Showing papers by "Peretz Lavie published in 2003"

Phenotypic and Functional Characterization of Blood γδ T Cells in Sleep Apnea

Abstract: Hypoxia-induced lymphocyte dysfunction may be implicated in endothelial cell damage in obstructive sleep apnea (OSA) syndrome. T cells’ unique migration, cytotoxic features, and accumulation in atherosclerotic plaques are considered critical in cardiovascular disorders. We characterized the phenotype, cytokine profile, adhesion properties, and cytotoxicity of T cells in patients with OSA and control subjects. The following is a summary of our major findings regarding OSA T cells: (1) a significant increase in the expression of the inhibitory natural killer B1 receptors was found; (2) the intracellular content of proinflammatory cytokines tumor necrosis factor (TNF)- and interleukin-8 was increased, and the content of the antiinflammatory cytokine interleukin-10 was decreased; (3) T cells of patients with OSA adhered significantly more avidly to nonactivated endothelial cells in culture than those of control subjects; (4) L-selectin expression was higher; (5) anti–E/P-selectin antibodies and anti–TNF- antibodies decreased the adhesion index of OSA T lymphocytes/endothelial cells but not of control subjects; and (6 ) cytotoxicity of OSA T lymphocytes against endothelial cells in culture was 2.5-fold higher than that of control subjects and could be prevented by pretreatment with anti–TNF-. Collectively these

Sleep complaints are not corroborated by objective sleep measures in post-traumatic stress disorder: a 1-year prospective study in survivors of motor vehicle crashes.

Abstract: Disturbed sleep is a common complaint among patients with post-traumatic stress disorder (PTSD). However, laboratory studies of sleep in PTSD have provided inconsistent evidence of objective sleep disturbances. A major shortcoming of most previous studies is the fact that they were performed retrospectively in patients with chronic PTSD, often complicated by comorbid psychiatric disorders and drug abuse. Thus, little is known about the development of sleep disturbances in recently traumatized subjects. In this study, 102 motor vehicle collision (MVC) survivors were followed from the time of collision throughout 1 year. Nineteen subjects hospitalized for elective surgery served as a comparison group. Subjective quality of sleep was assessed using the mini-Sleep Questionnaire and the Sleep Habit Questionnaire. In addition, a 48-h actigraphic recording was obtained 1 week, 3 and 12 months after the collision. At 12 months, a structured clinical interview (SCID) was administered to reach a formal diagnosis of PTSD. Twenty-six of the MVC survivors, but none of the comparison subjects, met the diagnostic criteria for PTSD. While MVC survivors with PTSD reported markedly poorer sleep as reflected by significantly higher scores on the mini-Sleep Questionnaire, there were no significant differences between the three groups on the actigraphic measures that were largely normal. These results, which were obtained in subjects with no evidence of active psychiatric symptoms at the time of trauma and free of psychotropic or hypnotic medications, further support previous polysomnographic (PSG) studies suggesting that altered sleep perception, rather than sleep disturbance per se, may be the key problem in PTSD.

Plasma Levels of Nitric Oxide and L-Arginine in Sleep Apnea Patients

Abstract: Sleep apnea syndrome has been shown to be associated with decreased levels of circulating nitric oxide (NO) after waking up from sleep. In this study we investigated overnight plasma concentrations of NO in sleep apnea patients before and after nasal continuous positive airway pressure (nCPAP) treatment and the effects of nCPAP on morning levels of L-arginine. In experiment 1, NO concentrations measured hourly during sleep were found to be significantly lower in a group of eight sleep apnea patients in comparison with six age-similar snorers and six normal young adults. In experiment 2, overnight NO concentrations were compared in 5 sleep apnea patients before and 9.3±3.9 mo after treatment with nCPAP. A significant increase in NO concentrations was found in four out of five patients, and a significant increase in L-arginine was found in all five patients after treatment. In experiment 3, removal of nCPAP for a single night in seven sleep apnea patients caused a significant decrease in morning levels of NO and L-arginine. These results demonstrate that sleep apnea is associated with a chronic state of diminished circulating NO concentrations that can be ameliorated by nCPAP treatment.

Pituitary-gonadal function in men with obstructive sleep apnea. The effect of continuous positive airways pressure treatment.

