Table 3.
Effect of Treatment on Measures of Glucose Metabolism for CPAP versus Oral Placebo Groups*
| CPAP Group (n = 26) |
Oral Placebo Group (n = 12) |
|||||
|---|---|---|---|---|---|---|
| Baseline | Change after 2 Weeks | Baseline | Change after 2 Weeks | Treatment Difference | P Value† | |
| Fasting glucose, mg/dl | 104.1 (100.7 to 107.5) | −4.1 (−7.2 to −1.0) | 100.9 (95.8 to 105.9) | −1.3 (−5.6 to 3.1) | −2.8 (−8.1 to 2.5) | 0.30 |
| Fasting insulin, pmol/L | 73.6 (60.0 to 87.3) | −5.7 (−16.5 to 5.1) | 69.7 (49.4 to 90.0) | 13.0 (−2.1 to 28.1) | −18.7 (−37.3 to −0.1) | 0.05 |
| 2-h glucose, mg/dl | 153.4 (141.2 to 165.7) | −3.8 (−12.4 to 4.8) | 147.9 (129.7 to 166.2) | 10.2 (−1.7 to 22.1) | −14.0 (−28.7 to 0.6) | 0.06 |
| 2-h insulin, pmol/L | 766.8 (603.9 to 929.7) | −73.2 (−192.7 to 46.4) | 728.0 (485.9 to 970.0) | −118.6 (−284.7 to 47.5) | 45.5 (−159.1 to 250.1) | 0.66 |
| AUCglucose, (mg/dL) · min | 19,564.9 (18,548.3 to 20,581.5) | −794.2 (−1,446.4 to −142.0) | 19,723.4 (18,212.2 to 21,234.6) | 482.7 (−422.2 to 1,387.7) | −1,276.9 (−2,392.4 to −161.5) | 0.03 |
| AUCinsulin, (pmol/L) · min | 77,158.4 (62,515.6 to 91,801.2) | −9,506.9 (−19,161.9 to 148.0) | 70,252.0 (48,486.6 to 92,017.4) | −2,228.9 (−15,628.3 to 11,170.5) | −7,278.1 (−23,792.9 to 9,236.7) | 0.39 |
| AUCinsulin secretion, pmol/min | 35,773.1 (32,266.5 to 39,279.7) | −1,915.3 (−4,006.0 to 175.4) | 34,954.3 (29,741.3 to 40,167.4) | −2,318.5 (−5,217.6 to 580.6) | 403.2 (−3,171.0 to 3,977.4) | 0.83 |
| SI, (mU/L)−1 · min−1 | 2.3 (1.9 to 2.7) | 0.31 (−0.11 to 0.74) | 2.8 (2.2 to 3.4) | −0.46 (−1.07 to 0.15) | 0.77 (0.03 to 1.52) | 0.04 |
| AIRg, (mU/L) · min | 445.7 (342.3 to 549.1) | 26.2 (−35.1 to 87.5) | 282.7 (129.2 to 436.2) | 99.7 (10.6 to 188.8) | −73.5 (−181.6 to 34.7) | 0.18 |
Definition of abbreviations: AIRg = acute insulin response to glucose; AUCglucose = area under the glucose curve during oral glucose tolerance test (OGTT); AUCinsulin = area under the insulin curve during OGTT; AUCinsulin secretion = area under the curve of the insulin secretion rate; CPAP = continuous positive airway pressure; SI = insulin sensitivity.
Data are mean (95% confidence interval). Change after 2 weeks (i.e., treatment effect) was calculated from the regression models as the post-treatment – baseline effect for each treatment group. Treatment difference between the two groups was also calculated from the regression models as the CPAP − oral placebo 2-week changes (i.e., the interaction effect from the model). P values for the treatment difference are from the test of the treatment group–by-time interaction using linear mixed model approach. AUC was calculated according to the trapezoidal rule between the 0 and 120 minutes during the OGTT.
All available data were used in the primary analysis (see online supplement for further details). Data are from n = 25 in CPAP and n = 12 in oral placebo for SI and AIRg.
Analyses were adjusted for age, body mass index, and ethnicity-based diabetes risk.