N-6 and n-3 fatty acid cholesteryl esters in relation to incident stroke in a Dutch adult population: a nested case-control study

Fatty Acid Levels and Their Inflammatory Metabolites Are Associated with the Nondipping Status and Risk of Obstructive Sleep Apnea Syndrome in Stroke Patients

Background: This paper discusses the role of inflammation in the pathogenesis of nondipping blood pressure and its role in the pathogenesis of obstructive sleep apnea syndrome. The aim of the study was to assess the impact of free fatty acids (FAs) and their inflammatory metabolites on the nondipping phenomenon and the risk of sleep apnea in stroke patients. Methods: Sixty-four ischemic stroke patients were included in the prospective study. Group I consisted of 33 patients with a preserved physiological dipping effect (DIP), while group II included 31 patients with the nondipping phenomenon (NDIP). All subjects had FA gas chromatography and inflammatory metabolite measurements performed with the use of liquid chromatography, their 24 h blood pressure was recorded, and they were assessed with the Epworth sleepiness scale (ESS). Results: In the nondipping group a higher level of C16:0 palmitic acid was observed, while lower levels were observed in regard to C20:0 arachidic acid, C22:0 behenic acid and C24:1 nervonic acid. A decreased leukotriene B4 level was recorded in the nondipping group. None of the FAs and derivatives correlated with the ESS scale in the group of patients after stroke. Correlations were observed after dividing into the DIP and NDIP groups. In the DIP group, a higher score of ESS was correlated with numerous FAs and derivatives. Inflammation of a lower degree and a higher level of anti-inflammatory mediators from EPA and DHA acids favored the occurrence of the DIP. A high level of C18: 3n6 gamma linoleic acid indicating advanced inflammation, intensified the NDIP effect. Conclusions: We demonstrated potential novel associations between the FA levels and eicosanoids in the pathogenesis of the nondipping phenomenon. There are common connections between fatty acids, their metabolites, inflammation, obstructive sleep apnea syndrome and nondipping in stroke patients.

Associations of erythrocyte polyunsaturated fatty acids with incidence of stroke and stroke types in adult Chinese: a prospective study of over 8000 individuals

PURPOSE

There is limited and inconsistent evidence about the relationships of erythrocyte polyunsaturated fatty acids (PUFAs) with stroke and stroke types, particularly in China where the stroke rates are high. We aimed to investigate the associations of different erythrocyte PUFAs with incidence of total stroke, ischemic stroke (IS), and intracerebral hemorrhage (ICH) in Chinese adults.

METHODS

In the prospective China Kadoorie Biobank, erythrocyte PUFAs were measured using gas chromatography in 10,563 participants who attended 2013-14 resurvey. After a mean follow-up of 3.8 years, 412 incident stroke cases (342 IS, 53 ICH) were recorded among 8,159 participants without prior vascular diseases or diabetes. Cox regression yielded adjusted hazard ratios (HRs) for stroke associated with 13 PUFAs.

RESULTS

Overall, the mean body mass index was 24.0 (3.4) kg/m² and the mean age was 58.1 (9.9) years. In multivariable analyses, 18:2n-6 was positively associated with ICH (HR = 2.33 [95% CIs 1.41, 3.82] for top versus bottom quintile, P_trend = 0.007), but inversely associated with IS (0.69 [0.53,0.90], P_trend = 0.027), while 20:3n-6 was positively associated with risk of IS (1.64 [1.32,2.04], P_trend < 0.001), but not with ICH. Inverted-U shape curve associations were observed of 20:5n-3 with IS (P_nonlinear = 0.002) and total stroke (P_nonlinear = 0.008), with a threshold at 0.70%. After further adjustment for conventional CVD risk factors and dietary factors, these associations remained similar.

CONCLUSION

Among relatively lean Chinese adults, erythrocyte PUFAs 18:2n-6, 20:3n-6 and 20:5n-3 showed different associations with risks of IS and ICH. These results would improve the understanding of stroke etiology.

Omega-3 polyunsaturated fatty acid biomarkers and risk of type 2 diabetes, cardiovascular disease, cancer, and mortality

BACKGROUND & AIMS

Considerable attention has focused on the role of omega-3 polyunsaturated fatty acids (PUFA) in the prevention of cardiometabolic diseases, which has led to dietary recommendations to increase omega-3 fatty acid intake. A meta-analysis was conducted to summarize evidence from prospective studies regarding associations between omega-3 PUFA biomarkers and risk of developing major chronic diseases.

METHODS

Four electronic databases were searched for articles from inception to March 1, 2022. Random-effects model was used to estimate the pooled relative risk (RR) and 95% confidence intervals (CIs) for the association of omega-3 PUFAs, including α-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA), with risk of developing type 2 diabetes (T2D), cardiovascular disease (CVD), including coronary heart disease (CHD) and stroke, cancer, and mortality. The Grades of Recommendation, Assessment, Development and Evaluation assessment tool was used to rates the confidence in estimates.

