CONTEXT: Widespread thyroid hormone actions offer the possibility of developing 
selective thyromimetic analogs with salutary metabolic properties. Consequently, 
effects of diiodothyropropionic acid (DITPA) on body weight, serum lipoproteins, 
and bone metabolism markers were studied in a prospective, controlled, 
double-blind 24-wk trial, which was primarily designed to assess treatment of 
stable chronic heart failure.
DESIGN: Eighty-six patients (aged 66 +/- 11 yr, mean +/- sd) were randomized 
(1:2) to placebo or an escalating DITPA dose (90 to 180, 270, and 360 mg/d) over 
8 wk until serum TSH was less than 0.02 mU/liter. Patients were studied at 2, 4, 
6, 8, 16, and 24 wk and after 4 wk off study drug. Only 21 DITPA-treated and 27 
placebo patients completed the full 24 wk of therapy.
RESULTS: DITPA therapy lowered serum TSH levels and, to a lesser extent, serum 
T(3) and T(4), but there were no differences in clinical manifestations of 
thyrotoxicosis or hypothyroidism. Serum total and low-density lipoprotein 
cholesterol levels both decreased on DITPA; there was a transient decrease in 
triglycerides and no change in high-density lipoprotein cholesterol. DITPA 
therapy was associated with significant reduction in body weight, 12.5 lb at 24 
wk. Increases in serum osteocalcin, N-telopeptide, and deoxypyridinoline levels 
were consistent with increased bone turnover on DITPA.
CONCLUSION: This investigation of DITPA actions demonstrated its efficacy in 
reducing body weight and lowering total and low-density lipoprotein cholesterol 
levels. However, DITPA's adverse effects at doses used resulted in a high 
dropout rate and potentially dangerous skeletal actions were observed.