Key result
Sympathetic activity increased around apnoeas/hypopnoeas in OSAHS patients, with low frequency power rising to 229+/-38 ms2 compared to 106+/-18 ms2 during undisturbed sleep.
Why the study?
Are sympathovagal balance and nocturnal autonomic activity altered around apnoeas/hypopnoeas in OSAHS patients compared to undisturbed sleep and healthy controls?
Observational (n=21)
Are sympathovagal balance and nocturnal autonomic activity altered around apnoeas/hypopnoeas in OSAHS patients compared to undisturbed sleep and healthy controls?
Sympathetic activity increases around apneas/hypopneas, suggesting that recurrent nocturnal fluctuations of sympathovagal balance may contribute to the development of cardiovascular disease in sleep apnea patients.
Nocturnal sympathetic surges may contribute to cardiovascular risk in OSAHS; hypothesis-generating and requires prospective validation.
A recent study has shown that daytime heart rate variability is reduced in obstructive sleep apnoea/hypopnoea syndrome (OSAHS) patients. In the present study, the hypothesis was that sympathovagal balance around apnoeas/hypopnoeas and nocturnal autonomic activity are altered in OSAHS patients. Frequency- and time-domain analyses of RR intervals were performed to monitor sympathovagal activity noninvasively. Fourteen untreated OSAHS patients and seven healthy subjects underwent overnight polysomnography. Low (LF) and total (TF) frequency power increased 2 min around the end of apnoeas/hypopnoeas (LF 229+/-38 ms2 TF 345+/-45 ms2) compared with undisturbed sleep (LF 106+/-18 ms2, TF 203+/-23 ms2). The increase in high frequency (HF) power was not significant. LF increase was proportionally higher than the HF increase (normalised LF (LFn) 67+/-1 units, normalised HF (HFn) 33+/-1 units) compared with undisturbed sleep (LFn 52+/-2 units, HFn 48+/-2 units). RR duration did not change around apnoeas/hypopnoeas (RR 904+/-28 ms). The LF and TF power increase was greater around arousal-inducing (LF 260+/-45 ms2 TF 390+/-65 ms2) compared with self-terminating (LF 161+/-31 ms2, TF 249+/-40 ms2) apnoeas/hypopnoeas; the LF and LFn increases were significant in both groups compared with undisturbed sleep and HF power differences were nonsignificant. RR intervals were longer around self-terminating apnoeas/hypopnoeas (RR 914+/-29 ms); the differences were not significant compared with undisturbed sleep. RR interval spectral power was not influenced by the event type. RR duration decreased (912+/-28 ms) and LF, HF and TF power increased (LF 111+/-16 ms2 , HF 62+/-6 ms , TF 173+/-21 ms2) across patients, compared with healthy controls (RR 1138+/-91 ms, LF 57+/-3 ms2, HF 35+/-3 ms2, TF 91+/-6 ms2). LFn and HFn did not change significantly. Sympathetic activity increases around apnoeas/hypopnoeas. The recurrent nocturnal fluctuations of sympathovagal balance and the overall increase of nocturnal autonomic activity may be of importance in the development of cardiovascular disease in sleep apnoea patients.
No takes yet. Share an insight, caveat, or question.
Dingli et al. (2003) conducted an observational in Obstructive sleep apnoea/hypopnoea syndrome (OSAHS) (n=21). Apnoeas/hypopnoeas vs. Undisturbed sleep and healthy controls was evaluated on Sympathovagal balance (frequency- and time-domain analyses of RR intervals). Sympathetic activity increased around apnoeas/hypopnoeas in OSAHS patients, with low frequency power rising to 229+/-38 ms2 compared to 106+/-18 ms2 during undisturbed sleep.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: