Intermittent Vagal Nerve Block for Improvements in Obesity, Cardiovascular Risk Factors, and Glycemic Control in Patients with Type 2 Diabetes Mellitus: 2-Year Results of the VBLOC DM2 Study

Background: One-year results of the VBLOC DM2 study found that intermittent vagal blocking (VBLOC therapy) was safe among subjects with obesity and type 2 diabetes mellitus (T2DM) and led to significant weight loss and improvements in glycemic parameters and cardiovascular risk factors. Longer-term data are needed to determine whether the results are sustained. Methods: VBLOC DM2 is a prospective, observational study of 28 subjects with T2DM and body mass index (BMI) between 30 and 40 kg/m² to assess mid-term safety and weight loss and improvements in glycemic parameters, and other cardiovascular risk factors with VBLOC therapy. Continuous outcome variables are reported using mixed models. Results: At 24 months, the mean percentage of excess weight loss was 22 % (95 % CI, 15 to 28, p < 0.0001) or 7.0 % total body weight loss (95 % CI, 5.0 to 9.0, p < 0.0001). Hemoglobin A_1c decreased by 0.6 percentage points (95 % CI, 0.2 to 1.0, p = 0.0026) on average from 7.8 % at baseline. Fasting plasma glucose declined by 15 mg/dL (95 % CI, 0 to 29, p = 0.0564) on average from 151 mg/dL at baseline. Among subjects who were hypertensive at baseline, systolic blood pressure declined 10 mmHg (95 % CI, 2 to 19, p = 0.02), diastolic blood pressure declined by 6 mmHg (95 % CI, 0 to 12, p = 0.0423), and mean arterial pressure declined 7 mmHg (95 % CI, 2 to 13, p = 0.014). Waist circumference was significantly reduced by 7 cm (95 % CI, 4 to 10, p < 0.0001) from a baseline of 120 cm. The most common adverse events were mild or moderate heartburn, implant site pain, and constipation. Conclusions: Improvements in obesity and glycemic control were largely sustained after 2 years of treatment with VBLOC therapy with a well-tolerated risk profile.