Factor analysis of fatty acids in serum lipids as a measure of dietary fat quality in relation to the metabolic syndrome in men1–3

A specific fatty acid (FA) composition in plasma lipid esters is related to the metabolic syndrome (MetS) and may influence the development of the MetS.The objective was to define and study FA factors as measures of dietary fat quality and endogenous FA metabolism in relation to MetS.Principal factor analysis was performed to define specific FA factors in men participating in a population-based cohort study-the Uppsala Longitudinal Study of Adult Men. The factors were generated at ages 50 (n = 2009) and 70 (n = 576) y, and relations between FA factors and MetS (National Cholesterol Education Program) were studied in cross-sectional and prospective (20 y) analyses.The factor analysis generated 3 major FA factors: a low-linoleic acid (LA) factor, a dietary saturated FA factor, and an n-3 polyunsaturated FA (PUFA) factor. All factors differed between those subjects with MetS (n = 281 of 2009) and those without MetS at age 50 y; only the low-LA factor differed at age 70 y, which suggests an association between MetS and fat quality. The low-LA factor (odds ratio: 1.51; 95% CI: 1.28, 1.79; P < 0.0001) and the n-3 PUFA factor (0.76; 0.64, 0.90; P < 0.001) predicted MetS development over 20 y, independent of smoking habits, physical activity, and BMI.The generated FA factors, which presumably represent dietary fat quality and endogenous FA metabolism, may be important in the development of MetS. This finding supports current dietary recommendations to increase PUFA intakes and restrict saturated FA intakes.