Table 3.
Thyroid parameters at symptomatically hypothyroid versus asymptomatic presentations.
| Parameter | Asymptomatic mean (95% CI)1 |
Symptomatic mean (95% CI)1 |
p-value |
|---|---|---|---|
| Visits (n) | 2270 | 152 | |
| Gender (female/male) | 71%/29% | 64%/36% | 0.08 |
| Age | 53.3 [51.6; 55.0] | 53.7 [51.9; 55.4] | 0.08 |
| BMI | 27.2 [26.7; 27.7] | 27.2 [26.8; 27.6] | 1.0 |
| Weight-adjusted LT4 dose (µg/kg BW/day) | 1.94 [1.89; 2.00] | 1.86 [1.79; 1.93] | <0.001 |
| FT3 (pmol/l) | 5.43 [5.35; 5.52] | 5.20 [5.05; 5.36] | 0.001 |
| FT4 (pmol/l) | 22.8 [22.4; 23.2] | 21.4 [20.6; 22.1] | <0.001 |
| TSH (mIU/l) | 0.10 [0.08; 0.12] | 0.17 [0.12; 0.23] | <0.001 |
| Deiodinase activity (nmol/s) | 22.1 [21.7; 22.5] | 22.5 [21.9; 23.2] | 0.11 |
1
This excludes temporary LT4 withdrawal for radioiodine treatment. Thyroid parameters were obtained under nonhypothyroid stable conditions, and adjusted for gender, age and BMI (except for LT4 dose) in a multivariable mixed model. TSH was logarithmically transformed.
BW, body weight; FT3, free triiodothyronine; FT4, free thyroxine; LT4, levothyroxine; TSH, thyroid stimulating hormone.