Table 3

Clinical and biochemical features of study population, grouped according to the presence and severity of OSAS (n=80)

ParameterNon-OSAS subjects (n=28)OSAS subjects (n=52)P value
OSAS versus non- OSAS
Mild OSAS (n=29)Severe OSAS (n=23)p Value
mild versus severe OSAS
Age (years)11.7±1.911.3±2.10.46911.4±1.911.2±2.50.759
Gender n (%) males18 (64%)27 (52%)0.29015 (52%)12 (52%)0.999
BMI (kg/m2)26.4±5.928.3±4.90.12928.4±5.128.5±5.00.994
BMI z-score1.77±0.652.04±0.680.1012.03±0.532.09±0.480.671
Obese subjects n (%)18 (64%)41 (79%)0.18623 (79%)18 (78%)0.928
Waist circumference (cm)89.0±5.489.8±3.90.49290.0±4.589.5±2.90.676
Waist circumference z-score1.95±0.832.01±0.760.4921.97±0.692.09±0.860.640
Systolic BP (mm Hg)113±16111±90.569111±10113±130.613
Diastolic BP (mm Hg)67±868±80.54068±869±80.892
Insulin (μU/mL)15.1±10.713.1±9.10.38115.0±9.611.6±9.40.213
Glucose (mg/dL)87±1585±150.45983±1187±160.316
HOMA-IR3.14±2.102.88±2.020.4603.11±2.162.49±2.100.213
ISI3.55±2.572.64±1.990.1102.66±1.602.65±1.390.962
Triglyceride (mg/dL)105±51116±750.409127±83108±560.305
Total cholesterol (mg/dL)159±28163±370.337167±42160±340.582
HDL-C (mg/dL)43±742±70.46840±643±7*0.127
Diabetes n (%)1 (4%)1 (2%)0.8120%1 (4%)0.613
Metabolic syndrome n (%)3 (11%)10 (19%)0.5056 (21%)4 (17%)*0.591
Abdominal obesity n (%)19 (67%)31 (60%)0.89119 (66%)12 (52%)0.602
Hypertension n (%)5 (19%)6 (13%)0.6942 (7%)4 (17%)0.191
Hypertriglyceridemia n (%)6 (21%)16 (31%)0.27112 (41%)4 (17%)0.119
Low HDL-C n (%)9 (32%)13 (25%)0.51310 (34%)3 (13%)0.147
IFG/diabetes n (%)5 (18%)9 (17%)0.9985 (17%)4 (17%)0.479
Adiponectin (ng/mL)22.7±2.420.9±1.80.01421.0±2.020.7±1.40.513
Resistin (pg/mL)29 886±11 99136 921±29 3260.55437 102±32 01235 112±10 9400.890
RBP-4 (mg/mL)2.9±1.13.3±1.30.1713.26±1.873.33±1.250.867
C-reactive protein (mg/L)1.6±0.41.5±0.40.7631.6±0.41.5±0.50.661
IL-6 (pg/mL)11.0±5.611.5±5.90.75911.8±6.410.5±4.30.226
Leptin (ng/mL)18.9±7.719.5±9.60.75518.9±9.722.3±8.10.567
TNF-α (pg/mL)6.8±2.16.6±2.20.7566.5±2.37.2±2.10.549
L/M ratio0.022±0.0270.059±0.040<0.0010.041±0.0300.088±0.045<0.001
Pathological L/M ratio (%)2 (7%)26 (50%)<0.00110 (34%)16 (69%)0.026
LPS (EU/mL)1.97±0.522.83±0.41<0.0012.70±0.202.98±0.190.010
AHI (events/h)0.58±0.304.99±3.07<0.0012.15±1.21†8.77±3.05†<0.001
ODI0.62±0.601.45±1.110.0350.91±0.64‡2.14±1.00†0.009
TST (h)7.8±0.88.0±0.70.2528.1±0.87.9±0.70.305
Mean SaO2 (%)96.4±0.994.6±0.8<0.00193.7±0.7*92.0±0.8‡0.022
Nadir SaO2 (%)90.8±1.186.4±1.3<0.00188.0±1.6‡84.5±1.2†0.011
SaO2 <90% (%TST)12±1346±21<0.00140±15†55±18†<0.001
ETpCO2 (mm Hg)44.0±3.548.9±7.0<0.00147.1±4.352.0±7.80.028
AST (IU/L)33±1637±180.29532±1344±180.049
ALT (IU/L)34±1541±150.08138±1742±160.744
GGT (IU/L)18±621±160.22921±1721±120.813
CK-18 (U/L)208±54301±62<0.001291±55339±460.007
Hyaluronic acid (ng/mL)1124±4551401±4660.0091224±5411626±528‡0.005
  • Data are reported as mean±SD, unless otherwise specified. Differences were considered statistically significant at p<0.05. Statistically significant differences are highlighted in bold.

  • Severe OSAS: AHI≥5 events/h. Obesity, BMI ≥95th percentile.

  • *p<0.05 versus non-OSAS subjects.

  • †<0.0001 versus non-OSAS subjects.

  • ‡p<0.01 versus non-OSAS subjects.

  • AHI (apnoea/hypopnoea index, number of apnoea/hypopnoeas per hour of sleep; ALT, alanine transaminase; AST, aspartate aminotransferase; BMI, body mass index; BP, blood pressure; CK18, cytokeratin-18 fragments; ETpCO2, mean end-tidal pCO2; GGT, gamma-glutamyl transpeptidase; HOMA-IR, homeostasis model assessment of insulin resistance; IL, interleukin; ISI, insulin sensitivity index; LPS, lipopolysaccharide; ODI, oxygen desaturation index; OSAS, obstructive sleep apnoea syndrome; pathological L/M ratio, an L/M ratio ≥0.03 between fractional excretion of lactulose and the fractional excretion of mannitol was considered abnormal; RBP, retinol-binding protein; SaO2 <90%, total duration of haemoglobin desaturation, expressed as %TST; TNF, tumour necrosis factor; TST, total sleep time (min).