Submit a Letter to the Editor for:
E R Seaquist, S E Kahn, P M Clark, C N Hales, D Porte, R P Robertson
J Clin Invest. 1996;
97(2):455
doi:10.1172/JCI118435
Abstract |
Full text
|
PDF
T
he cause of disproportionate hyperproinsulinemia in patients with type II diabetes is controversial. To examine whether increased beta cell demand might contribute, we measured proinsulin and insulin concentrations in clinically healthy humans who had undergone hemipancreatectomy for the purpose of organ donation, a procedure previously demonstrated to increase beta cell demand and diminish insulin secretory reserve capacity. Subjects were studied at least 1 yr after hemipancreatectomy. Seven donors were followed prospectively and serves as their own controls. Nine additional donors were matched with normal controls (cross-sectional group). Fasting serum concentrations of intact proinsulin and conversion intermediates (total) were measured by a two-step radioimmunoassay; independent determinations of intact proinsulin and 32,33 split proinsulin were performed using an immunoradiometric assay. Serum total proinsulin values were significantly greater in hemipancreatectomized groups than controls (prospective group: predonation = 6.24 +/- 1.14 pM, postdonation = 34.63 +/- 17.47 pM, P < 0.005; cross-sectional group: controls = 5.78 +/- 1.12 pM, donors = 15.22 +/- 5.20 pM, P < 0.025). The ratio of total proinsulin to immunoreactive insulin was directly correlated with fasting plasma glucose and showed a significant inverse relationship to secretory reserve capacity. Both absolute and relative hyperproinsulinemia is found in hemipancreatectomized donors. These data demonstrate that partial pancreatectomy with its associated increase in beta cell demand raises measures of proinsulin in humans.
Guidelines:
The Editorial Board will only consider letters that we deem relevant and of interest to our readers. We will not post data that have not been subjected to peer review, nor will we post letters that are essentially a reiteration of another letter. All accepted letters will be posted on our website within one week of acceptance. The Editors reserve the right to edit any letter for length, content, and clarity. Authors of all accepted letters will be asked to preview any changes. Authors will be notified by e-mail if their letters were not accepted. As this is a final decision, no appeals will be considered.
Specific requirements: All letters must be 400 words or fewer. You may enter the letter as plain text or HTML, if you wish. The author's name and e-mail address are required, and will be posted with the letter. All possible conflicts of interest must be noted, even if they are not posted. If you wish to include a figure (keep in mind that non-peer-reviewed data will not be posted), please contact the editor directly at editors@the-jci.org.
