Changes in urinary odd‐chain and even‐chain saturated fatty acids in Alzheimer’s Disease

Background The health benefits of odd-chain saturated fatty acids (ocSAFA) have recently been recognized. We previously showed decreased unesterified ocSAFA in cerebrospinal fluid (CSF) AD compared to MCI and cognitively healthy (CH). However, changes relative even-chain (ecSAFA) not determined other biofluids. Therefore, we aim determine if levels ecSAFA may reveal pathology urine. Methods used neuropsychology CSF measures Ab42 T-tau classify groups elderly subjects as (CH) with negative (CH-Ab-), positive (CH-Ab+), MCI, AD. collected urine after an overnight fast quantified (UFA) esterified (EFA) using gas chromatography coupled negative-ion chemical ionization mass spectrometry. For data normalization, measured species (C15:0, C17:0, C19:0) (14:0, C16:0, C18:0, C20:0, C22:0, C24:0) a proportion the sum all UFA or EFA > C14:0 calculated group differences ordinary ANOVA Tukey’s multiple comparison tests. Results Urine C15:0 were significantly higher than CT (p = 0.0016). Similarly, (p<0.0001). Although Aβ42 CH-Aβ+ are different, C15:0, C19:0, total CH-Aβ+. Urinary did change CH MCI. In contrast, CH. While C16:0 decreased, C18:0 increased These result significant decrease C18:0/C16:0 ratio (Fig. 1). was (p<0.0001) 2). Conclusions studies suggest that can AD-associated pathology. measurement be monitor AD-linked biochemical pathways therapies targeting acid metabolism