Associations between omega-6 polyunsaturated fatty acids, hyperinsulinemia and incident diabetes by race/ethnicity: The Multi-Ethnic Study of Atherosclerosis

• Published in: Clinical nutrition (Edinburgh, Scotland) Scotland), 2020-10, Vol.39 (10), p.3031-3041
• Main Authors: Weir, Natalie L., Nomura, Sarah O., Steffen, Brian T., Guan, Weihua, Karger, Amy B., Klein, Ronald, Klein, Barbara E.K., Cotch, Mary Frances, Tsai, Michael Y.
• Format: Article
• Language: English
• Subjects: African Americans; Aged; Aged, 80 and over; Asian Americans; Biomarkers - blood; Cross-Sectional Studies; Diabetes Mellitus, Type 2 - blood; Diabetes Mellitus, Type 2 - diagnosis; Diabetes Mellitus, Type 2 - ethnology; Fatty acids; Fatty Acids, Omega-6 - blood; Female; Hispanic or Latino; HOMA-IR; Humans; Hyperinsulinemia; Hyperinsulinism - blood; Hyperinsulinism - diagnosis; Hyperinsulinism - ethnology; Incidence; Insulin Resistance - ethnology; Male; Middle Aged; Omega-6; Prevalence; Prognosis; Race Factors; Race/ethnicity; Racial Groups; Risk Assessment; Risk Factors; Type 2 diabetes; United States - epidemiology; Whites
• ISSN: 0261-5614; 1532-1983
• DOI: 10.1016/j.clnu.2020.01.003

Omega-6 polyunsaturated fatty acids (PUFAs) have been shown to relate to insulin resistance and type 2 diabetes (T2D), but influence of race/ethnicity has not been investigated. The aim of this study was to determine whether omega-6 PUFAs, and estimated desaturase enzyme activity, are associated with fasting glucose, insulin, homeostasis model assessment of insulin resistance (HOMA-IR) and incident T2D, and whether associations differ by race/ethnicity. This study was conducted in the Multi-Ethnic Study of Atherosclerosis (MESA) (N = 6282). Associations between baseline plasma phospholipid fatty acids (LA, Linoleic Acid; GLA, γ-linoleic acid; DGLA, Dihomo-γ-linolenic acid; AA, arachidonic acid; D5D, delta-5 desaturase; D6D, delta-6 desaturase), fasting glucose, insulin, and HOMA-IR [(fasting insulin – fasting glucose)/22.5] were evaluated using linear regression. Associations between omega-6 PUFAs (N = 5508 after excluding diabetics at baseline) and T2D incidence were assessed using Cox proportional hazards regression. Analyses were replicated/stratified by race/ethnicity (White, Black, Chinese, Hispanic) and tests for interaction were assessed by inclusion of a cross-product term in models. In fully adjusted models, insulin and HOMA-IR were positively associated with LA (insulin: 0.213 per SD, p = 0.01; HOMA-IR: 0.252 per SD, p