Table 2

Associations between baseline sleep quality and BMI, parasympathetic tone and cardiorespiratory fitness

VariableMOS SPI score (95% CI)OR of MOS SPI >25 (95% CI)
BMI (kg/m2)
 Q1: ≥34.727.95 (24.54 to 31.36)1.00 (Referent)
 Q2: 31.7 to <34.724.37 (20.92 to 27.82)0.60 (0.35 to 1.03)
 Q3: 28.6 to <31.730.48 (27.03 to 33.94)1.14 (0.67 to 1.96)
 Q4: <28.628.85 (25.46 to 32.24)0.98 (0.58 to 1.68)
 Linear p0.260.53
rMSSD (ms)
 Q1: <15.031.77 (27.95 to 35.59)1.00 (Referent)
 Q2: 15.0 to <20.924.77 (21.04 to 28.51)*0.53 (0.29 to 0.97)
 Q3: 20.9 to <29.025.22 (21.36 to 29.09)*0.43 (0.23 to 0.81)
 Q4: ≥29.026.50 (22.64 to 30.35)*0.46 (0.25 to 0.86)
 Linear p0.080.01
VO2peak (ml/kg/min)
 Q1: <13.429.55 (25.86 to 33.25)1.00 (Referent)
 Q2: 13.4 to <15.228.80 (25.35 to 32.25)1.22 (0.70 to 2.13)
 Q3: 15.2 to <17.028.60 (25.05 to 32.15)1.04 (0.58 to 1.87)
 Q4: ≥17.024.91 (21.41 to 28.42)0.63 (0.34 to 1.14)
 Linear p0.100.09
  • Continuous baseline MOS SPI scores (left panels) and ORs of having significant sleep disturbance at baseline (MOS SPI >25) (right panels) across quartiles of baseline BMI, rMSSD and VO2peak. All analyses adjusted for age, BMI, sleep medication use and HRT use, except when the covariate quartile was the independent variable.

  • * Significant difference (p≤0.05) in MOS SPI score compared with quartile 1 (referent group).

  • BMI, body mass index; MOS, Medical Outcomes Study; Q, quartile; rMSSD, square root of the mean of the sum of the squares of differences between adjacent R–R intervals; SPI, Sleep Problems Index; VO2peak, peak rate of oxygen consumption.