Table 1

Baseline characteristics of patients investigated according to treatment time (either all hypertension medications upon awakening or ≥1 medications at bedtime)

AwakeningBedtimeP between groups
Demographic characteristics
n232216
 Sex (% men)59.154.60.345
 Obstructive sleep apnea (%)13.411.60.568
 Metabolic syndrome (%)86.686.60.984
 Cigarette smoking (%)8.67.90.773
 Obesity (%)66.864.80.656
 Microalbuminuria (%)28.026.90.782
 Previous CVD events (%)8.29.30.688
 Duration of known diabetes (years)8.9 ± 8.48.7 ± 8.00.804
 Duration of known hypertension (years)7.4 ± 8.27.6 ± 8.70.674
Anthropometric variables and clinic blood pressure
 Age (years)62.5 ± 10.962.5 ± 10.70.935
 Height (cm)160.6 ± 9.2159.3 ± 9.00.117
 Weight (kg)83.5 ± 16.981.1 ± 16.00.124
 BMI (kg/m2)32.1 ± 5.531.9 ± 5.20.631
 Waist circumference (cm)102.9 ± 13.9102.0 ± 11.60.442
 Clinic SBP (mmHg)158.1 ± 24.7161.9 ± 22.20.085
 Clinic DBP (mmHg)85.7 ± 13.687.0 ± 12.30.303
 Clinic PP (mmHg)72.4 ± 16.974.9 ± 17.80.117
 Clinic HR (bpm)75.6 ± 10.576.6 ± 13.70.391
Clinical laboratory test values
 HbA1c (%)6.9 ± 1.76.8 ± 1.70.627
 Glucose (mg/dL)157.2 ± 49.1150.8 ± 51.20.178
 Creatinine (mg/dL)1.03 ± 0.251.01 ± 0.270.393
 Uric acid (mg/dL)6.1 ± 2.06.0 ± 1.60.271
 Total cholesterol (mg/dL)203.3 ± 45.7202.7 ± 42.00.886
 Triglycerides (mg/dL)126.9 ± 63.2120.6 ± 68.30.321
 HDL cholesterol (mg/dL)44.3 ± 13.646.6 ± 15.20.092
 LDL cholesterol (mg/dL)134.9 ± 38.1131.7 ± 35.50.378
 Fibrinogen (mg/dL)357.7 ± 78.1346.8 ± 88.30.265
 Erythrocyte sedimentation rate (mm)19.1 ± 16.817.6 ± 15.40.349
 Glomerular filtration rate71.0 ± 18.272.7 ± 17.10.206
Ambulatory blood pressure
 Duration of nocturnal rest (h)9.2 ± 1.39.2 ± 1.20.902
 Awake SBP mean (mmHg)135.4 ± 17.9135.9 ± 15.80.762
 Asleep SBP mean (mmHg)128.5 ± 21.7129.2 ± 20.20.702
 48-h SBP mean (mmHg)133.2 ± 18.6133.5 ± 16.50.837
 Sleep time relative SBP decline (%)5.2 ± 8.35.0 ± 8.70.779
 Awake DBP mean (mmHg)76.7 ± 11.077.3 ± 11.00.553
 Asleep DBP mean (mmHg)68.3 ± 11.469.3 ± 10.90.346
 48-h DBP mean (mmHg)73.9 ± 10.874.6 ± 10.60.538
 Sleep time relative DBP decline (%)10.7 ± 8.710.1 ± 8.90.432
 Nondipper (%)72.470.00.558
  • Data are means ± SD unless otherwise indicated. Metabolic syndrome is determined by the National Cholesterol Education Program Adult Treatment Panel III (ATP-III) revised definition (19). The sleep time relative blood pressure decline, an index of blood pressure dipping, is defined as the percent decline in mean blood pressure during nocturnal sleep relative to the mean blood pressure during daytime activity, and calculated as [(awake blood pressure mean – asleep blood pressure mean)/awake blood pressure mean] × 100. HR, heart rate; Nondipper, patients with sleep time relative SBP decline <10% using data sampled by ABPM for 48 consecutive hours; obesity, BMI ≥30 kg/m2; PP, pulse pressure.

  • †Values correspond to the average of six conventional blood pressure measurements obtained for each subject at the clinic before starting ABPM.

  • ‡Glomerular filtration rate (mL/min/1.73 m2) was estimated using the Chronic Kidney Disease Epidemiology Collaboration equation (20).