INCREASED PLASMA PANCREASTATIN-LIKE IMMUNOREACTIVITY LEVELS IN NONOBESE PATIENTS WITH ESSENTIAL-HYPERTENSION

Design: Pancreastatin, a novel peptide, is known to inhibit insulin se cretion and to have a glycogenolytic effect, and is present in many en docrine and chromaffin cells. Both the plasma insulin levels and the a drenergic activity accompanying insulin resistance have been shown to be increased in hypertensive subjects. Our working hypothesis was that pancreastatin might play a role in these pathological phenomena. Meth ods: We studied the plasma pancreastatin level in non-obese essential hypertensive patients in response to an intravenous glucose load. We f urther measured the responses to the glucose challenge of insulin, glu cagon, catecholamines and free fatty acids, as well as other factors r elated to insulin resistance (i.e. lipoproteins and apolipoproteins). We separated the hypertensive patients into three groups according to their response to an oral glucose-tolerance test: normoinsulinaemic, h yperinsulinaemic and glucose-intolerant. Matched normotensive control subjects were also studied. Results: Pancreastatin levels did not chan ge in the control group after the glucose challenge. However, all hype rtensive patients showed an increase in plasma pancreastatin levels af ter glucose loading. The normoinsulinaemic hypertensive patients also had elevated basal pancreastatin levels. The increase in pancreastatin levels was in the ranking: normoinsulinaemic > hyperinsulinaemic > gl ucose-intolerant. The pancreastatin: insulin ratio showed that the sec retion of pancreastatin and insulin may be regulated differently. Basa l free fatty acid and glucagon levels were found to be elevated both i n the hyperinsulinaemic and in the glucose-intolerant group. Fasting t riglycerides levels were increased in all of the hypertensive patients . Other risk factors for coronary artery disease were also found to be altered: elevated very low-density lipoprotein-cholesterol and decrea sed high-density lipoprotein-cholesterol, with ranking: normoinsulinae mic < hyperinsulinaemic < glucose-intolerant. Conclusions: These resul ts show an increase in pancreastatin levels in hypertensive patients, suggesting that pancreastatin might play a role in the pathophysiology of essential hypertension.