Functional brain MRI in the setting of drug correction of obesity

AIMS. Study of the dynamics of brain activity using functional MRI (fMRI) in obese patients treated with sibutramine (Reduxine®).MATERIALS AND METHODS. The study enrolled patients with a body mass index (BMI) ≥30 kg/m2 . All participants underwent initial brain fMRI mapping. The obesity cohort was treated with sibutramine at a dose of 10 or 15 mg per day for 3 months. After treatment patients with obesity underwent a second fMRI mapping to assess changes against the initial mapping.RESULTS. The study included: 30 patients (86,7% women) with mean age of 31 [27.25; 36] years, mean body weight (BW)  - 106 [95.75; 121.75] kg, mean BMI 37.4 [33.55; 41.9] kg/m2 , mean waist circumference (WC) - 109 [100; 114.75] cm. The most marked activation volume (via fMRI) was observed in patients with obesity (before treatment) in the visual cortex (occipital lobes). After 3 months of treatment with sibutramine, 80% of patients lose ≥5% of BW. Mean BW decrease was -7.2 [-13.46; -5.37] kg, BMI decrease — -7.2 [-13.49; -5.34] кг/м2 , WC decrease — -6.9 [-11.88; -4.03] см, p <0,05. According to fMRI data, a  decrease in brain activation in the projection of the occipital lobes (35%), left insula (44%), and increase inactivation by 70% in the area of the left DMPF.CONCLUSION. A dynamic study of brain activity using fMRI in obese patients showed that during treatment with sibutramine, a decrease in body weight is accompanied by a decrease in activation in the projection of the occipital lobes and the left insular lobe of the brain, and an increase in activation in the area of the left DMPFC. These data may indicate a decrease in the emotional perception of high-calorie food, a decrease in motivation to eat it, and an increase in cognitive control. In general, the noted dynamics of the functional activity of the brain in obese patients against the background of obesity therapy can be regarded as a change in previously formed patterns of eating behavior.