Assessment of Suspected Insulinoma by 48-hour Fasting Test: A Retrospective Monocentric Study of 23 Cases

 

 Buy Article Permissions and Reprints

Abstract

Objective: Insulinoma causes fasting hypoglycaemia due to inappropriate insulin secretion. The diagnosis of insulinoma is based on Whipple's triad during a supervised fasting test. The aim of our study was to evaluate retrospectively the percentage of positive 48-hour fasting tests in a large series of patients with insulinoma.

Design, Patients and Methods: In a retrospective study, we identified 39 patients (24 females, 15 men; average age 47 years [range 12-78 years]) with insulinoma. Sixteen patients were diagnosed by spontaneous hypoglycaemia. Twenty-three patients with insulinoma were tested with a 48-hour fasting test and compared to 31 healthy controls who had a negative fasting test and were followed up for at least two years.

Results: The fast was terminated due to neuroglycopenic symptoms in 4 patients (17.4%) at the 12th hour, in 17 patients (73.9%) at the 24th hour, and in 22 patients (95.7%) at the 48th hour. One patient with insulinoma had no neuroglycopenic symptoms, but was diagnosed by glucose and insulin levels during the 48-hour fast. Healthy controls had significantly higher blood glucose and lower insulin levels, and a lower insulin-glucose ratio than patients with insulinoma at the end of the fast.

Conclusions: In conclusion, the 48-hour fasting test was successful in the diagnosis of insulinoma in 95.7% of patients. In this series we did not observe a need for fasting beyond 48 hours.

References

• 1 Service FJ, Natt N. The prolonged fast.  J Clin Endocrinol Metab. 2000;  85 3973-3974
  CrossrefPubMedGoogle Scholar
• 2 Service FJ, Dale AJ, Elveback LR, Jiang NS. Insulinoma: clinical and diagnostic features of 60 consecutive cases.  Mayo Clin Proc. 1976;  51 417-429
  PubMedGoogle Scholar
• 3 Hirshberg B, Livi A, Bartlett DL, Libutti SK, Alexander HR, Doppman JL, Skarulis MC, Gorden P. Forty-eight-hour fast: the diagnostic test for insulinoma.  J Clin Endocrinol Metab. 2000;  85 3222-3226
  PubMedGoogle Scholar
• 4 Sawicki PT, Heinemann L, Starke A, Berger M. Hyperinsulinaemia is not linked with blood pressure elevation in patients with insulinoma.  Diabetologia. 1992;  35 649-652
  CrossrefPubMedGoogle Scholar
• 5 Skillern PG, Rynearson EH. Medical aspects of hypoglycemia.  J Clin Endocrinol Metab. 1953;  13 587-603
  PubMedGoogle Scholar
• 6 Breidahl HD, Priestley JT, Rynearson EH. Hyperinsulinism: surgical aspects and results.  Ann Surg. 1955;  142 698-706
  PubMedGoogle Scholar
• 7 Laroche GP, Erris DO, Priestley JT, Scholz DA, Dockerty MB. Hyperinsulinism. Surgical results and management of occult functioning islet cell tumor: review of 154 cases.  Arch Surg. 1968;  96 763-772
  PubMedGoogle Scholar
• 8 Fendrich V, Bartsch DK, Langer P, Zielke A, Rothmund M. Diagnosis and surgical treatment of insulinoma-experiences in 40 cases.  Dtsch Med Wochenschr. 2004;  129 941-946
  Article in Thieme ConnectPubMedGoogle Scholar
• 9 Dizon AM, Kowalyk S, Hoogwerf BJ. Neuroglycopenic and other symptoms in patients with insulinomas.  Am J Med. 1999;  106 307-310
  CrossrefPubMedGoogle Scholar
• 10 Wiesli P, Schmid C, Perren A, Pfammatter T, Spinas GA, Keller U. Hypoglycemia in response to glucose and glucagon in insulinoma patients with a negative prolonged fast: functional and morphological properties.  J Endocrinol Invest. 2004;  27 832-838
  PubMedGoogle Scholar
• 11 Doppman JL, Chang R, Fraker DL, Norton JA, Alexander HR, Miller DL, Collier E, Skarulis MC, Gorden P. Localization of insulinomas to regions of the pancreas by intra-arterial stimulation with calcium.  Ann Intern Med. 1995;  123 269-273
  PubMedGoogle Scholar
• 12 Pasieka JL, MacLeod MK, Thompson NW, Burney RE. Surgical approach to insulinomas. Assessing the need for preoperative localization.  Arch Surg. 1992;  127 442-447
  PubMedGoogle Scholar
• 13 Finlayson E, Clark OH. Surgical treatment of insulinomas.  Surg Clin North Am. 2004;  84 775-785
  CrossrefPubMedGoogle Scholar
• 14 Grant CS. Surgical aspects of hyperinsulinemic hypoglycemia.  Endocrinol Metab Clin North Am. 1999;  28 533-554
  CrossrefPubMedGoogle Scholar
• 15 Grant CS. Insulinoma.  Best Pract Res Clin Gastroenterol. 2005;  19 783-798
  CrossrefPubMedGoogle Scholar
• 16 Wiesli P, Brandle M, Pfammatter T, Zapf J, Spinas GA, Schmid C. Insulin determination by specific and unspecific immunoassays in patients with insulinoma evaluated by the arterial stimulation and venous sampling test.  Eur J Endocrinol. 2004;  151 123-126
  CrossrefPubMedGoogle Scholar
• 17 Gorden P, Skarulis MC, Roach P, Comi RJ, Fraker DL, Norton JA, Alexander HR, Doppman JL. Plasma proinsulin-like component in insulinoma: a 25-year experience.  J Clin Endocrinol Metab. 1995;  80 2884-2887
  CrossrefPubMedGoogle Scholar
• 18 Shimizu T, Sasakuma F, Ishikawa O, Matsumiya K, Hasegawa K, Sasaki A. Assessment of immunoassays for insulin in diagnostic tests for insulinoma.  Diabetes Res Clin Pract. 1994;  26 149-154
  CrossrefPubMedGoogle Scholar
• 19 Gama R, Teale JD, Marks V. Best practice No 173: clinical and laboratory investigation of adult spontaneous hypoglycaemia.  J Clin Pathol. 2003;  56 641-646
  CrossrefPubMedGoogle Scholar

Correspondence

M. QuinklerMD 

Clinical Endocrinology

Internal Medicine Centre for Gastroenterology, Hepatology, and Endocrinology

Charité Campus Mitte

Charitéplatz 1

10117 Berlin

Germany

Phone: +49/30/45051 41 52

Fax: +49/30/45051 49 52

Email: marcus.quinkler@charite.de