Can thyroxine halt the progression of peripheral arterial disease?

Fifteen women with claudication and increased serum thyrotrophin (TSH) were treated with L-thyroxine (25-75 micrograms). These women were selected from a group of 80 consecutive women presenting with claudication, rest pain or gangrene. One year after their TSH was normal, their progress, serum lipids and lipoproteins were compared with the 58 women with normal levels of serum TSH; the remainder were already receiving thyroxine. Non-invasive assessment showed that three of the 15 (20%) women treated with thyroxine had progression of arterial disease, two in the legs and one in the legs and coronary arteries; two women showed improvement of ankle/brachial pressure indices. There was no accelerated angina, myocardial infarction, stroke or death in this group. Fifty-six of the 58 patients with normal levels of TSH were alive at follow-up and there was progression of distal disease in 24 (43%), coronary artery disease in 6 (11%), increasing carotid stenosis in four and two complained of transient ischaemic attacks. In this group, disease progression affected 32/56 (57%) of the women and this is significantly greater than in the thyroxine treated group chi 2 (P less than 0.05). Treatment with L-thyroxine caused a significant increase in HDL-cholesterol from 1.29 +/- 0.34 to 1.45 +/- 0.49 mmol/L (P less than 0.05) and a significant decrease in cholesterol from 8.0 +/- 1.3 to 7.2 +/- 1.1 mmol/L (P less than 0.01) and apolipoprotein B from 1.23 +/- 0.20 to 1.04 +/- 0.16 g/l (P less than 0.001). Significant changes in apolipoprotein B were observed after 3 months of treatment.(ABSTRACT TRUNCATED AT 250 WORDS)