Acute Insulin Withdrawal and the Regulation of Plasma Triglyceride Removal in Diabetic Subjects

The effects of acute insulin deprivation on the enzyme lipoprotein lipase (LPL) and on triglyceride (TG) removal from plasma in man are unknown. To assess the role of insulin availability on TG removal, plasma TG concentration and postheparin lipolytic activity (PHLA)—an indirect means of quantitating LPL—were measured in seven insulin-dependent diabetics before and forty-eight hours after insulin withdrawal. The TG elevation (p < .01) and diminished PHLA levels (p < .01) observed in all subjects were consistent with impaired TG removal. The delayed disappearance of C-14-labeled TG after insulin deprivation (p < .01) demonstrated in two subjects further suggests that insulin is required for maintaining normal LPL and TG removal.