Functional assessment of pancreatic beta-cell area in humans.
OBJECTIVE
beta-Cell mass declines progressively during the course of diabetes, and various antidiabetic treatment regimens have been suggested to modulate beta-cell mass. However, imaging methods allowing the monitoring of changes in beta-cell mass in vivo have not yet become available. We address whether pancreatic beta-cell area can be assessed by functional test of insulin secretion in humans.


METHODS
A total of 33 patients with chronic pancreatitis (n = 17), benign pancreatic adenomas (n = 13), and tumors of the ampulla of Vater (n = 3) at various stages of glucose tolerance were examined with an oral glucose load before undergoing pancreatic surgery. Indexes of insulin secretion were calculated and compared with the fractional beta-cell area of the pancreas.


RESULTS
beta-Cell area was related to fasting glucose concentrations in an inverse linear fashion (r = -0.53, P = 0.0014) and to 120-min postchallenge glycemia in an inverse exponential fashion (r = -0.89). beta-Cell area was best predicted by a C-peptide-to-glucose ratio determined 15 min after the glucose drink (r = 0.72, P < 0.0001). However, a fasting C-peptide-to-glucose ratio already yielded a reasonably close correlation (r = 0.63, P < 0.0001). Homeostasis model assessment (HOMA) beta-cell function was unrelated to beta-cell area.


CONCLUSIONS
Glucose control is closely related to pancreatic beta-cell area in humans. A C-peptide-to-glucose ratio after oral glucose ingestion appears to better predict beta-cell area than fasting measures, such as the HOMA index.
Meier
Juris J
JJ
Department of Medicine I, St Josef-Hospital, Ruhr-University Bochum, Germany. juris.meier@ruhr-uni-bochum.de
Menge
Bjoern A
BA
Breuer
Thomas G K
TG
Müller
Christophe A
CA
Tannapfel
Andrea
A
Uhl
Waldemar
W
Schmidt
Wolfgang E
WE
Schrader
Henning
H
D000236:Adenoma / Q000097:blood / Q000473:pathology* / Q000601:surgery; D001786:Blood Glucose / Q000378:metabolism; D002096:C-Peptide / Q000097:blood; D003920:Diabetes Mellitus / Q000097:blood / Q000473:pathology; D005215:Fasting; D005260:Female; D054777:Hair Cells, Ampulla / Q000473:pathology; D006801:Humans; D007328:Insulin / Q000097:blood; D050417:Insulin-Secreting Cells / Q000166:cytology / Q000473:pathology / Q000502:physiology*; D008297:Male; D010190:Pancreatic Neoplasms / Q000097:blood / Q000473:pathology* / Q000601:surgery; D050500:Pancreatitis, Chronic / Q000097:blood / Q000473:pathology* / Q000601:surgery
D001786:Blood Glucose; D002096:C-Peptide; D007328:Insulin