Table 1.
Anthropometry, polysomnography, vascular risk factors, free fatty acids, intramyocellular lipid content and extramyocellular lipid content as well as maximal oxygen uptake and physical activity of untreated obstructive sleep apnea patients and controls and their respective nonobese and obese strata
| All | Nonobese | Obese | ||||||
|---|---|---|---|---|---|---|---|---|
| Control | OSA | Control | OSA | Control | OSA | ANOVA | ||
| No. | 23 | 26 | 11 | 9 | 12 | 17 | 49 | |
| Age | y | 45.4 ± 1.2 | 48.8 ± 1.4 | 45.0 ± 1.7 | 52.2 ± 1.7b | 45.8 ± 1.7 | 47.0 ± 1.7d | a |
| Body ht | cm | 180.2 ± 1.2 | 176.2 ± 3.0 | 182.1 ± 1.8 | 180.0 ± 2.5 | 178.5 ± 1.6 | 174.2 ± 4.4 | |
| Body wt | kg | 94.4 ± 2.5 | 102.1 ± 4.5 | 84.3 ± 1.8 | 83.1 ± 2.8 | 103.7 ± 2.3f | 112.2 ± 5.3f | f |
| BMI | kg m−2 | 29.3 ± 0.9 | 30.9 ± 0.9 | 25.8 ± 0.7 | 25.6 ± 0.8 | 32.5 ± 0.6f | 33.7 ± 0.5f | f |
| Subcutaneous fat, thigh | cm3 | 3766 ± 279 | 4064 ± 226 | 2693 ± 181 | 3050 ± 242 | 4481 ± 307 | 4605 ± 218 | f |
| AHI | h–1 | 5.3 ± 0.8 | 48.8 ± 4.6c | 5.8 ± 1.3 | 41.8 ± 6.8c | 4.8 ± 1.0 | 52.8 ± 6.1c | c |
| Time < 90% SaO2 | min | 1.86 ± 0.79 | 64.5 ± 15.0c | 0.81 ± 0.43 | 47.32 ± 17.46b | 2.82 ± 1.43 | 73.6 ± 21.0c | c |
| Mean SaO2 | % | 94.3 ± 0.2 | 92.5 ± 0.4b | 94.2 ± 0.2 | 92.9 ± 0.5a | 94.3 ± 0.3 | 92.2 ± 0.5b | c |
| Heart rate at rest | min–1 | 64.8 ± 2.0 | 72.0 ± 2.2a | 68.5 ± 3.3 | 70.4 ± 4.7 | 61.4 ± 2.0 | 72.9 ± 2.4a | a |
| BP systolic | mm Hg | 137.5 ± 2.0 | 146.6 ± 3.4a | 136.0 ± 1.4 | 136.8 ± 5.5 | 138.8 ± 2.7 | 151.6 ± 3.1a,d | a,d |
| BP diastolic | mm Hg | 88.0 ± 1.1 | 94.4 ± 2.0b | 86.9 ± 1.5 | 89.6 ± 3.2 | 89.0 ± 1.7 | 97.1 ± 2.3b | a,d |
| cIMT | mm | 0.62 ± 0.02 | 0.70 ± 0.03a | 0.61 ± 0.03 | 0.71 ± 0.06 | 0.63 ± 0.03 | 0.70 ± 0.03 | a |
| HbA1c | % | 5.50 ± 0.05 | 5.70 ± 0.08a | 5.48 ± 0.06 | 5.71 ± 0.06a | 5.50 ± 0.09 | 5.70 ± 0.12 | a |
| Glucose, fasted | mg 100 mL–1 | 92.3 ± 1.5 | 98.5 ± 2.5a | 93.3 ± 1.9 | 98.0 ± 4.3 | 91.3 ± 2.3 | 98.8 ± 3.1 | |
| Insulin, fasted | µU mL–1 | 7.69 ± 1.25 | 12.35 ± 1.51a | 5.45 ± 0.98 | 8.64 ± 2.12 | 9.93 ± 2.15 | 14.21 ± 1.88 | d |
| HOMA-IR | 1.77 ± 0.30 | 3.04 ± 0.39a | 1.24 ± 0.22 | 2.15 ± 0.59 | 2.30 ± 0.53 | 3.48 ± 0.47 | a,d | |
| TNF, circulating | pg mL–1 | 9.01 ± 1.16 | 6.93 ± 0.28 | 8.93 ± 2.27 | 7.56 ± 0.66 | 9.08 ± 0.74 | 6.58 ± 0.19b | |
