Effects of Individualized Step Targets on Physical Activity in COPD. A Randomized Study

Area of Science:

• Pulmonary Medicine
• Exercise Physiology
• Biochemistry

Background:

• Physical activity (PA) is crucial for managing chronic obstructive pulmonary disease (COPD).
• While goal setting can enhance PA, long-term adherence remains a challenge.
• Myokines, like Growth differentiation factor-15 (GDF-15), are implicated in exercise responses.

Purpose of the Study:

• To evaluate the impact of individualized target step counts on PA and myokine levels in COPD patients.
• To assess if tailored step goals improve sustained physical activity and related biomarkers over six months.

Main Methods:

• A randomized parallel group, open-label study (INTAR-Step) comparing target provision (intervention) versus usual care (control).
• Primary outcome: proportion of subjects achieving target step count; Secondary outcomes: changes in PA parameters and myokines.
• 73 COPD patients were analyzed (intervention n=38, control n=35).

Main Results:

• No significant difference in achieving target step counts between groups (p=0.157).
• Significant increases in step count and duration of activity (≥3.0 metabolic equivalents) in the intervention group.
• Elevated levels of GDF-15, fatty acid-binding protein-3, and Irisin in the intervention group.
• Higher GDF-15 levels correlated with increased step counts.

Conclusions:

• Individualized step targets did not significantly increase target achievement but enhanced overall step counts in COPD patients.
• The findings suggest GDF-15 may be involved in mediating the positive effects of increased physical activity in COPD.