Skip to main content

Table 3 Isotemporal substitution of inactive time (30 min/day) with time in bed and physical activity measured with an accelerometer in body composition changes: longitudinal analyses in completers-only

From: Targeting body composition in an older population: do changes in movement behaviours matter? Longitudinal analyses in the PREDIMED-Plus trial

  Percentage of body fat VAT (g) Percentage of muscle mass Muscle-to-fat mass ratio
β (95% CI) p value β (95% CI) p value β (95% CI) p value β (95% CI) p value
Inactive time with time in bed
 Minimally-adjusted − 0.10 (− 0.20; 0.00) 0.051 − 26.9 (− 46.5; − 7.27) 0.007 0.09 (− 0.01; 0.19) 0.067 0.93 (0.03; 1.83) 0.042
 Multivariable-adjusted − 0.09 (− 0.19; 0.01) 0.079 − 23.8 (− 43.3; − 4.27) 0.017 0.08 (− 0.02; 0.18) 0.097 0.89 (− 0.01; 1.79) 0.052
Inactive time with LPA
 Minimally-adjusted − 0.13 (− 0.25; − 0.00) 0.044 − 11.8 (− 36.1; 12.6) 0.343 0.12 (0.00; 0.24) 0.046 0.87 (− 0.24; 1.97) 0.124
 Multivariable-adjusted − 0.13 (− 0.25; − 0.00) 0.042 − 11.2 (− 35.4; 13.0) 0.363 0.12 (0.00; 0.25) 0.042 0.90 (− 0.20; 2.01) 0.110
Inactive time with MVPA
 Minimally-adjusted − 0.53 (− 0.76; − 0.29) < 0.001 − 98.7 (− 146; − 52.0) < 0.001 0.50 (0.27; 0.73) < 0.001 3.51 (1.43; 5.60) 0.001
 Multivariable-adjusted − 0.54 (− 0.78; − 0.31) < 0.001 − 92.4 (− 139; − 45.6) < 0.001 0.51 (0.28; 0.74) < 0.001 3.74 (1.64; 5.85) < 0.001
  1. The values show the β coefficients (95% CIs). These represent the change in outcome variables when substituting 30 min/day of inactive time with time in bed and physical activity. Isotemporal mixed-effects linear models with random intercepts at recruiting centre, family and patient level were used. Analyses included only completers. Minimally-adjusted model: age, sex, intervention arm, time and total wear time. The multivariable-adjusted model was further adjusted for baseline variables, such as educational level, smoking, diabetes, height, and repeatedly measured total energy intake. The n of each outcome at baseline was for the percentage of body fat n = 388, for VAT n = 380, for the percentage of muscle mass n = 388 and for muscle-to-fat mass ratio n = 388; at 6 months was for the percentage of body fat n = 262, for VAT n = 255, for the percentage of muscle mass n = 262 and for muscle-to-fat mass ratio n = 262; at 12 months was for the percentage of body fat n = 303, for VAT n = 299, for the percentage of muscle mass n = 303 and for muscle-to-fat mass ratio n = 303
  2. VAT visceral adipose tissue, LPA light physical activity, MVPA moderate-vigorous physical activity