Elevated brain myo-inositol (m-Ins) concentration (a putative marker of neuroinflammation) has been reported in patients suffering from type 2 diabetes mellitus (T2DM). Obesity alone and T2DM have been found to be associated with a lower concentration of N-acetyloaspartate and N-acetylaspartylglutamate (tNAA, a marker of neuronal integrity, reflecting neuronal loss or metabolic derangement). It is not clear if these changes reverse with weight loss. The intra-gastric balloon (IGB) is an endoscopic bariatric therapy that leads to massive weight loss and improvement of glycemic control. In this study we evaluated if tNAA/tCr and m-Ins/tCr metabolite ratios are affected by weight loss, where tCr is the signal of creatine containing compounds. Twenty-three morbidly obese patients, 12 of them with T2DM (OD) and 11 without T2DM (OB), as well as 11 healthy controls of normal weight (CON), underwent single voxel spectroscopy at 3 T. Spectra were obtained within a region in the left parietal white matter one month before IGB insertion, three months after IGB insertion, and one month after IGB removal. Before IGB insertion, m-Ins/tCr was 15% higher in OD than in OB (p = 0.005) and 12% higher in OD than in CON (p = 0.03). m-Ins/tCr decreased significantly by 8% over the first three months after IGB insertion (p = 0.01) and remained normal after IGB removal. tNAA/tCr was normal in all groups throughout the study, pointing to normal brain metabolism. Normalization of m-Ins/tCr is consistent with remission of neuroinflammation in patients with T2DM. An evaluation of long-term effects of IGB treatment is necessary.
Keywords: bariatric therapy; brain; intra-gastric balloon; morbid obesity; myo-inositol; type 2 diabetes mellitus.
© 2018 John Wiley & Sons, Ltd.