Physical activity and adiposity markers at older ages: accelerometer vs questionnaire data.
OBJECTIVE
Physical activity is critically important for successful aging, but its effect on adiposity markers at older ages is unclear as much of the evidence comes from self-reported data on physical activity. We assessed the associations of questionnaire-assessed and accelerometer-assessed physical activity with adiposity markers in older adults.


METHODS
This was a cross-sectional study on 3940 participants (age range 60-83 years) of the Whitehall II study who completed a 20-item physical activity questionnaire and wore a wrist-mounted accelerometer for 9 days in 2012 and 2013.


METHODS
Total physical activity was estimated using metabolic equivalent hours/week for the questionnaire and mean acceleration for the accelerometer. Time spent in moderate-and-vigorous physical activity (MVPA) was also assessed by questionnaire and accelerometer. Adiposity assessment included body mass index, waist circumference, and fat mass index. Fat mass index was calculated as fat mass/height² (kg/m²), with fat mass estimated using bioimpedance.


RESULTS
Greater total physical activity was associated with lower adiposity for all adiposity markers in a dose-response manner. In men, the strength of this association was 2.4 to 2.8 times stronger with the accelerometer than with questionnaire data. In women, it was 1.9 to 2.3 times stronger. For MVPA, questionnaire data in men suggested no further benefit for adiposity markers past 1 hour/week of activity. This was not the case for accelerometer-assessed MVPA where, for example, compared with men undertaking <1 hour/week of accelerometer-assessed MVPA, waist circumference was 3.06 (95% confidence interval 2.06-4.06) cm lower in those performing MVPA 1-2.5 hours/week, 4.69 (3.47-5.91) cm lower in those undertaking 2.5-4 hours/week, and 7.11 (5.93-8.29) cm lower in those performing ≥4 hours/week.


CONCLUSIONS
The association of physical activity with adiposity markers in older adults was stronger when physical activity was assessed by accelerometer compared with questionnaire, suggesting that physical activity might be more important for adiposity than previously estimated.
Department of Epidemiology and Public Health, University College London, London, United Kingdom; University Versailles St-Quentin, Boulogne-Billancourt, France. Electronic address: s.sabia@ucl.ac.uk.
Séverine
S
Sabia
INSERM, U1018, Center for Research in Epidemiology and Population Health, Villejuif, France.
Pol
P
Cogranne
MoveLab-Physical Activity and Exercise Research, Institute of Cellular Medicine, Newcastle University, United Kingdom.
Vincent T
VT
van Hees
Department of Epidemiology and Public Health, University College London, London, United Kingdom.
Joshua A
JA
Bell
INSERM, U1018, Center for Research in Epidemiology and Population Health, Villejuif, France; University Paris 11, Villejuif, France.
Alexis
A
Elbaz
Department of Epidemiology and Public Health, University College London, London, United Kingdom.
Mika
M
Kivimaki
Department of Epidemiology and Public Health, University College London, London, United Kingdom; University Versailles St-Quentin, Boulogne-Billancourt, France; INSERM, U1018, Center for Research in Epidemiology and Population Health, Villejuif, France; University Paris 11, Villejuif, France; Centre de Gérontologie, Hôpital Ste Périne, AP-HP, France.
Archana
A
Singh-Manoux
D061725:Accelerometry / Q000379:methods*; D050154:Adiposity / Q000502:physiology*; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D015438:Health Behavior; D006801:Humans; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D009043:Motor Activity / Q000502:physiology*; D057566:Self Report; D011795:Surveys and Questionnaires
Physical activity; accelerometer; adiposity; body mass index; questionnaire; waist circumference