Evaluation of the Pituitary Function with Insulin Tolerance (Hypoglycaemia) Testing

[~MaryO~]

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Evaluation of the Pituitary Function with Insulin Tolerance (Hypoglycaemia) Testing: Are There Any Differences Using Insulin Lispro Compared to Regular Insulin?

 

Kevin C.J. Yuena, Rakesh Aminb, Marie B. Cooka, Sharon A. Rhoadsa, David M. Cooka

 

Department of Endocrinology, Oregon Health and Science University, Portland, Oreg., USA;

Department of Endocrinology, Royal Manchester Children's Hospital, Manchester, UK

 

Horm Res 2008;69:233-239 (DOI: 10.1159/000113024)

 

Key Words

 

* Insulin tolerance test

* Hypoglycaemia

* Insulin lispro

* Regular insulin

 

Abstract

 

Background/Aim: The insulin tolerance test (ITT) remains the gold standard for evaluating the pituitary function, but has potential risks when hypoglycaemia is induced. There are scarce data using short-acting insulin analogs for ITTs. This pilot study compares the effects of insulin lispro (LPI) with regular insulin (RGI) during an ITT.

 

Methods: Patients with suspected hypopituitarism (n = 103) randomly received either LPI (n = 51) or RGI (n = 52).

 

Results: All patients reported signs and symptoms when hypoglycaemia was induced. In the LPI group, hypoglycaemia occurred sooner (23.6 ? 1.6 vs. 28.3 ? 1.4 min, p < 0.05), and duration of hypoglycaemia (25.0 ? 1.7 vs. 31.9 ? 1.9 min, p < 0.05) and time for blood glucose levels to return to a 'safe' level (>3.3 mmol/l; 56.5 ? 2.3 vs. 76.0 ? 2.1 min, p < 0.001) were shorter as compared with the RGI group. No differences in peak growth hormone and cortisol levels were observed between the two groups.

 

Conclusions: Our data suggest that despite inducing similar symptomatology, LPI exerted a quicker onset and a shorter duration of hypoglycaemia as compared with RGI. Thus, using LPI might reduce the potential risks associated with an ITT by shortening the hypoglycaemic phase of the test.

 

Copyright ? 2008 S. Karger AG, Basel

 

Author Contacts

 

Dr. Kevin C.J. Yuen

Department of Endocrinology, Oregon Health and Science University

3181 SW Sam Jackson Park Road, mailcode L607

Portland, OR 97239-3098 (USA)

Tel. +1 503 494 0175, Fax +1 503 494 6990, E-Mail yuenk@ohsu.edu

 

Article Information

 

Received: December 11, 2006

Accepted: June 7, 2007

Published online: January 21, 2008

Number of Print Pages : 7

Number of Figures : 1, Number of Tables : 2, Number of References : 36

 

Free Abstract Article (Fulltext) Article (PDF 164 KB)

[cat lady]

Can someone point me in the right direction to find out how this test would affect someone who has an elevated insulin level to begin with and/or how having an elevated insulin level would affect test results? (My insulin is way over the normal range).