Abstract: OBJECTIVES Decreased libido and a decline in morning serum testosterone levels were reported in men with obstructive sleep apnea (OSA). Our study aimed to evaluate the pituitary-gonadal axis in middle age men with OSA before and after treatment with nasal continuous positive airway pressure (CPAP). MATERIAL AND METHODS Measurement of the nocturnal serum luteinizing hormone (LH) and testosterone levels and sleep recordings before and after nine months of CPAP treatment in five men with OSA aged 49.5+/-5.2 years. Patients were evaluated during nocturnal sleep at base line and during CPAP treatment. Serum LH and testosterone levels were determined at 20 minutes interval between 1900h and 0700h with concomitant determination of sleep quality, respiration and oxygen saturation. RESULTS At base line, patients had higher RDI and PaO2<90%, lower mean and integrated (AUC) values of LH and testosterone. During CPAP treatment, RDI and PaO2<90% were normal. Mean and AUC values of testosterone and LH increased. CONCLUSIONS OSA in men is associated with dysfunction of the pituitary-gonadal axis. The central suppression of nocturnal testosterone in these patients is partially corrected during chronic CPAP treatment.

Haptoglobin polymorphism is a risk factor for cardiovascular disease in patients with obstructive sleep apnea syndrome.

Abstract: sleep apnea syndrome but without cardiovascular disease. No difference in the haptoglobin phenotype frequency was found between controls with and without cardiovascular disease. Log linear analysis revealed a significant interaction effect of haptoglobin phenotype and the presence of sleep apnea on the presence of cardiovascular disease. Logistic regression analysis revealed that the risk of cardiovascular disease in sleep apnea patients younger than 55 years with haptoglobin 2-2 was 2.32-fold higher than in their counterparts with haptoglobin 2-1. Conclusions: These results suggest that haptoglobin phenotype is an important risk factor in determining susceptibility to cardiovascular disease in obstructive sleep apnea syndrome, which may be mediated by the decreased antioxidant and antiinflammatory actions of the haptoglobin 2 allelic protein product.

The KickStrip: a novel testing device for periodic limb movement disorder.

Abstract: STUDY OBJECTIVES In light of the ongoing debate over the clinical significance of periodic limb movement disorder (PLMD) and its monitoring in overnight sleep studies, we introduce a novel, portable, low-cost device for PLMD testing. The KickStrip is a disposable device, which includes a movement sensor, a central processing unit with real-time software, and a display. In the present study, the KickStrip final score (Kscore) is validated against the traditional periodic limb movement index (PLMI) based on overnight recordings in the sleep laboratory. DEISGN: Patients underwent full polysomnographic recordings concomitantly with the use of the KickStrip for a single night. SETTING Sleep Disorders Unit at Loewenstein Rehabilitation Hospital and Sleep Medicine Center at Rambam Medical Center, Israel. PATIENTS Eighty-two patients referred for overnight sleep recordings due to sleep disturbance of any kind. INTERVENTIONS N/A. MEASUREMENTS AND RESULTS The Kscores were collected and the PLMI computed for each leg separately. Pearson correlations between Kscores and PLMI ranged between r = 0.83 to r = 0.88 (p < 0.001). Sensitivity and specificity values of the Kscores for increasing PLMD thresholds showed sensitivity ranging from 50% to 100% and specificity ranging from 83% to 100%. Receiver operating characteristic curves showed area-under-the-curve values ranging from 82% to 92%. Bland-Altman plot showed high agreement between the methods. CONCLUSIONS Comparisons between the Kscores and the traditional PLMI show increased accuracy with severity level and excellent agreement. The KickStrip is a valuable tool for PLMD testing for both clinical and research purposes.

O R I G I N A L A R T I C L E Pituitary-gonadal function in men with obstructive sleep apnea. The effect of continuous positive airways pressure treatment

Abstract: OBJECTIVES: Decreased libido and a decline in morning serum testosterone levels were reported in men with obstructive sleep apnea (OSA). Our study aimed to evaluate the pituitary-gonadal axis in middle age men with OSA before and after treatment with nasal continuous positive airway pressure (CPAP). MATERIAL AND METHODS: Measurement of the nocturnal serum luteinizing hormone (LH) and testosterone levels and sleep recordings before and after nine months of CPAP treatment in five men with OSA aged 49.5±5.2 years. Patients were evaluated during nocturnal sleep at base line and during CPAP treatment. Serum LH and testosterone levels were determined at 20 minutes interval between 1900h and 0700h with concomitant determination of sleep quality, respiration and oxygen saturation. RESULTS: At base line, patients had higher RDI and PaO2<90%, lower mean and integrated (AUC) values of LH and testosterone. During CPAP treatment, RDI and PaO2<90% were normal. Mean and AUC values of testosterone and LH increased. CONCLUSIONS: OSA in men is associated with dysfunction of the pituitarygonadal axis. The central suppression of nocturnal testosterone in these patients is partially corrected during chronic CPAP treatment.