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

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 .