The Associations of C-Reactive Protein with Serum Levels of Polyunsaturated Fatty Acids and Trans Fatty Acids Among Middle-Aged Men from Three Populations

Dose-dependent effects of omega-3 polyunsaturated fatty acids on C-reactive protein concentrations in cardiometabolic disorders: a dose-response meta-analysis of randomized clinical trials

BACKGROUND

Based on current knowledge, omega-3 fatty acids help to reduce the concentration of C-reactive protein (CRP). However, the dose-response effect and the strength of this effect are not entirely clear.

METHODS

We systematically searched and screened databases to include eligible studies. This study incorporates a random effect, as well as dose-response meta-analyses using a restricted cubic spline model.

RESULTS

Forty randomized clinical trials were analyzed. Results demonstrated significant non-linear dose-response efficacy in the reduction of CRP concentration in patients with cardiovascular disease, metabolic syndrome, and hypertension up to 1200 mg/day of EPA and DHA. In addition, there was a linear decrease in CRP concentration in the dyslipidemia population. The meta-analysis results did not show any significant reduction of CRP in overweight and obese participants, and the dose-response analysis failed to show any apparent reduction. In type 2 diabetes, pooling the results revealed a significant reduction in CRP; however, the combination of EPA and DHA failed to show significant dose-response efficacy in changing CRP concentration.

CONCLUSION

1200 mg/day of EPA and DHA may help to reduce CRP concentration in patients with cardiometabolic disorders. This reduction is clinically significant, and thus intervention with omega-3 fatty acids should be considered for this population.

Omega-3 Polyunsaturated Fatty Acids Can Reduce C-Reactive Protein in Patients with Cancer: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

ABSTRACTSOmega-3 polyunsaturated fatty acids (PUFAs) possess anti-inflammatory properties. There is a lack of consensus regarding the effects of omega-3 PUFAs on C-reactive protein (CRP), a marker of systemic inflammation, in cancer patients. Herein, a meta-analysis of randomized controlled trials was conducted to evaluate the effects of omega-3 PUFAs on CRP levels in patients with cancer. PubMed and EMBASE were searched until May 2020 to identify randomized controlled trials that examined the effects of omega-3 PUFA administration on CRP levels in cancer patients. Standardized mean differences (SMDs) with their 95% confidence intervals (CIs) were calculated to determine the differences in omega-3 PUFA administration and control conditions. Seventeen eligible studies involving 916 cancer patients were included in this meta-analysis. Significant heterogeneity was present among individual studies (P_{heterogeneity} = 0.000; I² = 74.5%). The overall SMDs of CRP levels between omega-3 PUFA administration and control conditions were 0.628 (95% CI: 0.342-0.914) and 0.456 (95% CI: 0.322-0.590) by the random-effect and fixed-effect models, respectively. Sources of heterogeneity were not found through subgroup and meta-regression analyses. Existing publication bias contributed slightly to the effect size. Omega-3 PUFAs can reduce systemic inflammation, as indicated by CRP levels in cancer patients. The use of omega-3 PUFAs is recommended for cancer patients due to their anti-inflammatory properties.

Elevated Serum Elaidic Acid Predicts Risk of Repeat Revascularization After Percutaneous Coronary Intervention in Japan

BACKGROUND

Trans-fatty acid (TFA) intake increases the risk of coronary artery disease (CAD). Our previous cross-sectional survey showed that middle-aged patients with CAD in Japan have elevated serum TFA. In this study, we longitudinally investigated whether elevated TFA is a risk factor in the secondary prevention of CAD for the same-age patients.

