The change in low-density lipoprotein cholesterol concentration is positively related to plasma docosahexaenoic acid but not eicosapentaenoic acid

Marine-derived n-3 fatty acids therapy for stroke

BACKGROUND

Currently, with stroke burden increasing, there is a need to explore therapeutic options that ameliorate the acute insult. There is substantial evidence of a neuroprotective effect of marine-derived n-3 polyunsaturated fatty acids (PUFAs) in animal models of stroke, leading to a better functional outcome.

OBJECTIVES

To assess the effects of administration of marine-derived n-3 PUFAs on functional outcomes and dependence in people with stroke.

SEARCH METHODS

We searched the Cochrane Stroke Trials Register (last searched 31 May 2021), the Cochrane Central Register of Controlled Trials (CENTRAL; 2021, Issue 5), MEDLINE Ovid (from 1948 to 31 May 2021), Embase Ovid (from 1980 to 31 May 2021), CINAHL EBSCO (Cumulative Index to Nursing and Allied Health Literature; from 1982 to 31 May 2021), Science Citation Index Expanded ‒ Web of Science (SCI-EXPANDED), Conference Proceedings Citation Index-Science - Web of Science (CPCI-S), and BIOSIS Citation Index. We also searched ongoing trial registers, reference lists, relevant systematic reviews, and used the Science Citation Index Reference Search.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing marine-derived n-3 PUFAs to placebo or open control (no placebo) in people with a history of stroke or transient ischaemic attack (TIA), or both.

DATA COLLECTION AND ANALYSIS

At least two review authors independently selected trials for inclusion, extracted data, assessed risk of bias, and used the GRADE approach to assess the certainty of the body of evidence. We contacted study authors for clarification and additional information on stroke/TIA participants. We conducted random-effects meta-analysis or narrative synthesis, as appropriate. The primary outcome was efficacy (functional outcome) assessed using a validated scale, for example, the Glasgow Outcome Scale Extended (GOSE) dichotomised into poor or good clinical outcome, the Barthel Index (higher score is better; scale from 0 to 100), or the Rivermead Mobility Index (higher score is better; scale from 0 to 15). Our secondary outcomes were vascular-related death, recurrent events, incidence of other type of stroke, adverse events, quality of life, and mood.

MAIN RESULTS

We included 30 RCTs; nine of them provided outcome data (3339 participants). Only one study included participants in the acute phase of stroke (haemorrhagic). Doses of marine-derived n-3 PUFAs ranged from 400 mg/day to 3300 mg/day. Risk of bias was generally low or unclear in most trials, with a higher risk of bias in smaller studies. We assessed results separately for short (up to three months) and longer (more than three months) follow-up studies. Short follow-up (up to three months) Functional outcome was reported in only one pilot study as poor clinical outcome assessed with the GOSE (risk ratio (RR) 0.78, 95% confidence interval (CI) 0.36 to 1.68, P = 0.52; 40 participants; very low-certainty evidence). Mood (assessed with the GHQ-30, lower score better) was reported by only one study and favoured control (mean difference (MD) 1.41, 95% CI 0.07 to 2.75, P = 0.04; 102 participants; low-certainty evidence). We found no evidence of an effect of the intervention for the remainder of the secondary outcomes: vascular-related death (two studies, not pooled due to differences in population, RR 0.33, 95% CI 0.01 to 8.00, P = 0.50, and RR 0.33, 95% CI 0.01 to 7.72, P = 0.49; 142 participants; low-certainty evidence); recurrent events (RR 0.41, 95% CI 0.02 to 8.84, P = 0.57; 18 participants; very low-certainty evidence); incidence of other type of stroke (two studies, not pooled due to different type of index stroke, RR 6.11, 95% CI 0.33 to 111.71, P = 0.22, and RR 0.63, 95% CI 0.25 to 1.58, P = 0.32; 58 participants; very low-certainty evidence); and quality of life (physical component, MD -2.31, 95% CI -4.81 to 0.19, P = 0.07, and mental component, MD -2.16, 95% CI -5.91 to 1.59, P = 0.26; 1 study; 102 participants; low-certainty evidence). Adverse events were reported by two studies (57 participants; very low-certainty evidence), one trial reporting extracranial haemorrhage (RR 0.25, 95% CI 0.04 to 1.73, P = 0.16) and the other one reporting bleeding complications (RR 0.32, 95% CI 0.01 to 7.35, P = 0.47). Longer follow-up (more than three months) One small trial assessed functional outcome with both the Barthel Index for activities of daily living (MD 7.09, 95% CI -5.16 to 19.34, P = 0.26), and the Rivermead Mobility Index for mobility (MD 1.30, 95% CI -1.31 to 3.91, P = 0.33) (52 participants; very low-certainty evidence). We carried out meta-analysis for vascular-related death (RR 1.02, 95% CI 0.78 to 1.35, P = 0.86; 5 studies; 2237 participants; low-certainty evidence) and fatal recurrent events (RR 0.69, 95% CI 0.31 to 1.55, P = 0.37; 3 studies; 1819 participants; low-certainty evidence). We found no evidence of an effect of the intervention for mood (MD 1.00, 95% CI -2.07 to 4.07, P = 0.61; 1 study; 14 participants; low-certainty evidence). Incidence of other type of stroke and quality of life were not reported. Adverse events (all combined) were reported by only one study (RR 0.94, 95% CI 0.56 to 1.58, P = 0.82; 1455 participants; low-certainty evidence).

