<p><b>OBJECTIVE</b>To evaluate islet beta
cell response to intravenous
glucagon (a non-
glucose secretagogue) stimulation in
diabetes mellitus.</p><p><b>
METHODS</b>Nineteen
patients with
type 1 diabetes (T1D) and 131
patients with
type 2 diabetes (T2D) were recruited in this study. T2D
patients were divided into two groups according to
therapy 36 cases treated with
insulin and 95 cases treated with
diet or oral
therapy. The
serum C-peptide levels were determined at
fasting and six minutes after
intravenous injection of 1 mg of
glucagon.</p><p><b>RESULTS</b>Both
fasting and 6-minute post-
glucagon-stimulated
C-peptide levels in T1D
patients were significantly lower than those of T2D
patients (0.76 +/- 0.36 ng/mL vs. 1.81 +/- 0.78 ng/mL, P < 0.05; 0.88 +/- 0.42 ng/mL vs. 3.68 +/- 0.98 ng/mL, P < 0.05). In T1D
patients, the
C-peptide level after
injection of
glucagon was
similar to the
fasting level. In T2D,
patients treated with
diet or oral
drug had a significantly greater
fasting and stimulated
C-peptide level than those
patients received
insulin therapy (2.45 +/- 0.93 ng/mL vs. 1.61 +/- 0.68 ng/mL, P < 0.05; 5.26 +/- 1.24 ng/mL vs. 2.15 +/- 0.76 ng/mL, P < 0.05). The
serum C-peptide level after
glucagon stimulation was positively correlated with
C-peptide levels at
fasting in all three groups (r = 0.76, P < 0.05).</p><p><b>CONCLUSIONS</b>The 6-minute
glucagon test is valuable in assessing the function of islet beta
cell in
patients with
diabetes mellitus. It is helpful for
diagnosis and
treatment of
diabetes mellitus.</p>