Table 1.
Characteristics of included studies.
| Study | Study design | SCH mean age* (Years) | Controls mean age (Years) | Country | Scales for depression | Definition for SCH | Conclusions |
|---|---|---|---|---|---|---|---|
| Blum et al. (11) | Cohort | 75.66 ± 3.4 | 74.96 ± 3.2 | Dutch | GDS | TSH ≥ 4.5 mIU/L, fT4 12–18 pmol/L | NA |
| Jorde et al. (12) | Cohort | 62.5 ± 11.7 | 61.0 ± 12.5 | Norway | GHQ-30 | TSH 3.5–10.0 mIU/L, fT3 and T4 were normal | NA |
| Kim et al. (6) | Cohort | 39.8 ± 6.6 | 30.7 ± 7.2 | South Korea | CES-D | TSH ≥ 5 mIU/L, fT4 0.93–1.7 ng/dL | NA |
| Park et al. (13) | Cross-sectional | 76.8 ± 9.0 | 76.5 ± 9.0 | Korea | GDS-K | TSH ≥ 4.1mIU/L, fT4 0.7–1.8 ng/dL | NA |
| Baldini et al. (14) | Cohort | 55.2 ± 8.8 | 50.3 ± 9.2 | Italy | HRSD | TSH ≥ 4.6 mIU/L, fT3 2.6–5.6 pg/mL, fT4 6.3–15.3 pg/mL | NA |
| Gussekloo et al. (15) | Cohort | 85 | 85 | Netherlands | HADS | TSH > 4 mIU/L, fT3 and T4 were normal | NA |
| Engum et al. (16) | Cohort | 40–89 | 40–89 | Norway | HADS | TSH > 4 mIU/L, fT3 and T4 were normal | NA |
| Fjaellegaard et al. (5) | Cross-sectional | 42–63 | 43–63 | Denmark | MDI | TSH ≥ 4.6 mIU/L, fT3 2.6–5.6 pg/mL, fT4 6.3–15.3 pg/mL | NA |
| Almeida et al. (17) | Cross-sectional | 75.3 ± 4.1 | 75.3 ± 4.1 | Australia | GDS-15 | TSH ≥ 4 mIU/L, fT4 10–22 pmoL/L | NA |
| Roberts et al. (18) | Cohort | ≥65 | ≥65 | England | HADS | TSH ≥ 5.5 mIU/L, fT4 9–20 pmoL/L | NA |
| Pop et al. (19) | Cohort | 49.2 ± 2.2 | 49.2 ± 2.2 | Netherlands | EDS | TSH ≥ 6 mIU/L, fT4 8–26 pmoL/L | NA |
| Demartini et al. (4) | Case-control | 62.5 ± 13.4 | 52.0 ± 14.7 | Italy | MADRS | TSH ≥ 4.97 mIU/L, fT3 2.64–5.68 pmoL/L, fT4 9.1–19.6 pmoL | A |
| Larisch et al. (20) | Cohort | 47 ± 12 | 61 ± 14 | Germany | GHQ-12 | TSH 4.4–13 mIU/L, fT3 and fT4 were normal | A |
| Almeida et al. (21) | Cross-sectional | 49.1 ± 10.3 | 44.8 ± 9.6 | Brazil | HAMD | TSH ≥ 4 mIU/L, fT4 0.8–1.8 ng/dL | A |
| Chueire et al. (22) | Cohort | ≥60 | ≥60 | Brazil | DSMIV | TSH ≥ 4.5 mIU/L, fT4 0.74–2.1 ng/dL | A |
| Yu et al. (7) | Case-control | 46.53 ± 6.61 | 45.12 ± 5.34 | China | HAMD | TSH ≥4 mIU/L, fT3 and fT4 were normal | A |
| Gulseren et al. (23) | Case-control | 40.9 ± 14.2 | 40.5 ± 7.6 | Turkey | HAM-D | TSH ≥ 5 mIU/L, fT3 3.1–6.8 pmoL/L, fT4 12–22 pmoL/L | A |
| Vishnoi et al. (24) | Case-control | 52.5 ± 11.5 | 52.4 ± 11.5 | India | DSMIV | TSH ≥ 4.5 mIU/L, fT4 0.74–2.1 ng/dL | A |
| Chueire et al. (25) | Case-control | 60–89 | 60–92 | Brazil | CES-D | TSH≥ 4.5 mIU/L, fT3 andT4 were normal | A |
| Manciet et al. (26) | Cohort | ≥65 | ≥65 | France | PHQ-9 | TSH ≥ 6.68 mIU/L, fT4 0.89 ± 1.76 ng/dL | NA |
| Hong et al. (8) | Cross-sectional | 47.9 ± 1.8 | 44.4 ± 0.4 | Korea | DSM-IV | TSH ≥ 4.5 mIU/L,fT3 60–200 ng/dL, fT4 4.5–11.5 ug/mL | NA |
The mean age of the enrolled patients.
SCH, subclinical hypothyroidism; TSH, thyroid-stimulating hormone; fT3, free triiodothyronine; fT4, free thyroxine; GDS-15, The Geriatric Depression Scale 15; GHQ-30, The General Health Questionnaire; CES-D, The Center for Epidemiologic Studies Depression scale; GDS-K, The geriatric depression scale; HRSD, Hamilton rating scale for depression; HADS, Hospital Anxiety and Depression Scale; MDI, Major (ICD-10) Depression Inventory; EDS, The Edinburgh Depression Scale; MADRS, Montgomery-Asberg Depression Rating Scale; HAM-D, Hamilton Rating Scale for Depression; GHQ-12, Twelve item general health questionnaire; DSM-IV, Diagnostic and Statistical Manual of Mental Disorders-IV; HDRS, The Hamilton Depression Rating Scale; RDC, The Research Diagnostic Criteria; NA, No association; A, Significant association.