Application study of apnea-hypopnea duration for assessing adult obstructive sleep apnea.

BACKGROUND: Obstructive sleep apnea (OSA) is a common sleep disordered breathing disorder, which can cause serious damage to multiple human systems. Although polysomnography (PSG) is the current gold standard for diagnosis, it is complex and expensive. Therefore, it is of great significance to find a simple, economical and rapid primary screening and diagnosis method to replace PSG for the diagnosis of OSA. OBJECTIVE: The purpose of this study is to propose a new method for the diagnosis and classification of OSA, which is used to automatically detect the duration of sleep apnea hypopnea events (AHE), so as to estimate the ratio(S) of the total duration of all-night AHE to the total sleep time only based on the sound signal of sleep respiration, and to identify OSA. METHODS: We performed PSG tests on participants and extracted relevant sleep breathing sound signal data. This study is carried out in two stages. In the first stage, the relevant PSG report data of eligible subjects were recorded, the total duration of AHE in each subject's data was extracted, and the S value was calculated to evaluate the severity of OSA. In the second stage, only the sleep breath sound signal data of the same batch of subjects were used for automatic detection, and the S value in the sleep breath sound signal was extracted, and the S value was compared with the PSG diagnosis results to calculate the accuracy of the experimental method. RESULTS: Among 225 subjects. Using PSG as the reference standard, the S value extracted from the PSG diagnostic data report can accurately diagnose OSA(accuracy rate 99.56%) and distinguish its severity (accuracy rate 95.11%). The accuracy of the S value detected in the sleep breathing sound signal in the diagnosis of severe OSA reached 100%. CONCLUSION: The results show that the experimental parameter S value is feasible in OSA diagnosis and classification. OSA can be identified and evaluated only by sleep breathing sounds. This method helps to simplify the diagnostic grading of traditional OSA and lays a foundation for the subsequent development of simple diagnostic grading equipment.

The value of using ELISA to detect orexin-A in cerebrospinal fluid in the diagnosis of narcolepsy.

Orexin in cerebrospinal fluid (CSF) is a neuropeptide synthesized by a cluster of neurons in the lateral hypothalamus. It mainly functions to maintain arousal, regulate feeding, and participate in reward mechanisms. Radioimmunoassay (RIA) and enzyme-linked immunosorbent assay (ELISA) can detect CSF orexin. At present, RIA is widely used but is limited by various conditions, which is not conducive to its widespread development. We aimed to determine whether ELISA can replace RIA in detecting orexin in CSF. We investigated the results of 20 patients with central disorders of hypersomnolence, including 11 with narcolepsy type 1, 2 with narcolepsy type 2, 5 with idiopathic hypersomnia, and 2 with other causes of somnolence. RIA and ELISA were used to detect CSF orexin, and P values <.05 were considered to be significant. In the narcolepsy and non-narcolepsy type 1 groups, there was no correlation between the RIA and ELISA results (P > .05). In the narcolepsy type 1 group, the ELISA and RIA results were significantly different (P < .05), but this was not observed in the non-narcolepsy type 1 group (P > .05). The accuracy of ELISA to detect CSF orexin was lower than that of RIA (P < .05). ELISA cannot replace RIA in the measurement of CSF orexin, and RIA is recommended as the first choice when narcolepsy is suspected.

Association between cytokines and fatigue in patients with type 1 narcolepsy.

BACKGROUND: Fatigue is a frequent complaint among patients with narcolepsy. Studies have shown that inflammatory cytokines are associated with fatigue in neurological disorders; however, this association has not been identified in patients with type 1 narcolepsy. The purpose of this study was to investigate the potential relationship between cytokines and fatigue in patients with type 1 narcolepsy. METHODS: We investigated the association between 12 inflammatory cytokines and fatigue in 49 patients with type 1 narcolepsy. The Multidimensional Fatigue Inventory-20 was used to assess the fatigue severity. The associations of fatigue were identified using Spearman and Pearson correlation analyses. A linear regression analysis model was used to adjust the confounding factors and evaluate the associations of fatigue. RESULTS: Correlation analysis showed that the plasma interleukin (IL)-2 level (r = 0.409, p = 0.004) was positively correlated with fatigue in patients with narcolepsy type 1. After adjusting for confounding factors, the linear regression model revealed a positive association between the IL-2 level (ß = 1.148, p = 0.04) and fatigue in individuals diagnosed with type 1 narcolepsy. CONCLUSION: IL-2 levels show a positive correlation with fatigue in type 1 narcolepsy, suggesting its potential role in the pathophysiology of fatigue.

