Objective: To examine whether a telephone-delivered intervention (TDI), designed to improve glycemic control in patients with non-insulin-dependent diabetes mellitus (NIDDM), improved coronary risk factors in high-risk patients.
Research design and methods: This randomized controlled trial involved 275 veterans with NIDDM followed in a general medical clinic. Intervention (TDI) patients were telephoned at least monthly by a nurse. Calls emphasized compliance with the medical regimen (diet, medications, and exercise), encouraged behavioral changes, and facilitated referrals to a dietitian or smoking cessation clinic. Control patients received no such calls. Baseline and 12-month follow-up measurements included fasting lipid profiles, weight, smoking status (self-reported; cessation verified by measurement of exhaled CO), adherence to diet and exercise (self-reported), appointments, and medications (hospital computerized data base).
Results: After 12 months, equal numbers of obese patients in the two groups reported adhering to a diabetic diet and exercising, although more obese TDI patients had seen a dietitian (30 vs. 7%, P = 0.003). Weight loss was not seen in either group (-0.9 +/- 5.3 vs. -0.1 +/- 3.6 kg, P = 0.202). Hyperlipidemic TDI patients were more likely to see a dietitian (31 vs. 6%, P = 0.003) and receive lipid-lowering medications (22 vs. 9%, P = 0.096), but serum cholesterol reduction was similar between groups (-11.7 +/- 33.4 vs. -4.3 +/- 32.7 mg/dl, P = 0.270); comparable results were seen for high-density lipoprotein, low-density lipoprotein, and triglyceride levels. More TDI group smokers reported quitting (26 vs. 0%, P = 0.033), but the difference was not significant for CO-verified abstention (10 vs. 0%, P = 0.231).
Conclusions: The TDI improved self-reported adherence to regimens that might reduce coronary risk, but had little effect on objective measures of risk.