Urine levels of catecholamines in Greek children with obstructive sleep-disordered breathing.

INTRODUCTION: Adults with obstructive sleep apnea have increased sympathetic activity. It was hypothesized that in children with symptoms of obstructive sleep-disordered breathing (SDB), morning urine levels of catecholamines correlate with severity of nocturnal hypoxemia. METHODS: Children with snoring referred for polysomnography and controls without snoring were recruited. Morning urine norepinephrine, epinephrine, normetanephrine, and metanephrine levels were measured (ng/mg urine creatinine). RESULTS: Twelve children (age 5.2 +/- 2.3 years) with severe hypoxemia (oxygen saturation of hemoglobin-SpO2 nadir < or =86%), 20 subjects (age 6.1 +/- 2.1 years) with moderate hypoxemia (SpO2 nadir < or =90% and >86%), 22 children (age 6.6 +/- 1.5 years) with mild nocturnal hypoxemia (SpO2 nadir >90%), and 10 controls (age 7.1 +/- 2.8 years) were studied. Children with severe hypoxemia had significantly higher log-transformed norepinephrine levels (1.63 +/- 0.29) compared to those with moderate hypoxemia (1.43 +/- 0.22; P < 0.05) or compared to controls (1.39 +/- 0.31; P < 0.05). In subjects with SDB, log-transformed oxygen desaturation of hemoglobin index or SpO2 nadir predicted log-transformed norepinephrine levels after adjustment by age, gender and body mass index (r2 = 0.24; and r2 = 0.24, respectively; P < 0.01). CONCLUSIONS: Severity of nocturnal hypoxemia in children with intermittent upper airway obstruction during sleep correlates with morning urine levels of norepinephrine suggesting increased sympathetic tone.

Liver fat, visceral adiposity, and sleep disturbances contribute to the development of insulin resistance and glucose intolerance in nondiabetic dialysis patients.

Hemodialysis patients exhibit insulin resistance (IR) in target organs such as liver, muscles, and adipose tissue. The aim of this study was to identify contributors to IR and to develop a model for predicting glucose intolerance in nondiabetic hemodialysis patients. After a 2-h, 75-g oral glucose tolerance test (OGTT), 34 hemodialysis patients were divided into groups with normal (NGT) and impaired glucose tolerance (IGT). Indices of insulin sensitivity were derived from OGTT data. Measurements included liver and muscle fat infiltration and central adiposity by computed tomography scans, body composition by dual energy X-ray absorptiometer, sleep quality by full polysomnography, and functional capacity and quality of life (QoL) by a battery of exercise tests and questionnaires. Cut-off points, as well as sensitivity and specificity calculations were based on IR (insulin sensitivity index by Matsuda) using a receiver operator characteristics (ROC) curve analysis. Fifteen patients were assigned to the IGT, and 19 subjects to the NGT group. Intrahepatic fat content and visceral adiposity were significantly higher in the IGT group. IR indices strongly correlated with sleep disturbances, visceral adiposity, functional capacity, and QoL. Visceral adiposity, O2 desaturation during sleep, intrahepatic fat content, and QoL score fitted into the model for predicting glucose intolerance. A ROC curve analysis identified an intrahepatic fat content of > 3.97% (sensitivity, 100; specificity, 35.7) as the best cutoff point for predicting IR. Visceral and intrahepatic fat content, as well as QoL and sleep seemed to be involved at some point in the development of glucose intolerance in hemodialysis patients. Means of reducing fat depots in the liver and splachnic area might prove promising in combating IR and cardiovascular risk in hemodialysis patients.

Absence of blood pressure, metabolic, and inflammatory marker changes after adenotonsillectomy for sleep apnea in Greek children.

