [134]. All these data together with the observation of a shift toward higher levels in the distribution of TSH with age [135] may suggest the increase of TSH as a possible adaptive response to several changes in TH metabolism with increasing age. Few reports analyzed specifically the QOL in elderly subjects [89] [94] without finding any association. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Subclinical hypothyroidism (sHT) is a common condition in the general population, the prevalence increases with age, especially in women. An association between sHT and increased coronary heart disease (CHD) and heart failure (HF) risk and mortality has been described. However, this association is far to be established in older people (>65 years), especially in the oldest old (>85 years). Individuals with sHT may experience symptoms that resemble those observed in the overt form of the disease, leading to an impaired quality of life (QoL). Although very old people are frequently frail and potentially more susceptible to the effects of a disease, few studies were designed to assess the effect of sHT on QoL in this subset of population. Interestingly, the serum TSH concentration curve of general population has a skewed distribution with a "tail" toward higher values, which is amplified with aging. Thus, the diagnosis of sHT and the interpretation of its potential effects on CV function and QoL in older people may be a challenge for the clinician. Giving these premises, we reviewed the English scientific literature available on National Library of Medicine (www.pubmed.com) since 1980 regarding hypothyroidism, sHT, elderly, cardiovascular risk, CHD or HF events and mortality, health-related QoL, and LT4 therapy. Consistent results among large prospective cohort studies suggest an age-independent relationship between sHT and HF progression, while an impact of sHT on CHD events and mortality is essentially reported in young adults (aged below 65-70 years) with long-lasting disease. Scanty data are available on QoL of older people with sHT (>65 years) and, generally, no significant alterations are described.
    Frontiers in Endocrinology 10/2014; 5:153. DOI:10.3389/fendo.2014.00153
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: With an increase in age, marked changes in thyroid hormone production, metabolism, and action occur. This results in an increased prevalence of (subclinical) thyroid disease in the elderly. In general, subclinical thyroid disease is associated with an increased risk of overt thyroid dysfunction and with different negative clinical parameters. In the elderly, however, it is unclear whether these changes represent physiologic changes in thyroid hormone levels with advancing age or whether they represent true (subclinical) thyroid disease. This review describes the changes in thyroid hormone levels with aging and the mechanisms behind these changes, and also discusses whether subclinical thyroid disease should be treated in the elderly.
    Hormones (Athens, Greece) 01/2008; 7(1):28-35. DOI:10.14310/horm.2002.1111035 · 1.24 Impact Factor
  • Source
Show more