Kidney Week

Abstract: TH-PO288

Fragmented Physical Activity and Mortality in Patients on Hemodialysis: Insights from the Fitbit Study

Session Information

• Hemodialysis and Frequent Dialysis - 1
  October 24, 2024 | Location: Exhibit Hall, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Dialysis

• 801 Dialysis: Hemodialysis and Frequent Dialysis

Authors

• Malhotra, Rakesh, University of California San Diego, La Jolla, California, United States

Rakesh Malhotra, MD, MPH, FASN

• Larsen, Britta, University of California San Diego, La Jolla, California, United States

Britta Larsen, PhD

• Dasgupta, Subhasis, University of California San Diego, La Jolla, California, United States

Subhasis Dasgupta, PhD

• Chopra, Tushar, University of Virginia, Charlottesville, Virginia, United States

Tushar Chopra, MD, FASN

• Schrauben, Sarah J., University of Pennsylvania, Philadelphia, Pennsylvania, United States

Sarah J. Schrauben, MD, MS

• Drew, David A., Tufts Medical Center, Boston, Massachusetts, United States

David A. Drew, MD, MS

• Ikizler, Talat Alp, Vanderbilt University, Nashville, Tennessee, United States

Talat Alp Ikizler, MD, FASN

• Kotanko, Peter, Renal Research Institute, New York, New York, United States

Peter Kotanko, MD, FASN

• Ix, Joachim H., University of California San Diego, La Jolla, California, United States

Joachim H. Ix, MD, FASN

Background

Limited data suggest that lower physical activity (PA) overall is associated with poor health outcomes in hemodialysis (HD). Above and beyond total PA, little is known about fragmentation of PA (activity time before breaks). This study evaluates the association between PA fragmentation, and mortality risk among HD patients.

Methods

HD patients wore wearable activity trackers (Fitbit) between March 2018 and April 2020, with mortality data collected until December 2023. Minute-by-minute activity data over a 7-day period were used to categorize each minute as active (≥10 steps/minute) or sedentary (<10 steps/minute). Activity was further categorized by activity patterns: activity fragmentation (active to sedentary transition probability, calculated as the reciprocal of the average active bout duration), and segment length of consecutive active minutes (<5, 5-10, and ≥10 minutes). Cox proportional hazards models were used to assess the associations between activity patterns and mortality risk, adjusting for demographic, device wear time and comorbidities.

Results

We collected data on 85 HD patients (mean [SD] age, 62 [13] years; 45% women), 37 died (44%) during follow-up (mean [SD] of 3.1 [1.6] years. Participants who died tended to have a 10% higher activity fragmentation (mean [SD], 47% [6%] vs 37% [8%]; P<0.001), and a higher percentage of short activity segments (<5 minutes) (mean [SD], 51% [12%] vs 35% [10%]; P<0.001), than those who were alive at follow-up. In fully adjusted analyses, greater activity fragmentation was linked to an increased mortality risk (HR 1.54, 95% CI, 1.08-2.04). Short activity segments of < 5 minutes were associated with higher mortality risk (HR 1.32, 95% CI, 1.08-1.66) but activity segments of 5-10 and ≥ to minutes were not associated with mortality risk (Figure 1).

Conclusion

Our findings suggest that fragmented daily physical activity, especially short activity bouts < 5 minutes, is associated with mortality risk in HD patients.