| HDL | mg 100 mL–1 | 48.3 ± 2.0 | 42.8 ± 2.7 | 51.5 ± 3.2 | 42.9 ± 2.5 | 45.3 ± 2.3 | 42.8 ± 4.0 | |
| LDL | mg 100 mL–1 | 138.4 ± 6.6 | 138.2 ± 9.6 | 153.7 ± 6.4 | 147.0 ± 17.2 | 124.4 ± 9.7d | 133.3 ± 11.6 | |
| Total cholesterol | mg 100 mL–1 | 203.3 ± 8.0 | 214.1 ± 7.8 | 219.6 ± 8.9 | 229.0 ± 15.2 | 188.4 ± 11.1d | 205.8 ± 8.3 | d |
| Triglycerides | mg 100 mL–1 | 110.1 ± 12.7 | 165.8 ± 21.5 | 95.6 ± 12.6 | 214.7 ± 40.9a | 123.3 ± 21.2 | 138.4 ± 22.7 | a,g |
| Total FFAs, C12-C24 | mg mL–1 | 5.29 ± 0.31 | 14.72 ± 3.33b | 5.05 ± 0.33 | 16.95 ± 6.75a | 5.51 ± 0.53 | 13.54 ± 3.76 | a |
| Palmitic acid, 16:0 | mg mL–1 | 1.11 ± 0.07 | 2.96 ± 0.67a | 1.02 ± 0.07 | 3.47 ± 1.37a | 1.21 ± 0.12 | 2.69 ± 0.74 | a |
| IMCL | a.u. | 13.55 ± 2.03 | 21.06 ± 2.68a | 9.06 ± 1.15 | 19.36 ± 3.91a | 17.66 ± 3.39d | 21.97 ± 3.61 | a |
| EMCL | a.u. | 15.89 ± 2.39 | 22.22 ± 2.04a | 11.81 ± 1.80 | 24.00 ± 3.83b | 19.64 ± 4.07 | 21.28 ± 2.44 | a |
| VO2max | l min–1 | 3.24 ± 0.13 | 2.79 ± 0.16a | 3.51 ± 0.16 | 2.43 ± 0.27b | 2.94 ± 0.18d | 2.95 ± 0.20 | a,g |
| VO2max/kg | mL min–1 kg–1 | 35.4 ± 2.1 | 28.5 ± 1.5b | 41.9 ± 2.5 | 29.5 ± 3.2b | 28.3 ± 1.6f | 28.0 ± 1.6 | b,e,h |
| Physical activity | h wk–1 | 2.59 ± 0.63 | 1.00 0.27a | 3.86 ± 0.24 | 1.11 ± 1.76 | 1.42 ± 0.50 | 0.94 ± 0.30 | a,d |
Data represent mean ± SEM.
Abbreviations: AHI, apnea-hypopnea index; ANOVA, analysis of variance; a.u., arbitrary units; BMI, body mass index; BP, brachial arterial blood pressure; cIMT, carotid intima media thickness; EMCL, extramyocellular lipid content; FFAs, free fatty acids; HbA1c, glycated hemoglobin A1c; HDL, high-density lipoprotein; HOMA-IR, homeostasis assessment model index of insulin resistance (see “Materials and Methods”); IMCL, intramyocellular lipid content; LDL, low-density lipoprotein; OSA, obstructive sleep apnea; SaO2, oxygen saturation; TNF, tumor necrosis factor; VO2max, maximal oxygen uptake with or without normalization for body weight in kg.
a P less than .05; bP less than .01; cP less than .001 OSA vs control.
d P less than .05; eP less than .01; fP less than .001 obese vs nonobese.
g P less than .05; hP less than .01 for interaction of factor OSA and obesity by ANOVA (for details see “Materials and Methods”).