Table 1 Summary of published studies and proposed trials of omega-3 fatty acid supplementation in chronic obstructive pulmonary disease (COPD)
Author | Broekhuizen et al. | Shahar et al. | McKeever et al. | de Batlle et al. | Hirayama et al. | Barr (Investigator) protocol | Engelen (Investigator) protocol | Proposed study |
|---|---|---|---|---|---|---|---|---|
Year | 2005 | 1994 | 2008 | 2011 | 2010 | 2012 (recruiting) | 2012 (recruiting) | 2012 |
Country | Netherlands | United States | Netherlands | Spain | Japan | United States | United States | Australia |
Study type | Randomized controlled trial | Cross sectional | Cross sectional | Cross sectional | Case controlled | Interventional pilot | Randomized controlled trial | Interventional feasibility |
Retrospective/prospective | Prospective | Retrospective | Retrospective | Retrospective | Retrospective | Prospective | Prospective | Prospective |
Sample size (n) | 102 | 7,902 | 13,820 | 250 | 618 | 40-45 | 77 | 40 |
n with COPD | 102 (100%) | 197 (2.5%) | 553 (4%) | 250 (100%) | 278 (45%) | 40-45 (100%) | Unclear | 40 (100%) |
Definition of COPD | PBD, ≥ GOLD stage 2 (at least 50%≤FEV1 <80% predicted) | FEV1 ≤65% | ≥ GOLD stage 2 (at least 50%≤FEV1 <80% predicted) Not PBD | PBD FEV1/FVC <0.70 | PBD FEV1/FVC <0.70 | PBD FEV1/FVC <0.70 and PBDFEV1 <65% predicted | PBD FEV1 <70% predicted | PBD FEV1/FVC <0.70 |
Mean Age (SD) | A- 64 (10) | 54 (6)e | 42.2 (11.2) | 68 (8) | 65.8 (6)e | N/A | N/A | N/A |
P- 62 (8) | ||||||||
Mean PBD FEV1 % (SD) | A- 38.2 (13.1) | 90 (18)e | Not reported | 53 (16) | Not reported | N/A | N/A | N/A |
P- 35.8 (15.1) | ||||||||
Intervention | PUFA blendd | No | No | No | No | Fish oil | Fish oil | Fish oil |
Placebo | Palm oil (80%) & sunflower oil (20%) | No | No | No | No | Corn oil | Olive oil | Corn oil |
Control group | Yes | No | No | No | Yes | Yes | Yes | Yes |
Supplementation duration | 8 weeks | N/A | N/A | N/A | N/A | 6 months (2g EPA/ 0.5g DHA per day) | 4 weeks (3.5g or 2.0g omega-3 per day) | 4 months (3.4g omega-3 per day) |
Six-minute walk test | No | No | No | No | No | Yes | No | Yes |
Bicycle ergometry | Yes | No | No | No | No | No | No | No |
Pulmonary function | Yes | Yes | Yes | Yes | Yes | Yes | No | Yes |
Blood biomarkers | Yes | No | No | Yes | No | Yes | Yes | Yes |
HADS | No | No | No | No | No | No | No | Yes |
Dyspnea questionnaire | No | No | No | No | Yes | No | No | Yes |
QOL questionnaire | No | No | No | No | No | Yes | No | Yes |
FFQ | No | Yes (61-item, intake past year) | Yes (178 item, past years intake) | Yes (122 item, past 2 years intake) | Yes (138 item, past 5 years intake) | No | No | Yes (74 item, past years intake) |
Endothelial function | No | No | No | No | No | Yes | No | No |
Muscle strength(skeletal & respiratory) | Yes | No | No | No | No | No | Yes | No |
Muscle protein synthesis & breakdown | No | No | No | No | No | No | Yes | No |
Oxidative capacity | No | No | No | No | No | No | Yes | No |
Duel-Energy X-ray absorptiometry | No | No | No | No | No | No | Yes | No |
Statistical test | Linear regression | Logistic regression | Nonlinear regression | Logistic regression | Logistic regression | Association between n-3 intake and endothelial function | Association between n-3 intake and protein synthesis | ANOVA |
Comparison PUFA and placebo group after 8 week intervention. | Association between n-3 intake and COPD | Association between n-6 intake and COPD | Association between PUFA and biomarkers | Association between PUFA intake and COPD | Â | |||
Results | Greater ↑ exercise capacity in PUFA compared to placebo group*. | COPD strongly and inversely associated with intake of n-3 fatty acids*b | No association between COPD and n-3 intake. | ↑ ALA associated with↓ TNF-α *a | ↑ prevalence COPD associated with, ↓ PUFA intake *b, ↓ n-6 intake *b, ↓ n-3 intake *b | N/A | N/A | N/A |
↑ intake of four of the n-6 fatty acids associated with ↑ risk of COPD*c. | ↑ LA and AA associated with ↑ CRP *c | |||||||
PUFA no effect on FEV1 or muscle strength. | ||||||||
|  | No change in blood biomarkers in either group. |  |  | ↑ AA associated with ↑ IL-6 *c |  |  |  |  |