Improved glycaemic control by switching from insulin NPH to insulin glargine: a retrospective observational study.
BACKGROUND
Insulin glargine (glargine) and insulin NPH (NPH) are two basal insulin treatments. This study investigated the effect on glycaemic control of switching from a NPH-based regimen to a glargine-based regimen in 701 patients with type 1 (n= 304) or type 2 (n= 397) diabetes, using unselected primary care data.


METHODS
Data for this retrospective observational study were extracted from a UK primary care database (The Health Improvement Network). Patients were required to have at least 12 months of data before and after switching from NPH to glargine. The principal analysis was the change in HbA(1c) after 12 months treatment with glargine; secondary analyses included change in weight and total daily insulin dose. Inconsistent reporting of hypoglycemic episodes precludes reliable reporting of this outcome. Multivariate analyses were used to adjust for baseline characteristics and confounding variables.


RESULTS
After adjustment, both diabetic cohorts showed statistically significant reductions in mean HbA(1c) 12 months after the switch, by 0.38% (p < 0.001) in type 1 patients and 0.31% (p < 0.001) in type 2 patients. Improvement in HbA1c was positively correlated with baseline HbA(1c); patients with baseline HbA(1c) > or = 8% had reductions of 0.57% (p < 0.001) and 0.47% (p < 0.001), respectively. There was no significant change in weight or total daily insulin dose while on glargine. The majority of patients received a basal-bolus regimen prior to and after the switch (mean 79.3% before and 77.2% after switch in type 1 patients, and 80.4% and 76.8%, respectively in type 2 patients, p > 0.05).


CONCLUSIONS
In routine clinical practice, switching from NPH to glargine provides the opportunity for improving glycaemic control in diabetes patients inadequately controlled by NPH.
Sharplin
Peter
P
CHKS Health Economics Unit, Health Park, Cardiff, UK. info@chks.co.uk
Gordon
Jason
J
Peters
John R
JR
Tetlow
Anthony P
AP
Longman
Andrea J
AJ
McEwan
Philip
P
D000328:Adult; D001835:Body Weight / Q000187:drug effects; D015331:Cohort Studies; D016208:Databases, Factual; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000188:drug therapy*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000188:drug therapy*; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis*; D006801:Humans; D007003:Hypoglycemia / Q000139:chemically induced; D007328:Insulin / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000627:therapeutic use; D000069036:Insulin Glargine; D007336:Insulin, Isophane / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D049528:Insulin, Long-Acting; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D055815:Young Adult
D006442:Glycated Hemoglobin; D007328:Insulin; D000069036:Insulin Glargine; D007336:Insulin, Isophane; D049528:Insulin, Long-Acting