..132 participants had Hypothyroid Symptoms scores greater than 30, and 133 had Tiredness scores greater than 40. Among the group with high symptom burden, the Hypothyroid Symptoms score improved similarly between those receiving L-thyroxine (mean within-group change, −12.3 [95% CI, −16.6 to −8.0]) and those receiving placebo (mean within-group change, −10.4 [CI, −15.3 to −5.4]) at 1 year; the adjusted between-group difference was −2.0 (CI, −5.5 to 1.5; P = 0.27).
Improvements in Tiredness scores were also similar between those receiving L-thyroxine (mean within-group change, −8.9 [CI, −14.5 to −3.3]) and those receiving placebo (mean within-group change, −10.9 [CI, −16.0 to −5.8]); the adjusted between-group difference was 0.0 (CI, −4.1 to 4.0; P = 0.99). There was no evidence that baseline Hypothyroid Symptoms score or Tiredness score modified the effects of L-thyroxine versus placebo (P for interaction = 0.20 and 0.82, respectively).
Post hoc analysis, small sample size, and examination of only patients with 1-year outcome data.
In older adults with SCH and high symptom burden at baseline, L-thyroxine did not improve hypothyroid symptoms or tiredness compared with placebo