RSS Feeds
Risks and Benefits of Insulin-like Growth Factor
The Editors welcome submissions for possible publication in the Letters section. Authors of letters should:
•Include no more than 300 words of text, three authors, and five references
•Type with double-spacing
•Send three copies of the letter, an authors' form signed by all authors, and a cover letter describing any conflicts of interest related to the contents of the letter.
Letters commenting on an Annals article will be considered if they are received within 6 weeks of the time the article was published. Only some of the letters received can be published. Published letters are edited and may be shortened; tables and figures are included only selectively. Authors will be notified that the letter has been received. If the letter is selected for publication, the author will be notified about 3 weeks before the publication date. Unpublished letters cannot be returned.
Annals welcomes electronically submitted letters.
TO THE EDITOR:
I report some additional uses and potentially serious side effects of intravenous IGF-I not mentioned in the recently published NIH conference on clinical uses of IGF-I [1]. We have shown that high-dose (500 µg/kg of body weight), bolus intravenous IGF-I therapy resulted in both temporal and prolonged insulin sensitivity in two patients with type I diabetes complicated by severe insulin resistance [2-4]. In both patients, daily subcutaneous IGF-I administration with insulin resulted in temporal glycemic control, but severe resistance returned 48 hours after therapy was discontinued. Therapy had to be discontinued after 2 to 6 weeks because of severe arthralgia and multiple cranial nerve palsies.
However, 500-µg/kg IGF-I bolus therapy (with maximal serum IGF-I concentrations of approximately 6000 µg/L) resulted in daily insulin dose requirement reductions from several thousand units administered intravenously to 1 U/kg daily given subcutaneously for 7 to 10 days. Lower serum IGF-I concentrations resulting from 250-µg/kg boluses were ineffective in decreasing serum glucose acutely or in inducing sustained insulin sensitivity [4].
Most importantly, both patients experienced severe dyspnea associated with a short-term decrease in serum phosphate levels within 10 minutes of receiving the intravenous IGF-I bolus [2, 3]. This side effect was reversed and prevented during subsequent IGF-I administration by coadministration of intravenous potassium phosphate. When an adequate phosphate dose was administered, weekly or alternate-week bolus IGF-I therapy had no discernible adverse reactions in the two patients.
Anton-Lewis Usala, MD
East Carolina University Diabetes Center; Greenville, NC 27858-4354
The Editors welcome submissions for possible publication in the Letters section. Authors of letters should:
•Include no more than 300 words of text, three authors, and five references
•Type with double-spacing
•Send three copies of the letter, an authors' form signed by all authors, and a cover letter describing any conflicts of interest related to the contents of the letter.
Letters commenting on an Annals article will be considered if they are received within 6 weeks of the time the article was published. Only some of the letters received can be published. Published letters are edited and may be shortened; tables and figures are included only selectively. Authors will be notified that the letter has been received. If the letter is selected for publication, the author will be notified about 3 weeks before the publication date. Unpublished letters cannot be returned.
Annals welcomes electronically submitted letters.
- Copyright ©2004 by the American College of Physicians
