Effects of basal insulin glargine and omega-3 on lower limb arterial disease outcome in patients with dysglycaemia: An analysis of the Outcome Reduction with an Initial Glargine INtervention (ORIGIN) trial

Effect of Glucose Levels on Cardiovascular Risk

Cardiovascular diseases remain the leading cause of death and disability. The development of cardiovascular diseases is traditionally associated with various risk factors, most of which are somehow related to an unhealthy lifestyle (smoking, obesity, lack of physical activity, etc.). There are also risk factors associated with genetic predisposition, as well as the presence of concomitant diseases, especially chronic ones. One of the most striking examples is, of course, type 2 diabetes. This metabolic disorder is associated with impaired carbohydrate metabolism. The main clinical manifestation of type 2 diabetes is elevated blood glucose levels. The link between diabetes and CVD is well known, so it is logical to assume that elevated glucose levels may be important, to some extent, in the context of heart and vascular disease. In this review, we tried to summarize data on the possible role of blood glucose as a risk factor for the development of CVD.

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.

Omega-3 Polyunsaturated Fatty Acid Supplementation in Patients with Lower Extremity Arterial Disease

BACKGROUND

Omega-3 polyunsaturated fatty acid (PUFA) supplements are used to treat lower extremity arterial disease (LEAD), but their effects on patient outcomes remain controversial.

OBJECTIVE

We aimed to investigate the effect of omega-3 PUFA supplements on outcomes in LEAD patients.

DESIGN

We systematically searched for randomized controlled trials (RCTs) published before February 2020 in PubMed, the Cochrane Library, EMBASE, Medline, and ClinicalTrials.gov. Three researchers extracted the study design, sample size, omega-3 PUFA dosage, and patient characteristics. A random-effects model was used. The primary outcomes were the mean change in the ankle-brachial index (ABI) and pain-free and maximal walking distance. The secondary outcomes were the mean changes in triglycerides and other lipid profiles, high-sensitivity C-reactive protein level, blood pressure, flow-mediated vasodilatation, and incidence of cardiovascular events.

RESULTS

Sixteen RCTs and 1,852 patients were analyzed. Most of the included RCTs had a low risk of bias. The grade quality was moderate in ABI, C-reactive protein, and cardiovascular events; very low in triglyceride; and low in the other outcomes. The use of omega-3 PUFAs was not significantly associated with the primary outcomes, but it was significantly associated with a reduced triglyceride level, with a moderate effect size (Hedges' g=-0.34, 95% CI [-0.55-0.13], p < 0.01, I²=32.5%). This significant association was only found for marine-based omega-3 PUFAs. Omega-3 PUFAs and eicosapentaenoic acid dosages >2 g per day were associated with reduced levels of triglycerides. Meta-regression also showed that the use of eicosapentaenoic acid was significantly negatively associated with the triglyceride level in a dosage-dependent manner. No significant association was found in the other secondary outcomes.

CONCLUSION

This meta-analysis showed that the use of marine-based omega-3 PUFAs was significantly associated with a reduced level of triglycerides. The strength of the association depended on the dosage of eicosapentaenoic acid. (CRD42020168416 at PROSPERO.).