Thyroid dysfunction and hypercholesterolaemia in the general population of Glasgow, Scotland.

As part of a screening programme for coronary heart disease risk factors, fasting plasma cholesterol was measured in 2,250 people from the east-end of Glasgow. Plasma thyrotropin (TSH) was measured in the 90 individuals (4% of the population studied) who had a cholesterol level greater than or equal to 8.0 mmol/l. Four had unequivocal biochemical evidence of hypothyroidism-TSH greater than 34 mU/l and a low plasma thyroxine (T4) less than or equal to 45 nmol/l. A further 8 were found to have raised TSH levels suggesting they may have subclinical hypothyroidism. These data indicate that thyroid dysfunction may make a significant contribution to hypercholesterolaemia in the general population.