Study of the Effect of Moxonidine and Diet on Sympathetic Functions in Young Adults With Obesity

The prevalence of obesity is increasing rapidly among adults and has more than doubled in the past 10 years. The metabolic syndrome (MS) is often associated with obesity. It is characterized by abdominal obesity, high blood pressure, unfavorable blood cholesterol profile, elevated blood sugar and impaired insulin action. Persons with the MS have an increased risk of developing type 2 diabetes as well as heart and kidney disease.

The prevalence of obesity and MS is also very high in children and young adults. While there are increasing numbers of studies assessing risk factors for cardiovascular and kidney disease in middle aged to older obese subjects, few studies have addressed the issue of the presence of obesity in young adults and its association with MS on early damage to the organs such as the kidneys, the heart and the blood vessels. The investigators' laboratory has a particular interest on the sympathetic nervous system, which is an important regulatory mechanism of both metabolic and cardiovascular function, as altered sympathetic activity may play a role in the complications of obesity.

Moxonidine is a medication that is approved in Australia by the Therapeutic Goods Administration to treat high blood pressure. It works by decreasing the activity of the sympathetic nervous system. With the elevation of the sympathetic activity in obesity, the investigators believe moxonidine may have a favourable role in rescuing early organ damage associated with obesity. This study will assess whether treating obese subjects with moxonidine have positive effects on blood vessels, cardiac and kidney function and anxiety disorder. The investigators will also examine the influence of the sympathetic nervous system activity in these possible altered cardiac, kidney and vessel functions.