AUTHORS' CONCLUSIONS

We are very uncertain of the effect of marine-derived n-3 PUFAs therapy on functional outcomes and dependence after stroke as there is insufficient high-certainty evidence. More well-designed RCTs are needed, specifically in acute stroke, to determine the efficacy and safety of the intervention. Studies assessing functional outcome might consider starting the intervention as early as possible after the event, as well as using standardised, clinically relevant measures for functional outcomes, such as the modified Rankin Scale. Optimal doses remain to be determined; delivery forms (type of lipid carriers) and mode of administration (ingestion or injection) also need further consideration.

Icosapent ethyl: safely reducing cardiovascular risk in adults with elevated triglycerides

INTRODUCTION

In patients at high cardiovascular risk, the rate of events remains elevated despite traditional, evidence-based lipid-lowering therapy. Residual hypertriglyceridemia is an important contributor to this risk. However, prior medications with triglyceride-lowering effects have not reduced adverse clinical outcomes in the statin era.

AREAS COVERED

The present review summarizes evidence and recommendations related to triglyceride-lowering therapy in the primary and secondary preventive settings. We provide an overview of findings from recent meta-analyses, important observational studies, and a detailed description of landmark trials, including the Reduction of Cardiovascular Events with Icosapent Ethyl-Intervention Trial (REDUCE-IT). We further review recommendations from current guidelines.

EXPERT OPINION

Icosapent ethyl is a stable, highly purified ethyl ester of eicosapentaenoic acid that safely and effectively reduces cardiovascular events in the contemporary setting. It is prescribed at a dose of 2 grams twice daily and is indicated in patients at high cardiovascular risk who have fasting or non-fasting triglyceride levels ≥150 mg/dl despite maximally tolerated statin treatment, or in individuals with triglyceride levels ≥500 mg/dl. Conversely, omega-3 fatty acid preparations containing a combination of eicosapentaenoic acid and docosahexaenoic acid are not indicated for reduction of cardiovascular risk and should be actively deprescribed.

Clinical effectiveness of fish oil on arterial stiffness: A systematic review and meta-analysis of randomized controlled trials

AIMS

The increase of arterial stiffness is an independent risk factor for cardiovascular diseases (CVD). Fish oil supplementation was shown to reduce the risk of CVD outcomes. However, the effects of fish oil on arterial stiffness remains controversial. This meta-analysis summarized existing randomized clinical trials (RCTs) to determine whether fish oil can affect arterial stiffness in adults.

DATA SYNTHESIS

Systematic searches were performed using the PubMed/Medline, EMbase, Cochrane database, Clinical trials, and Web of Science. All RCTs assessed the effect of fish oil intervention on carotid to femoral-Pulse Wave Velocity (cf-PWV), brachial to ankle-PWV (ba-PWV), augmentation index (AIx) and AIx75 were considered. A fixed-effect model was used to calculate the pooled effect. A total of 14 RCTs were included. The pooled data analysis showed that fish oil significantly reduced PWV levels (SMD: -0.145, 95%CI: -0.265 to -0.033, P = 0.012) compared to the control group. In subgroup analyses, a significant decrease in PWV was found in trials that fish oil with low dosages (≤1.8 g/d), short time (<24 weeks), low DHA to EPA ratio (DHA/EPA<1) and among young participant (<50 years old). Besides, the effect of fish oil was more obvious in ba-PWV compared to cf-PWV. In contrast, the effect of fish oil supplementation on AIx (WMD: -0.588%, 95% CI: -2.745 to 1.568, P = 0.593) and AIx75 (WMD: 0.542%, 95% CI: -1.490 to 2.574, P = 0.601) was nonsignificant.

CONCLUSIONS

The current study showed that fish oil supplementation had a beneficial effect on pulse wave velocity.

Omega-3 fatty acids for the primary and secondary prevention of cardiovascular disease

BACKGROUND

Omega-3 polyunsaturated fatty acids from oily fish (long-chain omega-3 (LCn3)), including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)), as well as from plants (alpha-linolenic acid (ALA)) may benefit cardiovascular health. Guidelines recommend increasing omega-3-rich foods, and sometimes supplementation, but recent trials have not confirmed this.

OBJECTIVES

To assess the effects of increased intake of fish- and plant-based omega-3 fats for all-cause mortality, cardiovascular events, adiposity and lipids.

