Table 2.
Glucose Tolerance and Pancreatic β-Cell Function Among Subjects with Different Severities of OSA
| Variables | Normal Glucose Tolerance | P value | Prediabetes | P value | P valuea | P valueb | P valuec | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Control (n=124) | Mild-to-Moderate OSA (n=89) | Severe OSA (n=62) | Control (n=41) | Mild-to-Moderate OSA (n=59) | Severe OSA (n=47) | ||||||
| Age (years) | 24.35 ± 5.42 | 26.44 ± 7.02* | 31.95 ± 7.30*† | <0.001 | 26.15 ± 6.61 | 28.49 ± 7.68 | 34.26 ± 7.44*† | <0.001 | 0.085 | 0.096 | 0.108 |
| Male gender, n (%) | 60 (48.39) | 62 (69.66)* | 55 (88.71)*† | <0.001 | 15 (36.59) | 33 (55.93) | 36 (76.60)*† | 0.001 | 0.188 | 0.088 | 0.092 |
| BMI (kg/m2) | 34.43 ± 4.12 | 35.20 ± 5.79 | 34.25 ± 7.24 | 0.495 | 34.56 ± 5.97 | 34.51 ± 5.45 | 36.68 ± 6.62 | 0.133 | 0.875 | 0.472 | 0.075 |
| Neck circumference (cm) | 40.87 ± 2.93 | 42.03 ± 4.48 | 43.21 ± 4.68* | 0.002 | 39.86±4.18 | 41.71 ± 3.67* | 44.96 ± 3.89*† | <0.001 | 0.232 | 0.683 | 0.068 |
| Smoking, n (%) | 6 (4.84) | 9 (10.11) | 14 (22.58)*† | 0.001 | 2 (4.88) | 3 (5.08) | 9 (19.15)*† | 0.024 | 0.992 | 0.273 | 0.664 |
| AHI (events/h) | 1.55 (0.70–2.60) | 11.60 (7.60–17.30)* | 58.10 (42.40–77.00)*† | <0.001 | 1.50 (0.75–3.15) | 10.60 (7.10–18.40)* | 59.00 (51.00–83.60)*† | <0.001 | 0.444 | 0.469 | 0.334 |
| ODI (events/h) | 4.25 (1.63–10.18) | 12.90 (7.40–24.20)* | 66.10 (45.60–83.45)*† | <0.001 | 4.50 (3.10–12.10) | 17.15 (6.70–32.58)* | 71.70 (61.15–89.75)*† | <0.001 | 0.296 | 0.123 | 0.243 |
| Mean SpO2 (%) | 96.54 ± 1.50 | 95.61 ± 2.18 | 91.61 ± 4.18*† | <0.001 | 96.68 ± 1.06 | 95.62 ± 1.86 | 89.93 ± 5.91*† | <0.001 | 0.890 | 0.861 | 0.210 |
| LSpO2 (%) | 88.56 ± 6.61 | 82.53 ± 8.95* | 62.12 ± 17.85*† | <0.001 | 87.00 ± 6.68 | 81.00 ± 9.92* | 58.90 ± 17.84*† | <0.001 | 0.143 | 0.329 | 0.303 |
| TS90 (%) | 0.00 (0.00–0.20) | 0.30 (0.01–1.45)* | 18.95 (4.95–37.13)*† | <0.001 | 0.05 (0.00–0.35) | 0.80 (0.10–2.80)* | 25.70 (9.90–43.40)*† | <0.001 | 0.118 | 0.199 | 0.171 |
| HbA1c (%) | 5.45 ± 0.60 | 5.45 ± 0.38 | 5.62 ± 0.40 | 0.169 | 5.78 ± 0.56 | 5.65 ± 0.62 | 6.21 ± 0.66*† | <0.001 | 0.006 | 0.027 | <0.001 |
| Fasting glucose (mmol/L) | 4.94±0.39 | 5.03 ± 0.46 | 5.03 ± 0.44 | 0.231 | 5.38 ± 0.61 | 5.29 ± 0.64 | 5.87 ± 0.72*† | <0.001 | <0.001 | 0.008 | <0.001 |
| 30-min glucose (mmol/L) | 8.43 ± 1.18 | 8.67 ± 1.39 | 9.21 ± 1.38*† | 0.001 | 9.98 ± 2.01 | 9.57 ± 1.42 | 10.15 ± 1.65 | 0.186 | <0.001 | <0.001 | 0.001 |
| 1-h glucose (mmol/L) | 8.31 ± 1.71 | 8.92 ± 1.90* | 9.53 ± 1.80*† | <0.001 | 11.44 ± 2.41 | 11.17 ± 1.80 | 11.89 ± 1.97 | 0.199 | <0.001 | <0.001 | <0.001 |
