Effect of Macronutrients or Micronutrients Supplementation on Nutritional Status, Physical Functional Capacity and Quality of Life in Patients with COPD: A Systematic Review and Meta-Analysis

Abstract

Given the importance that a correct and balanced nutrition has on patients with chronic obstructive pulmonary disease (COPD), supplementation of macro and micronutrients has been proposed, but the results of previous meta-analyses are contrasting. We performed an update of the latest evidence through a systematic review and meta-analysis of studies to assess the role of nutritional supplements in improving nutritional status, pulmonary function, physical performance, and quality of life of these patients.

We included randomized controlled trials (RCTs) published between 01-01-2010 and 11-01-2023 evaluating the effectiveness of nutritional support in patients affected by stable COPD with an intervention of at least 2 weeks. Primary outcomes were changes in body mass index (BMI) and fat free mass index (FFMI). Secondary outcomes were exercise tolerance (6-min walking test, 6MWT), quality of life (St George’s Respiratory Questionnaire, SGRQ) and respiratory function (FEV₁). According with supplements type (macronutrients or micronutrients), we calculated the pooled adjusted mean difference (MD) and 95% confidence intervals (95%CIs) of the selected outcomes, using random-effects models in presence of high heterogeneity (I²>50%) or fixed-effects models otherwise. The risk of publication bias was evaluated with the trim and fill method.

From 967 articles, 20 RCTs were included. Macronutrients supplementation improved BMI (MD 1.0 kg/m², 95%CI 0.21-1.79), FFMI (MD 0.77 Kg/m², 95%CI 0.48-1.06), 6MQT (MD 68.39 m, 95%CI 40.07-96.71), and SGRQ (MD −5.14, 95% CI −7.31-2.97), while it does not ameliorate respiratory function (MD 0.26% 95%CI −1.87-2.40). Micronutrients supplementation alone did not improve any of the considered outcomes.

Keywords:

• Chronic obstructive pulmonary disease
• body mass index
• quality of life
• functional status
• supplementation
• dietary

Acknowledgments

We have not received substantial contributions from non-authors.

Authors’ contributions

GL, DL, and CP designed the meta-analysis and defined the scope and inclusion/exclusion criteria. GL and DL performed the bibliographic research. GL extracted the data and drafted the manuscript. DL performed the statistical analysis and contributed to drafting the manuscript. All the authors contributed to the interpretation of the results and reviewed the draft for important intellectual content.

Disclosure statement

The authors report there are no competing interests to declare.

Data availability statement

Data are available on reasonable request to the corresponding author.

Additional information

Funding

This research was not funded.