METHODS AND RESULTS

A total of 112 patients (age, 21-66 years) who underwent percutaneous coronary intervention were followed up for up to 2 years. Serum elaidic acid was measured using gas chromatography/mass spectrometry as a marker of TFA intake and divided into quartiles. The primary endpoint was ischemia-driven target lesion revascularization (TLR). The hazard ratio (HR) for TLR increased significantly with higher serum elaidic acid (P<0.01). The significant positive trend remained unchanged after adjusting for conventional lipid profile and bare-metal stent usage. In contrast, although triglycerides and low-density lipoprotein cholesterol were positively correlated with elaidic acid, they were not associated with TLR. On multivariable Cox proportional hazard analysis, elevated elaidic acid was independently associated with TLR risk after adjusting for conventional coronary risks (HR, 10.7, P<0.01).

CONCLUSIONS

Elevated elaidic acid is associated with higher TLR rate in middle-aged patients with CAD, suggesting that excessive TFA intake is becoming a serious health problem in Japan.

The associations of serum n-6 polyunsaturated fatty acids with serum C-reactive protein in men: the Kuopio Ischaemic Heart Disease Risk Factor Study

BACKGROUND/OBJECTIVES

There are concerns that high intake of n-6 polyunsaturated fatty acids (PUFA) may promote inflammation, because the end-product of n-6 PUFA metabolism, arachidonic acid, is a precursor for pro-inflammatory eicosanoids. Our aim was to investigate cross-sectional associations of the serum n-6 PUFAs, objective biomarkers for exposure, with serum high-sensitivity C-reactive protein (CRP), a key inflammation marker.

SUBJECTS/METHODS

The study included 1287 generally healthy men aged 42-60 years from the population-based Kuopio Ischaemic Heart Disease Risk Factor Study, examined in 1984-1989. ANCOVA and logistic regression were used for analyses.

RESULTS

In the multivariable-adjusted analyses, both serum total n-6 PUFA and linoleic acid, the predominant n-6 PUFA, were associated with lower CRP. The mean CRP concentrations in quartiles of linoleic acid were 1.86, 1.51, 1.53, and 1.37 mg/L (P-trend = 0.001). The odds ratio for elevated CRP (>3 mg/L) in the highest vs. the lowest quartile was 0.47 (95% confidence interval (CI) 0.25-0.87, P-trend = 0.01). Arachidonic acid or the mainly endogenously produced n-6 PUFAs, gamma-linolenic acid and dihomo-gamma-linolenic acid, were not associated with higher CRP, either. Age, body mass index, or serum long-chain n-3 PUFA concentration did not modify the associations (P-interactions > 0.14).

CONCLUSIONS

Serum n-6 PUFAs were not associated with increased inflammation in men. In contrast, the main n-6 PUFA linoleic acid had a strong inverse association with the key inflammation marker, CRP.

Impact of the dietary fatty acid intake on C-reactive protein levels in US adults

Growing evidence suggests that the effects of diet on cardiovascular disease (CVD) occur through mechanisms involving subclinical inflammation. We assessed whether reported dietary fatty acid intake correlates with a serum high-sensitivity C-reactive protein (hs-CRP) concentration in a population-based sample of US men and women.In this cross-sectional analysis, participants were selected from the US National Health and Nutrition Examination Survey (NHANES) and restricted to those with available data on dietary intake, biochemical and anthropometric measurements from 2001 to 2010. All statistical analyses accounted for the survey design and sample weights by using SPSS Complex Samples v22.0 (IBM Corp, Armonk, NY).Of the 17,689 participants analyzed, 8607 (48.3%) were men. The mean age was 45.8 years in the overall sample, 44.9 years in men, and 46.5 years in women (P = 0.047). The age-, race-, and sex-adjusted mean dietary intakes of total polyunsaturated fatty acids (PUFAs), PUFAs 18:2 (octadecadienoic), and PUFAs 18:3 (octadecatrienoic) monotonically decreased across hs-CRP quartiles (P < 0.001), whereas dietary cholesterol increased across hs-CRP quartiles (P < 0.001)This study provides further evidence of an association between fatty acid intake and subclinical inflammation markers. hs-CRP concentrations are likely modulated by dietary fatty acid intake. However, the causality of this association needs to be demonstrated in clinical trials.