Kidney Week

Abstract: FR-PO532

Intermuscular Fat in Patients with CKD Inversely Correlates with Physical Activity and Mitochondrial Function

Session Information

• Physical Activity, Body Composition, Metabolism: Clinical
  October 26, 2018 | Location: Exhibit Hall, San Diego Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Health Maintenance, Nutrition, and Metabolism

• 1302 Health Maintenance, Nutrition, and Metabolism: Clinical

Authors

• Gamboa, Jorge, Vanderbilt University, Nashville, Tennessee, United States

Jorge Gamboa,

• Keller, Chad Alexander, Vanderbilt University , Nashville, Tennessee, United States

Chad Alexander Keller,

• Roshanravan, Baback, University of Washington - Kidney Research Institute, Seattle, Washington, United States

Baback Roshanravan,

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

Talat Alp Ikizler,

Background

Patients with chronic kidney disease (CKD) have higher prevalence of sarcopenia, defined as reduction in muscle mass and/or muscle strength. Muscle quality (in particular, fat infiltration) may provide insight into the links between muscle metabolic health and physical functioning beyond traditional muscle mass assessment. We hypothesize that intermuscular fat is increased in patients with chronic kidney disease and it is inversely associated with physical activity and mitochondrial function.

Methods

In a cross-sectional study, we evaluated 51 subjects (20 with CKD stage 3-4, 15 with CKD stage 5 on hemodialysis, and 16 matched controls with no history of CKD). Intermuscular fat was evaluated in the quadriceps muscle using sequential thigh magnetic resonance images. Physical performance was measured using the six-minute walk test. Mitochondrial function was evaluated by measuring phosphocreatine (PCr) recovery after exercise using ³¹phosphorus magnetic resonance spectroscopy (³¹P-MRS). A longer PCR recovery results in a greater time constant tau (τ), which indicates worsening mitochondrial function.

Results

Groups were matched by gender, body mass index, and history of diabetes and hypertension. Patients with CKD stage 5 were younger than patients with CKD stage 3-4 (47.7±11.7 vs. 63.6±9.0) but had similar age compared to controls (46.9±9.5). Intermuscular fat was greater in patients with CKD stage 5 compared to patients with CKD stage 3-4 and controls (Figure 1A). We also found a negative correlation between quadriceps intermuscular fat and physical performance (Figure 1B). In addition, mitochondrial dysfunction (greater time constant τ) was associated with increased intermuscular fat (Figure 1C).

Conclusion

CKD is associated with greater intermuscular fat which associates with poor physical performance and impaired mitochondrial function. Future studies should evaluate the effectiveness of interventions that not only increase muscle mass but also improve muscle quality in patients with CKD.

Funding

• NIDDK Support