SEARCH METHODS

We searched CENTRAL, MEDLINE and Embase to February 2019, plus ClinicalTrials.gov and World Health Organization International Clinical Trials Registry to August 2019, with no language restrictions. We handsearched systematic review references and bibliographies and contacted trial authors.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that lasted at least 12 months and compared supplementation or advice to increase LCn3 or ALA intake, or both, versus usual or lower intake.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion, extracted data and assessed validity. We performed separate random-effects meta-analysis for ALA and LCn3 interventions, and assessed dose-response relationships through meta-regression.

MAIN RESULTS

We included 86 RCTs (162,796 participants) in this review update and found that 28 were at low summary risk of bias. Trials were of 12 to 88 months' duration and included adults at varying cardiovascular risk, mainly in high-income countries. Most trials assessed LCn3 supplementation with capsules, but some used LCn3- or ALA-rich or enriched foods or dietary advice compared to placebo or usual diet. LCn3 doses ranged from 0.5 g a day to more than 5 g a day (19 RCTs gave at least 3 g LCn3 daily). Meta-analysis and sensitivity analyses suggested little or no effect of increasing LCn3 on all-cause mortality (risk ratio (RR) 0.97, 95% confidence interval (CI) 0.93 to 1.01; 143,693 participants; 11,297 deaths in 45 RCTs; high-certainty evidence), cardiovascular mortality (RR 0.92, 95% CI 0.86 to 0.99; 117,837 participants; 5658 deaths in 29 RCTs; moderate-certainty evidence), cardiovascular events (RR 0.96, 95% CI 0.92 to 1.01; 140,482 participants; 17,619 people experienced events in 43 RCTs; high-certainty evidence), stroke (RR 1.02, 95% CI 0.94 to 1.12; 138,888 participants; 2850 strokes in 31 RCTs; moderate-certainty evidence) or arrhythmia (RR 0.99, 95% CI 0.92 to 1.06; 77,990 participants; 4586 people experienced arrhythmia in 30 RCTs; low-certainty evidence). Increasing LCn3 may slightly reduce coronary heart disease mortality (number needed to treat for an additional beneficial outcome (NNTB) 334, RR 0.90, 95% CI 0.81 to 1.00; 127,378 participants; 3598 coronary heart disease deaths in 24 RCTs, low-certainty evidence) and coronary heart disease events (NNTB 167, RR 0.91, 95% CI 0.85 to 0.97; 134,116 participants; 8791 people experienced coronary heart disease events in 32 RCTs, low-certainty evidence). Overall, effects did not differ by trial duration or LCn3 dose in pre-planned subgrouping or meta-regression. There is little evidence of effects of eating fish. Increasing ALA intake probably makes little or no difference to all-cause mortality (RR 1.01, 95% CI 0.84 to 1.20; 19,327 participants; 459 deaths in 5 RCTs, moderate-certainty evidence),cardiovascular mortality (RR 0.96, 95% CI 0.74 to 1.25; 18,619 participants; 219 cardiovascular deaths in 4 RCTs; moderate-certainty evidence), coronary heart disease mortality (RR 0.95, 95% CI 0.72 to 1.26; 18,353 participants; 193 coronary heart disease deaths in 3 RCTs; moderate-certainty evidence) and coronary heart disease events (RR 1.00, 95% CI 0.82 to 1.22; 19,061 participants; 397 coronary heart disease events in 4 RCTs; low-certainty evidence). However, increased ALA may slightly reduce risk of cardiovascular disease events (NNTB 500, RR 0.95, 95% CI 0.83 to 1.07; but RR 0.91, 95% CI 0.79 to 1.04 in RCTs at low summary risk of bias; 19,327 participants; 884 cardiovascular disease events in 5 RCTs; low-certainty evidence), and probably slightly reduces risk of arrhythmia (NNTB 91, RR 0.73, 95% CI 0.55 to 0.97; 4912 participants; 173 events in 2 RCTs; moderate-certainty evidence). Effects on stroke are unclear. Increasing LCn3 and ALA had little or no effect on serious adverse events, adiposity, lipids and blood pressure, except increasing LCn3 reduced triglycerides by ˜15% in a dose-dependent way (high-certainty evidence).

AUTHORS' CONCLUSIONS

This is the most extensive systematic assessment of effects of omega-3 fats on cardiovascular health to date. Moderate- and low-certainty evidence suggests that increasing LCn3 slightly reduces risk of coronary heart disease mortality and events, and reduces serum triglycerides (evidence mainly from supplement trials). Increasing ALA slightly reduces risk of cardiovascular events and arrhythmia.

Marine-derived n-3 fatty acids therapy for stroke

BACKGROUND

Currently, with stroke burden increasing, there is a need to explore therapeutic options that ameliorate the acute insult. There is substantial evidence of a neuroprotective effect of marine-derived n-3 polyunsaturated fatty acids (PUFAs) in experimental stroke, leading to a better functional outcome.

OBJECTIVES

To assess the effects of administration of marine-derived n-3 PUFAs on functional outcomes and dependence in people with stroke.Our secondary outcomes were vascular-related death, recurrent events, incidence of other type of stroke, adverse events, quality of life, and mood.

