Year: 2017
Type: dissertation
Study design: Observational Study
Abstract: Type 2 diabetes mellitus (T2DM) is a chronic disease of glucose dysregulation leading to elevated blood glucose. Given that fatty acid and glucose metabolism are tightly entwined and that limited long-term data are available on this relationship, the objective of this thesis is to investigate the longitudinal associations of fatty acids from four lipid fractions on insulin sensitivity and beta-cell function. Data from an observational cohort of adults at risk for T2DM (n=477) was used, where 22 fatty acids in phospholipid, cholesteryl ester, triacylglycerol (TAG), and non-esterified fatty acid (NEFA) fractions were quantified. Insulin sensitivity and beta-cell function indices were computed using glucose and insulin obtained from a 75g oral glucose tolerance test. Results from the analyses of these data show that fatty acids have differential associations with the pathogenesis of T2DM, dependent on the lipid fraction and on the species. Fatty acids within either phospholipid or TAG fractions showed varied and strong associations with insulin sensitivity and moderate associations with beta-cell function, while few associations were seen in the cholesteryl ester or NEFA fraction. Some results of particular note: higher phospholipid palmitic acid associated with 6-year declines in beta-cell function; phospholipid and TAG cis-vaccenic acid had consistent and strong beneficial associations with insulin sensitivity and beta-cell function; four TAG fatty acids strongly clustered together and higher levels strongly associated with lower insulin sensitivity, of which these four fatty acids are also indicative of higher de novo lipogenesis; and, higher total NEFA concentration associated with lower beta-cell function, independent of the specific fatty acid composition. These results emphasize that fatty acids have complex and differential associations on glucose metabolism and highlight potential areas of future research, for instance, on the de novo lipogenesis fatty acids or with cis-vaccenic acid, the study of which may lead to better prevention or management strategies for T2DM.
Source: TSpace (University of Toronto)
Author: Luke Johnston
Language: English
Subfield: Nutrition and Dietetics
Field: Nursing
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W3136827761