Relationship between Subclinical Thyroid Dysfunction and the Risk of Cardiovascular Outcomes: A Systematic Review and Meta-Analysis of Prospective Cohort Studies

Table 1

Baseline characteristics of subclinical thyroid dysfunction in included studies.

First author, year	Sample	Mean age (range) (y)	Follow-up	TSH cutoff value (mIU/L) (Shypo/Shyper)	Thyroxine measured (Shypo/Shyper)	Exclusion of thyroid hormone/antithyroid drug recipients	Outcome (Shypo or Shyper)
Parle et al. [43]	1187	70.4 (>60)	8.2 y	>5.0/<0.44	Yes/yes	Yes/yes	CHD, CHD mortality, total, and cardiovascular mortality
Gussekloo et al. [42]	527	85	3.7 y	>4.8/<0.3	Yes/yes	Yes/yes	CHD, CHD mortality, total, and cardiovascular mortality
Rodondi et al. [41]	2730	74.7 (70–79)	4 y	≥4.5/NA	Yes/NA	NR/NA	CHD, HF, total, and cardiovascular mortality
Walsh et al. [24]	1890	49.8 (17–89)	20 y	>4.0/<0.4	Yes/yes	NR/NR	CHD and cardiovascular mortality
Cappola et al. [23]	3182	72.7 (≥65)	12.5 y	>4.5/<0.45	Yes/yes	Yes/yes	CHD, AF, total, and cardiovascular mortality
Bauer et al. [40]	487	71.7 (≥65)	11.9 y	>5.5/≤0.5	NR/NR	NR/NR	Total and cardiovascular mortality
Rodondi et al. [39]	3044	72.6 (≥65)	15 y	>4.5/<0.45	Yes/yes	Yes/yes	HF
Razvi et al. [38]	2350	45.4 (18–92)	20 y	>6/NA	NR/NA	Yes/NA	CHD, CHD mortality, and total mortality
Boekholdt et al. [5]	13,141	58 (45–79)	10.6 y	>4/<0.4	Yes/yes	Yes/yes	CHD, CHD mortality, and total mortality
Ittermann et al. [44]	3883	48.9 (20–79)	8.5 y	NA/<0.25	NA/yes	NA/yes	CHD, CHD mortality, AF, and total mortality
Jongh et al. [21]	1197	75.5 (>65)	10.7 y	>4.5/<0.3	Yes/yes	Yes/yes	CHD, CHD mortality, total, and cardiovascular mortality
Schultz et al. [35]	605	67.8 (50–91)	5 y	>4/<0.4	Yes/yes	NR/NR	Total mortality
Nanchen et al. [33]	5316	75 (70–82)	3.2 y	≥4.5/<0.45	Yes/yes	Yes/yes	CHD, HF, AF, total, and cardiovascular mortality
Asvold et al. [34]	26,475	53.7	12.3 y	>3.6/<0.49	Yes/yes	NR/NR	CHD, CHD mortality, and HF
Ceresini et al. [32]	931	75.5 (>65)	6 y	>4.68/<0.49	Yes/yes	Yes/yes	Total mortality
Hyland et al. [31]	4863	73.5 (>65)	10 y	>4.5/NA	Yes/NA	NR/NA	CHD, cardiovascular mortality, and HF

Shypo: subclinical hypothyroidism; Shyper: subclinical hyperthyroidism; CHD: coronary heart disease; AF: atrial fibrillation; HF: heart failure; TSH: thyroid-stimulating hormone; NR: not reported; NA: not applicable (because the outcome was not examined in the study).