Table 1.
Selected characteristics of the study population by blood pressure dipping status: Jackson Heart Study, 2000–2004
| Characteristic | Dipper (N = 268) |
Nondipper (N = 569) |
P value |
|---|---|---|---|
| Age, years | 57.4 (10.6) | 60.1 (10.7) | <0.001 |
| Female sex, % | 67.9 | 69.6 | 0.623 |
| Body mass index, kg/m2 | 30.1 (6.1) | 31.3 (6.6) | 0.007 |
| Current smoker, % | 12.7 | 8.8 | 0.08 |
| Alcohol consumption, grams/day | 6.1 (22.6) | 2.5 (10.4) | 0.015 |
| Physical activity score | 2.2 (0.8) | 2.1 (0.8) | 0.315 |
| Sleep duration, h | 6.4 (1.5) | 6.4 (1.5) | 0.669 |
| Sodium, grams/day | 3.9 (2.4) | 3.9 (2.0) | 0.974 |
| Potassium, grams/day | 2.7 (1.4) | 2.7 (1.2) | 0.670 |
| Office blood pressure, mm Hg | |||
| Systolic BP | 126.5 (17.0) | 127.8 (18.0) | 0.329 |
| Diastolic BP | 77.5 (10.5) | 77.0 (10.2) | 0.522 |
| Hypertension, % | 64.9 | 70.5 | 0.232 |
| Antihypertensive medication use, % | 54.9 | 61.3 | 0.121 |
| Use within 24-h of clinic visit, % | 81.2 | 80.6 | 0.336 |
| Diabetes, % | 15.7 | 22.3 | 0.013 |
| Cardiovascular disease, % | 6.4 | 11.0 | 0.034 |
A dipper is defined as a decline >10% in the mean systolic BP (SBP) during sleep compared to awake SBP.
BP, blood pressure.