Table 1.
Measures of Anthropometry and Sleep at Baseline, 9 Months, and 18 Months, according to Randomized Arm (Intention to Treat)
| |
|
Randomized LGB |
Randomized CPAP |
AdjustedP Values (between Arms) |
|||||
|---|---|---|---|---|---|---|---|---|---|
| Baseline (n = 28) | 9 mo (n = 25) | 18 mo (n = 24) | Baseline (n = 21) | 9 mo (n = 18) | 18 mo (n = 16) | 9 mo | 18 mo | ||
| Anthropometry |
|||||||||
| BMI, kg/m2 |
39.1 ± 2.9 | 35.9 ± 3.5* | 35.7 ± 3.9* | 38.7 ± 3.1 | 37.4 ± 3.7 | 37.4 ± 4.5 | 0.01 | 0.09 | |
| Weight, kg |
115.4 ± 16.9 | 106.7 ± 18.0* | 106.1 ± 18.0* | 111.1 ± 16.1 | 106.0 ± 13.4 | 106.3 ± 16.0 | 0.45 | 0.60 | |
| Neck circumference, cm |
40.9 ± 4.3 | 40.1 ± 4.8 | 40.6 ± 3.8 | 42.6 ± 4.4 | 41.5 ± 4.1* | 42.3 ± 3.9 | 0.04 | 0.08 | |
| Waist circumference, cm |
123.5 ± 10.3 | 116.4 ± 13.2* | 115.0 ± 12.5* | 120.5 ± 8.1 | 115.7 ± 11.4* | 116.5 ± 10.2* | 0.70 | 0.52 | |
| Hip circumference, cm |
127.5 ± 8.6 | 120.8 ± 8.4* | 120.8 ± 8.9* | 124.1 ± 7.4 | 116.0 ± 16.9* | 120.7 ± 9.2 | 0.36 | 0.80 | |
| Sleep measures |
|||||||||
| AHI off CPAP treatment, events/h |
51.5 ± 23.5 | 39.3 ± 26.4* | 34.1 ± 24.6* | 47.5 ± 31.5 | 34.7 ± 31.6 | 36.4 ± 23.2 | 0.28 | 0.93 | |
| Effective AHI, events/h† |
N/A | 29.5 ± 23.4 | 20.9 ± 16.0 | N/A | 20.0 ± 25.3 | 21.4 ± 17.6 | 0.02 | 0.89 | |
| ESS, out of 24 |
10.4 ± 4.2 | 7.6 ± 4.7* | 8.0 ± 4.5* | 9.8 ± 5.0 | 7.8 ± 4.8 | 6.2 ± 3.7* | 0.53 | 0.19 | |
| Effective AHI <5 events/h, n (%) |
N/A | 1 (4%) | 3 (13%) | N/A | 4 (22%) | 3 (19%) | 0.14 | 0.67 | |
| Effective AHI <15 events/h, n (%) | N/A | 7 (28%) | 11 (46%) | N/A | 11 (61%) | 8 (50%) | 0.06 | 1.00 | |
| CPAP adherence, h/night | 4.5 ± 2.7 | 4.7 ± 2.8 | N/A | N/A | |||||
Definition of abbreviations: AHI = apnea–hypopnea index; BMI = body mass index; CPAP = continuous positive airway pressure; ESS = Epworth Sleepiness Scale; LGB = laparoscopic gastric banding; N/A = not applicable.
Data are presented as mean ± SD unless otherwise indicated. Outcome data are not transformed.
Between-arm P values for continuous outcomes were obtained from models adjusted for stratification factors (recruitment clinic, baseline BMI category, and sex). AHI was log-transformed at 9 months only. BMI was log-transformed at 18 months only. Hip circumference, effective AHI, and ESS scores were log-transformed at 9 months and 18 months.
P < 0.05 testing if the within-arm difference from baseline was different from zero (within-arms t test or a signed-rank test depending on distribution).
Note that an effective AHI was calculated for any patient using CPAP regardless of randomized arm.