title: The contribution of metformin to glycaemic control in patients with Type 2 diabetes mellitus receiving combination therapy with insulin.
abstract: Combination therapy of oral hypoglycaemic agents and insulin is a therapeutic option for those who have deterioration in glycaemic control. We examined the contribution of metformin by withdrawing it from Type 2 diabetic patients who had been stabilised on combination therapy. Fifty-one subjects with Type 2 diabetes and secondary oral hypoglycaemic agent failure were studied in a randomised, open and parallel study. In the first phase of 36 weeks, subjects were stabilised on combined therapy of sulphonylureas and nocturnal insulin, with or without metformin. During the second phase, metformin was withdrawn. The primary variables for efficacy were HbA(1c), fasting plasma glucose and 3-point capillary blood glucose profiles. After stabilisation with combination therapy, those subjects on metformin used less insulin to maintain glycaemic control (13.7+/-6.8 vs. 23.0+/-9.4 U/day, P=0.001) and had lower HbA(1c) values (8.13+/-0.89 vs. 9.05+/-1.30%, P=0.003) compared with those not given metformin. Withdrawal of metformin therapy caused deterioration in HbA(1c) (P=0.001). This study confirms that metformin plays an important role in the success of the combination therapy. The rational use of metformin and sulphonylurea together with insulin will help to improve metabolic control in Type 2 diabetes patients who have secondary drug failure.
authors.affiliation: Department of Medicine and Therapeutics, Division of Endocrinology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, NT, Hong Kong. ptong@cuhk.edu.hk
authors.forename: P C
authors.initials: PC
authors.lastname: Tong
authors.forename: C C
authors.initials: CC
authors.lastname: Chow
authors.forename: L N
authors.initials: LN
authors.lastname: Jorgensen
authors.forename: C S
authors.initials: CS
authors.lastname: Cockram
mesh_terms: D001786:Blood Glucose / Q000378:metabolism*; D015992:Body Mass Index; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000188:drug therapy* / Q000503:physiopathology; D004359:Drug Therapy, Combination; D005215:Fasting; D005260:Female; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D007336:Insulin, Isophane / Q000627:therapeutic use*; D008297:Male; D008687:Metformin / Q000627:therapeutic use*; D008875:Middle Aged; D019518:Postprandial Period; D013453:Sulfonylurea Compounds / Q000627:therapeutic use
chemical_list: D001786:Blood Glucose; D007004:Hypoglycemic Agents; D013453:Sulfonylurea Compounds; D007336:Insulin, Isophane; D008687:Metformin