Timothy B. Seaton

Reduction of Glycosylated Hemoglobin and Postprandial Hyperglycemia by Acarbose in Patients With NIDDM: A placebo-controlled dose-comparison study

OBJECTIVE To compare the safety and efficacy of three doses of acarbose (100, 200, and 300 mg three times daily) with placebo for the treatment of non-insulin-dependent diabetes mellitus (NIDDM) in patients maintained on dietary therapy alone. RESEARCH DESIGN AND METHODS This multicenter double-blind placebo-controlled trial was 22 weeks in duration. The trial consisted of a 2-week screening period, a 4-week placebo run-in period, and a 16-week double-blind treatment period. The primary measure of drug efficacy was the mean change from baseline in HbA1c levels. Additional efficacy variables included the mean change from baseline in fasting and postprandial plasma glucose and serum insulin levels. RESULTS After 16 weeks of treatment, acarbose-treated patients had statistically significant reductions in mean HbA1c levels of 0.78, 0.73, and 1.10% (relative to placebo) in the 100-, 200-, and 300-mg t.i.d. groups, respectively. Significant reductions in fasting and postprandial plasma glucose levels, glucose area under the time-concentration curve, and maximum glucose concentration were also observed in acarbose-treated patients. Although there were no statistically significant differences among the 100-, 200-, and 300-mg treatment groups, there was a trend toward a dose-response relationship for most plasma glucose variables that were measured. Gastrointestinal side effects (e.g., abdominal pain, flatulence, and diarrhea) and serum transaminase elevations (e.g., aspartate aminotransferase [AST] and alanine aminotransferase [ALT] were more frequently reported in the acarbose-treated patients than in the placebo-treated control patients. Transaminase elevations occurred only at the 200-, and 300-mg dosages and were readily reversible on discontinuation of treatment. CONCLUSIONS Acarbose at doses of 100, 200, and 300 mg administered three times daily for 16 weeks significantly reduced HbA1c levels and postprandial hyperglycemia. Treatment with acarbose is a safe and effective adjunct to dietary therapy for the treatment of NIDDM.

A Double-Blind Placebo-Controlled Trial Evaluating the Safety and Efficacy of Acarbose for the Treatment of Patients With Insulin-Requiring Type II Diabetes

OBJECTIVE To determine whether a forced titration of acarbose (from 50 to 300 mg three times daily) administered over a 24-week period, in conjunction with diet and insulin therapy, improves glycemic control and reduces daily insulin requirements in insulin-requiring type II diabetes. RESEARCH DESIGN AND METHODS This multicenter, randomized, double-blind, placebo-controlled trial was 36 weeks in duration. The trial consisted of a 6-week pretreatment period, a 24-week double-blind treatment period, and a 6-week post-treatment follow-up period. The primary efficacy variables were the mean change from baseline in HbA1c levels and the mean percentage change from baseline in total daily insulin dose. RESULTS Treatment with acarbose was associated with significant reductions in HbA1c levels of 0.40% (P = 0.0001) and in total daily insulin dose of 8.3% (P = 0.0015). There were also significant reductions in all plasma glucose variables measured, including a 0.9 mmol/l reduction in fasting glucose (P = 0.0440), a 2.6 mmol/l reduction in glucose Cmax (P = 0.0001) and a 270 mmol·min−1·l−1 reduction in glucose area under the curve (P = 0.0002). Although acarbose treatment was associated with a greater incidence of adverse events than was placebo treatment, primarily flatulence and diarrhea, these events did not generally prevent patients from completing the study. CONCLUSIONS The results of this study suggest that acarbose is a safe and effective adjunct to diet and insulin therapy for the management of insulin-requiring type II diabetes.

Control of metabolism

Publisher Summary This chapter discusses control of metabolism. Cells carry out the manifold chemical activities by which growth and metabolic functions are achieved. Enzymes are present in the cytosol, in membranes and organelles, they catalyze the interconversion of small molecules, polymerize to give macromolecules, and transport metabolites across boundaries. A large body of research is concerned with identifying and investigating the details of how various effectors act on particular enzymes. The intensive study of enzymes by in vitro methods has led to the most significant advances in understanding of the elementary processes in the cell. Kinetic and thermodynamic analysis of some enzymes has given detailed information on the reaction mechanism, the fundamental constants, the transition states, the solvation complexes, and the dynamics of the three-dimensional structure.