| 2-h glucose (mmol/L) | 6.15 ± 1.04 | 6.18 ± 1.03 | 6.12 ± 1.03 | 0.965 | 9.06 ± 0.97 | 9.39 ± 1.12 | 9.18 ± 1.38 | 0.368 | <0.001 | <0.001 | <0.001 |
| Fasting insulin (mU/mL) | 18.43 (13.34–25.03) | 19.21 (12.48–26.74) | 15.81 (9.94–23.85) | 0.386 | 21.99 (14.72–28.43) | 19.29 (13.60–29.48) | 19.95 (11.77–25.56) | 0.776 | 0.169 | 0.406 | 0.091 |
| 2-h insulin (mU/mL) | 109.80 (63.30–158.73) | 103.60 (57.36–156.95) | 109.15 (51.69–161.18) | 0.891 | 172.70 (96.97–297.35) | 184.60 (115.20–349.50) | 112.40 (84.46–162.90)*† | 0.002 | <0.001 | <0.001 | 0.329 |
| HOMA-IR (μIU·mol·L−2) | 4.01 (2.84–5.76) | 4.13 (2.68–6.17) | 3.46 (2.31–5.32) | 0.258 | 5.38 (3.11–6.73) | 4.15 (2.98–7.29) | 5.49 (3.11–6.94) | 0.853 | 0.053 | 0.220 | 0.005 |
| HOMA-β (IU/mol) | 263.25 (187.51–359.67) | 256.17 (168.73–370.13) | 203.77 (123.62–320.03)* | 0.029 | 229.14 (174.68–355.13) | 228.65 (140.00–330.94) | 170.57 (120.00–213.15)*† | 0.010 | 0.286 | 0.421 | 0.188 |
| ΔI30/ΔG30 (IU/mol) | 37.40 (26.16–57.13) | 33.31 (19.93–59.37) | 27.53 (16.02–41.00)* | 0.005 | 23.02 (12.27–35.67) | 21.45 (12.08–37.67) | 14.32 (8.50–25.71)† | 0.054 | <0.001 | <0.001 | <0.001 |
| AUC-I180 (μIU/mL·h) | 351.24 (227.44–514.82) | 320.87 (243.76–418.76) | 344.16 (220.78–469.11) | 0.731 | 464.36 (280.65–612.75) | 406.43 (264.51–679.97) | 302.84 (232.77–398.98)*† | 0.008 | 0.084 | 0.012 | 0.346 |
| DIO (L2/mmol2) | 671.72 (556.54–816.16) | 637.33 (527.63–763.06) | 627.77 (527.73–770.51) | 0.099 | 463.30 (349.01–559.39) | 458.46 (345.60–575.72) | 329.40 (284.26–411.86)*† | 0.001 | <0.001 | <0.001 | <0.001 |
Notes: Data are presented as mean ± SD or median with inter-quartile range if variables were not normally distributed. *P <0.05 vs. control group; †P <0.05 vs. mild-to-moderate OSA group. P valuea for normal glucose tolerance vs prediabetes in control group; P valueb for normal glucose tolerance vs. prediabetes in mild-to-moderate OSA group; P valuec for normal glucose tolerance vs prediabetes in severe OSA group.
Abbreviations: OSA, obstructive sleep apnea; AHI, apnea-hypopnea index; ODI, oxygen desaturation index; Mean SpO2, mean pulse oxygen saturation; LSpO2, lowest pulse oxygen saturation; TS90, percent of total sleep time spent below 90% oxygen saturation; HbA1c, glycosylated hemoglobin A1; HOMA-IR, homeostasis model assessment–insulin resistance; HOMA-β, homeostasis model assessment-β; ΔI30/ΔG30, the early phase (0 min−30 min) insulinogenic index; AUC-I180, total area under the curve of insulin in 180 minutes; DIO, oral disposition index.