SEARCH METHODS

We searched the Cochrane Stroke Group trials register (6 August 2018), the Cochrane Central Register of Controlled Trials (CENTRAL; Issue 1, January 2019), MEDLINE Ovid (from 1948 to 6 August 2018), Embase Ovid (from 1980 to 6 August 2018), CINAHL EBSCO (Cumulative Index to Nursing and Allied Health Literature; from 1982 to 6 August 2018), Science Citation Index Expanded ‒ Web of Science (SCI-EXPANDED), Conference Proceedings Citation Index-Science - Web of Science (CPCI-S), and BIOSIS Citation Index. We also searched ongoing trial registers, reference lists, relevant systematic reviews, and used the Science Citation Index Reference Search.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing marine-derived n-3 PUFAs to placebo or open control (no placebo) in people with a history of stroke or transient ischaemic attack (TIA), or both.

DATA COLLECTION AND ANALYSIS

At least two review authors independently selected trials for inclusion, extracted data, assessed risk of bias, and used the GRADE approach to assess the quality of the body of evidence. We contacted study authors for clarification and additional information on stroke/TIA participants. We conducted random-effects meta-analysis or narrative synthesis, as appropriate. The primary outcome was efficacy (functional outcome) assessed using a validated scale e.g. Glasgow Outcome Scale Extended (GOSE) dichotomised into poor or good clinical outcome, Barthel Index (higher score is better; scale from 0 to 100) or Rivermead Mobility Index (higher score is better; scale from 0 to 15).

MAIN RESULTS

We included 29 RCTs; nine of them provided outcome data (3339 participants). Only one study included participants in the acute phase of stroke (haemorrhagic). Doses of marine-derived n-3 PUFAs ranged from 400 mg/day to 3300 mg/day. Risk of bias was generally low or unclear in most trials, with a higher risk of bias in smaller studies. We assessed results separately for short (up to three months) and longer (more than three months) follow-up studies.Short follow-up (up to three months)Functional outcome was reported in only one pilot study as poor clinical outcome assessed with GOSE (risk ratio (RR) 0.78, 95% confidence interval (CI) 0.36 to 1.68; 40 participants; very low quality evidence). Mood (assessed with GHQ-30, lower score better), was reported by only one study and favoured control (mean difference (MD) 1.41, 95% CI 0.07 to 2.75; 102 participants; low-quality evidence).We found no evidence of an effect of the intervention for the remainder of the secondary outcomes: vascular-related death (two studies, not pooled due to differences in population, RR 0.33, 95% CI 0.01 to 8.00, and RR 0.33, 95% CI 0.01 to 7.72; 142 participants; low-quality evidence); recurrent events (RR 0.41, 95% CI 0.02 to 8.84; 18 participants; very low quality evidence); incidence of other type of stroke (two studies, not pooled due to different type of index stroke, RR 6.11, 95% CI 0.33 to 111.71, and RR 0.63, 95% CI 0.25 to 1.58; 58 participants; very low quality evidence); and quality of life (physical component mean difference (MD) -2.31, 95% CI -4.81 to 0.19, and mental component MD -2.16, 95% CI -5.91 to 1.59; one study; 102 participants; low-quality evidence).Adverse events were reported by two studies (57 participants; very low quality evidence), one trial reporting extracranial haemorrhage (RR 0.25, 95% CI 0.04 to 1.73) and the other one reporting bleeding complications (RR 0.32, 95% CI 0.01 to 7.35).Longer follow-up (more than three months)One small trial assessed functional outcome with both Barthel Index (MD 7.09, 95% CI -5.16 to 19.34) for activities of daily living, and Rivermead Mobility Index (MD 1.30, 95% CI -1.31 to 3.91) for mobility (52 participants; very low quality evidence). We carried out meta-analysis for vascular-related death (RR 1.02, 95% CI 0.78 to 1.35; five studies; 2237 participants; low-quality evidence) and fatal recurrent events (RR 0.69, 95% CI 0.31 to 1.55; three studies; 1819 participants; low-quality evidence).We found no evidence of an effect of the intervention for mood (MD 1.00, 95% CI -2.07 to 4.07; one study; 14 participants; low-quality evidence). Incidence of other type of stroke and quality of life were not reported.Adverse events (all combined) were reported by only one study (RR 0.94, 95% CI 0.56 to 1.58; 1455 participants; low-quality evidence).

AUTHORS' CONCLUSIONS

We are very uncertain of the effect of marine-derived n-3 PUFAs therapy on functional outcomes and dependence after stroke as there is insufficient high-quality evidence. More well-designed RCTs are needed, specifically in acute stroke, to determine the efficacy and safety of the intervention.Studies assessing functionality might consider starting the intervention as early as possible after the event, as well as using standardised clinically-relevant measures for functional outcomes, such as the modified Rankin Scale. Optimal doses remain to be determined; delivery forms (type of lipid carriers) and mode of administration (ingestion or injection) also need further consideration.