RESULTS

A total of 67 prospective studies comprised of 310,955 participants were identified. Individual omega-3 PUFAs showed divergent associations with the study outcomes of interest. A significant inverse association with T2D risk was observed across categories of ALA (relative risk [RR]: 0.89, 95% confidence interval [CI]: 0.82-0.96), EPA (RR: 0.85, 95% CI: 0.72-0.99) and DPA (RR: 0.84, 95% CI: 0.73-0.96) biomarkers. The marine-origin omega-3 fatty acids biomarkers but not ALA was significantly associated with lower risks of total CVD, CHD, and overall mortality, with RRs ranging from 0.70 for DHA-CHD association to 0.85 for EPA-CHD association. A lower risk of colorectal cancer was observed at higher levels of DPA (RR: 0.76, 95% CI: 0.59-0.98) and DHA (RR: 0.80; 95% CI: 0.65-0.99), whereas no association was noted for other outcomes. In addition, a dose-response relationship was observed between an increasing level of EPA, DPA, or DHA biomarker and lower risk of CVD.

CONCLUSIONS

Higher concentrations of marine-derived omega-3 PUFA biomarkers were associated with a significantly reduced risk of total CVD, CHD, and total mortality. Levels of ALA were inversely associated with a lower risk of T2D but not CVD-related outcomes. These data support the dietary recommendations advocating the role of omega-3 PUFAs in maintaining an overall lower risk of developing cardiovascular disease and premature deaths.

Role of polyunsaturated fatty acids in ischemic stroke - A perspective of specialized pro-resolving mediators

Polyunsaturated fatty acids (PUFAs) have been proposed as beneficial for cardiovascular health. However, results from both epidemiological studies and clinical trials have been inconsistent, whereas most of the animal studies showed promising benefits of PUFAs in the prevention and treatment of ischemic stroke. In recent years, it has become clear that PUFAs are metabolized into various types of bioactive derivatives, including the specialized pro-resolving mediators (SPMs). SPMs exert multiple biofunctions, such as to limit excessive inflammatory responses, regulate lipid metabolism and immune cell functions, decrease production of pro-inflammatory factors, increase anti-inflammatory mediators, as well as to promote tissue repair and homeostasis. Inflammation has been recognised as a key contributor to the pathophysiology of acute ischemic stroke. Owing to their potent pro-resolving actions, SPMs are potential for development of novel anti-stroke therapy. In this review, we will summarize current knowledge of epidemiological studies, basic research and clinical trials concerning PUFAs in stroke prevention and treatment, with special attention to SPMs as the unsung heroes behind PUFAs.

Lipoxins, RevD1 and 9, 13 HODE as the most important derivatives after an early incident of ischemic stroke

There is limited information available regarding the association of plasma free fatty acids (FFA) and inflammation mediators with ischemic stroke. At the same time, new treatment strategies are being pursued. The aim of this study was to carry out a thorough analysis of inflammation with multiple FFA-derivative mediators after and ischemic stroke and standard treatment. HPLC separations of 17 eicosanoids were performed using an Agilent Technologies 1,260 liquid chromatograph. The profiles of the esters of fatty acids were labelled by means of gas chromatography. FFA, and eicosanoid profiles in the group of patients after ischemic stroke significantly differed from the profile of the control group. Studies confirmed the involvement of derivative synthesis pathways responsible for the inflammation, especially palmitic acid (9 and 13 HODE), arachidonic acid, EPA and DHA. Arachidonic acid derivatives were synthesised on 5LOX, 15 LOX and COX pathways with the participation of prostaglandins while omega 3 derivatives strengthened the synthesis of resolvins, RevD1 in particular. The ability to accelerate the quenching of inflammation after ischemic stroke seems to be a promising strategy of stroke treatment in its early stage. In this context, our study points to lipoxins, RevD1, and 9, 13 HODE as the most important derivatives.

Biomarker of dietary linoleic acid and risk for stroke: A systematic review and meta-analysis

OBJECTIVE

Previous observational studiíes provided conflicting findings on the relationship between linoleic acid (LA) and the risk for stroke. The aim of this study was to evaluate the association of LA levels in blood or adipose tissue samples with risk for stroke.

METHODS

PubMed, Web of Science, and Embase databases were searched until February 29, 2020 to identify eligible observational studies, including cohort studies, nested case-control studies, case-cohort studies, and case-control studies, reporting the association of LA with the risk for stroke and its subtypes. We pooled hazard ratio (HR) estimates with 95% confidence intervals (CIs) and conducted heterogeneity test. Sensitivity analysis and publication bias test were also carried out.

