Decreased High Density Lipoprotein Cholesterol in Hypopituitarism*

Serum triglyceride, cholesterol, and high density lipoprotein cholesterol (HDL-C) levels were measured in 10 men and 3 women with hypopituitarism. The mean total cholesterol and triglyceride levels were significantly increased but were within the range of controls. The mean HDL-C concentration and the HDL-C to total cholesterol ratio were significantly decreased. Similar findings were present in a patient with isolated GH deficiency. Two men with Kallman's syndrome and 3 patients with active acromegaly had values that were either within or just below the normal range. Replacement therapy with thyroid hormone and prednisone resulted in a normalization of HDL-C concentrations in four of the five patients studied. This improvement suggests a role for thyroid hormone and/or glucocorticoids in the maintenance of normal HDL-C concentrations. These observations also suggest that the distribution of plasma lipoprotein fractions is dependent in part, either directly or indirectly, on pituitary hormones.