Light-intensity physical activities and mortality in the United States general population and CKD subpopulation.
OBJECTIVE
Sedentary behavior is associated with increased mortality in the general population. Whether replacing sedentary behavior with low- or light-intensity activities confers a survival benefit in the general or CKD populations is unknown.


METHODS
This observational analysis of the 2003-2004 National Health and Nutrition Examination Survey examined the associations of low- and light-intensity activities with mortality. On the basis of the number of counts/min recorded by an accelerometer, durations of sedentary (<100/min), low (100-499/min), light (500-2019/min), and moderate/vigorous (≥2020/min) activity were defined and normalized to 60 minutes. The mortality associations of 2 min/hr less sedentary duration in conjunction with 2 min/hr more (tradeoff) spent in one of the low, light, or moderate/vigorous activity durations while controlling for the other two activity durations were examined in multivariable Cox regression models in the entire cohort and in the CKD subgroup.


RESULTS
Of the 3626 participants included, 383 had CKD. The mean sedentary duration was 34.4±7.9 min/hr in the entire cohort and 40.8±6.8 in the CKD subgroup. Tradeoff of sedentary duration with low activity duration was not associated with mortality in the entire cohort or the CKD subgroup. Tradeoff of sedentary duration with light activity duration was associated with a lower hazard of death in the entire cohort (hazard ratio, 0.67; 95% confidence interval, 0.48 to 0.93) and CKD subgroup (hazard ratio, 0.59; 95% confidence interval, 0.35 to 0.98). Tradeoff of sedentary duration with moderate/vigorous activity duration had a nonsignificant lower hazard in the entire cohort and CKD subgroup.


CONCLUSIONS
Patients with CKD are sedentary nearly two thirds of the time. Interventions that replace sedentary duration with an increase in light activity duration might confer a survival benefit.
Veterans Affairs Salt Lake City Healthcare System, Salt Lake City, Utah; Department of Medicine, University of Utah School of Medicine, Salt Lake City, Utah; Srinivasan.beddhu@hsc.utah.edu.
Srinivasan
S
Beddhu
Department of Medicine, University of Utah School of Medicine, Salt Lake City, Utah;
Guo
G
Wei
Department of Physical Therapy, University of Utah College of Health, Salt Lake City, Utah; and.
Robin L
RL
Marcus
Division of Renal Diseases and Hypertension, University of Colorado Denver, Aurora, Colorado.
Michel
M
Chonchol
Department of Medicine, University of Utah School of Medicine, Salt Lake City, Utah;
Tom
T
Greene
D056044:Actigraphy; D000328:Adult; D000368:Aged; D005260:Female; D006304:Health Status; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D009749:Nutrition Surveys; D011379:Prognosis; D016016:Proportional Hazards Models; D065840:Protective Factors; D051436:Renal Insufficiency, Chronic / Q000175:diagnosis / Q000401:mortality* / Q000503:physiopathology; D018570:Risk Assessment; D012307:Risk Factors; D040242:Risk Reduction Behavior; D057185:Sedentary Behavior; D013997:Time Factors; D014481:United States / Q000453:epidemiology
chronic kidney disease; obesity; quality of life