Omega-3 fatty acids for the primary and secondary prevention of cardiovascular disease

BACKGROUND

Researchers have suggested that omega-3 polyunsaturated fatty acids from oily fish (long-chain omega-3 (LCn3), including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)), as well as from plants (alpha-linolenic acid (ALA)) benefit cardiovascular health. Guidelines recommend increasing omega-3-rich foods, and sometimes supplementation, but recent trials have not confirmed this.

OBJECTIVES

To assess effects of increased intake of fish- and plant-based omega-3 for all-cause mortality, cardiovascular (CVD) events, adiposity and lipids.

SEARCH METHODS

We searched CENTRAL, MEDLINE and Embase to April 2017, plus ClinicalTrials.gov and World Health Organization International Clinical Trials Registry to September 2016, with no language restrictions. We handsearched systematic review references and bibliographies and contacted authors.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that lasted at least 12 months and compared supplementation and/or advice to increase LCn3 or ALA intake versus usual or lower intake.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion, extracted data and assessed validity. We performed separate random-effects meta-analysis for ALA and LCn3 interventions, and assessed dose-response relationships through meta-regression.

MAIN RESULTS

We included 79 RCTs (112,059 participants) in this review update and found that 25 were at low summary risk of bias. Trials were of 12 to 72 months' duration and included adults at varying cardiovascular risk, mainly in high-income countries. Most studies assessed LCn3 supplementation with capsules, but some used LCn3- or ALA-rich or enriched foods or dietary advice compared to placebo or usual diet. LCn3 doses ranged from 0.5g/d LCn3 to > 5 g/d (16 RCTs gave at least 3g/d LCn3).Meta-analysis and sensitivity analyses suggested little or no effect of increasing LCn3 on all-cause mortality (RR 0.98, 95% CI 0.90 to 1.03, 92,653 participants; 8189 deaths in 39 trials, high-quality evidence), cardiovascular mortality (RR 0.95, 95% CI 0.87 to 1.03, 67,772 participants; 4544 CVD deaths in 25 RCTs), cardiovascular events (RR 0.99, 95% CI 0.94 to 1.04, 90,378 participants; 14,737 people experienced events in 38 trials, high-quality evidence), coronary heart disease (CHD) mortality (RR 0.93, 95% CI 0.79 to 1.09, 73,491 participants; 1596 CHD deaths in 21 RCTs), stroke (RR 1.06, 95% CI 0.96 to 1.16, 89,358 participants; 1822 strokes in 28 trials) or arrhythmia (RR 0.97, 95% CI 0.90 to 1.05, 53,796 participants; 3788 people experienced arrhythmia in 28 RCTs). There was a suggestion that LCn3 reduced CHD events (RR 0.93, 95% CI 0.88 to 0.97, 84,301 participants; 5469 people experienced CHD events in 28 RCTs); however, this was not maintained in sensitivity analyses - LCn3 probably makes little or no difference to CHD event risk. All evidence was of moderate GRADE quality, except as noted.Increasing ALA intake probably makes little or no difference to all-cause mortality (RR 1.01, 95% CI 0.84 to 1.20, 19,327 participants; 459 deaths, 5 RCTs),cardiovascular mortality (RR 0.96, 95% CI 0.74 to 1.25, 18,619 participants; 219 cardiovascular deaths, 4 RCTs), and CHD mortality (1.1% to 1.0%, RR 0.95, 95% CI 0.72 to 1.26, 18,353 participants; 193 CHD deaths, 3 RCTs) and ALA may make little or no difference to CHD events (RR 1.00, 95% CI 0.80 to 1.22, 19,061 participants, 397 CHD events, 4 RCTs, low-quality evidence). However, increased ALA may slightly reduce risk of cardiovascular events (from 4.8% to 4.7%, RR 0.95, 95% CI 0.83 to 1.07, 19,327 participants; 884 CVD events, 5 RCTs, low-quality evidence with greater effects in trials at low summary risk of bias), and probably reduces risk of arrhythmia (3.3% to 2.6%, RR 0.79, 95% CI 0.57 to 1.10, 4,837 participants; 141 events, 1 RCT). Effects on stroke are unclear.Sensitivity analysis retaining only trials at low summary risk of bias moved effect sizes towards the null (RR 1.0) for all LCn3 primary outcomes except arrhythmias, but for most ALA outcomes, effect sizes moved to suggest protection. LCn3 funnel plots suggested that adding in missing studies/results would move effect sizes towards null for most primary outcomes. There were no dose or duration effects in subgrouping or meta-regression.There was no evidence that increasing LCn3 or ALA altered serious adverse events, adiposity or lipids, except LCn3 reduced triglycerides by ˜15% in a dose-dependant way (high-quality evidence).