RESULTS

Twelve studies from 11 observational articles involving 47 836 individuals were included in the meta-analysis. We observed an inverse association between biomarkers of dietary LA and risk for total stroke (HR, 0.88; 95% CI, 0.83-0.94; P < 0.001). Meta-regression analysis suggested that ethnicity (P = 0.029) and study design (P = 0.049) contributed to between-study heterogeneity. Subgroup analysis showed that the association was statistically significant among studies conducted in white (P < 0.001) and Asian (P = 0.032) populations, and those with cohort (P = 0.001) and case-cohort design (P = 0.007). Moreover, we found that higher LA levels were associated with a reduced risk for ischemic stroke (HR, 0.87; 95% CI, 0.80-0.95; P = 0.001), although no statistically significant association was found between LA levels and the risk for hemorrhagic stroke.

CONCLUSIONS

The present study supported an inverse association of LA levels with the risk for stroke, particularly ischemic stroke. Racial disparity exists in the association between LA and the risk for stroke, which deserves further studies.

Roles for circulating polyunsaturated fatty acids in ischemic stroke and modifiable factors: a Mendelian randomization study

Background

Available data about the effects of circulating polyunsaturated fatty acids (PUFAs) on ischemic stroke (IS) and its main risk factors remains limited and conflicting. Therefore, we conducted Mendelian randomization (MR) to assess whether genetically predicted PUFA affected IS, lipids and blood pressure (BP).

Methods

Genetic instruments associated with IS were derived from ISGC Consortium (n = 29,633), with lipids were derived from GLGC(n = 188,577), with BP were derived from Neale Lab(n = 337,000). The inverse-variance weighted method was the main analysis to estimate the effect of exposure on outcome. Sensitivity analyses included principal components analysis, MR-Egger, weighted median, and weighted mode.

Results

Per SD increases in serum α-linolenic acid (ALA) were associated with lower IS risk, with odd ratio (OR) of 0.867(0.782,0.961), arachidonic acid (AA) were associated with higher IS risk (OR: 1.053(1.014,1.094)). Likewise, Per SD increases in ALA were associated with the lower-level low-density lipoprotein cholesterol(LDL-C), high-density lipoprotein cholesterol (HDL-C), total cholesterol (TC) (β:-0.122(− 0.144, − 0.101), − 0.159(− 0.182, − 0.135), − 0.148(− 0.171, − 0.126), respectively), AA were associated with the higher-level of LDL-C, HDL-C and TC (β:0.045(0.034,0.056), 0.059(0.050,0.067), 0.055(0.046,0.063), respectively). Linoleic acid (LA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and docosapentaenoic acid (DPA) had little or no association with IS, lipids or BP at Bonferroni-corrected significance. Different analytic methods supported these findings. The intercept test of MR-Egger implied no pleiotropy.

Conclusions

High-level plasma ALA was protective for IS but AA was the opposite. LA, EPA, DHA, and DPA had no effects on IS.

Marine n-3 fatty acids and CVD: new insights from recent follow-up studies and clinical supplementation trials

Marine n-3 PUFA exert beneficial effects that might inhibit atherosclerosis and reduce vascular disease. Previous studies have, however, reported conflicting results and here we have summarised the early history and the most recent findings from follow-up studies and randomised clinical trials investigating marine n-3 PUFA in relation to the risk of atherosclerotic CVD. Most follow-up studies have suggested that the intake of marine n-3 PUFA may be associated with a lower risk of CVD. Recent studies have also shown that it is important to focus on substitution issues and dietary patterns. Further, the use of gold standard biomarkers of fatty acid exposure such as adipose tissue should be encouraged. Findings from clinical supplemental trials have shown conflicting results and findings from previous meta-analyses and guidelines have generally not supported the use of fish oil supplements for the prevention of CVD. However, a recent meta-analysis including three recent large clinical trials with fish oil supplements reported a moderate beneficial effect on cardiovascular endpoints. Interestingly, results from a large clinical trial (REDUCE-IT) have suggested that supplementation with a high dose of purified EPA ethyl ester for 4⋅9 years significantly and markedly reduced the risk of cardiovascular events in patients with CVD and mild hypertriglyceridaemia; findings that need to be confirmed. While it seems appropriate to recommend consumption of fish, particular fatty fish for prevention of CVD, an effect of fish oil supplements is probably at best marginal perhaps apart from patients with hypertriglyceridaemia.

