Table 2

Changes over 1-year follow-up among the DPS participants by sleep duration at baseline

Baseline sleep duration
P*Pinteraction
≤6.5 h7.0–8.5 h9.0–9.5 h≥10.0 h
Control group
    n271164762
    Weight (kg)−0.13−1.15−1.61−0.410.218
    Waist circumference (cm)0.03−1.21−2.81−1.110.092
    Fasting plasma glucose (mmol/l)0.180.01−0.050.070.458
    2-h plasma glucose (mmol/l)−0.28−0.48−0.27−0.010.568
    HOMA-IR−0.38−0.23−0.25−0.470.881
    CRP (mg/l)−0.95−0.50−0.94−0.420.846
    IL-6 (pg/ml)0.100.180.120.390.935
    Sleep duration (h/24 h)−1.2−0.20.40.70.032
    Nap during daytime (% participants)10.227.039.232.00.101
    Total LTPA (h/week)0.00.61.1−1.70.038
    Alcohol (g/day)1.7−1.9−3.51.30.034
    Total fat (energy %)−2.8−2.0−2.2−2.10.946
    Saturated fat (energy %)−2.1−1.3−1.1−1.10.717
    Carbohydrates (energy %)0.51.63.31.50.300
    Fiber (g/1,000 kcal)0.70.60.51.10.783
Intervention group
    n201066869
    Weight (kg)−5.20−4.62−4.44−4.110.8240.451
    Waist circumference (cm)−3.59−4.15−4.06−5.370.3490.176
    Fasting plasma glucose (mmol/l)−0.15−0.19−0.28−0.270.6130.687
    2-h plasma glucose (mmol/l)−1.02−0.83−0.76−0.850.9460.709
    HOMA-IR−0.79−0.73−0.95−0.400.4670.451
    CRP (mg/l)−1.47−0.78−1.41−1.790.2560.609
    IL-6 (pg/ml)−0.46−0.56−0.11−0.390.8830.871
    Sleep duration (h/24 h)0.9−0.2−0.1−0.60.0240.088
    Nap during daytime (% participants)44.717.726.030.80.0840.034
    Total LTPA (h/week)0.30.30.1−0.30.8810.363
    Alcohol (g/day)−1.2−3.3−5.2−3.30.2770.488
    Total fat (energy %)−5.5−3.2−2.9−3.80.4100.803
    Saturated fat (energy %)−3.7−2.6−2.5−2.80.5540.960
    Carbohydrates (energy %)4.63.13.63.10.8190.473
    Fiber (g/1,000 kcal)3.02.42.62.40.9460.827
  • Data are mean changes adjusted for baseline levels of the respective variable, except the daytime nap, which is reported as prevalence at 1-year follow-up. HOMA-IR, homeostasis model assessment of insulin resistance; LTPA, leisure-time physical activity.

  • *P value for test of equal change between the sleep duration groups.

  • P value for test of interaction between sleep duration and treatment group.

  • P < 0.05 compared with the 7.0–8.5 h group.