AUTHORS' CONCLUSIONS

This is the most extensive systematic assessment of effects of omega-3 fats on cardiovascular health to date. Moderate- and high-quality evidence suggests that increasing EPA and DHA has little or no effect on mortality or cardiovascular health (evidence mainly from supplement trials). Previous suggestions of benefits from EPA and DHA supplements appear to spring from trials with higher risk of bias. Low-quality evidence suggests ALA may slightly reduce CVD event and arrhythmia risk.

A longitudinal study of the association of the eicosapentaenoic acid/arachidonic acid ratio derived from fish consumption with the serum lipid levels: a pilot study

It has been demonstrated that regular fish consumption is associated with a reduced mortality from atherosclerotic cardiovascular disease (ASCVD). However, data are scarce regarding the correlation between the changes in the serum eicosapentaenoic acid/arachidonic acid (EPA/AA) ratio associated with regular fish consumption and the changes in the serum lipid profile variables. This study was designed as a hospital-based longitudinal study to investigate the relationship between the changes in the serum EPA/AA ratio and changes of the serum lipid levels in patients with one or more risk factors for ASCVD. In 475 patients followed-up for at least 1 year, univariable and multivariable regression analyses conducted after adjustments for the risk factors of ASCVD revealed that the absolute change of the EPA/AA ratio (∆EPA/AA ratio) was independently and significantly associated with the changes of the serum levels of low-density lipoprotein cholesterol (LDL-C) (β = - 0.129, p = 0.005), triglyceride (TG) (β = - 0.108, p = 0.019), non-high-density lipoprotein cholesterol (non-HDL-C) (β = - 0.149, p = 0.001), and TG/HDL-C ratio, a marker of the LDL particle size (β = - 0.104, p = 0.02), while not being correlated with any other lipid parameters. On the other hand, while the ∆ docosahexaenoic acid (DHA)/AA ratio was inversely correlated with the changes of the serum HDL-C level and positively correlated with the changes of the TG/HDL-C ratio, possibly serving to promote development of atherosclerosis. The results suggest that an increase of the EPA/AA ratio might be associated with decrease of the serum levels of LDL-C, TG and non-HDL-C levels, as well as with an increase of the TG/HDL-C ratio, which represents increased LDL particle size, all of which play a role in the development of ASCVD. A high EPA/AA ratio, but not DHA/AA ratio, derived from fish consumption might reduce the risk of ASCVD through reducing the risk of development of atherosclerosis.Clinical Trial Registration Information: UMIN ( http://www.umin.ac.jp/ ), Study ID: UMIN000010603.

Omega-3 fatty acids for the primary and secondary prevention of cardiovascular disease

BACKGROUND

Researchers have suggested that omega-3 polyunsaturated fatty acids from oily fish (long-chain omega-3 (LCn3), including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)), as well as from plants (alpha-linolenic acid (ALA)) benefit cardiovascular health. Guidelines recommend increasing omega-3-rich foods, and sometimes supplementation, but recent trials have not confirmed this.

OBJECTIVES

To assess effects of increased intake of fish- and plant-based omega-3 for all-cause mortality, cardiovascular (CVD) events, adiposity and lipids.

SEARCH METHODS

We searched CENTRAL, MEDLINE and Embase to April 2017, plus ClinicalTrials.gov and World Health Organization International Clinical Trials Registry to September 2016, with no language restrictions. We handsearched systematic review references and bibliographies and contacted authors.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that lasted at least 12 months and compared supplementation and/or advice to increase LCn3 or ALA intake versus usual or lower intake.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion, extracted data and assessed validity. We performed separate random-effects meta-analysis for ALA and LCn3 interventions, and assessed dose-response relationships through meta-regression.

