Low-grade chronic inflammation and superoxide anion production by NADPH oxidase are the main determinants of physical frailty in older adults.
BACKGROUND
Physical performance measured by gait speed is being recognized as a major instrument for clinical evaluation in older adults, because it predicts physical frailty, loss of autonomy, hospitalization and decreased survival. Low-grade chronic inflammation and oxidative stress, mediated partly by the superoxide anion produced by NADPH oxidase, are closely linked and could be involved in age-related physical decline.


OBJECTIVE
To determine whether slow gait speed is associated with superoxide anion overproduction by NADPH oxidase and low-grade chronic inflammation.


METHODS
Observational study among the 280 elderly of an ambulatory geriatric care unit (191 women, 89 men, 79.9 ± 6.1 years old).


METHODS
Gait speed was evaluated by walking at self-chosen usual pace. Usual gait speed < 0.8 m/s was defined as slow gait speed. Superoxide anion production was evaluated using a lucigenin-based chemiluminescence method. Inflammation was evaluated by CRP, fibrinogen and leukocyte count.


RESULTS
Among the 280 participants, 179 (63.9%) walked with a gait speed < 0.8 m/s (slow walkers) and 101 (36.1%) with a gait speed ≥ 0.8 m/s. Superoxide production and inflammation markers, such as fibrinogen, were more important in slow walkers (p = 0.004 and p = 0.006, respectively). In multivariate analysis, superoxide anion overproduction and fibrinogen were independently associated with physical frailty assessed by slow gait speed (p = 0.028 and p = 0.007, respectively).


CONCLUSIONS
Physical frailty in older people is associated with superoxide anion overproduction by NADPH oxidase and low-grade chronic inflammation.
Department of Internal Medicine and Geriatrics, University Hospital of Montpellier, Antonin Balmes Center, Montpellier Cedex 5, France.
Gregory
G
Baptista
Anne-Marie
AM
Dupuy
Audrey
A
Jaussent
Richard
R
Durant
Emilie
E
Ventura
Pauline
P
Sauguet
Marie-Christine
MC
Picot
Claude
C
Jeandel
Jean Paul
JP
Cristol
D000368:Aged; D000369:Aged, 80 and over; D000838:Anions / Q000378:metabolism; D002908:Chronic Disease; D005260:Female; D016330:Frail Elderly; D005684:Gait / Q000502:physiology; D015577:Geriatric Assessment; D006801:Humans; D007249:Inflammation / Q000378:metabolism*; D008297:Male; D015999:Multivariate Analysis; D019255:NADPH Oxidases / Q000378:metabolism*; D013481:Superoxides / Q000378:metabolism*
D000838:Anions; D013481:Superoxides; D019255:NADPH Oxidases