Table 1.
Baseline Characteristics of the Study Participants.*
| Characteristic | Weight Loss (N = 61) |
CPAP (N = 58) |
CPAP and Weight Loss (N = 62) |
P Value |
|---|---|---|---|---|
| Age — yr | 48.3 | 49.8 | 49.0 | 0.75 |
| Male sex — no. (%) | 36 (59) | 35 (60.3) | 33 (53.2) | 0.70 |
| Race — no. (%)† | 0.95 | |||
| White | 33 (54) | 34 (59.6) | 36 (59.0) | |
| Black | 25 (41) | 23 (40.4) | 25 (41.0) | |
| Mixed or other | 3 (5) | 1 (1.72) | 1 (1.61) | |
| Height — cm | 172.5±10 | 170.2±14.2 | 165.9±23 | 0.09 |
| Weight — kg | 114.5±21.9 | 115.1±21.7 | 111.5±28.1 | 0.68 |
| Body-mass index‡ | 38.1±5.8 | 39.8±7.1 | 38.4±6.4 | 0.29 |
| Cholesterol — mg/dl | ||||
| Total | 188.1±46.1 | 196.4±46 | 177.1±44.4 | 0.07 |
| HDL | 43.1±11.7 | 43.1±10.6 | 40±12.6 | 0.23 |
| LDL | 116.7±35 | 123.8±31.1 | 107±32 | 0.02 |
| Cholesterol particle size — nm | ||||
| LDL | 20.5 (0.73) | 20.5 (0.71) | 20.5 (0.65) | 0.96 |
| HDL | 8.7 (0.32) | 8.8 (0.41) | 8.7 (0.31) | 0.62 |
| Triglycerides — mg/dl | 130±72.3 | 133.1±63.4 | 145.3±98.5 | 0.53 |
| Hypertension — no. (%) | 25 (41) | 26 (45) | 24 (39) | 0.79 |
| Insulin sensitivity index§ | 1.4±0.82 | 1.2±1.03 | 1.4±1.14 | 0.63 |
| Apoprotein — mg/dl | ||||
| A-I | 120.6 (31.2) | 125.7 (25.86) | 118.7 (32.69) | 0.45 |
| B | 87.3 (29.98) | 92.5 (26.23) | 85.1 (24.06) | 0.33 |
| High-sensitivity C-reactive protein — mg/liter | 0.74 | |||
| Median | 4.4 | 4.7 | 4.3 | |
| Interquartile range | 1.9–8.5 | 2.5–8.2 | 2.1–9.3 | |
| Blood pressure — mm Hg | ||||
| Systolic | 126.5±10.02 | 129.9±14.87 | 123±19.91 | 0.053 |
| Diastolic | 78.9±7.5 | 80.1±8.98 | 76.8±13.71 | 0.22 |
| AHI — events/hr¶ | 39.7±20.3 | 41.2±20.96 | 47.1±26.86 | 0.17 |
| Oxygen desaturation index — no. of events/hr | ||||
| >3% drop from baseline | 22.6±18.8 | 25.5±22.1 | 27.6±25.7 | 0.47 |
| >4% drop from baseline | 18.3±17.4 | 20.7±20.4 | 23.3±24.7 | 0.44 |
| Sleep time with Spo2 <90% — % | 5.0±8.4 | 6.9±13.8 | 8.7±15.6 | 0.29 |
| Mean Spo2 during sleep — % | ||||
| Nadir | 78±14.8 | 76.7±11.1 | 73.7±20.7 | 0.34 |
| Mean | 94.8±1.8 | 94.7±2.3 | 94.1±2.4 | 0.17 |
| Arousal index — no. of arousals/hr of sleep | 31.7±15.8 | 37±20.5 | 39.6±20.1 | 0.07 |
| Score on Epworth Sleepiness Scale∥ | 9.3±4.3 | 9.8±4.6 | 8.9±4.8 | 0.55 |
| Current or former smoker — no. (%) | 21 (34) | 20 (35) | 12 (19) | 0.11 |
| Medication use — no. (%) | ||||
| Statin | 12 (20) | 12 (21) | 13 (21) | 0.99 |
| Antihypertensive medication | 25 (41) | 24 (41) | 21 (34) | 0.63 |
Plus–minus values are means ±SD. Spo2 denotes oxygen saturation level as measured by pulse oximetry. To convert values for low-density lipoprotein (LDL), high-density lipoprotein (HDL), and total cholesterol to millimoles per liter, multiply by 0.02586. To convert values for triglycerides to millimoles per liter, multiply by 0.01129.
Race was self-reported.
The body-mass index is the weight in kilograms divided by the square of the height in meters.
The insulin sensitivity index was calculated with the use of values from frequently sampled glucose tolerance tests. Higher levels indicate greater insulin sensitivity.
The apnea–hypopnea index (AHI) is the number of apnea and hypopnea episodes per hours of sleep time.
Scores on the Epworth Sleepiness Scale range from 0.0 to 24.0, with higher scores indicating more daytime sleepiness.