Adelaide Institute for Sleep Health: A Flinders Centre of Research Excellence, College of Medicine and Public Health, Flinders University, Bedford Park, South Australia.
Appleton Institute, Central Queensland University, Adelaide, South Australia.
Sleep. 2021 Jan 21;44(1). doi: 10.1093/sleep/zsaa132.
We investigated biological and behavioral rhythm period lengths (i.e. taus) of delayed sleep-wake phase disorder (DSWPD) and non-24-hour sleep-wake rhythm disorder (N24SWD). Based on circadian phase timing (temperature and dim light melatonin onset), DSWPD participants were dichotomized into a circadian-delayed and a circadian non-delayed group to investigate etiological differences.
Participants with DSWPD (n = 26, 17 m, age: 21.85 ± 4.97 years), full-sighted N24SWD (n = 4, 3 m, age: 25.75 ± 4.99 years) and 18 controls (10 m, age: 23.72 ± 5.10 years) participated in an 80-h modified constant routine. An ultradian protocol of 1-h "days" in dim light, controlled conditions alternated 20-min sleep/dark periods with 40-min enforced wakefulness/light. Subjective sleepiness ratings were recorded prior to every sleep/dark opportunity and median reaction time (vigilance) was measured hourly. Obtained sleep (sleep propensity) was derived from 20-min sleep/dark opportunities to quantify hourly objective sleepiness. Hourly core body temperature was recorded, and salivary melatonin assayed to measure endogenous circadian rhythms. Rhythm data were curved using the two-component cosine model.
Patients with DSWPD and N24SWD had significantly longer melatonin and temperature taus compared to controls. Circadian non-delayed DSWPD had normally timed temperature and melatonin rhythms but were typically sleeping at relatively late circadian phases compared to those with circadian-delayed DSWPD.
People with DSWPD and N24SWD exhibit significantly longer biological circadian rhythm period lengths compared to controls. Approximately half of those diagnosed with DSWPD do not have abnormally delayed circadian rhythm timings suggesting abnormal phase relationship between biological rhythms and behavioral sleep period or potentially conditioned sleep-onset insomnia.
我们研究了延迟性睡眠-觉醒时相障碍（DSWPD）和非 24 小时睡眠-觉醒节律障碍（N24SWD）的生物和行为节律周期长度（即 tau）。基于昼夜节律相位计时（温度和暗光褪黑素起始时间），将 DSWPD 参与者分为昼夜节律延迟和昼夜节律非延迟组，以研究病因学差异。
26 名 DSWPD 参与者（17 名男性，年龄：21.85±4.97 岁）、4 名全盲 N24SWD 参与者（3 名男性，年龄：25.75±4.99 岁）和 18 名对照者（10 名男性，年龄：23.72±5.10 岁）参加了 80 小时的改良恒常性程序。在暗光、受控条件下，1 小时的“天”交替进行 20 分钟的睡眠/黑暗期和 40 分钟的强制清醒/光照期。在每次睡眠/黑暗机会之前记录主观嗜睡评分，并每小时测量中位反应时间（警觉性）。从 20 分钟的睡眠/黑暗机会中获取睡眠（睡眠倾向），以量化每小时的客观嗜睡。每小时记录核心体温，并测定唾液褪黑素以测量内源性昼夜节律。使用双分量余弦模型对节律数据进行曲线拟合。
DSWPD 和 N24SWD 患者的褪黑素和体温 tau 明显长于对照组。昼夜非延迟性 DSWPD 的体温和褪黑素节律时间正常，但与昼夜延迟性 DSWPD 相比，通常在相对较晚的昼夜相位睡眠。
与对照组相比，DSWPD 和 N24SWD 患者的生物昼夜节律周期长度明显更长。大约一半被诊断为 DSWPD 的患者的昼夜节律时间没有异常延迟，这表明生物节律与行为睡眠周期之间的相位关系异常或潜在的条件性睡眠起始失眠。
