Decreased Post-Heparin Lipases in Graves’s Disease

The plasma post-heparin lipolytic activity (PHLA) and post-heparin monoglyceridase activity (PHMA) were determined in patients with Graves's disease and treated toxic nodular goiter. Both enzymes were markedly reduced in patients with active Graves's disease. Fasting serum triglycerides were normal or slightly below normal despite low post-heparin lipases. In these patients, restudied after propranolol therapy or within six months of euthyroid control with 131l, propylthiouracil or methimazole, PHLA and PHMA remained below normal. A separate group of patients with treated Graves's disease, who were euthyroid for as long as six years, also had low post-heparin lipases. Enzyme activity did not correlate with the presence of the long acting thyroid stimulator. In contrast, patients with treated toxic nodular goiter had normal PHLA and PHMA. Control subjects made hypermetabolic with tri-iodothyronine or thyroxine had normal post-heparin enzyme activities. Persistently low PHLA and PHMA may be a marke...