Cell-based vs enzyme-linked immunosorbent assay for detection of anti-Tribbles homolog 2 autoantibodies in Chinese patients with narcolepsy.

STUDY OBJECTIVES: Narcolepsy type 1 is attributed to a deficiency in cerebrospinal fluid orexin and is considered linked to autoimmunity. The levels of anti-Tribbles homolog 2 (TRIB2) autoantibodies are elevated in the sera of some patients with narcolepsy with cataplexy. Additionally, injecting mice with serum immunoglobulin from patients with narcolepsy with positive anti-TRIB2 antibodies can induce hypothalamic neuron loss and alterations in sleep patterns. Consequently, we hypothesized the existence of a potential association between anti-TRIB2 antibodies and narcolepsy. To test this possibility, we used cell-based assays (CBAs) and enzyme-linked immunosorbent assays (ELISAs) to detect the presence of anti-TRIB2 antibodies in Chinese patients with narcolepsy. METHODS: We included 68 patients with narcolepsy type 1, 39 patients with other central disorders of hypersomnolence, and 43 healthy controls. A CBA and a conventional ELISA were used to detect anti-TRIB2 antibody levels in patients' sera. RESULTS: CBA was used to detect serum anti-TRIB2 antibodies in Chinese patients with narcolepsy, and the results were negative. However, when the ELISA was used, only 2 patients with narcolepsy type 1 had TRIB2 antibody titers higher than the mean titer plus 2 standard deviations of the healthy controls. CONCLUSIONS: In our study, ELISA identified TRIB2 autoantibodies in sera of patients with narcolepsy where CBA failed to demonstrate them. Contrary to our hypothesis, this intriguing finding deserves further research to elucidate the potential association between TRIB2 and narcolepsy type 1. Exploring the implications of TRIB2 autoantibodies in narcolepsy and disparate outcomes between ELISA and CBA could provide crucial insights. CITATION: Zhong X, Yuan Y, Zhan Q, et al. Cell-based vs enzyme-linked immunosorbent assay for detection of anti-Tribbles homolog 2 autoantibodies in Chinese patients with narcolepsy. J Clin Sleep Med. 2024;20(6):941-946.

Association between cytokines and symptoms of depression and anxiety in patients with type 1 narcolepsy.

BACKGROUND: Symptoms of depression and anxiety are common complications of narcolepsy. Earlier studies have shown that narcolepsy type 1 (NT1) is an autoimmune inflammatory disease and symptoms of depression and anxiety are closely related to fluctuations in inflammatory cytokines. The objective of the current research was to investigate the potential correlation between cytokines and symptoms of depression and anxiety in patients with NT1. METHODS: We collected demographic and clinical data and information on cytokine levels from 50 patients with NT1 and used Self-Rating Depression Scale (SDS) and Self-Rating Anxiety Scale (SAS) to assess the severity of depression and anxiety symptoms. Patients with SDS scores ≥ 53 points were defined as depressive narcolepsy type 1 (D-NT1) and those with SDS scores < 53 points as non-depressive narcolepsy type 1 (ND-NT1). Patients with SAS scores ≥ 50 points were defined as anxious narcolepsy type 1 (A-NT1) and those with SAS scores < 50 points as non-anxious narcolepsy type 1 (NA-NT1). A binary logistic regression model was employed to identify the influencing factors of depressive and anxiety symptoms. RESULTS: Levels of IL-10 (p = 0.02), IL-4 (p = 0.049) and disease duration (p = 0.049) were decreased, while SAS scores (p < 0.001) and total sleep duration (p = 0.03) were increased in D-NT1 relative to ND-NT1 patients. A-NT1 patients had higher SDS scores (p < 0.001) compared to NA-NT1 patients. Binary logistic regression analysis revealed associations of longer disease duration (OR=0.83; 95 % CI: 0.70-0.97) and increased IL-10 (OR=0.40; 95 % CI: 0.17-0.90) with reduced risk of depression and worsening anxiety (SAS score; OR=1.17; 95 % CI: 1.06-1.30) with increased risk of depression in patients with NT1. Consistently, worsening depression (SDS score; OR=1.22; 95 % CI: 1.07-1.39) was correlated with increased risk of anxiety in the NT1 group. CONCLUSION: Our finding that higher IL-10 levels correlate with a lower risk of depression in NT1 patients provides a reference for further exploration of the pathophysiological mechanisms of depressive symptoms in NT1 patients.