Blood-cell bioenergetics are associated with physical function and inflammation in overweight/ XXXX older adults.

@entity1 @entity650 @entity121 @entity28
BACKGROUND: Physical function and strength decline with age and lead to limited mobility and independence in older adults. Alterations in mitochondrial function are thought to underlie numerous age-related changes, including declining physical ability. Recent studies suggest that systemic changes in bioenergetic capacity may be reported by analyzing mitochondrial function in circulating cells. The objective of this study was to determine whether the bioenergetic capacity of peripheral blood mononuclear cells (PBMCs) is related to differences in physical function among older, overweight/ @entity28 , adults. To address this, we tested the hypothesis that greater PBMC respirometric capacity would be associated with better physical function, muscular strength, leg lean mass, and @entity121 . Furthermore, we tested whether the respirometric capacity of PBMCs is related to cellular composition and inflammatory status reported by @entity650 ( @entity650 ). METHODS: Fasted PBMC respiration (pmol/min/500,000 cells), expanded short physical performance battery (Ex-SPPB), peak knee extensor (KE) strength (Nm), grip strength (kg), leg lean mass (kg, via dual energy X-ray absorptiometry [DXA]), @entity121 (Nm/kg), and plasma @entity650 (pg/mL) were analyzed in 15 well-functioning, community-dwelling, sedentary overweight/ @entity28 older @entity1 (n=9) and @entity1 (n=6) aged 65 to 78 (mean 68.3  3.5years). Pearson and partial correlations were calculated to determine associations between PBMC respiration and these variables. RESULTS: Higher maximal respiration of PBMCs was associated with better Ex-SPPB (r=0.58, p=0.02), greater KE strength (r=0.60, p=0.02), greater grip strength (r=0.52, p=0.05) and lower @entity650 (r=-0.58, p=0.04). Higher spare respiratory capacity was associated with better Ex-SPPB (r=0.59, p=0.02), greater KE strength (r=0.60, p=0.02), greater grip strength (r=0.54, p=0.04), greater leg @entity121 (r=0.56, p=0.04), and lower @entity650 (r=-0.55, p=0.05). Monocyte and lymphocyte counts were not related to PBMC respiratory capacity. CONCLUSIONS: Our results indicate that respirometric profiles of readily obtainable blood cells are associated with physical function and strength. Future studies should be undertaken in order to determine whether blood-based bioenergetic profiling can provide an objective index of systemic mitochondrial health.
