Kulkas A, Leppänen T, Sahlman J, Tiihonen P, Mervaala E, Kokkarinen J, Randell J, Seppä J, Töyräs J, Tuomilehto H
Department of Clinical Neurophysiology, Seinäjoki Central Hospital, Hanneksenrinne 6, 60220, Seinäjoki, Finland.
Department of Applied Physics, University of Eastern Finland, Kuopio, Finland.
Med Biol Eng Comput. 2015 Oct;53(10):975-88. doi: 10.1007/s11517-015-1290-y. Epub 2015 Apr 17.
Severity of obstructive sleep apnea (OSA) is estimated based on respiratory events per hour [i.e., apnea-hypopnea index (AHI)]. The aim of this study was to investigate effects of weight change on the severity of respiratory events. Respiratory event severity, including duration and morphology, was estimated by determining parameters quantifying obstruction and desaturation event lengths and areas, respectively. Respiratory events of 54 OSA patients treated with dietary intervention were evaluated at baseline and after 5-year follow-up in subgroups with different levels of weight change. AHI, oxygen desaturation index (ODI) and obstruction event severities decreased during weight loss. In lower level weight loss, the decrease was milder in obstruction severity than in AHI and ODI, indicating that the decrease in the number of events is more focused on less severe events. In weight gain groups, parameters incorporating obstruction event severity, AHI and ODI increased, although increase was greater in parameters incorporating obstruction event severity. The number and severity of respiratory events were modulated differently by the level of weight change. AHI misses this change in the severity of respiratory events. Therefore, parameters incorporating information on the respiratory event severities may bring additional information on the health effects obtained with dietary treatment of OSA.
阻塞性睡眠呼吸暂停（OSA）的严重程度是根据每小时的呼吸事件[即呼吸暂停低通气指数（AHI）]来估计的。本研究的目的是调查体重变化对呼吸事件严重程度的影响。通过分别确定量化阻塞和去饱和事件长度及面积的参数来估计呼吸事件的严重程度，包括持续时间和形态。对54例接受饮食干预治疗的OSA患者在基线时以及在体重变化水平不同的亚组中进行5年随访后，评估其呼吸事件。在体重减轻期间，AHI、氧去饱和指数（ODI）和阻塞事件严重程度均下降。在体重减轻程度较低时，阻塞严重程度的下降比AHI和ODI的下降更为轻微，这表明事件数量的减少更集中在不太严重的事件上。在体重增加组中，包含阻塞事件严重程度的参数、AHI和ODI均增加，尽管包含阻塞事件严重程度的参数增加幅度更大。呼吸事件的数量和严重程度受体重变化水平的调节方式不同。AHI未体现呼吸事件严重程度的这种变化。因此，包含呼吸事件严重程度信息的参数可能会为OSA饮食治疗所获得的健康影响带来额外信息。