MAIN RESULTS

We included 79 RCTs (112,059 participants) in this review update and found that 25 were at low summary risk of bias. Trials were of 12 to 72 months' duration and included adults at varying cardiovascular risk, mainly in high-income countries. Most studies assessed LCn3 supplementation with capsules, but some used LCn3- or ALA-rich or enriched foods or dietary advice compared to placebo or usual diet.Meta-analysis and sensitivity analyses suggested little or no effect of increasing LCn3 on all-cause mortality (RR 0.98, 95% CI 0.90 to 1.03, 92,653 participants; 8189 deaths in 39 trials, high-quality evidence), cardiovascular mortality (RR 0.95, 95% CI 0.87 to 1.03, 67,772 participants; 4544 CVD deaths in 25 RCTs), cardiovascular events (RR 0.99, 95% CI 0.94 to 1.04, 90,378 participants; 14,737 people experienced events in 38 trials, high-quality evidence), coronary heart disease (CHD) mortality (RR 0.93, 95% CI 0.79 to 1.09, 73,491 participants; 1596 CHD deaths in 21 RCTs), stroke (RR 1.06, 95% CI 0.96 to 1.16, 89,358 participants; 1822 strokes in 28 trials) or arrhythmia (RR 0.97, 95% CI 0.90 to 1.05, 53,796 participants; 3788 people experienced arrhythmia in 28 RCTs). There was a suggestion that LCn3 reduced CHD events (RR 0.93, 95% CI 0.88 to 0.97, 84,301 participants; 5469 people experienced CHD events in 28 RCTs); however, this was not maintained in sensitivity analyses - LCn3 probably makes little or no difference to CHD event risk. All evidence was of moderate GRADE quality, except as noted.Increasing ALA intake probably makes little or no difference to all-cause mortality (RR 1.01, 95% CI 0.84 to 1.20, 19,327 participants; 459 deaths, 5 RCTs),cardiovascular mortality (RR 0.96, 95% CI 0.74 to 1.25, 18,619 participants; 219 cardiovascular deaths, 4 RCTs), and it may make little or no difference to CHD events (RR 1.00, 95% CI 0.80 to 1.22, 19,061 participants, 397 CHD events, 4 RCTs, low-quality evidence). However, increased ALA may slightly reduce risk of cardiovascular events (from 4.8% to 4.7%, RR 0.95, 95% CI 0.83 to 1.07, 19,327 participants; 884 CVD events, 5 RCTs, low-quality evidence), and probably reduces risk of CHD mortality (1.1% to 1.0%, RR 0.95, 95% CI 0.72 to 1.26, 18,353 participants; 193 CHD deaths, 3 RCTs), and arrhythmia (3.3% to 2.6%, RR 0.79, 95% CI 0.57 to 1.10, 4,837 participants; 141 events, 1 RCT). Effects on stroke are unclear.Sensitivity analysis retaining only trials at low summary risk of bias moved effect sizes towards the null (RR 1.0) for all LCn3 primary outcomes except arrhythmias, but for most ALA outcomes, effect sizes moved to suggest protection. LCn3 funnel plots suggested that adding in missing studies/results would move effect sizes towards null for most primary outcomes. There were no dose or duration effects in subgrouping or meta-regression.There was no evidence that increasing LCn3 or ALA altered serious adverse events, adiposity or lipids, although LCn3 slightly reduced triglycerides and increased HDL. ALA probably reduces HDL (high- or moderate-quality evidence).

AUTHORS' CONCLUSIONS

This is the most extensive systematic assessment of effects of omega-3 fats on cardiovascular health to date. Moderate- and high-quality evidence suggests that increasing EPA and DHA has little or no effect on mortality or cardiovascular health (evidence mainly from supplement trials). Previous suggestions of benefits from EPA and DHA supplements appear to spring from trials with higher risk of bias. Low-quality evidence suggests ALA may slightly reduce CVD event risk, CHD mortality and arrhythmia.

Omega-3 fatty acids related to cognitive impairment in patients with schizophrenia

Cognitive impairment is strongly associated with functional outcome in patients with schizophrenia but its pathophysiology remains largely unclear. Involvement of omega-3 fatty acids in the cognitive function of healthy individuals and patients with neuropsychiatric disease has received increasing attention. The aim of this study was to examine the relationship between omega-3 fatty acids with cognitive function, social function, and psychiatric symptoms in patients with schizophrenia. The subjects included 30 patients with schizophrenia or schizoaffective disorder. Psychiatric symptoms, cognitive function, and social function were assessed using the Positive and Negative Syndrome Scale, the Brief Assessment of Cognition in Schizophrenia (BACS), and the Social Functioning Scale (SFS), respectively. Blood serum omega-3 fatty acids were assessed using gas chromatography. The BACS composite score was significantly correlated with blood eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) levels. In addition, a daily dose of antipsychotic medication was negatively and significantly correlated with the blood DHA level and with the BACS composite score. Step-wise multiple regression analyses demonstrated that the SFS score was significantly associated with the BACS composite score. Our results indicate that reduced blood omega-3 fatty acids are associated with cognitive impairment, which then impacts social functioning outcomes in schizophrenia.