Plasma levels of ceramides relate to ischemic stroke risk and clinical severity

Recent studies have suggested that specific plasma ceramides are independently associated with atherosclerosis and cardiovascular diseases, but it is currently unknown whether plasma ceramide levels are associated with ischemic stroke. Here, we examined whether ceramides were associated with both ischemic stroke risk and clinical severity at admission. We measured three previously identified high-risk plasma ceramide molecules [Cer(d18:1/16:0), Cer(d18:1/22:0), and Cer(d18:1/24:0)] in 202 patients with acute ischemic stroke and 202 age and sex matched control cases. Plasma ceramides levels were measured by a targeted liquid chromatography-tandem mass spectrometry assay at baseline. The median age of the 202 stroke patients was 66 (interquartile range [IQR], 58-75) years and 54.0 % were men. Plasma levels of C16:0, C22:0, and C24:0 ceramides in stroke patients were significantly higher than in those control cases (P < 0.001, all). In multivariate logistic regression analysis adjusted for other risk factors, higher levels of C16:0, C22:0, and C24:0 ceramides were associated with higher risk of ischemic stroke (odd ratio [OR] for one IQR increase: 2.15[1.42-2.99]; 2.90[2.13-4.01] and 1.29[1.10-1.69]; respectively). At admission, 103 patients (51.0 %) had a minor stroke (NIHSS < 6). In these patients, plasma levels of C16:0, C22:0, and C24:0 ceramides were lower than that observed in patients with moderate-to-high clinical severity (P < 0.001, all). In multivariate logistic regression analysis adjusted for other risk factors, higher levels of C16:0, C22:0, and C24:0 ceramides were associated with higher risk of moderate-to-high stroke (OR for one IQR increase: 2.96 [2.05-4.22], 3.03 [2.01-4.25] and 1.72 [1.25-3.31], respectively). An elevated plasma levels of ceramides were predictors of both risk and severity at admission in ischemic stroke patients. The underlying mechanisms of these associations remain to be investigated.

Circulating Fatty Acids and Risk of Coronary Heart Disease and Stroke: Individual Participant Data Meta-Analysis in Up to 16 126 Participants

Background We aimed at investigating the association of circulating fatty acids with coronary heart disease (CHD) and stroke risk. Methods and Results We conducted an individual-participant data meta-analysis of 5 UK-based cohorts and 1 matched case-control study. Fatty acids (ie, omega-3 docosahexaenoic acid, omega-6 linoleic acid, monounsaturated and saturated fatty acids) were measured at baseline using an automated high-throughput serum nuclear magnetic resonance metabolomics platform. Data from 3022 incident CHD cases (13 104 controls) and 1606 incident stroke cases (13 369 controls) were included. Logistic regression was used to model the relation between fatty acids and odds of CHD and stroke, adjusting for demographic and lifestyle variables only (ie, minimally adjusted model) or with further adjustment for other fatty acids (ie, fully adjusted model). Although circulating docosahexaenoic acid, but not linoleic acid, was related to lower CHD risk in the fully adjusted model (odds ratio, 0.85; 95% CI, 0.76-0.95 per standard unit of docosahexaenoic acid), there was evidence of high between-study heterogeneity and effect modification by study design. Stroke risk was consistently lower with increasing circulating linoleic acid (odds ratio for fully adjusted model, 0.82; 95% CI, 0.75-0.90). Circulating monounsaturated fatty acids were associated with higher CHD risk across all models and with stroke risk in the fully adjusted model (odds ratio, 1.22; 95% CI, 1.03-1.44). Saturated fatty acids were not related to increased CHD risk in the fully adjusted model (odds ratio, 0.94; 95% CI, 0.82-1.09), or stroke risk. Conclusions We found consistent evidence that linoleic acid was associated with decreased risk of stroke and that monounsaturated fatty acids were associated with increased risk of CHD. The different pattern between CHD and stroke in terms of fatty acids risk profile suggests future studies should be cautious about using composite events. Different study designs are needed to assess which, if any, of the associations observed is causal.

Dietary linoleic acid and human health: Focus on cardiovascular and cardiometabolic effects

This narrative review aims to discuss the more relevant evidence on the role of linoleic acid (LA), a n-6 essential fatty acid that constitutes the predominant proportion of dietary polyunsaturated fatty acids (PUFA), in cardiovascular health. Although LA can be metabolized into Arachidonic Acid (AA), a 20 carbon PUFA which is the precursor of eicosanoids, including some with proinflammatory or prothrombotic-vasoconstrictor action, the large majority of experimental and clinical studies have assessed the potential benefit of increasing dietary intake of LA. Overall, data from clinical studies and meta-analyses suggest an association between high dietary intakes or tissue levels of n-6 PUFA, and specifically LA, and the improvement of cardiovascular risk (mainly of the plasma lipid profile), as well as long-term glycaemic control and insulin resistance. Most observational data show that elevated/increased dietary intake or tissue levels of LA is associated with a reduced incidence of cardiovascular diseases (mainly coronary artery diseases) and of new onset metabolic syndrome or type 2 diabetes. The effects of LA (or n-6 PUFA) in other physio-pathological areas are less clear. High quality clinical trials are needed to assess both the actual amplitude and the underlying mechanisms of the health effects related to dietary intake of this essential fatty acid.

