Table 3.
Longitudinal multivariable analyses using Cox proportional hazards models to explore the relationship between sleep duration at baseline and hypertension incidence over follow-up
| Incident hypertension over follow-up HR (95% CI) | |||||||
|---|---|---|---|---|---|---|---|
| Sleep duration in hours | Incident HTN cases, No. | Model 1a | Model 2b | Model 3c | Model 4d | Model 5e | Model 6f |
| NHS-II, 2001, ages 37–54 years | |||||||
| ≤ 5 | 701 | 1.40 (1.30–1.52) | 1.38 (1.27–1.50) | 1.37 (1.26–1.48) | 1.23 (1.13–1.33) | 1.18 (1.09–1.28) | 1.26 (1.16–1.37) |
| 6 | 2,493 | 1.14 (1.09–1.21) | 1.14 (1.09–1.20) | 1.14 (1.08–1.19) | 1.07 (1.02–1.13) | 1.05 (1.00–1.11) | 1.09 (1.04–1.15) |
| 7 | 3,981 | 1.00 (referent) | 1.00 (referent) | 1.00 (referent) | 1.00 (referent) | 1.00 (referent) | 1.00 (referent) |
| 8 | 2,097 | 0.97 (0.92–1.03) | 0.97 (0.92–1.03) | 0.97 (0.92–1.02) | 0.98 (0.93–1.03) | 0.98 (0.93–1.03) | 0.97 (0.92–1.02) |
| ≥9 | 520 | 1.11 (1.01–1.21) | 1.09 (1.00–1.20) | 1.07 (0.98–1.18) | 1.05 (0.96–1.15) | 1.01 (0.92–1.11) | 1.02 (0.93–1.12) |
| NHS-I, 1986, ages 40–65 years | |||||||
| ≤5 | 346 | 1.20 (1.08–1.35) | 1.20 (1.07–1.34) | 1.20 (1.07–1.34) | 1.11 (0.99–1.24) | 1.10 (0.98–1.23) | 1.15 (1.02–1.29) |
| 6 | 1,965 | 1.14 (1.08–1.21) | 1.14 (1.08–1.21) | 1.14 (1.08–1.21) | 1.10 (1.04–1.16) | 1.09 (1.03–1.16) | 1.12 (1.05–1.18) |
| 7 | 2,864 | 1.00 (referent) | 1.00 (referent) | 1.00 (referent) | 1.00 (referent) | 1.00 (referent) | 1.00 (referent) |
| 8 | 1,671 | 1.03 (0.97–1.10) | 1.03 (0.97–1.09) | 1.03 (0.97–1.09) | 1.02 (0.96–1.09) | 1.04 (0.97–1.10) | 1.04 (0.97–1.10) |
| ≥9 | 276 | 1.06 (0.94–1.20) | 1.06 (0.93–1.20) | 1.06 (0.94–1.20) | 1.03 (0.91–1.17) | 1.03 (0.91–1.17) | 1.05 (0.93–1.19) |
| NHS-I, 2000, ages 54–79 years | |||||||
| ≤5 | 262 | 1.03 (0.94–1.14) | 1.03 (0.93–1.14) | 1.03 (0.93–1.14) | 1.02 (0.92–1.12) | 1.01 (0.91–1.12) | 1.01 (0.91–1.12) |
| 6 | 1,043 | 1.02 (0.97–1.08) | 1.02 (0.97–1.08) | 1.02 (0.97–1.08) | 1.01 (0.96–1.07) | 1.01 (0.96–1.07) | 1.01 (0.96–1.07) |
| 7 | 2,506 | 1.00 (referent) | 1.00 (referent) | 1.00 (referent) | 1.00 (referent) | 1.00 (referent) | 1.00 (referent) |
| 8 | 3,031 | 0.96 (0.91–1.01) | 0.96 (0.91–1.01) | 0.96 (0.91–1.01) | 0.96 (0.91–1.01) | 0.96 (0.91–1.01) | 0.97 (0.92–1.02) |
| ≥9 | 2,119 | 0.97 (0.89–1.06) | 0.96 (0.88–1.05) | 0.97 (0.88–1.06) | 0.93 (0.85–1.02) | 0.92 (0.84–1.01) | 0.94 (0.86–1.03) |
Abbreviations: CI, confidence interval; HR, hazard ratio; HTN, Hypertension; NHS-I, Nurses’ Health Study I; NHS-II, Nurses’ Health Study II.
aModel 1: Controlling for age.
bModel 2: Controlling for age and diabetes.
cModel 3: Controlling for age and hypercholesterolemia.
dModel 4: Controlling for age and body mass index.
eModel5: Controlling for age, diabetes, hypercholesterolemia, body mass index, race, Hispanic ethnicity, menopause, smoking, physical activity, alcohol, caffeine, Dietary Approaches to Stop Hypertension diet, aspirin, acetaminophen, nonaspirin Non-Steroidal Anti-Inflammatory Drugs, family history of hypertension, snoring, and shift work.
fModel 6: Controlling for all variables in model 5 except for body mass index.