TY - JOUR
T1 - Stimulation of insulin secretion by a rapid intravenous calcium infusion in patients with β-cell neoplasms of the pancreas
AU - Brunt, L. Michael
AU - Veldhuis, Johannes D.
AU - Dilley, William G.
AU - Farndonj, John R.
AU - Santen, Richard J.
AU - Leight, George S.
AU - Wells, Samuel A.
PY - 1986/1
Y1 - 1986/1
N2 - The effects of calcium on fasting plasma insulin and glucose levels were compared in 16 normal subjects and 11 patients with β-cell neoplasms of the pancreas. Calcium was administered iv either as a rapid calcium infusion (RCI; 2 mg/kg in 1 min) or as a long calcium infusion (LCI; 12 mg/kg in 3 h). In normal subjects, the RCI produced a rise in mean plasma insulin from 11 ± 1 (±SEM) μU/ml basally to a peak of 18 ± 2μU/ml (P < 0.001). No consistent pattern of change in insulin levels occurred during the LCI, and plasma glucose levels did not change significantly with either test. In the patients with β-cell neoplasms, the RCI resulted in a rapid increase in mean plasma insulin from 36 ± 6 μU/ml to a peak level of 312 ± 67 (P < 0.002). With the LCI, a more gradual rise in insulin from 35 ± 11 to 92 ± 36 μU/ml occurred (P < 0.002). The mean increase in insulin in the patients with β-cell neoplasms was significantly greater for the RCI than for the LCI (P < 0.01). Pronounced increments in plasma insulin occurred in all 11 patients after the RCI, but in only 3 of 8 patients during the LCI. Plasma glucose levels declined significantly from 69 ± 7 to 56 ± 8 mg/dl during the RCI (P < 0.05) and from 69 ± 8 to 49 ± 7 mg/dl during the LCI (P < 0.005). Symptomatic hypoglycemia developed in 3 patients during the LCI but did not occur after the RCI. These data indicate that calcium is a more effective insulin secretagogue in patients with β-cell neoplasms when administered as an RCI than as an LCI, and suggest that the RCI may be a useful test for the diagnosis of insulin-secreting tumors.
AB - The effects of calcium on fasting plasma insulin and glucose levels were compared in 16 normal subjects and 11 patients with β-cell neoplasms of the pancreas. Calcium was administered iv either as a rapid calcium infusion (RCI; 2 mg/kg in 1 min) or as a long calcium infusion (LCI; 12 mg/kg in 3 h). In normal subjects, the RCI produced a rise in mean plasma insulin from 11 ± 1 (±SEM) μU/ml basally to a peak of 18 ± 2μU/ml (P < 0.001). No consistent pattern of change in insulin levels occurred during the LCI, and plasma glucose levels did not change significantly with either test. In the patients with β-cell neoplasms, the RCI resulted in a rapid increase in mean plasma insulin from 36 ± 6 μU/ml to a peak level of 312 ± 67 (P < 0.002). With the LCI, a more gradual rise in insulin from 35 ± 11 to 92 ± 36 μU/ml occurred (P < 0.002). The mean increase in insulin in the patients with β-cell neoplasms was significantly greater for the RCI than for the LCI (P < 0.01). Pronounced increments in plasma insulin occurred in all 11 patients after the RCI, but in only 3 of 8 patients during the LCI. Plasma glucose levels declined significantly from 69 ± 7 to 56 ± 8 mg/dl during the RCI (P < 0.05) and from 69 ± 8 to 49 ± 7 mg/dl during the LCI (P < 0.005). Symptomatic hypoglycemia developed in 3 patients during the LCI but did not occur after the RCI. These data indicate that calcium is a more effective insulin secretagogue in patients with β-cell neoplasms when administered as an RCI than as an LCI, and suggest that the RCI may be a useful test for the diagnosis of insulin-secreting tumors.
UR - http://www.scopus.com/inward/record.url?scp=0022657251&partnerID=8YFLogxK
U2 - 10.1210/jcem-62-1-210
DO - 10.1210/jcem-62-1-210
M3 - Article
C2 - 2999178
AN - SCOPUS:0022657251
SN - 0021-972X
VL - 62
SP - 210
EP - 216
JO - Journal of Clinical Endocrinology and Metabolism
JF - Journal of Clinical Endocrinology and Metabolism
IS - 1
ER -