Published in:
01-01-2014 | Original Research
Phase Angle, Frailty and Mortality in Older Adults
Published in: Journal of General Internal Medicine | Issue 1/2014
Login to get accessABSTRACT
BACKGROUND
Frailty is a multidimensional phenotype that describes declining physical function and a vulnerability to adverse outcomes in the setting of physical stress such as illness or hospitalization. Phase angle is a composite measure of tissue resistance and reactance measured via bioelectrical impedance analysis (BIA). Whether phase angle is associated with frailty and mortality in the general population is unknown.
OBJECTIVE
To evaluate associations among phase angle, frailty and mortality.
DESIGN
Population-based survey.
SETTING
Third National Health and Nutritional Examination Survey (1988–1994).
PARTICIPANTS
In all, 4,667 persons aged 60 and older.
MEASUREMENTS
Frailty was defined according to a set of criteria derived from a definition previously described and validated.
RESULTS
Narrow phase angle (the lowest quintile) was associated with a four-fold higher odds of frailty among women and a three-fold higher odds of frailty among men, adjusted for age, sex, race-ethnicity and comorbidity. Over a 12-year follow-up period, the adjusted relative hazard for mortality associated with narrow phase angle was 2.4 (95 % confidence interval [95 % CI] 1.8 to 3.1) in women and 2.2 (95 % CI 1.7 to 2.9) in men. Narrow phase angle was significantly associated with mortality even among participants with little or no comorbidity.
LIMITATIONS
Analyses of BIA and frailty were cross-sectional; BIA was not measured serially and incident frailty during follow-up was not assessed. Participants examined at home were excluded from analysis because they did not undergo BIA.
CONCLUSIONS
Narrow phase angle is associated with frailty and mortality independent of age and comorbidity.