Effective treatment with oral sulfonylureas in patients with diabetes due to sulfonylurea receptor 1 (SUR1) mutations.
OBJECTIVE
Neonatal diabetes can result from mutations in the Kir6.2 or sulfonylurea receptor 1 (SUR1) subunits of the ATP-sensitive K(+) channel. Transfer from insulin to oral sulfonylureas in patients with neonatal diabetes due to Kir6.2 mutations is well described, but less is known about changing therapy in patients with SUR1 mutations. We aimed to describe the response to sulfonylurea therapy in patients with SUR1 mutations and to compare it with Kir6.2 mutations.


METHODS
We followed 27 patients with SUR1 mutations for at least 2 months after attempted transfer to sulfonylureas. Information was collected on clinical features, treatment before and after transfer, and the transfer protocol used. We compared successful and unsuccessful transfer patients, glycemic control before and after transfer, and treatment requirements in patients with SUR1 and Kir6.2 mutations.


RESULTS
Twenty-three patients (85%) successfully transferred onto sulfonylureas without significant side effects or increased hypoglycemia and did not need insulin injections. In these patients, median A1C fell from 7.2% (interquartile range 6.6-8.2%) on insulin to 5.5% (5.3-6.2%) on sulfonylureas (P = 0.01). When compared with Kir6.2 patients, SUR1 patients needed lower doses of both insulin before transfer (0.4 vs. 0.7 units x kg(-1) x day(-1); P = 0.002) and sulfonylureas after transfer (0.26 vs. 0.45 mg x kg(-1) x day(-1); P = 0.005).


CONCLUSIONS
Oral sulfonylurea therapy is safe and effective in the short term in most patients with diabetes due to SUR1 mutations and may successfully replace treatment with insulin injections. A different treatment protocol needs to be developed for this group because they require lower doses of sulfonylureas than required by Kir6.2 patients.
Rafiq
Meena
M
Institute of Biomedical and Clinical Science, Peninsula Medical School, Exeter, UK.
Flanagan
Sarah E
SE
Patch
Ann-Marie
AM
Shields
Beverley M
BM
Ellard
Sian
S
Hattersley
Andrew T
AT
D018528:ATP-Binding Cassette Transporters / Q000235:genetics*; D000293:Adolescent; D000328:Adult; D019943:Amino Acid Substitution; D002096:C-Peptide / Q000097:blood; D002648:Child; D002675:Child, Preschool; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy* / Q000235:genetics*; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D007223:Infant; D008875:Middle Aged; D009154:Mutation; D015221:Potassium Channels / Q000235:genetics*; D024661:Potassium Channels, Inwardly Rectifying / Q000235:genetics*; D011955:Receptors, Drug / Q000235:genetics*; D013453:Sulfonylurea Compounds / Q000627:therapeutic use*; D064233:Sulfonylurea Receptors; D017211:Treatment Failure; D016896:Treatment Outcome
D018528:ATP-Binding Cassette Transporters; D002096:C-Peptide; D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents; D015221:Potassium Channels; D024661:Potassium Channels, Inwardly Rectifying; D011955:Receptors, Drug; D013453:Sulfonylurea Compounds; D064233:Sulfonylurea Receptors; C577507:ABCC8 protein, human