Is combination sulfonylurea and insulin therapy useful in NIDDM patients? A metaanalysis.
OBJECTIVE
To assess the efficacy of combination therapy with insulin and sulfonylurea in the treatment of NIDDM.


METHODS
Studies published between January 1966 and January 1991 were identified through a computerized Medline search and by hand searching the bibliographies of identified articles. We identified 17 eligible randomized, controlled trials of combination therapy in NIDDM. These trials had a minimum duration of 8 wk and at least one of three outcome measures (fasting glucose, HbA1, or C-peptide) with SD or SE of the mean reported to do metaanalysis. With standardized forms, three independent reviews abstracted measures of study quality and specific descriptive information about population, intervention, and outcome measurements.


RESULTS
We calculated effect size and weighted mean changes of the three outcome measures for control and treatment groups. In the treatment group, the fasting plasma glucose decreased from a mean of 11.4 mM (206 mg/dl) at baseline to a mean of 9.16 mM (165 mg/dl) posttreatment, whereas the control group decreased from (11.3 to 10.8 mM) (204 to 194 mg/dl) (effect size 0.39, P less than 0.0001). For HbA1, the treatment group decreased from a baseline of 11.0 to 10.2% compared to 11.0 and 11.2% in the control group (effect size 0.43, P less than 0.0001). For fasting C-peptide, the treatment group increased from 0.49 to 0.58 nM (1.45 to 1.75 ng/ml) compared with 0.47 and 0.43 (1.42 and 1.30) for the control group (effect size 0.26, P less than 0.017).


CONCLUSIONS
Combined insulin-sulfonylurea therapy leads to modest improvement in glycemic control compared with insulin therapy alone. With combined therapy, lower insulin doses may be used to achieve similar control. Obese patients with higher fasting C-peptides may be more likely to respond than others.
Pugh
J A
JA
Audie L. Murphy Memorial Veterans Hospital, San Antonio, Texas 78284.
Wagner
M L
ML
Sawyer
J
J
Ramirez
G
G
Tuley
M
M
Friedberg
S J
SJ
D001786:Blood Glucose / Q000032:analysis; D002096:C-Peptide / Q000097:blood; D002747:Chlorpropamide / Q000627:therapeutic use; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000188:drug therapy*; D004359:Drug Therapy, Combination; D005907:Gliclazide / Q000627:therapeutic use; D005905:Glyburide / Q000627:therapeutic use; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D007328:Insulin / Q000627:therapeutic use*; D016239:MEDLINE; D015201:Meta-Analysis as Topic; D008875:Middle Aged; D010506:Periodicals as Topic; D013453:Sulfonylurea Compounds / Q000627:therapeutic use*; D014042:Tolazamide / Q000627:therapeutic use; D016896:Treatment Outcome; D014481:United States
D001786:Blood Glucose; D002096:C-Peptide; D002747:Chlorpropamide; D005907:Gliclazide; D005905:Glyburide; D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents; D007328:Insulin; D013453:Sulfonylurea Compounds; D014042:Tolazamide