Loss of regular oscillatory insulin secretion in islet cell antibody positive non-diabetic subjects.
Basal insulin secretion was compared in nine islet-cell antibody positive, non-diabetic first-degree relatives of children with Type 1 (insulin-dependent) diabetes mellitus and nine normal control subjects matched for age, sex and weight. Acute insulin responses to a 25 g intravenous glucose tolerance test were similar in the two groups (243 (198-229) vs 329 (285-380) mU.l-1 x 10 min-1, mean (+/- SE), p = 0.25). Fasting plasma insulin was assayed in venous samples taken at one min intervals for 2 h. Time series analysis was used to demonstrate oscillatory patterns in plasma insulin. Autocorrelation showed that regular oscillatory activity was generally absent in the islet-cell antibody-positive group, whereas a regular 13 min cycle was shown in control subjects (p less than 0.0001). Fourier transformation did, however, show a 13 min spectral peak in the islet-cell antibody positive group, consistent with intermittent pulsatility. We conclude that overall oscillatory patterns of basal insulin secretion are altered in islet-cell antibody positive subjects even when the acute insulin response is within the normal range.
Bingley
P J
PJ
Department of Diabetes and Metabolism, St. Bartholomew's Hospital, London.
Matthews
D R
DR
Williams
A J
AJ
Bottazzo
G F
GF
Gale
E A
EA
D000204:Activity Cycles; D000328:Adult; D001323:Autoantibodies / Q000032:analysis*; D001786:Blood Glucose / Q000032:analysis*; D003922:Diabetes Mellitus, Type 1 / Q000235:genetics / Q000276:immunology*; D005215:Fasting; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood / Q000378:metabolism*; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000276:immunology*; D008297:Male; D012016:Reference Values
D001323:Autoantibodies; D001786:Blood Glucose; D007328:Insulin; C024211:islet cell antibody