Polyunsaturated Fatty Acids and Risk of Ischemic Stroke

Ischemic stroke is a major cause of death and morbidity worldwide. It has been suggested that polyunsaturated fatty acids (PUFAs) may be associated with a lower risk ischemic stroke, but this has been far less studied than their role for coronary heart disease. In this paper, we summarize the main findings from previous follow-up studies investigating associations between intake or biomarkers of the major PUFAs including alpha-linolenic acid (ALA), marine n-3 PUFAs and linoleic acid (LA) and the development of ischemic stroke. Several follow-up studies have suggested that marine n-3 PUFAs may be associated with a lower risk of ischemic stroke although results have not been consistent and limited knowledge exist on the individual marine n-3 PUFAs and ischemic stroke and its subtypes. The role of ALA is less clear, but most studies have not supported that ALA is appreciably associated with ischemic stroke risk. Some studies have supported that LA might be associated with a lower risk of total ischemic stroke, while limited evidence exist on PUFAs and ischemic stroke subtypes. The associations may depend on the macronutrients that PUFAs replace and this substitution aspect together with focus on dietary patterns represent interesting areas for future research.

Biomarkers of Dietary Omega-6 Fatty Acids and Incident Cardiovascular Disease and Mortality

BACKGROUND

Global dietary recommendations for and cardiovascular effects of linoleic acid, the major dietary omega-6 fatty acid, and its major metabolite, arachidonic acid, remain controversial. To address this uncertainty and inform international recommendations, we evaluated how in vivo circulating and tissue levels of linoleic acid (LA) and arachidonic acid (AA) relate to incident cardiovascular disease (CVD) across multiple international studies.

METHODS

We performed harmonized, de novo, individual-level analyses in a global consortium of 30 prospective observational studies from 13 countries. Multivariable-adjusted associations of circulating and adipose tissue LA and AA biomarkers with incident total CVD and subtypes (coronary heart disease, ischemic stroke, cardiovascular mortality) were investigated according to a prespecified analytic plan. Levels of LA and AA, measured as the percentage of total fatty acids, were evaluated linearly according to their interquintile range (ie, the range between the midpoint of the first and fifth quintiles), and categorically by quintiles. Study-specific results were pooled using inverse-variance-weighted meta-analysis. Heterogeneity was explored by age, sex, race, diabetes mellitus, statin use, aspirin use, omega-3 levels, and fatty acid desaturase 1 genotype (when available).

RESULTS

In 30 prospective studies with medians of follow-up ranging 2.5 to 31.9 years, 15 198 incident cardiovascular events occurred among 68 659 participants. Higher levels of LA were significantly associated with lower risks of total CVD, cardiovascular mortality, and ischemic stroke, with hazard ratios per interquintile range of 0.93 (95% CI, 0.88-0.99), 0.78 (0.70-0.85), and 0.88 (0.79-0.98), respectively, and nonsignificantly with lower coronary heart disease risk (0.94; 0.88-1.00). Relationships were similar for LA evaluated across quintiles. AA levels were not associated with higher risk of cardiovascular outcomes; in a comparison of extreme quintiles, higher levels were associated with lower risk of total CVD (0.92; 0.86-0.99). No consistent heterogeneity by population subgroups was identified in the observed relationships.

CONCLUSIONS

In pooled global analyses, higher in vivo circulating and tissue levels of LA and possibly AA were associated with lower risk of major cardiovascular events. These results support a favorable role for LA in CVD prevention.

APOE and the Association of Fatty Acids With the Risk of Stroke, Coronary Heart Disease, and Mortality

Background and Purpose- The role of dietary fat on cardiovascular health and mortality remains under debate. Because the APOE is central to the transport and metabolism of lipids, we examined associations between plasma fatty acids and the risk of stroke, coronary heart disease, and mortality by APOE-ε4 genotype. Methods- We included 943 FHS (Framingham Heart Study) and 1406 3C (Three-City) Bordeaux Study participants. Plasma docosahexaenoic, linoleic, arachidonic, and palmitic fatty acids were measured at baseline by gas chromatography. All-cause stroke, ischemic stroke, coronary heart disease, and all-cause mortality events were identified prospectively using standardized protocols. Each cohort used Cox models to separately relate fatty acid levels to the risk of developing each event during ≤10 years of follow-up adjusting for potential confounders and stratifying by APOE genotype (ε4 carriers versus noncarriers). We then meta-analyzed summary statistics using random-effects models. Results- On average, participants had a mean age of 74 years, 61% were women, and 21% (n=483) were APOE-ε4 carriers. Meta-analysis results showed that, only among APOE-ε4 carriers, every SD unit increase in linoleic acid was associated with a reduced risk of all-cause stroke (hazard ratio [HR], 0.54 [95% CI, 0.38-0.78]), ischemic stroke (HR, 0.48 [95% CI, 0.33-0.71]), and all-cause mortality (HR, 0.70 [95% CI, 0.57-0.85]). In contrast, every SD unit increase in palmitic acid was related to an increased risk of all-cause stroke (HR, 1.58 [95% CI, 1.16-2.17]), ischemic stroke (HR, 1.76 [95% CI, 1.26-2.45]), and coronary heart disease (HR, 1.48 [95% CI, 1.09-2.01]), also in APOE-ε4 carriers only. Results for docosahexaenoic acid and arachidonic acid were heterogeneous between cohorts. Conclusions- These exploratory results suggest that APOE-ε4 carriers may be more susceptible to the beneficial or adverse impact of fatty acids on cardiovascular disease and mortality. In this subgroup, higher linoleic acid was protective for stroke and mortality, whereas palmitic acid was a risk factor for stroke and coronary heart disease. The mechanisms underlying these novel findings warrant further investigation.

