ABSTRACT
BACKGROUND: Fatty acids (FA) play an important role in health and heart disease risk. OBJECTIVE: We evaluated relationships of plasma FA levels, especially omega-3 FA, with sex, age, and reported heart disease mortality rates by state in a very large clinical population. METHODS: Plasma FA were measured by gas chromatography/mass spectrometry after lipid extraction in 1,169,621 fasting United States subjects grouped according to sex (56.2% female), age (<30, 30-<45, 45-<55, 55-<65, ≥65 years; median age 58.2 years), and state of residence. RESULTS: Plasma FA index values (median±interquartile range), expressed as a percent of total plasma FA, in all subjects were: saturated (14:0+16:0+18:0) 31.4±1.5%; monounsaturated (16:1n7-cis+18:1n9-cis) 21.3±2.2%; trans (16:1n7-trans+18:1n9-trans) 0.45±0.08%; omega-6 (18:2n6-cis+20:3n6+20:4n6) 42.5±3.0%; and omega-3 (20:5n3+22:6n3) 2.57±0.81%. The median eicosapentaenoic acid (EPA, 20:5n3) concentration was 22.1±9.7 µg/mL. Females had significantly (P<0.0001) higher omega-3 FA indices (+6.82%) than males. Subjects ≥65 years of age had a higher omega-3 FA index (+29.68%) and higher EPA levels (+57.05%) than subjects <30 years of age (P<0.00001). EPA concentrations and omega-3 FA indices were below overall median levels in most southern and midwestern states. State-reported heart disease mortality rates were inversely correlated with EPA levels (r=-0.504) and omega-3 FA indices (r=-0.570), and positively correlated with saturated FA indices (r=0.450), all P<0.01. CONCLUSION: In our large population, females, subjects ≥65 years, and those living in northeastern and western states had higher omega-3 fatty acid levels and lower saturated fatty acid levels than other subjects. Such changes were associated with lower state-wide heart disease death rates.
