Correlation of postheparin hepatic triglyceride lipase activity to serum intermediate density lipoprotein and triiodothyroxine levels in patients on maintenance hemodialysis

To investigate the possible mechahism of serum intermediate density lipoprotein (IDL) retention in chronic uremia, we have determined postheparin lipoprotein lipase (LPL) and hepatic triglyceride lipase (H-TGL) activities, and serum levels of very low density lipoprotein (VLDL), IDL, low density lipoprotein (LDL) and thyroid hormone in 14 patients on maintenance hemodialysis and in 10 sex or age-matched normal controls . In addition, the relationship among various parameters of the patient group was also investigated. Consequently, the following findings were observed. 1. In the uremic patients, there were a slight increase in VLDL, a significant increase in IDL and a significant decrease in LDL, triiodothyroxine (T3) and H-TGL activity when compared to the respective parameters of normal controls. 2. Serum IDL and IDL-triglyceride levels showed a significant negative correlation to H-TGL activity, while there was no significant relationship between serum IDL ahd T3 levels. On the other hand, H-TGL activity had a slightly positive correlation to serum T3 levels. These results suggest that an increase in serum IDL levels could be due to low HRTGL activity which might be partially regulated by low T3 levels in patients on maintenance hemodialysis.