Plasma lipidome patterns associated with cardiovascular risk in the PREDIMED trial: A case-cohort study

BACKGROUND

The study of the plasma lipidome may help to better characterize molecular mechanisms underlying cardiovascular disease. The identification of new lipid biomarkers could provide future targets for prevention and innovative therapeutic approaches. In the frame of the PREDIMED trial, our aim was to examine the associations of baseline lipidome patterns or their changes with the risk of clinical CVD events.

METHODS

We included 983 participants in our case-cohort study. The end-point was the incidence of major CVD during 4.8years of median follow-up. We repeatedly measured 202 plasma known lipid metabolites at baseline and after 1-year of intervention. Principal component analysis was used to identify lipidome factors. Among the 15 identified factors, 7 were significantly associated with CVD. Considering common patterns among factors, lipids were grouped (summed) into scores.

RESULTS

After adjustment for traditional CVD risk factors, scores of baseline polyunsaturated phosphatidylcholines (PC)/lysoPC/PC-plasmalogens and polyunsaturated cholesterol esters (CE) showed inverse associations with CVD (p=0.036 and 0.012, respectively); whereas scores of monoacylglycerols (MAGs)/diacylglycerols (DAGs) and short triacylglycerols (TAGs) showed a direct association with CVD (p=0.026 and 0.037, respectively). Baseline phosphatidylethanolamines (PEs) and their 1-y changes tended to be associated with higher CVD risk (p=0.066 and 0.081, respectively). We did not find a significant effect of the intervention with the Mediterranean Diet on these scores.

CONCLUSIONS

Our study suggests that polyunsaturated PCs and CEs may confer protection against CVD. In contrast, MAGs, DAGs, TAGs and PEs appeared to be associated with higher CVD risk.

Linoleic Acid in Adipose Tissue and Development of Ischemic Stroke: A Danish Case-Cohort Study

Background

We investigated the association between the content of linoleic acid in adipose tissue, a biomarker of long‐term intake of linoleic acid, and the risk of ischemic stroke and its subtypes.

Methods and Results

The Danish cohort study Diet, Cancer and Health included 57 053 patients aged 50 to 65 years at enrollment. All participants had an adipose tissue biopsy performed at enrollment, while information on ischemic stroke during follow‐up was obtained from the Danish National Patient Register. Stroke diagnoses were all validated and classified according to the Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification. Cases and a randomly drawn subcohort of 3500 patients had their fatty acid composition in adipose tissue determined by gas chromatography. Hazard ratios with 95% confidence intervals were calculated using weighted Cox proportional hazard regression. During 13.5 years of follow‐up, 1879 ischemic stroke cases were identified, for which 1755 adipose biopsies were available, while adipose biopsies were available for 3203 participants in the subcohort. When comparing the highest and the lowest quartiles of adipose tissue content of linoleic acid there was a negative association with the rate of total ischemic stroke (hazard ratio, 0.78; 95% confidence interval, 0.65–0.93) and large artery atherosclerosis (hazard ratio, 0.61; 95% confidence interval, 0.43–0.88), while there was an indication of a negative association with small‐vessel occlusion (hazard ratio, 0.87; 95% confidence interval, 0.69–1.11). There was no clear association with the rate of cardioembolism.

Conclusions

The content of linoleic acid in adipose tissue was inversely associated with the risk of total ischemic stroke and stroke caused by large artery atherosclerosis.

Adipose tissue content of alpha-linolenic acid and the risk of ischemic stroke and ischemic stroke subtypes: A Danish case-cohort study

BACKGROUND

The plant-derived omega-3 fatty acid alpha-linolenic acid (ALA) may reduce the risk of cardiovascular disease.

OBJECTIVE

We have investigated associations between the content of ALA in adipose tissue and the risk of ischemic stroke and its subtypes.

METHODS

Incident cases of ischemic stroke among participants enrolled into the Danish Diet, Cancer and Health cohort (n = 57,053) were identified by linkage with the Danish National Patient Register. Subsequently, all potential cases were validated and classified into ischemic stroke subtypes. The fatty acid composition of adipose tissue was determined by gas chromatography in cases and in a randomly drawn sub-cohort (n = 3500). Statistical analyses were performed using weighted Cox regression.

