Plasma omega-3 fatty acids and incident diabetes in older adults
From the Divisions of Aging (LD) and Cardiovascular Medicine and Channing Laboratory (DM), Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA; the Geriatric Research, Education, and Clinical Center and Massachusetts Veterans Epidemiology and Research Information Center, Boston Veterans Affairs Healthcare System, Boston, MA (LD); the Department of Biostatistics, School of Public Health and Community Medicine (MLB), the Cardiovascular Health Research Unit, Department of Medicine (RNL and DSS) and the Department of Epidemiology (DSS), University of Washington, Seattle, WA; the Department of Internal Medicine, University of New Mexico, Albuquerque, NM (IBK); the Public Health Science Division, Fred Hutchinson Cancer Research Center, Seattle, WA (XS); the Division of Nephrology, University of California San Diego, San Diego, CA (JHI); and Nephrology Section, Veterans Affairs San Diego Healthcare System, San Diego, CA (JHI); the Division of General Medicine and Primary Care, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA (KJM); and the Departments of Epidemiology and Nutrition, Harvard School of Public Health, Boston, MA (DM).
Background: Although long-chain omega-3 fatty acid (n−3 FA) consumption estimated via food-frequency questionnaires has been associated with a higher incidence of diabetes, limited prospective data on diabetes risk are available that use objective biomarkers of n−3 FAs.
We sought to examine the relation between plasma phospholipid n−3 FAs and incident diabetes.
We prospectively analyzed data in 3088 older men and women (mean age: 75 y) from the Cardiovascular Health Study (1992–2007). Plasma phospholipid n−3 FAs were measured by using gas chromatography, and incident diabetes was ascertained by using information on hypoglycemic agents and serum glucose. We used Cox proportional hazards models to estimate multivariable-adjusted relative risks.
During a median follow-up of 10.6 y, 204 new cases of diabetes occurred. In a multivariable model that controlled for age, sex, race, clinic site, body mass index, alcohol intake, smoking, physical activity, LDL cholesterol, and linoleic acid, relative risks (95% CIs) for diabetes were 1.0 (reference), 0.96 (0.65, 1.43), 1.03 (0.69, 1.54), and 0.64 (0.41, 1.01) across consecutive quartiles of phospholipid eicosapentaenoic acid and docosahexaenoic acid (P for trend = 0.05). Corresponding relative risks (95% CIs) for phospholipid α-linolenic acid (ALA) were 1.0 (reference), 0.93 (0.65, 1.34), 0.99 (0.68, 1.44), and 0.57 (0.36, 0.90) (P for trend = 0.03).
With the use of objective biomarkers, long-chain n−3 FAs and ALA were not associated with a higher incidence of diabetes. Individuals with the highest concentrations of both types of FAs had lower risk of diabetes.
© 2011 American Society for Nutrition