BACKGROUND:
The
role of increased
insulin resistance in the pathogenesis of
type 2 diabetes has been emphasized in
Asian populations. Thus, we evaluated the proportion of
insulin resistance and the
insulin secretory capacity in
patients with early phase
type 2 diabetes in
Korea.
METHODS:
We performed a
cross-sectional analysis of 1,314
drug-naive
patients with newly diagnosed diabetes from
primary care clinics nationwide. The
homeostasis model assessment of
insulin resistance (HOMA-IR) was used as an index to
measure insulin resistance, which was defined as a HOMA-IR > or =2.5.
Insulin secretory defects were classified based on
fasting plasma C-peptide levels severe ( or =1.7 ng/mL).
RESULTS:
The mean
body mass index (BMI) was 25.2 kg/m2; 77% of
patients had BMIs >23.0 kg/m2. Up to 50% of
patients had
central obesity based on their
waist circumference (> or =90 cm in
men and 85 cm in
women), and 70.6% had
metabolic syndrome. Overall, 59.5% of subjects had
insulin resistance, and 20.2% demonstrated a moderate to severe
insulin secretory defect. Among those with
insulin resistance, a high proportion of subjects (79.0%) had a mild or no
insulin secretory defect. Only 2.6% of the
men and 1.9% of the
women had both
insulin resistance and a moderate to severe
insulin secretory defect.
CONCLUSION:
In this study,
patients with early phase
type 2 diabetes demonstrated increased
insulin resistance, but preserved
insulin secretion, with a high
prevalence of
obesity and
metabolic syndrome.