ABSTRACT
Objective To explore the relationship between the respiratory disturbance index (RDI) detected by cardiopulmonary coupling (CPC) and all parameters of polysomnography (PSG), and to analyze the correlation of the two different analytical techniques for the interpretation of sleep breathing events.Methods In this case-control study, the patients′ CPC and PSG were simultaneously recorded at the Sleep Clinic at Changzheng Hospital from Janunary 2016 to December 2016.Effective recordings were obtained from 292 patients (male/female: 173/119).According to PSG, these patients were divided into two groups: obstructive sleep apnea hyponea syndrome (OSAHS) group (n=173, aged (50.1±13.3) years) and non-OSAHS group (n=119, aged (50.5±11.7) years).All the PSG parameters and the RDI detected by CPC were compared between the two groups.Pearson correlation was used to analyze the relationship between the CPC-RDI and polysomnography parameters, and Bland-Altman chart was used to test the correlation of the two methods.The receiver operator characteristic curve was used to research the value of CPC-RDI in diagnosis of OSAHS.Results The OSAHS group showed higher levels of total sleep time (TST, (445.94±82.64) min), apnea times ((108.16±35.70)/h), hypopnea rate ((55.62±17.44)/h), apnea hyponea index (AHI, (22.78±20.73)/h), Epworth Sleeping Scale (ESS) scores ((11.21±5.30) scores), CPC-RDI ((32.98±22.19)/h) compared with the non-OSAHS group ((417.21±96.10) min,t=2.730;(7.89±5.41)/h,t=30.384;(11.05±2.23)/h, t=27.709;(5.51±3.11)/h,t=9.014;(7.61±2.29)scores,t=6.973;(11.16±8.63)/h,t=10.205, all P<0.01), and a significant decrease in N1 latency ((14.79±9.29) min vs (18.18±8.98)min, t=-3.106), N3% ((6.53±4.95)% vs(8.83±7.29)%,t=-3.212) and the lowest oxygen saturation (SaO2;(77.91±12.21)% vs(92.72±5.17)%, t=-12.479, all P<0.05 respectively).Pearson correlation analysis indicated that RDI was positively correlated with TST, N2 sleeping time, N3 sleeping time, AHI, microarousals index, leg movements index, and ESS scores (P<0.01 respectively).Remarkably, the correlation between CPC-RDI and PSG-AHI was excellent (r=0.801, P<0.01), and CPC-RDI was negatively correlated with lowest SaO2 (r=-0.765, P<0.01).Bland-Altman showed that the points in the limits of agreement accounted for more than 95% of all points.If CPC-RDI is higher than 18.95, the subjects were more likely with OSAHS.The sensitivity was 62.9% and the specificity was 88.7%.In addition, the enhanced low-frequency coupling parameters in the CPC analysis technique can clearly analyze the central respiratory rhythm disturbance.Conclusions CPC technology is an effective assessment technology to diagnose sleep-disordered breathing, and correlates well with AHI detected by traditional PSG.It shows the advantage of screening for central sleep apnea.
ABSTRACT
Objective:To observe the effect of ciliary neurotrophic factor (CNTF) on the increase of hippocampal neurons -[Ca~(2+)-]_i induced by thapsigargin (Tg), a sarco/endoplasmic reticulum Ca~(2+)-ATPase (SERCA2a) inhibitor. Methods: The primarily cultured hippocampal neurons of newborn SD rats(within 24 h of delivery) were prepared after 10-14 d culture. The intracellular -[Ca~(2+)-]_i was measured with Fura-2/AM in real time. The neurons were divided into 3 groups. Group A (n=20), EGTA (3 mmol/L);Group B (n=40), EGTA (3 mmol/L) + Tg (10 ?mol/L);and Group C (n=12), EGTA (3 mmol/L) +Tg (10 ?mol/L) +CNTF (500 U/?l). Results: When the extracellular Ca~(2+) was chelated by enough EGTA, -[Ca~(2+)-]_i was ≤(30.73?7.25) nmol/L; after EGTA+Tg was added, -[Ca~(2+)-]_i significantly increased(-[Ca~(2+)-]_i≥-[91.55?12.24-] nmol/L); and after EGTA+Tg+CNTF was added, -[Ca~(2+)-]_i was markedly reduced compared with that in group B (-[Ca~(2+)-]_i≤-[26.09?7.16-] nmol/L, P