Objectively assessed physical activity and lower limb function and prospective associations with mortality and newly diagnosed disease in UK older adults: an OPAL four-year follow-up study.
BACKGROUND
Objective measures of physical activity and function with a diverse cohort of UK adults in their 70s and 80s were used to investigate relative risk of all-cause mortality and diagnoses of new diseases over a 4-year period.


METHODS
Two hundred and forty older adults were randomly recruited from 12 general practices in urban and suburban areas of a city in the United Kingdom. Follow-up included 213 of the baseline sample.


METHODS
Socio-demographic variables, height and weight, and self-reported diagnosed diseases were recorded at baseline. Seven-day accelerometry was used to assess total physical activity, moderate-to-vigorous activity and sedentary time. A log recorded trips from home. Lower limb function was assessed using the Short Physical Performance Battery. Medical records were accessed on average 50 months post baseline, when new diseases and deaths were recorded.


METHODS
ANOVAs were used to assess socio-demographic, physical activity and lower limb function group differences in diseases at baseline and new diseases during follow-up. Regression models were constructed to assess the prospective associations between physical activity and function with mortality and new disease.


RESULTS
For every 1,000 steps walked per day, the risk of mortality was 36% lower (hazard ratios 0.64, 95% confidence interval (CI) 0.44-0.91, P=0.013). Low levels of moderate-to-vigorous physical activity (incident rate ratio (IRR) 1.67, 95% CI 1.04-2.68, P=0.030) and low frequency of trips from home (IRR 1.41, 95% CI 0.98-2.05, P=0.045) were associated with diagnoses of more new diseases.


CONCLUSIONS
Physical activity should be supported for adults in their 70s and 80s, as it is associated with reduced risk of mortality and new disease development.
Centre for Exercise, Nutrition and Health Sciences, University of Bristol, Bristol, Avon, UK.
Kenneth R
KR
Fox
Graduate Institute of Sports and Health, National Changhua University of Education, Changhua City, Taiwan.
Po-Wen
PW
Ku
Department of Sport and Health Sciences, University of Exeter, Exeter, UK.
Melvyn
M
Hillsdon
Centre for Exercise, Nutrition and Health Sciences, University of Bristol, Bristol, Avon, UK.
Mark G
MG
Davis
Centre for Exercise, Nutrition and Health Sciences, University of Bristol, Bristol, Avon, UK.
Bethany A J
BA
Simmonds
School of Sport, Exercise, and Rehabilitation Sciences, University of Birmingham, Birmingham, UK.
Janice L
JL
Thompson
Department for Health, University of Bath, Bath, UK.
Afroditi
A
Stathi
Department of Health and Applied Social Sciences, University of West of England, Bristol, UK.
Selena F
SF
Gray
Centre for Academic Primary Health Care, University of Bristol, Bristol, UK.
Deborah J
DJ
Sharp
Centre for Exercise, Nutrition and Health Sciences, University of Bristol, Bristol, Avon, UK.
Joanne C
JC
Coulson
D056044:Actigraphy; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000523:psychology; D004194:Disease; D004739:England; D005080:Exercise Test; D005260:Female; D005500:Follow-Up Studies; D015577:Geriatric Assessment / Q000379:methods*; D015438:Health Behavior; D007722:Health Knowledge, Attitudes, Practice; D006304:Health Status; D006801:Humans; D035002:Lower Extremity / Q000294:innervation*; D008297:Male; D009026:Mortality; D009043:Motor Activity; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D040242:Risk Reduction Behavior; D057185:Sedentary Behavior; D013997:Time Factors
mortality; newly diagnosed disease; older adults; physical activity; physical function