N-3 polyunsaturated fatty acids (PUFAs) have been associated with reduced inflammation. We tested the hypothesis that high serum concentrations of the n-3 PUFAs are associated with lower serum C-reactive protein (CRP) concentrations in healthy middle-aged Finnish men. We also examined whether exposure to mercury, an environmental contaminant in fish, which is also a major source of long-chain n-3 PUFA, was associated with CRP.
Data from the prospective, population-based Kuopio Ischaemic Heart Disease Risk Factor Study were analyzed cross-sectionally to determine the associations between serum n-3 PUFAs, hair mercury and serum CRP in 1395 healthy men, aged 42-60 years. Linear regression analyses were performed to analyze the associations.
In the multivariate models, the mean serum CRP in quartiles of serum total n-3 PUFA concentration was 1.23, 1.27, 1.18 and 1.08 mg/l, P for trend = 0.01. Statistically significant inverse associations were also observed with the total serum long-chain n-3 PUFA concentration and with the individual long-chain n-3 PUFAs docosapentaenoic acid and docosahexaenoic acid, but not with eicosapentaenoic acid or with the intermediate-chain n-3 PUFA alpha-linolenic acid. Hair methylmercury content was not associated with serum CRP levels and it did not modify the associations between serum n-3 PUFAs and CRP either.
Serum n-3 PUFAs and especially the long-chain n-3 PUFA concentration, a marker of fish or fish oil consumption, were inversely associated with serum CRP in men. Exposure to mercury was not associated with serum CRP.
Cardiovascular (CV) disease is the leading cause of death after renal transplantation. Marine n-3 polyunsaturated fatty acids (PUFAs) exert potential cardio-protective metabolic effects and might reduce CV morbidity and mortality in renal transplant recipients (RTRs).
In this cross-sectional study of 1990 Norwegian RTRs, transplanted between 1999 and 2011, associations between plasma phospholipid marine n-3 PUFA levels and various CV risk markers at 10 weeks after transplant were evaluated.
Higher plasma marine n-3 PUFA levels were associated with lower resting heart rate (rHR), lower fasting plasma glucose (fPG) levels, lower plasma triglyceride levels and higher plasma high-density lipoprotein (HDL) cholesterol levels. Plasma levels of eicosapentaenoic acid, but not docosahexaenoic acid, showed a positive association with plasma HDL cholesterol levels. Plasma marine n-3 PUFA levels were not associated with plasma low-density lipoprotein cholesterol levels, pulse wave velocity or systolic and diastolic blood pressure. A negative association between plasma marine n-3 PUFA levels and CV mortality was weakened by additional adjustment for plasma triglyceride levels and rHR. The ratio of n-6 to n-3 PUFAs showed similar associations with CV risk markers as absolute plasma marine n-3 PUFA levels.
This is the first study in RTRs showing that marine n-3 PUFAs are negatively associated with rHR and fPG in addition to beneficial effects on plasma HDL cholesterol and triglyceride levels. Especially, effects on autonomic nervous function and triglyceride metabolism might contribute to explain the lower CV mortality risk with higher plasma marine n-3 PUFA levels previously shown in this cohort.
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