Current Treatment of Dyslipidemia: Evolving Roles of Non-Statin and Newer Drugs

Since their introduction, statin (HMG-CoA reductase inhibitor) drugs have advanced the practice of cardiology to unparalleled levels. Even so, coronary heart disease (CHD) still remains the leading cause of death in developed countries, and is predicted to soon dominate the causes of global mortality and disability as well. The currently available non-statin drugs have had limited success in reversing the burden of heart disease, but new information suggests they have roles in sizeable subpopulations of those affected. In this review, the status of approved non-statin drugs and the significant potential of newer drugs are discussed. Several different ways to raise plasma high-density lipoprotein (HDL) cholesterol (HDL-C) levels have been proposed, but disappointments are now in large part attributed to a preoccupation with HDL quantity, rather than quality, which is more important in cardiovascular (CV) protection. Niacin, an old drug with many antiatherogenic properties, was re-evaluated in two imperfect randomized controlled trials (RCTs), and failed to demonstrate clear effectiveness or safety. Fibrates, also with an attractive antiatherosclerotic profile and classically used for hypertriglyceridemia, lacks evidence-based proof of efficacy, save for a subgroup of diabetic patients with atherogenic dyslipidemia. Omega-3 fatty acids fall into this category as well, even with an impressive epidemiological evidence base. Omega-3 research has been plagued with methodological difficulties yielding tepid, uncertain, and conflicting results; well-designed studies over longer periods of time are needed. Addition of ezetimibe to statin therapy has now been shown to decrease levels of low-density lipoprotein (LDL) cholesterol (LDL-C), accompanied by a modest decrease in the number of CV events, though without any improvement in CV mortality. Importantly, the latest data provide crucial evidence that LDL lowering is central to the management of CV disease. Of drugs that inhibit cholesteryl ester transfer protein (CETP) tested thus far, two have failed and two remain under investigation and may yet prove to be valuable therapeutic agents. Monoclonal antibodies to proprotein convertase subtilisin/kexin type 9, now in phase III trials, lower LDL-C by over 50 % and are most promising. These drugs offer new ability to lower LDL-C in patients in whom statin drug use is, for one reason or another, limited or insufficient. Mipomersen and lomitapide have been approved for use in patients with familial hypercholesterolemia, a more common disease than appreciated. Anti-inflammatory drugs are finally receiving due attention in trials to elucidate potential clinical usefulness. All told, even though statins remain the standard of care, non-statin drugs are poised to assume a new, vital role in managing dyslipidemia.

n-3 fatty acids effectively improve the reference memory-related learning ability associated with increased brain docosahexaenoic acid-derived docosanoids in aged rats

We investigated whether a highly purified eicosapentaenoic acid (EPA) and a concentrated n-3 fatty acid formulation (prescription TAK-085) containing EPA and docosahexaenoic acid (DHA) ethyl ester could improve the learning ability of aged rats and whether this specific outcome had any relation with the brain levels of EPA-derived eicosanoids and DHA-derived docosanoids. The rats were tested for reference memory errors (RMEs) and working memory errors (WMEs) in an eight-arm radial maze. Fatty acid compositions were analyzed by GC, whereas brain eicosanoid/docosanoids were measured by LC-ESI-MS-MS-based analysis. The levels of lipid peroxides (LPOs) were measured by thiobarbituric acid reactive substances. The administration of TAK-085 at 300 mg·kg⁻¹day⁻¹ for 17 weeks reduced the number of RMEs in aged rats compared with that in the control rats. Both TAK-085 and EPA administration increased plasma EPA and DHA levels in aged rats, with concurrent increases in DHA and decreases in arachidonic acid in the corticohippocampal brain tissues. TAK-085 administration significantly increased the formation of EPA-derived 5-HETE and DHA-derived 7-, 10-, and 17-HDoHE, PD1, RvD1, and RvD2. ARA-derived PGE2, PGD2, and PGF2α significantly decreased in TAK-085-treated rats. DHA-derived mediators demonstrated a significantly negative correlation with the number of RMEs, whereas EPA-derived mediators did not exhibit any relationship. Furthermore, compared with the control rats, the levels of LPO in the plasma, cerebral cortex, and hippocampus were significantly reduced in TAK-085-treated rats. The findings of the present study suggest that long-term EPA+DHA administration may be a possible preventative strategy against age-related cognitive decline.

An increase in the EPA/AA ratio is associated with improved arterial stiffness in obese patients with dyslipidemia

AIM

Previous epidemiological studies demonstrated that the ratio of n-6 to n-3 polyunsaturated fatty acids is associated with cardiovascular diseases. We herein investigated whether the beneficial effect of highly purified eicosapentaenoic acid(EPA) on arterial stiffness is associated with changes in the ratio of polyunsaturated fatty acids, such as EPA, docosahexaenoic acid(DHA) and dihomo-γ-linolenic acid(DGLA), relative to arachidonic acid(AA), in obese Japanese patients with dyslipidemia.

METHODS

The EPA/AA, DHA/AA and DGLA/AA ratios were compared between obese patients with(n=94) and without (n=31) dyslipidemia. Among the former group, 88 patients received either highly purified EPA treatment(1.8g daily, n=45) or treatment without EPA(control, n=43).

RESULTS

At baseline, the ratios of DHA/AA and DGLA/AA were significantly(P＜0.05) higher in obese patients with dyslipidemia than in those without, while the EPA/AA ratio was similar between patients with and without dyslipidemia. EPA significantly reduced the hemoglobin A1c, total cholesterol, triglycerides, CRP, cardio-ankle vascular index(CAVI)(an index of arterial stiffness) and the DGLA/AA ratio relative to the control at three months after the treatment. On the other hand, EPA significantly increased the adiponectin level and EPA/AA ratio(P＜0.05). A multivariate regression analysis revealed that only age, an increase in the EPA/AA ratio and a decrease in the CRP level were significant determinants of a reduction of the CAVI by EPA.

CONCLUSION

These findings suggest that EPA improves the arterial stiffness in association with an increase in the EPA/AA ratio and a decrease in inflammation in obese patients with dyslipidemia.