AIM: Pediatric studies revealed associations of obstructive sleep-disordered breathing (SDB) with inflammation, metabolic dysfunction, and elevated blood pressure. Evidence about effects of adenotonsillectomy on these abnormalities is scarce. Aim of this investigation was to assess changes in C-reactive protein (CRP), circulating intercellular adhesion molecule-1 (cICAM-1), insulin and blood pressure levels after adenotonsillectomy for SDB in Greek children. METHODS: Polysomnography was performed pre- and postoperatively in children with SDB and controls undergoing adenotonsillectomy for recurrent tonsillitis or otitis. Outcome measures were changes in serum markers and blood pressure. RESULTS: Fifty-eight patients (6.2 +/- 2.5 years old) and 17 controls (6.5 +/- 2) were studied. After surgery, apnea-hypopnea index (AHI) decreased (mean: -5.9 episodes/hr; 95% confidence interval: -7.8 to -4) in patients. Patients and controls were similar regarding outcomes: CRP (-0.11 mg/dl [-0.25 to 0.02] vs. 0.13 [-0.19 to 0.46]; P = 0.11), cICAM-1 (-11.6 ng/ml [-38.6 to 15.4] vs. -46.6 [-101.7 to 8.6]; P = 0.23), insulin (2.49 mU/L [0.32-4.67] vs. -0.16 [-2.47 to 2.16]; P = 0.21), systolic blood pressure index (5.2% [2.1-8.3] vs. 10.8 [3.6-17.9]; P = 0.1) and diastolic blood pressure index (-3.2% [-7.2 to 0.8] vs. 2.8 [-5.5 to 11.2]; P = 0.16). Patients with CRP > 0.3 mg/dl had reduced values after AT (P = 0.003) and those with postoperative AHI < or = 1 had a decrease in diastolic blood pressure (P = 0.02). CONCLUSIONS: Although adenotonsillectomy improves SDB, it has variable effects on inflammatory and metabolic markers or blood pressure.

Obstructive sleep-disordered breathing and fasting insulin levels in nonobese children.

A positive correlation of severity of sleep-disordered breathing with morning fasting insulin levels, which is independent of obesity, was reported in adults and obese children. We hypothesized that both severity of sleep-disordered breathing and relative body mass index predict fasting insulin and homeostasis model assessment (HOMA) index values in nonobese children with habitual snoring. One hundred and ten subjects with habitual snoring (median age, 6 years; range, 2-13 years) underwent polysomnography and measurement of morning fasting insulin and glucose levels. The HOMA index was calculated. Thirty children had an apnea-hypopnea index (AHI) >/= 5 episodes/hr (median, 7.8 episodes/hr; range, 5-42.3 episodes/hr), and 80 subjects had an AHI < 5 episodes/hr (median, 1.9 episodes/hr; range, 0.2-4.9 episodes/hr). Insulin and HOMA index values were similar in children with AHI >/= 5 episodes/hr (median insulin, 4.9 mU/l; range, 1.66-19.9 mU/l; and median HOMA, 1; range, 0.36-4.95) and in subjects with AHI < 5 episodes/hr (median insulin, 5.8 mU/l; range, 0.74-41.1 mU/l; and median HOMA, 1.3; range, 0.13-9.72) (P > 0.05). No significant correlations were identified between insulin or HOMA index values and any polysomnography indices (P > 0.05). When multiple linear regression was carried out, relative body mass index was a significant predictor of log-transformed insulin levels or HOMA index values, but AHI and percentage of sleep time with saturation <95% were not. In conclusion, contrary to findings in adults and in obese children, severity of sleep-disordered breathing is not a significant predictor of fasting insulin or HOMA index values in nonobese children with habitual snoring.

Strongyloides hyperinfection in a patient with sarcoidosis.

A 51-year-old-woman presented with chronic eosinophilia, a diffuse interstitial lung pattern on CT and splenomegaly with hypodense lesions. A diagnosis of sarcoidosis was determined from a lung biopsy. Hyperinfection with strongyloides following treatment with systemic steroids explains the presence of eosinophilia and splenic involvement.