Unrefined Salmon Oil as Dietary Supplement in Patient With Chronic Obstructive Pulmonary Disease

This study is a double-blind, placebo-controlled, randomized trial, investigating unrefined salmon oil, CARDIO®, additional to standard care for patients suffering from COPD. The investigational product is an unrefined salmon oil based soft-gel formulation containing 21 different fatty acids (more than 99.1%), lipopeptides (less than 0.9%), antioxidants and other micro metabolites. Research has shown that marine foods carry nutritional characteristics that promote human health, particularly the high intake of long-chain n-3 polyunsaturated fatty acid (n-3 PUFA), eicosapentaeonic acid (EPA), and docosahexaenoic acid (DHA). Cell culture and mouse studies have shown that n-3 PUFAs, such as EPA and DHA, reduce lung leucocyte infiltration and decrease inflammatory cytokines.

Accumulating evidence points to elevated circulating levels of oxidative low-density lipoprotein (ox-LDL) as a key factor that couples COPD with coronary artery disease (CAD). When normal lipoprotein (LDL) becomes oxidized, the structural alteration confers highly pro-inflammatory properties, inducing inflammation and oxidative stress processes central to both COPD and CAD. Ox-LDL is a potent activator of eosinophils, after which the eosinophils appear to mediate chronic inflammation. Based on the literature and studies on the investigational product, the investigators will investigate if CARDIO® can influence eosinophilic inflammation and ox-LDL. This could have positive consequences for improving COPD control and reducing the risk of exacerbations and cardiovascular events. The generalized anti-inflammatory effects and inflammation-resolution promoting effects of unrefined salmon oil might reduce systemic inflammation and benefit COPD patients with co-existing CAD. In this study, the investigators intend to recruit patients with raised oxidative stress represented by patients with serum ox-LDL level at the 25th percentile and above. Therefore, the investigators intend to recruit 20 participants (part 1) with the same inclusion criteria as in part 2, but only measure/analysis serum ox-LDL. The ox-LDL levels derived from part 1 of the study will provide a cut-off level of ox-LDL for patient inclusion into the study part 2. Patient with an ox-LDL value above the 25th percentile will be asked to participate in part 2 of the study. The investigators believe that this will provide the most accurate inclusion of patients to part 2 of the study - the intervention study.

However, clinical trials in humans diagnosed with COPD, have shown varied results investigating n-3 PUFA supplementation. The objective of this study is to evaluate specifically the impact of CARDIO® compared to placebo, on ox-LDL, forced expiratory airflow, blood eosinophils and markers of inflammation in COPD.

Data will be collected by pulmonary function tests (spirometry), blood sample, nutritional log, quality of life questionnaires (CAT), and blood and stool collected for research biobanking. Study intervention period will be 20 weeks, plus 4 weeks post-intervention follow-up, foremost of safety reasons.

As this study is explorative in nature, a sample size which balance the need of statistical power and resource constraints is chosen. The available resources, predetermine those 100 participants, 50 in each arm, can be recruited. Expecting a drop-out rate of about 20% in total (10 subjects per group), and assuming a standard deviation of Ox-LDL of 6 ng/mL the given sample size enables us to detect a mean difference in ox-LDL levels of 3.85 ng/mL. This corresponds to an effect size of 0.64 and shows that the study is reasonably powered. These calculations are done under the standard assumption of power equal to 80% and a significance level of 5%.