Raised serum thyrotrophin in women with peripheral arterial disease

Women with symptomatic peripheral arterial disease were screened for impaired thyroid function using a sensitive immunoradiometric assay for thyrotrophin (TSH). The arterial disease in the aortotibial segment was documented by an abnormal brachial/ankle pressure index in 80 patients. An age-matched control group of elderly women (n = 30) with a normal pressure index was established. In the control group the mean serum TSH was 1.6 +/- 1.1 milliunits/l, median 1.5 milliunits/l and this established a normal range of 0.2-3.9 milliunits/l. Seven patients (8.8 per cent) were already receiving treatment for myxoedema. In the remaining patients, the overall distribution of serum TSH was skewed to higher levels; the mean was 3.7 milliunits/l, median 2.4 milliunits/l, P less than 0.001 compared with controls and 15 (19 per cent) had a serum TSH greater than 4 milliunits/l, compared with only one (3.3 per cent) of the controls. Therefore 22 patients (28 per cent) had myxoedema or a raised serum TSH. For all subjects with a normal TSH, there was a positive correlation of serum TSH with serum cholesterol, r = 0.68, P less than 0.001. For patients with a raised TSH, there was a continuing, but non-linear, increase of serum cholesterol with TSH. These results suggest that a raised serum TSH may be one of the risk factors for the development of peripheral arterial disease in women, possibly by increasing cholesterol levels.