Table 7.

Incidence of cardiovascular events, death, and other outcomes in people with subclinical hypothyroidism in cohort studies

Reference	Place	Sample/follow-up	Age of participants	Results	Observations
van den Beld et al3	US	403 independent and ambulatory living men; follow-up of 4 years	73–94 years	Low FT4 was associated with a better 4-year survival	These results may reflect an adaptive mechanism to prevent excessive catabolism
Rodondi et al78	US	2730 men and women; follow-up of 4 years	70–79 years	In multivariate analysis using euthyroid subjects as the reference category, relative risk of congestive heart failure in subjects with TSH of 7.0–9.9 mIU/L was of 2.58 (95% CI, 1.19–5.60); and TSH ≥10.0 mIU/L, 3.26 (95% CI, 1.37–7.77)	Subclinical hypothyroidism was not associated with increased risk for coronary heart disease, stroke, peripheral artery disease, or cardiovascular or total mortality
Cappola et al20	US	3233 community-dwelling individuals; follow-up of 2 years	65 years or older	There was no difference in the cardiovascular or mortality outcomes in subjects with overt or subclinical hypothyroidism compared to euthyroid subjects	Individuals with subclinical hypothyroidism had an adjusted hazard ratio of 1.07 (95% CI, 0.90–1.28) for incident coronary heart disease
Kalra et al79	United Kingdom	131 elderly patients that underwent surgical treatment for hip fracture; 1-year follow-up	Mean age 82.0 (8.9) years Range 61–94 years	Presence of subclinical hypothyroidism (15%) did not affect 1-year mortality
Sgarbi et al80	Brazil	1110 Japanese-Brazilians; follow-up of 7.5 years	57 years (68.8% of the sample with age ≥50 years)	In multivariate analysis, subclinical hypothyroidism was associated to all-cause mortality (HR, 2.3; 95% CI, 1.2–4.4) but not with cardiovascular mortality, using euthyroid subjects as the reference category
Razvi et al81	United Kingdom	2376 community-dwelling subjects	Mean age 45.5 years	There is an association between incident ischemic coronary heart disease and ischemic heart disease mortality with subclinical hypothyroidism (HR, 1.76; 95% CI, 1.15–2.71 and HR 1.79; 95% CI, 1.02–3.56, respectively)	Subsequent treatment of subclinical hypothyroidism with L-thyroxine appears to attenuate ischemic heart disease morbidity and mortality
De Jongh et al82	The Netherlands	1219 subjects without thyroid diseases from a population-based cohort; follow-up of 10.7 years	65 years or older	Subclinical hypothyroidism was not associated with increased overall mortality risk (HR, 0.89; 95% CI, 0.59–1.35) using euthyroid subjects as the reference group	The study does not support disadvantageous effects of subclinical thyroid disorders on physical and cognitive function, depression, or mortality in an older population
Lee et al83	US	3567 US community dwelling adults; follow-up of 14 years	65 years or older	Men with subclinical hypothyroidism presented a higher risk of hip fracture compared to euthyroid men (OR, 2.45, 1.27–4.73); no relationship between subclinical hypothyroidism and hip fractures was observed in women

Abbreviations: F4, free-thyroxine; OR, odds ratio; 95% CI, 95% confidence interval; HR, hazard ratio.