RESULTS

During a median of 13.4 years of follow-up, 1735 cases of total ischemic stroke were identified including 297 cases of large artery atherosclerosis, 772 cases of small-vessel occlusion, 99 cases of cardio-embolism, 91 cases with stroke of other etiology and 476 cases with stroke of undetermined etiology. The median content of ALA in adipose tissue within the sub-cohort was 0.84% (95% central range: 0.53-1.19%). Multivariable analyses showed a U-shaped association between adipose tissue content of ALA and the rate of total ischemic stroke, but this association was not statistically significant (p = 0.172). In analyses of ischemic stroke subtypes, we observed a statistically significant U-shaped association between ALA and the rate of ischemic stroke due to large artery atherosclerosis (p = 0.017), whereas no appreciable association was observed between ALA and the rate of small-vessel occlusion (p = 0.427). A positive but statistically non-significant association was observed between ALA and the rate of ischemic stroke due to cardio-embolism (p = 0.162).

CONCLUSIONS

The content of ALA in adipose tissue was statistically non-significantly U-shaped associated with risk of total ischemic stroke. For ischemic stroke subtypes a statistically significant, U-shaped association with large artery atherosclerosis was observed.

Dietary Intake of α-Linolenic Acid Is Not Appreciably Associated with Risk of Ischemic Stroke among Middle-Aged Danish Men and Women

Background

Intake of the plant-derived omega-3 (n-3) fatty acid α-linolenic acid (ALA) may reduce the risk of ischemic stroke.

Objective

We have investigated the associations between dietary intake of ALA and the risk of ischemic stroke and ischemic stroke subtypes.

Methods

This was a follow-up study. A total of 57,053 participants aged 50-64 y were enrolled into the Danish Diet, Cancer and Health cohort between 1993 and 1997. Intake of ALA was assessed by a validated semiquantitative food frequency questionnaire. Potential incident cases of ischemic stroke were identified in the Danish National Patient Register, validated, and classified into subtypes based on assumed etiology. Statistical analyses were performed via Cox proportional hazard regression with adjustment for established ischemic stroke risk factors.

Results

A total of 1859 ischemic stroke cases were identified during a median of 13.5 y of follow-up. In multivariable analyses using restricted cubic splines adjusting for traditional risk factors for ischemic stroke, we observed no clear associations between dietary intake of ALA and the risk of total ischemic stroke or any of its subtypes including ischemic stroke due to large artery atherosclerosis, ischemic stroke due to small-vessel occlusion, and ischemic stroke due to cardio-embolism.

Conclusion

Dietary intake of ALA was neither consistently nor appreciably associated with the risk of ischemic stroke or ischemic stroke subtypes among middle-aged Danish men and women. This study was registered at clinicaltrials.gov as NCT03258983.

Metabolomics and Lipidomics of Ischemic Stroke

Ischemic stroke is a sudden loss of brain function due to the reduction of blood flow. Brain tissues cease to function with subsequent activation of the ischemic cascade. Metabolomics and lipidomics are modern disciplines that characterize the metabolites and lipid components of a biological system, respectively. Because the pathogenesis of ischemic stroke is heterogeneous and multifactorial, it is crucial to establish comprehensive metabolomic and lipidomic approaches to elucidate these alterations in this disease. Fortunately, metabolomic and lipidomic studies have the distinct advantages of identifying tissue/mechanism-specific biomarkers, predicting treatment and clinical outcome, and improving our understanding of the pathophysiologic basis of disease states. Therefore, recent applications of these analytical approaches in the early diagnosis of ischemic stroke were discussed. In addition, the emerging roles of metabolomics and lipidomics on ischemic stroke were summarized, in order to gain new insights into the mechanisms underlying ischemic stroke and in the search for novel metabolite biomarkers and their related pathways.

Circulating long-chain n-3 polyunsaturated fatty acid and incidence of stroke: a meta-analysis of prospective cohort studies

Background

Circulating long-chain (LC) n-3 polyunsaturated fatty acid (PUFA) can provide objective measures that reflect both dietary consumption and relevant biological processes. Nevertheless, prospective cohort studies on circulating LC n-3 PUFA in relation to incidence of stroke have yielded inconsistent results. We therefore conducted a meta-analysis to quantitatively evaluate the association.

Results

A total of 2,836 stroke events occurred among 20,460 individuals aged 35–79 yr from 10 prospective cohort studies. Circulating LC n-3 PUFA was significantly associated with reduced risk of stroke (RR: 0.86; 95% CI: 0.76, 0.98; I² = 0.00%), especially 22:5n-3 (RR: 0.74; 95% CI: 0.60, 0.92) and 22:6n-3 (RR: 0.78; 95% CI: 0.65, 0.94). The associations were more pronounced with ischemic stroke (RR: 0.81; 95% CI: 0.68, 0.96), but not with hemorrhagic stroke (RR: 0.95; 95% CI: 0.60, 1.49). A 1% increment of 22:5n-3 and 22:6n-3 proportions in circulating blood was associated with 25% (RR: 0.75; 95% CI: 0.64, 0.87) and 11% (RR: 0.89; 95% CI: 0.83, 0.95) reduced risk of stroke, respectively.

