Table 5.
Crude and Adjusted Risk Ratios* for Incident Hypertension† and Metabolic Sydrome‡ at 2- to 7-Year Follow-up according to Apnea–Hypopnea Index and Oxygen Desaturation Index§ at the Follow-up Assessment
| Sleep Characteristic | n/N (%) | Crude Risk Ratios |
Adjusted Risk Ratios |
||
|---|---|---|---|---|---|
| Estimate (95% CI) | P Value | Estimate (95% CI) | P Value | ||
| AHI | |||||
| Incident hypertension | |||||
| AHI < 5 (referent) | 45/918 (4.9) | 1.00 | 0.0008 | 1.00 | 0.0271 |
| AHI ⩾ 5 | 21/124 (16.9) | 3.45 (2.13–5.60) | 2.01 (1.17–3.46) | ||
| AHI = 0 (referent) | 4/118 (3.4) | 1.00 | 0.0048 | 1.00 | 0.0580 |
| 0 < AHI < 5 | 41/800 (5.1) | 1.51 (0.55–4.14) | Trend tests: | 1.11 (0.39–3.15) | Trend tests: |
| 5 ⩽ AHI < 15 | 11/94 (11.7) | 3.45 (1.14–10.49) | 0.0015 linear | 1.67 (0.50–5.57) | 0.0131 linear |
| AHI ⩾ 15 | 10/30 (33.3) | 9.83 (3.31–29.19) | 0.3869 quadratic | 4.18 (1.19–14.76) | 0.2783 quadratic |
| Metabolic syndrome | |||||
| AHI < 5 (referent) | 122/911 (13.4) | 1.00 | <0.0001 | 1.00 | 0.0073 |
| AHI ⩾ 5 | 54/127 (42.5) | 3.18 (2.45–4.12) | 1.51 (1.14–2.00) | ||
| AHI = 0 (referent) | 11/116 (9.5) | 1.00 | <0.0001 | 1.00 | 0.0073 |
| 0 < AHI < 5 | 111/795 (14.0) | 1.47 (0.82–2.65) | Trend tests: | 1.00 (0.57–1.75) | Trend tests: |
| 5 ⩽ AHI < 15 | 34/96 (35.4) | 3.73 (2.00–6.97) | <0.0001 linear | 1.32 (0.71–2.46) | 0.0079 linear |
| AHI ⩾ 15 | 20/31 (64.5) | 6.80 (3.66–12.65) | 0.5670 quadratic | 2.14 (1.11–4.15) | 0.1936 quadratic |
| ODI | |||||
| Incident hypertension | |||||
| ODI < 5 (referent) | 28/695 (4.0) | 1.00 | 0.0002 | 1.00 | 0.0349 |
| ODI ⩾ 5 | 38/347 (11.0) | 2.72 (1.70–4.35) | 1.75 (1.05–2.92) | ||
| ODI < 5 (referent)‖ | 28/695 (4.0) | 1.00 | 0.0004 | 1.00 | 0.0244 |
| 5 ⩽ ODI < 15 | 23/279 (8.2) | 2.05 (1.20–3.49) | Trend tests: | 1.52 (0.86–2.68) | Trend tests: |
| ODI ⩾ 15 | 15/68 (22.1) | 5.48 (3.08–9.74) | 0.0010 linear 0.5825 quadratic | 2.89 (1.50–5.57) | 0.0080 linear 0.6403 quadratic |
| Metabolic syndrome | |||||
| ODI < 5 (referent) | 71/689 (10.3) | 1.00 | <0.0001 | 1.00 | 0.0009 |
| ODI ⩾ 5 | 105/349 (30.1) | 2.92 (2.22–3.83) | 1.60 (1.21–2.12) | ||
| ODI = 0 (referent) | 2/22 (9.1) | 1.00 | <0.0001 | 1.00 | 0.0014 |
| 0 < ODI < 5 | 69/667 (10.3) | 1.14 (0.30–4.35) | Trend tests: | 0.74 (0.20–2.79) | Trend tests: |
| 5 ⩽ ODI < 15 | 68/280 (24.3) | 2.67 (0.70–10.18) | <0.0001 linear | 1.10 (0.29–4.16) | 0.3061 linear |
| ODI ⩾ 15 | 37/69 (53.6) | 5.90 (1.55–22.52) | 0.4812 quadratic | 1.57 (0.41–6.01) | 0.4813 quadratic |
Definition of abbreviations: AHI = apnea–hypopnea index; BMI = body mass index; CI = confidence interval; HDL-C = high-density lipoprotein cholesterol; HHS = Heart Healthy Study; ODI = oxygen desaturation index.
Poisson regression models are used for the analyses with robust error covariance used to compute CIs and to test for trends. P values are based on likelihood ratio tests. Analyses are adjusted for age and BMI (linear and quadratic) at the time of the HHS cardiovascular assessment, and race.
Women with baseline hypertension are excluded from the hypertension analyses.
Women with preexisting diabetes are excluded from the metabolic syndrome analyses. Metabolic syndrome is defined based on the presence of three of five of the following criteria: elevated waist circumference, elevated triglycerides or associated medication, elevated fasting glucose or associated medication, elevated blood pressure or associated medication, and reduced HDL-C or associated medication.
AHI is all apneas and hypopneas with ⩾3% oxygen desaturation per hour; ODI is the number of desaturations ⩾3% per hour of sleep.
There were no women in the ODI = 0 with hypertension, so the ODI = 0 group was combined with the 0 < ODI < 5 group for this analysis.