Effect of acute hypercalcaemia on glucose tolerance and insulin release in human beings

1980 ◽  
Vol 94 (2) ◽  
pp. 196-200 ◽  
Author(s):  
O. Gedik ◽  
S. Akalin ◽  
Zehra Koray
Keyword(s):  
Insulin Secretion ◽  
Glucose Tolerance ◽  
Serum Calcium ◽  
Calcium Gluconate ◽  
Oral Glucose ◽  
Human Beings ◽  
Glucose Challenge ◽  
Glucose Tolerance Curve ◽  
Obese Human ◽  
Tolerance Curve

Abstract. Insulin secretion in response to an oral glucose challenge during acute hypercalcaemia was studied. Oral glucose tolerance tests (OGTT) were performed in 12 non-diabetic, non-obese human volunteers, aged 20–28 years. Blood samples were collected for calcium, glucose and insulin determination. The next day the same volunteers received a 4 h infusion of calcium gluconate (15 mg/kg/4 h) and were administered glucose 1 h after starting the infusion. Serum calcium, glucose and insulin concentrations were measured again. Infusion of calcium gluconate resulted in an increase in serum calcium concentration of 5 mg/100 ml over 4 h. During these infusions no significant changes in glucose concentrations were noted. On the other hand, the total mean insulin concentration, expressed as the area under the 3 h glucose tolerance curve, and the insulin peak at 30 min were significantly increased during hypercalcaemia (P < 0.001). These data indicate that acute hypercalcaemia does not affect carbohydrate tolerance but increases insulin secretion in human beings.

Efficacy of cryohypophysectomy in the treatment of acromegaly

1977 ◽  
Vol 46 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Michael V. DiTullio ◽  
Robert W. Rand
Keyword(s):  
Growth Hormone ◽  
Glucose Tolerance ◽  
Oral Glucose ◽  
Oral Glucose Tolerance ◽  
Serum Growth Hormone ◽  
Beneficial Result ◽  
Content Type ◽  
Glucose Tolerance Curve ◽  
Tolerance Curve ◽  
Suprasellar Extension

✓ Between 1963 and 1974, 54 patients with acromegaly (28 men and 26 women) ranging in age from 23 to 61 years were evaluated. Each patient underwent thorough preoperative neurological, roentgenographic, and endocrinological surveys; most demonstrated mild-to-severe abnormalities in growth hormone immunoassay and oral glucose tolerance. Of those who underwent stereotaxic cryohypophysectomy, approximately 80% were considered to have a beneficial result. The efficacy of this form of therapy was judged on the basis of: 1) significant overall clinical improvement and regression of acromegalic features; 2) improvement in the glucose tolerance curve; and 3) a fall of serum growth hormone below 10 ng/ml. Complications including rhinorrhea, meningitis, and hemorrhage occurred in only a small number of cases. A comparison is made between this technique and others, including craniotomy, radiotherapy, and transnasal transsphenoidal hypophysectomy. The efficacy, low morbidity, and the ease with which the procedure may be performed make this our treatment of choice when dealing with growth-hormone-producing pituitary adenomas with no suprasellar extension.

A STUDY OF THE “FLAT” ORAL GLUCOSE TOLERANCE CURVE AND ITS RELATION TO RATE OF EMPTYING OF THE STOMACH

1956 ◽  
Vol 231 (1) ◽  
pp. 69-74 ◽  
Author(s):  
Charles E. Test ◽  
Russell L. Nichols ◽  
Richard L. Landau ◽  
Henry T. Ricketts ◽  
Ruth Loughead
Keyword(s):  
Glucose Tolerance ◽  
Oral Glucose ◽  
Oral Glucose Tolerance ◽  
Glucose Tolerance Curve ◽  
Tolerance Curve

ENHANCEMENT OF INSULIN RELEASE TO ACUTE GLYCAEMIC STIMULATION WITH DEPRESSION OF BASAL INSULIN PRODUCTION RATES IN INSULINOMA FOLLOWING DIAZOXIDE ADMINISTRATION

1970 ◽  
Vol 63 (3) ◽  
pp. 392-404 ◽  
Author(s):  
Richard E. Bailey ◽  
Albert Castro ◽  
Rosanne M. Kramer ◽  
Dorothy Macfarlane
Keyword(s):  
Insulin Secretion ◽  
Glucose Tolerance ◽  
Insulin Release ◽  
Plasma Insulin ◽  
Insulin Biosynthesis ◽  
Oral Glucose ◽  
Glucose Tolerance Tests ◽  
Tolerance Curve ◽  
Insulinoma Cells ◽  
Secretion Rates

ABSTRACT Single and double load oral glucose tolerance tests were performed repetitively both before and during administration of diazoxide to a 15-year old girl who had an insulin secreting islet cell tumour. Plasma insulin concentrations increased above baseline values by a greater magnitude in response to a single acute oral glycaemic stimulus following diazoxide treatment, compared to the increases resulting from comparable prediazoxide glucose tolerance tests, and plasma insulin either attained higher values or sustained elevations for a longer duration during the early part (first hour) of the single load tests. This provides evidence that diazoxide does not prevent the normal insulin release response to a glycaemic stimulus, and that enhanced insulin secretion rates may occur with insulinomas under the study conditions employed. Fasting plasma insulin concentrations were lower during the period of diazoxide administration which indicates that insulin biosynthesis was depressed under fasting steady-state conditions. Considering that the first part of the glucose tolerance curve reflects primarily insulin release, our data is consistent with the view that insulin storage within the insulinoma cells is preserved under the study conditions employed and may even be enhanced by diazoxide. Consequently, depression of insulin biosynthesis is considered to be a resultant effect and not a primary action of diazoxide. These results suggest a possible basis for »distinguishing« types of insulinomas should additional perspective reveal that glycaemic-induced enhancement of insulin secretion rates cannot be made to occur uniformly in diazoxide treated patients having insulinomas.

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