Table 2.
Characteristics of 19 prospective follow-up studies evaluating blood pressure levels before and after LT4 treatment in SCH patients.
| Studies | Study design | Country (Ethnicity) | No. of SCH patients (Female, %; Mean age, years) | Hypertension (%) | TSH criteria for SCH (mIU/L) | Mean baseline TSH (mIU/L) | TSH testing methods | L-T4 dosage (Mean or median dose, μg/day) | Treatment duration | Quality |
|---|---|---|---|---|---|---|---|---|---|---|
| Brenta et al. (50) | Prospective study | Argentina (Mixed) | 10 (90.0%; 50) | NA | >6 mIU/L | 11 | RIA | 75–150 μg daily (95 μg/day) | 6 months | 4 |
| Canturk et al. (51) | Prospective study | Turkey (Caucasians) | 35 (100%; 42.2) | NA | NA | 8.69 | CIA | Increased from 25 μg daily until normal TSH (NA) | 6 months | 6 |
| Taddei et al. (52) | Prospective study | Italy (Caucasians) | 9 (85.7%; 39.6) | 0% | >3.6 mIU/L | 8.30 | RIA | Increased from 25 μg daily until normal TSH (67.5 μg/day) | 6 months | 4 |
| Guang-Da et al. (53) | Prospective study | China (Asians) | 20 (100%; 40.5) | 0% | >5.5 mIU/L | 10.53 | RIA | Individualized dose to maintain normal TSH (NA) | 10 months | 5 |
| Nagasaki et al. (54) | Prospective study | Japan (Asians) | 42 (80.9%; 66.0) | 0% | >3.8 mIU/L | 6.88 | CIA | Increased from 12.5 μg daily until normal TSH (NA) | 4 months | 6 |
| Oflaz et al. (55) | Prospective study | Turkey (Caucasians) | 10 (90.0%; 44.3) | 0% | >4.2 mIU/L | 7.64 | CIA | Increased from 25 μg daily until normal TSH (NA) | 6 months | 4 |
| Unal et al. (56) | Prospective study | Turkey (Caucasians) | 16 (100%; 48.2) | 0% | >4.0 mIU/L | 8.0 | NA | Gradually increased dosages to maintain normal TSH (NA) | 16 weeks | 4 |
| Peleg et al. (57) | Prospective study | Israel (Caucasians) | 24 (94.1%; 51.5) | 23.5% | >4.0 mIU/L | 7.4 | NA | Increased from 50 μg daily until normal TSH (NA) | 7 months | 5 |
| Adrees et al. (23) | Prospective study | Ireland (Caucasians) | 56 (100%; 50) | 0% | >5.3 mIU/L | 13.2 | CIA | Increased from 50 μg daily until normal TSH (100 μg/day) | 18 months | 7 |
| Kebapcilar et al. (58) | Prospective study | Turkey (Caucasians) | 38 (100%; 49.8) | 0% | >5.0 mIU/L | 11.3 | CIA | Increased from 25 to 50 μg daily until normal TSH (101 μg/day) | 3 months | 6 |
| Kowalska et al. (59) | Prospective study | Poland (Caucasians) | 13 (100%; 51.8) | Part | >5.0 mIU/L | 8.83 | MEIA | Increased from 25 μg daily until normal TSH (66.2 μg/day) | 5 months | 4 |
| Traub-Weidinger et al. (60) | Prospective study | Austria (Caucasians) | 10 (70.0%; 43) | 0% | >5.0 mIU/L | 16.9 | CIA | 0.15–0.5 mg daily to maintain normal TSH (NA) | 6 months | 4 |
| Tadic et al. (26) | Prospective study | Serbia (Caucasians) | 54 (100%; 41) | 0% | >5.0 mIU/L | 8.8 | CIA | Increased from 0.36 μg/kg daily until normal TSH (1.13 μg/kg) | 1 year | 7 |
| Anagnostis et al. (61) | Prospective study | Greece (Caucasians) | 32 (93.7%; 52.1) | 13.2% | >4.0 mIU/L | 6.79 | CIA | NA (NA) | 6 months | 6 |
| Yazici et al. (62) | Prospective study | Turkey (Caucasians) | 23 (97.7%; 35.2) | 0% | >4.0 mIU/L | 5.9 | NA | NA (NA) | 6 months | 5 |
| Adamarczuk-Janczyszyn et al. (24) | Prospective study | Poland (Caucasians) | 100 (100%; 61.2) | Part | >4.1 mIU/L | 8.6 | CIA | NA (NA) | 6 months | 7 |
| Piantanida et al. (63) | Prospective study | Italy (Caucasians) | 28 (96.4%; 43.6) | 14.3% | >5.0 mIU/L | NA | RIA | NA (NA) | NA | 5 |
| Pandrc et al. (25) | Prospective study | Serbia (Caucasians) | 35 (82.9%; 51.6) | NA | 5–10 mIU/L | 7.0 | CIA | 25–75 μg daily (50 μg/day) | 3 months | 6 |
| Stratigou et al. (27) | Prospective study | Greece (Caucasians) | 16 (60.0%; 47.2) | 0% | >5.0 mIU/L | 9.0 | CIA | Increased from 25 μg daily until normal TSH (60 μg/day) | 9 months | 4 |
LT4, L-thyroxine or levothyroxine; SD, standard deviation; TSH, thyroid-stimulating hormone; ECLIA, electrochemiluminescence immunoassay; RIA, radioimmunoassay; CIA, chemiluminescent immunoassay; MEIA, microparticle enzyme immunoassay; NA, data were not available in included studies. Hypertension was diagnosed by the previous diagnostic criteria of hypertension among those included studies.