Effects of conjugated linoleic acid supplementation on serum levels of interleukin-6 and sirtuin 1 in COPD patients.

OBJECTIVE: Chronic obstructive pulmonary disease (COPD) is characterized by systemic inflammation and accelerated inflammaging of the lungs. Some studies showed that conjugated linoleic acid (CLA) has anti-inflammatory effects. The aim of the present study was to evaluate the effect of CLA supplementation on serum levels of interleukin (IL)-6 and sirtuin1 (SIRT1) in patients with COPD. MATERIALS AND METHODS: 82 patients with stable COPD were enrolled in a double blind clinical trial. Subjects were randomly assigned to two groups: placebo (n=42) and 3.2 g CLA daily supplementation (n=40). Forced expiratory volume in one second (FEV1%), BODE index, and serum levels of IL-6, and SIRT1 were measured at the baseline and six weeks after the intervention. In addition, the study parameters in the two groups were compared based on the Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria. RESULTS: After supplementation with CLA, serum levels of IL-6 and BODE index significantly decreased (p<0.05 and p<0.001, respectively). In addition, serum levels of SIRT1 (p<0.01) and FEV1 (p<0.001) significantly increased in the supplementation group. Based on GOLD criteria, the increase in SIRT1 and the decrease in IL-6 serum levels were found to be statistically significant in stages III and IV in the supplementation group (p<0.05 and p<0.01, respectively). CONCLUSION: Supplementation with CLA can modify the inflammatory markers and improve the health status of COPD patients. The results suggest that CLA supplementation in COPD patients can be useful in the management of the disease.

The effect of conjugated linoleic acid on oxidative stress and matrix metalloproteinases 2 and 9 in patients with COPD.

Background: Natural antioxidants in foods may be used in prevention and treatment of oxidative stress and inflammation in COPD. Therefore, this study aimed to evaluate the effect of conjugated linoleic acid (CLA) supplement as natural antioxidants on oxidative stress levels, and MMP2 and MMP9 serum levels in COPD patients. Materials and methods: This clinical trial study was conducted on 90 (supplement group=45 and control group=45) COPD patients in Ardabil city, Iran, in 2015. After obtaining written consent, general information was collected from each patient using a validated and reliable questionnaire. Supplement group received 3.2 g of CLA and those in the control group were given 3.2 g of placebo for 6 weeks on a daily basis. Fasting blood samples were taken from all of the patients for testing of malondialdehyde (MDA), MMP2, and MMP9 levels at the beginning and end of the study. Data were analyzed using Kolmogorov-Smirnov test, independent samples t-test, paired sample t-test, chi-square test, and ANOVA. Results: There were no significant differences between the two groups with regard to mean age, smoking status, and serum level of MDA at the beginning of the study. In the supplement group, the serum level of MDA decreased significantly at the end of the 6th week compared to that in the beginning of the study (p=0.0004), while in the placebo group, the difference was found to be insignificant. The serum level of MMP9 decreased significantly in the supplement group, while in the placebo group its level increased significantly as compared to that at the beginning of the study (p<0.05). The serum levels of MMP2 indicated no significant differences between the two groups neither at the beginning nor at the end of the study. Conclusion: These findings indicated that CLA supplementation may be helpful for COPD patients through inhibiting the production of oxidative stress and controlling MMP9 serum levels.

The effect of conjugated linoleic acid supplementation on the nutritional status of COPD patients.

BACKGROUND: COPD patients are susceptible to anorexia, reduction of caloric intake, weight loss, and malnutrition. One of the possible mechanisms is the increase of inflammatory markers such as interleukin 1ß (IL1ß), is highly correlated with anorexia. Considering the anti-inflammatory role of conjugated linoleic acid (CLA), this study aimed to investigate the effect of CLA supplementation on the nutritional status of COPD patients. PATIENTS AND METHODS: In a double-blind clinical trial, 93 COPD patients who volunteered to participate in the study and who filled out a written consent form, were randomly assigned to control or supplementation groups. The patients in the supplementation group received 3.2 g of CLA on a daily basis for 6 weeks, while those in the control group received placebo on a daily basis for 6 weeks. For IL1ß assessment, the patients' anthropometric indices and appetite score were checked and their blood samples were collected both before and after the treatment. Moreover, in order to investigate the changes in the caloric intake trend during the study, their dietary intake levels were assessed using 24-hour dietary recall, 3 days a week at the onset, in the 4th week, and at the end of the study. Eventually, 90 patients completed the study. RESULTS: The results demonstrated a significant increase in appetite score (P=0.001), average caloric intake (P=0.01), and macronutrient intake (P<0.05), while a significant decrease was observed in the serum level of IL1ß among the patients of the supplementation group (P=0.008). Meanwhile, although the supplementation group's body mass index was also higher on completion, compared to their own initial state as well as to that in the control group, the differences were not significant (P=0.13). CONCLUSION: The findings of this research indicate that the consumption of CLA supplementation can be effective in regulating the appetite and improving the nutritional status of patients suffering from COPD through adjusting the serum level of IL1ß.