Reduction of plasma triglyceride concentration by acute stress in man

Three different forms of stress all resulted in acute reduction of plasma triglyceride concentrations. Pyrogen reactions in two hypertriglyceridemic men resulted in the lowering of very-low-density lipoprotein (VLDL) triglyceride levels by 93% and 73% due to decreased secretion of this lipoprotein into plasma. More modest reductions in plasma triglycerides were observed after 2-deoxyglucose-induced intracellular glucopenia and insulin-induced hypoglycemia. With hypoglycemia, the lowering of plasma triglyceride concentration correlated significantly with the stimulation of urinary epinephrine output (r = 0.86) but with neither the urinary norepinephrine response nor with the increase in plasma immunoreactive glucagon levels. To further test whether these changes in plasma triglyceride levels were mediated via the sympathetic nervous system, hypoglycemia was evoked by insulin in subjects with traumatic spinal cord transections. Two such subjects, who demonstrated sympathetic stimulation in response to hypoglycemia, had evidence of reduced VLDL secretion into plasma, while in two who had no evidence of an adrenergic response, VLDL secretion was not inhibited. Thus, acute lowering of plasma triglyceride concentrations by certain forms of stress appears to be mediated via the sympathetic nervous system.