Materials and Methods

Pertinent studies were identified from Cochrane Library, PubMed and EMBASE database through June 2017. Multivariate-adjusted risk ratios (RRs) with 95% confidence interval (CI) for incident stroke when comparing the top with the bottom tertiles of baseline LC n-3 PUFA proportions in blood were pooled using a random-effect model.

Conclusions

Circulating LC n-3 PUFAs were linearly associated with reduced risk of stroke, especially 22:5n-3 and 22:6n-3. Such findings highlight the importance of circulating LC n-3 PUFA in the development of ischemic stroke.

Associations of serum n-3 and n-6 PUFA and hair mercury with the risk of incident stroke in men: the Kuopio Ischaemic Heart Disease Risk Factor Study (KIHD)

PUFA have been associated with lower risk of CVD, but less is known about their association with stroke risk. Fish, a major source of n-3 PUFA, may also contain methylmercury, which has been associated with higher risk of CVD and attenuation of the benefits of long-chain n-3 PUFA. We investigated the associations of serum n-3 and n-6 PUFA and hair Hg with risk of stroke in men. A total of 1828 men from the prospective, population-based Kuopio Ischaemic Heart Disease Risk Factor Study, aged 42-60 years and free of CVD at baseline in 1984-1989 were studied. Cox regression models were used for the analyses. During the mean follow-up of 21·2 years, 202 stroke cases occurred, of which 153 were ischaemic strokes. After adjustment for age and examination year, the only statistically significant association among the n-3 and n-6 PUFA was observed between the n-3 PUFA α-linolenic acid and risk of haemorrhagic stroke (hazard ratio in the highest v. the lowest quartile 0·33; 95 % CI 0·13, 0·86; P trend=0·03). However, further adjustments attenuated the association to statistically non-significant. Hair Hg was not associated with stroke risk, but among those with hair Hg above the median level, higher serum long-chain n-3 PUFA concentrations were associated with a higher risk of ischaemic stroke. In our cohort of men, serum n-3 or n-6 PUFA or hair Hg were not associated with stroke risk; however, the interaction between Hg and long-chain n-3 PUFA with regard to ischaemic stroke risk warrants further investigation.

Dairy products and the risk of stroke and coronary heart disease: the Rotterdam Study

PURPOSE

We examined whether consumption of total dairy and dairy subgroups was related to incident stroke and coronary heart disease (CHD) in a general older Dutch population.

METHODS

The study involved 4,235 participants of the Rotterdam Study aged 55 and over who were free of cardiovascular disease (CVD) and diabetes at baseline (1990-1993). Multivariable Cox proportional hazards models were used to calculate hazard ratios (HRs) for the intake of total dairy and dairy subgroups in relation to incident CVD events.

RESULTS

Median intake of total dairy was 397 g/day, which mainly comprised low-fat dairy products (median intake of 247 g/day). During a median follow-up time of 17.3 years, 564 strokes (182 fatal) and 567 CHD events (350 fatal) occurred. Total dairy, milk, low-fat dairy, and fermented dairy were not significantly related to incident stroke or fatal stroke (p > 0.2 for upper vs. lower intake categories). High-fat dairy was significantly inversely related to fatal stroke (HR of 0.88 per 100 g/day; 95% CI 0.79, 0.99), but not to incident stroke (HR of 0.96 per 100 g/day; 95% CI 0.90, 1.02). Total dairy or dairy subgroups were not significantly related to incident CHD or fatal CHD (HRs between 0.98 and 1.05 per 100 g/day, all p > 0.35).

CONCLUSIONS

In this long-term follow-up study of older Dutch subjects, total dairy consumption or the intake of specific dairy products was not related to the occurrence of CVD events. The observed inverse association between high-fat dairy and fatal stroke warrants confirmation in other studies.

A rapid and precise method for quantification of fatty acids in human serum cholesteryl esters by liquid chromatography and tandem mass spectrometry

We described a rapid and precise method for simultaneous quantification of eleven fatty acids in human serum cholesteryl esters (CEFAs) by liquid chromatography and tandem mass spectrometry (LC-MS/MS). After extraction of serum lipids with isopropanol, CEFAs were separated on reversed phase liquid chromatography and detected by mass spectrometry in positive ion mode with multiple reaction monitor. Individual CEFA was quantified by peak area normalization method and expressed as molar percent of total CEFAs. The run time was less than 5 min and detection limits were from 0.31 to 14.50 × 10(-5)mmol/L. Recoveries of the CEFAs ranged from 91.85% to 104.83% with a mean of 99.12%. The intra and total CVs for the measurement of CEFAs were 0.87-7.70% and 1.02-7.65%, respectively. This LC-MS/MS method required no internal standards, eliminated natural isotope interferences, and provided reproducible and reliable results for 11 major CEFAs in human serum. This method can be used in monitoring and evaluating dietary fatty acid intake. Additional studies are needed to evaluate the associations between serum CEFAs and cardiovascular disease risk factors.