11-octadecenoic-acid and Diabetes-Mellitus--Type-2

Determine whether plasma omega-7 vaccenic acid and palmitoleic acid levels are related to homeostasis model of insulin resistance scores and incident type II diabetes, and whether race/ethnicity modifies these associations.. Plasma phospholipid fatty acids were measured by gas chromatography with flame-ionization detection in Multi-Ethnic Study of Atherosclerosis participants. Linear regression determined associations of vaccenic acid and palmitoleic acid with log-transformed homeostasis model of insulin resistance scores (n=5689), and Cox regression determined associations with incident type II diabetes (n=5413, 660 cases). Race-interactions were tested.. Adjusting for typical risk factors, higher levels of plasma vaccenic acid were found to be inversely associated with insulin resistance scores across all four race/ethnicities, and a significant race-interaction was observed between Hispanics and Caucasians (P for interaction=0.03). Vaccenic acid was related to 17%, 32%, and 39% lower risks of incident type II diabetes in Black, Hispanic, and Chinese American participants, respectively. Differences in associations between races were detected (P for interactions<0.05). By contrast, higher levels of plasma palmitoleic acid were related to greater insulin resistance scores in Blacks (P<0.001) and Hispanics (P<0.001); significant race-based differences between associations were detected (P for interactions<0.05). Palmitoleic acid was correspondingly related to a 21% greater risk of incident type II diabetes in Black individuals.. Results suggest that plasma vaccenic acid and palmitoleic acid are markers of metabolic health and dysfunction, respectively. Coupled with previous evidence and the significant race-interactions, our findings have implications for future studies of the race-based differences in omega-7 fatty acids and their regulation in the context of deteriorating metabolic health.

Topics: Aged; Asian; Biomarkers; Black or African American; Diabetes Mellitus, Type 2; Fatty Acids, Monounsaturated; Female; Hispanic or Latino; Humans; Incidence; Insulin Resistance; Linear Models; Male; Metabolic Syndrome; Middle Aged; Oleic Acids; Proportional Hazards Models; White People

Trans-11 vaccenic acid (VA) is a fatty acid produced by ruminants entering the human food supply through meat and dairy products, which appears not to have the health risks associated with industrially produced trans-fatty acids. In this study, we investigated the effect of VA on insulin secretion in vivo in rats and in vitro in human and rat islets after diabetogenic insult.. Hyperglycemic clamp showed that VA dietary supplementation for 8 weeks significantly increased glucose turnover in rats with type 2 diabetes (T2D), accompanied by an elevated plasma C-peptide concentration, indicating improved insulin secretion. The β-cell area and proliferation rate were higher in T2D+VA than T2D group. Isolated islets from T2D+VA rats had higher glucose-stimulated insulin secretion (GSIS) than T2D group. In vitro, VA treatment for 24 and 48 h significantly enhanced GSIS in rat and human islets after diabetogenic challenges. The mRNA expression of G-protein-coupled receptor 40 (GPR40) and regenerating islet-derived 1α (REG-1α) were consistently increased by VA in both rat and human islets.. These results indicate that VA may improve insulin secretion and growth of islets in T2D, at least partly by altering GPR40 and REG-1α mRNA expression.

Topics: Aged; Animals; Cell Proliferation; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diet, High-Fat; Dietary Supplements; Glucose; Humans; Insulin; Insulin Secretion; Islets of Langerhans; Male; Middle Aged; Oleic Acids; Palmitic Acid; Rats, Sprague-Dawley; Receptors, G-Protein-Coupled; Tacrolimus