Serum Polyunsaturated Fatty Acid Composition and Serum High-Sensitivity C-Reactive Protein Levels in Healthy Japanese Residents: The KOBE Study.

BACKGROUND/OBJECTIVES: Serum polyunsaturated fatty acid (PUFA) composition reflects dietary intake and is related to risks for cardiovascular diseases. We hypothesized that serum n-3 PUFA composition, especially including long-chain n-3 PUFA such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), is associated with inflammatory status, which is related to increased risk for cardiovascular diseases. SUBJECTS/METHODS: We investigated the relationship between serum PUFA composition and high-sensitivity C-reactive protein (hs-CRP) levels in a cross-sectional study among 1,102 healthy men and women aged 40-74 years who reside in Kobe City. Multiple linear regression models that predict hs-CRP level were prepared to confirm the contribution of serum total n-3 PUFA, long-chain n-3 PUFA, EPA and DHA compositions after adjusting for other PUFAs and atherosclerotic risk factors. RESULTS: The serum n-3 PUFA, particularly long-chain n-3 PUFA, compositions were inversely associated with the hs-CRP levels. The standardized regression coefficient was -0.089 (p < 0.01) for total n-3 PUFA, -0.091 (p < 0.01) for long-chain n-3 PUFA, -0.071 (p = 0.03) for EPA, and -0.068 (p = 0.04) for DHA. The n-6 PUFA compositions were also inversely associated with the hs-CRP levels (-0.169 [p < 0.01] for total n-6 PUFA and -0.159 [p < 0.01] for linoleic acid). CONCLUSIONS: The serum n-3 PUFA compositions were inversely related with the hs-CRP levels, similar associations were also observed in n-6 PUFA compositions. Our results suggest that dietary PUFA intake was inversely associated with attenuated inflammation in healthy Japanese population.

Significant inverse association of marine n-3 fatty acids with plasma fibrinogen levels in Japanese in Japan but not in whites or Japanese Americans.

BACKGROUND/OBJECTIVES: Numerous studies reported beneficial effects of marine n-3 fatty acids (n-3 FAs) on cardiovascular disease (CVD) and its risk factors. However, the association of marine n-3 FAs with plasma fibrinogen, a risk factor for CVD, remains uncertain. SUBJECTS/METHODS: In a population-based, cross-sectional study of 795 men aged 40-49 without CVD (262 whites in Allegheny County, Pennsylvania, USA, 302 Japanese in Kusatsu, Japan and 229 Japanese Americans in Honolulu, Hawaii, USA), we examined the association of marine n-3 FAs with plasma fibrinogen. Serum FAs were measured by capillary gas-liquid chromatography. Marine n-3 FAs were defined as the sum of docosahexaenoic, eicosapentaenoic and docosapentaenoic acids. Plasma fibrinogen was measured by an automated clot-rate assay. Multiple linear regression analyses were performed to assess the association. RESULTS: White, Japanese and Japanese-American men had mean marine n-3 FAs levels of 3.47%, 8.78% and 4.46%, respectively. Japanese men had a significant inverse association of marine n-3 FAs with fibrinogen (standardized regression coefficient of -0.11, P=0.049), after adjusting for age, body-mass index and current smoking. The significant inverse association remained after further adjusting for diabetes, C-reactive protein, triglycerides and other variables. White or Japanese-American men did not show a significant association. CONCLUSIONS: We observed the significant inverse association of marine n-3 FAs with fibrinogen in Japanese, but not in whites or Japanese Americans. The observation suggests that marine n-3 FAs at very high levels, as seen in the Japanese, may decrease plasma fibrinogen levels.