Glucagon‐stimulated Plasma C‐peptide and Insulin Levels in Active and Non‐active Acromegalics

Roelfsema, Ferdinand; Frölich, Marijke; Geelhoed-Duyvestijn, P. H. L. M.; Kruseman, A. C. Nieuwenhuijzen; Looij, B. J.

doi:10.1111/j.1365-2265.1985.tb01123.x

Cited by 10 publications

(8 citation statements)

References 9 publications

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“…The results of the GH experiment in subject 1 are summarized in Table 1 Half-life and serum levels of C peptide are not decreased by renal hyperfiltration in acromegaly or during GH treatment (8,9). Therefore, normal insulin levels in the presence of decreased C peptide levels, as observed in the present study, must indicate a decrease of insulin degradation and consecutively a prolongation of its half-life.…”

Section: Resultssupporting

confidence: 55%

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Effects of recombinant insulin-like growth factor I on insulin secretion and renal function in normal human subjects.

Guler

Schmid

Zapf

et al. 1989

Proc. Natl. Acad. Sci. U.S.A.

298

186

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Insulin-like growth factor I (IGF-I) is an important mediator of growth hormone (GH) action and it appeared tempting to evaluate possible clinical applications. Recombinant IGF-I was infused s.c. at a dose of 20 jug/kg of body weight per hour during 6 days in two healthy adult subjects. Blood glucose and fasting insulin levels remained within normal limits and IGF-H levels were suppressed. In contrast to insulin, fasting C peptide levels were decreased. GH secretion was also suppressed by IGF-I. Our preliminary data allow us to distinguish between the effects of GH per se and those of IGF-I: GH causes hyperinsulinism, whereas IGF-I leads to decreased insulin secretion. Glomerular filtration rate, as estimated by creatinine clearance, increased to 130% of preinfusion values during the IGF-I infusion. Total creatinine and urea excretion remained unchanged. We conclude that IGF-I influences kidney function and, in contrast to GH, exerts an insulin-sparing effect. It may be speculated that the therapeutic spectrum of IGF-I is quite different from that of GH.

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Section: Resultssupporting

confidence: 55%

“…During GH administration in subject 1, insulin levels increased rapidly. In acromegalic patients, insulin secretion is always found to be increased, presumably because GH in excess leads to insulin resistance (8,9).…”

Section: Resultsmentioning

confidence: 99%

Effects of recombinant insulin-like growth factor I on insulin secretion and renal function in normal human subjects.

Guler

Schmid

Zapf

et al. 1989

Proc. Natl. Acad. Sci. U.S.A.

298

186

View full text Add to dashboard Cite

show abstract

“…found that presence of impaired metabolic parameters were markedly increased in the ACRO group when compared with both controls and the PRLoma and NFA groups. In a controlled study, it was shown that increased insulin secretion continued to accompany glucose uptake in patients with ACRO, even in the presence of normal GH levels, thereby emphasizing that this may be due to either persistently enhanced pancreatic β-cell mass or persistent peripheral insulin resistance [18]. In other words, this suggests that glucose metabolism disorders may persist despite remission being achieved [11].…”

Section: Discussionmentioning

confidence: 99%

Markers of Metabolic Syndrome in Patients with Pituitary Adenoma: A Case Series of 303 Patients

et al. 2019

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To assess the demographic characteristics and hormonal status of patients who presented to our clinic with pituitary adenoma and to demonstrate the presence, prevalence, and relationship of metabolic syndrome parameters in these patients. The study included 303 patients with known or newly diagnosed pituitary adenoma and 52 age- and sex-matched healthy controls. The patients were classified into 3 groups; acromegaly (ACRO) (n=54),prolactinoma (PRLoma) (n=163), and non-functional adenoma (NFA) (n=86). in 55.6% (n=172) and 52% (n=163) of the patients, respectively. The waist circumference of all patients (p<0.001) and body mass index (BMI) of patients with PRLoma (p=0.03) and ACRO (p<0.001) were found to be significantly higher than in the controls. The HbA1c, insulin and HOMA-IR values were significantly higher in the ACRO and PRLoma groups, whereas the insulin and HOMA-IR values were significantly higher in the NFA group compared with the control group (p<0.001 and p<0.001, respectively). When the 3 patient groups were compared, waist circumference and BMI were significantly higher in the ACRO group than in the PRLoma group (p=0.04 and p=0.03, respectively). In patients developing pituitary failure after treatment, age, waist circumference, plasma glucose, low-density lipoproteins and triglyceride values were significantly increased when compared with those without pituitary failure after treatment (p<0.001). In our study, it was found that there was increased metabolic and cardiovascular risk in functional pituitary adenoma and NFA.

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“…A 100-g glucose load failed to suppress GH levels below 2.5 mU/1 in all cases. A paradoxical GH response to TRH, defined as an increase of at least twice the basal GH level to a level > 5 mU/1 (Roelfsema et al, 1985), was seen in seven patients. After the studies described here, five of the six untreated patients were operated upon.…”

Section: Patients a N D Methodsmentioning

confidence: 94%

The Effect of Calcitonin on Growth Hormone Secretion in Acromegaly

Looij

Roelfsema

Frölich

1989

Clinical Endocrinology

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SUMMARY To determine whether human calcitonin inhibits GH secretion in acromegaly, as previously described for healthy subjects, the effect of an i. v. bolus injection of calcitonin or saline on GH levels in patients with active acromegaly was studied and compared to that of an i. v. bolus injection of the synthetic somatostatin analogue, octreotide. After the injection of calcitonin, GH levels decreased by 46% of initial values, whereas octreotide reduced GH levels by 87% and saline had no significant effect. Administration of calcitonin to acromegalics did not cause the transient rise in plasma PRL and TSH levels seen in normal subjects. Octreotide induced a decrease in plasma PRL in three out of seven patients. It is concluded that human calcitonin suppresses GH secretion in acromegaly, but not to normal levels; moreover the effect is less than that found for octreotide. In addition, acromegalic patients did not exhibit the PRL and TSH‐releasing activity of calcitonin found in normal subjects, while octreotide inhibited PRL secretion in some acromegalic patients.

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Glucagon‐stimulated Plasma C‐peptide and Insulin Levels in Active and Non‐active Acromegalics

Cited by 10 publications

References 9 publications

Effects of recombinant insulin-like growth factor I on insulin secretion and renal function in normal human subjects.

Effects of recombinant insulin-like growth factor I on insulin secretion and renal function in normal human subjects.

Markers of Metabolic Syndrome in Patients with Pituitary Adenoma: A Case Series of 303 Patients

The Effect of Calcitonin on Growth Hormone Secretion in Acromegaly

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