Metabolite changes in the posterior cingulate cortex could be a signature for early detection of Alzheimer’s disease: a systematic review and meta-analysis study based on 1H-NMR

Abstract

Abstract Background Posterior cingulate cortex (PCC) is a paralimbic cortical structure with a fundamental role in integrative functions of the default mode network (DMN). PCC activation and deactivation of interconnected structures within the medial temporal lobe is essential in memory recall. Aim Assessing the metabolomics content changes in PCC of the patients with Alzheimer’s disease (AD) compared to healthy controls (HC) to find a new method for early AD detection was the primary goal of this study. Methods We performed a comprehensive search through eight international indexing databases. Searches were done using the medical subject headings (Mesh) keywords. Outcome measures included Population (HC/AD), Age (y), Gender (Male/Female), MRI equipment, Tesla (T), MMSE (mean ± SD), absolute and ratio absolutes metabolites in the PCC. All meta-analyses were performed using STATA V.14 tools to provide pooled figures. Results Studies published from 1980 to 2019 using the 1H-NMR technique of 3,067 screened studies, 18 studies comprising 1647 people (658 males and 941 females, 921 HC and 678 AD cases) were included. The results revealed a significant increase in mI content and a substantial decrease in NAA, Glu, and Glx levels of the PCC in AD patients compared to HC. Conclusions Our meta-analysis showed that microstructural disruptions in the PCC could be used as a marker for early AD detection. Although NAA, mI, Glu, and (NAA, Cho, and mI)/Cr biomarkers are substantial metabolites for diagnosis and are most sensitive for diagnosis. Trial registration PROSPERO Registration: CRD42018099325.