Clinical Characteristics of Subjects with Sulfonylurea-Dependent Type 2 Diabetes.
BACKGROUND
Even though several oral anti-diabetic drugs (OAD) with various modes of action are replacing sulfonylurea (SU), some patients seem to be dependent on SU for adequate glycemic control. Therefore, we evaluated the clinical characteristics of such patients.


METHODS
We selected the patients with type 2 diabetes who met following criteria from 2009 to 2014 at Seoul National University Hospital: glycated hemoglobin (HbA1c) was maintained below 7.5% for at least 6 months under small dose of SU (glimepiride ≤2 mg/day or equivalent dose); after discontinuation of SU, HbA1c increased ≥1.2% within 3 months or ≥1.5% within 6 months; and after resuming SU, HbA1c reduction was ≥0.8% or reduction of fasting plasma glucose was ≥40 mg/dL within 3 months. Patients with impaired hepatic or renal function, and steroid users were excluded.


RESULTS
Nineteen subjects were enrolled: after averaged 4.8±1.5 months of SU-free period, HbA1c increased from 6.7%±0.4% to 8.8%±0.8% even though adding other OAD such as gliptins. However, HbA1c decreased to 7.4%±0.7% after resuming SU within 2.4±0.8 months. There was no sexual predominance. Despite their old age (67±11 years) and long duration of diabetes (18±10 years), fasting C-peptide was relatively well-reserved (3.9±2.6 ng/mL), and nephropathy was not observed (albumin-creatinine ratio 21.2±16.6 mg/g and estimated glomerular filtration rate 75.8±18.0 mL/min/1.73 m²). Strong family history was also noted (73.7%).


CONCLUSIONS
Despite hypoglycemia risk of SU, it seemed indispensable for a subset of patients with regard to insulin secretion. Genetic influences would be evaluated.
Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
Se Hee
SH
Min
Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
Soo Heon
SH
Kwak
Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
Young Min
YM
Cho
Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
Kyong Soo
KS
Park
Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea. junghs@snu.ac.kr.
Hye Seung
HS
Jung
Diabetes mellitus; Insulin secretion; Sulfonylurea