@article {1373, title = {The natural history of subclinical hypothyroidism in the elderly: the cardiovascular health study.}, journal = {J Clin Endocrinol Metab}, volume = {97}, year = {2012}, month = {2012 Jun}, pages = {1962-9}, abstract = {

CONTEXT: Studies of long-term outcomes of subclinical hypothyroidism have assessed only baseline thyroid function, despite natural transitions to euthyroidism and overt hypothyroidism over time.

OBJECTIVE: We provide estimates of persistence, resolution, and progression of subclinical hypothyroidism over 4 yr, stratified by baseline TSH, anti-thyroid peroxidase antibody (TPOAb) status, age, and sex.

DESIGN, SETTING, AND PARTICIPANTS: Participants were 3996 U.S. individuals at least 65 yr old enrolled in the Cardiovascular Health Study. Subclinical hypothyroidism was detected at baseline in 459 individuals not taking thyroid medication.

MAIN OUTCOME MEASURE: Thyroid function was evaluated at 2 and 4 yr and initiation of thyroid medication annually. Results were stratified by baseline TSH, TPOAb status, age, and sex.

RESULTS: Persistence of subclinical hypothyroidism was 56\% at 2 and 4 yr. At 2 yr, resolution was more common with a TSH of 4.5-6.9 mU/liter (46 vs. 10\% with TSH 7-9.9 mU/liter and 7\% with TSH >=10 mU/liter; P < 0.001) and with TPOAb negativity (48 vs. 15\% for positive; P < 0.001). Higher TSH and TPOAb positivity were independently associated with lower likelihood of reversion to euthyroidism (P < 0.05). TSH of 10 mU/liter or higher was independently associated with progression to overt hypothyroidism (P < 0.05). Transitions between euthyroidism and subclinical hypothyroidism were common between 2 and 4 yr. Age and sex did not affect transitions.

CONCLUSIONS: Subclinical hypothyroidism persists for 4 yr in just over half of older individuals, with high rates of reversion to euthyroidism in individuals with lower TSH concentrations and TPOAb negativity. Future studies should examine the impact of transitions in thyroid status on clinical outcomes.

}, keywords = {Age Distribution, Aged, Aged, 80 and over, Autoantibodies, Cardiovascular Diseases, Cohort Studies, Disease Progression, Female, Humans, Hypothyroidism, Iodide Peroxidase, Logistic Models, Longitudinal Studies, Male, Prevalence, Risk Factors, Seroepidemiologic Studies, Severity of Illness Index, Sex Distribution, Thyrotropin}, issn = {1945-7197}, doi = {10.1210/jc.2011-3047}, author = {Somwaru, Lily L and Rariy, Chevon M and Arnold, Alice M and Cappola, Anne R} } @article {6553, title = {Thyroid antibody status, subclinical hypothyroidism, and the risk of coronary heart disease: an individual participant data analysis.}, journal = {J Clin Endocrinol Metab}, volume = {99}, year = {2014}, month = {2014 Sep}, pages = {3353-62}, abstract = {

CONTEXT: Subclinical hypothyroidism has been associated with increased risk of coronary heart disease (CHD), particularly with thyrotropin levels of 10.0 mIU/L or greater. The measurement of thyroid antibodies helps predict the progression to overt hypothyroidism, but it is unclear whether thyroid autoimmunity independently affects CHD risk.

OBJECTIVE: The objective of the study was to compare the CHD risk of subclinical hypothyroidism with and without thyroid peroxidase antibodies (TPOAbs).

DATA SOURCES AND STUDY SELECTION: A MEDLINE and EMBASE search from 1950 to 2011 was conducted for prospective cohorts, reporting baseline thyroid function, antibodies, and CHD outcomes.

DATA EXTRACTION: Individual data of 38 274 participants from six cohorts for CHD mortality followed up for 460 333 person-years and 33 394 participants from four cohorts for CHD events.

DATA SYNTHESIS: Among 38 274 adults (median age 55 y, 63\% women), 1691 (4.4\%) had subclinical hypothyroidism, of whom 775 (45.8\%) had positive TPOAbs. During follow-up, 1436 participants died of CHD and 3285 had CHD events. Compared with euthyroid individuals, age- and gender-adjusted risks of CHD mortality in subclinical hypothyroidism were similar among individuals with and without TPOAbs [hazard ratio (HR) 1.15, 95\% confidence interval (CI) 0.87-1.53 vs HR 1.26, CI 1.01-1.58, P for interaction = .62], as were risks of CHD events (HR 1.16, CI 0.87-1.56 vs HR 1.26, CI 1.02-1.56, P for interaction = .65). Risks of CHD mortality and events increased with higher thyrotropin, but within each stratum, risks did not differ by TPOAb status.

CONCLUSIONS: CHD risk associated with subclinical hypothyroidism did not differ by TPOAb status, suggesting that biomarkers of thyroid autoimmunity do not add independent prognostic information for CHD outcomes.

}, keywords = {Adult, Aged, Aged, 80 and over, Autoantibodies, Coronary Disease, Female, Humans, Hypothyroidism, Incidence, Male, Middle Aged, Prevalence, Prognosis, Risk Factors, Seroepidemiologic Studies, Severity of Illness Index, Young Adult}, issn = {1945-7197}, doi = {10.1210/jc.2014-1250}, author = {Collet, Tinh-Hai and Bauer, Douglas C and Cappola, Anne R and Asvold, Bj{\o}rn O and Weiler, Stefan and Vittinghoff, Eric and Gussekloo, Jacobijn and Bremner, Alexandra and den Elzen, Wendy P J and Maciel, Rui M B and Vanderpump, Mark P J and Cornuz, Jacques and D{\"o}rr, Marcus and Wallaschofski, Henri and Newman, Anne B and Sgarbi, Jos{\'e} A and Razvi, Salman and V{\"o}lzke, Henry and Walsh, John P and Aujesky, Drahomir and Rodondi, Nicolas} }