Delay of insulin addition to oral combination therapy despite inadequate glycemic control: delay of insulin therapy.
BACKGROUND
Patients and providers may be reluctant to escalate to insulin therapy despite inadequate glycemic control.


OBJECTIVE
To determine the proportion of patients attaining and maintaining glycemic targets after initiating sulfonylurea and metformin oral combination therapy (SU/MET); to assess insulin initiation among patients failing SU/MET; and to estimate the glycemic burden incurred, stratified by whether HbA(1c) goal was attained and maintained.


METHODS
Longitudinal observational cohort study.


METHODS
Type 2 diabetes patients, 3,891, who newly initiated SU/MET between 1 January 1996 and 31 December 2000.


METHODS
Subjects were followed until insulin was added, health plan disenrollment, or until 31 December 2005. We calculated the number of months subjects continued SU/MET therapy alone, in total, and during periods of inadequate glycemic control; the A1C reached during those time periods; and total glycemic burden, defined as the estimated cumulative monthly difference between measured A1C and 8%.


RESULTS
During a mean follow-up of 54.6 +/- 28.6 months, 41.9% of the subjects added insulin, and 11.8% received maximal doses of both oral agents. Over half of SU/MET patients attained but failed to maintain A1C of 8%, yet continued SU/MET therapy for an average of nearly 3 years, sustaining glycemic burden equivalent to nearly 32 months of A1C levels of 9%. Another 18% of patients never attained the 8% goal with SU/MET, yet continued that therapy for an average of 30 months, reaching mean A1C levels of 10%.


CONCLUSIONS
Despite inadequate glycemic control, a minority of patients added insulin or maximized oral agent doses, thus, incurring substantial glycemic burden on SU/MET. Additional studies are needed to examine the benefits of rapid titration to maximum doses and earlier initiation of insulin therapy.
Nichols
Gregory A
GA
Kaiser Permanente Center for Health Research, Portland, OR 97227-1098, USA. greg.nichols@kpchr.org
Koo
Yuri H
YH
Shah
Sonali N
SN
D000284:Administration, Oral; D000368:Aged; D001786:Blood Glucose / Q000187:drug effects / Q000378:metabolism; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000188:drug therapy; D004359:Drug Therapy, Combination; D005260:Female; D005500:Follow-Up Studies; D038321:Glycemic Index / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage*; D007328:Insulin / Q000008:administration & dosage*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013997:Time Factors
D001786:Blood Glucose; D007004:Hypoglycemic Agents; D007328:Insulin