31 research outputs found

    Stability of the timing of food intake at daily and monthly timescales in young adults

    Get PDF
    Cross-sectional observations have shown that the timing of eating may be important for health-related outcomes. Here we examined the stability of eating timing, using both clock hour and relative circadian time, across one semester (n = 14) at daily and monthly time-scales. At three time points ~ 1 month apart, circadian phase was determined during an overnight in-laboratory visit and eating was photographically recorded for one week to assess timing and composition. Day-to-day stability was measured using the Composite Phase Deviation (deviation from a perfectly regular pattern) and intraclass correlation coefficients (ICC) were used to determine individual stability across months (weekly average compared across months). Day-to-day clock timing of caloric events had poor stability within individuals (~ 3-h variation; ICC = 0.12–0.34). The timing of eating was stable across months (~ 1-h variation, ICCs ranging from 0.54–0.63), but less stable across months when measured relative to circadian timing (ICC = 0.33–0.41). Our findings suggest that though day-to-day variability in the timing of eating has poor stability, the timing of eating measured for a week is stable across months within individuals. This indicates two relevant timescales: a monthly timescale with more stability in eating timing than a daily timescale. Thus, a single day’s food documentation may not represent habitual (longer timescale) patterns

    Effect of Dupilumab on Sleep Apnea Severity in Patients With Chronic Rhinosinusitis

    Get PDF
    Patients with chronic rhinosinusitis (CRS) report improved sleep quality after dupilumab, an anti IL4/13 therapy. Concurrent CRS and obstructive sleep apnea (OSA) cases are not rare, and CRS seemingly raises nasal resistance. Thus, we hypothesized that improved sleep quality by dupilumab therapy in CRS patients might be due to lowered nasal resistance and subsequent improvement of unrecognized comorbid OSA. Patients with concurrent CRS and OSA were recruited. Nasal resistance was measured invasively with transnasal pressure and flow data collected during normal respiration in the supine position. Results from the first five participants did not support our hypothesis. Subjective and objective measures for CRS and nasal resistance values were improved with dupilumab therapy in CRS patients with nasal polyps. However, apnea severity and sleep-related subjective parameters did not change. In the patients with CRS without nasal polyps, no significant changes in either CRS or OSA-related measures were observed

    Impact of Common Diabetes Risk Variant in MTNR1B

    Full text link
    The risk of type 2 diabetes (T2D) is increased by abnormalities in sleep quantity and quality, circadian alignment, and melatonin regulation. A common genetic variant in a receptor for the circadian-regulated hormone melatonin (MTNR1B) is associated with increased fasting blood glucose and risk of T2D, but whether sleep or circadian disruption mediates this risk is unknown. We aimed to test if MTNR1B diabetes risk variant rs10830963 associates with measures of sleep or circadian physiology in intensive in-laboratory protocols (n = 58–96) or cross-sectional studies with sleep quantity and quality and timing measures from self-report (n = 4,307–10,332), actigraphy (n = 1,513), or polysomnography (n = 3,021). In the in-laboratory studies, we found a significant association with a substantially longer duration of elevated melatonin levels (41 min) and delayed circadian phase of dim-light melatonin offset (1.37 h), partially mediated through delayed offset of melatonin synthesis. Furthermore, increased T2D risk in MTNR1B risk allele carriers was more pronounced in early risers versus late risers as determined by 7 days of actigraphy. Our results provide the surprising insight that the MTNR1B risk allele influences dynamics of melatonin secretion, generating a novel hypothesis that the MTNR1B risk allele may extend the duration of endogenous melatonin production later into the morning and that early waking may magnify the diabetes risk conferred by the risk allele

    Chronic sleep curtailment, even without extended (>16-h) wakefulness, degrades human vigilance performance

    No full text
    This is a data set derived from controlled in-laboratory conditions of individuals exposed to either control (equivalent to a sleep opportunity ~8h) or chronic sleep restricted conditions (equivalent to a sleep opportunity ~5.6h). This study was accomplished using a circadian forced desynchrony design on a 20-h day length. All subjects provided written informed consent prior to participation and all procedures were approved by the Partners Healthcare Institutional Review Board

    Robust stability of melatonin circadian phase, sleep metrics, and chronotype across months in young adults living in real‐world settings

    No full text
    Appropriate synchronization of the timing of behaviors with the circadian clock and adequate sleep are both important for almost every physiological process. The timing of the circadian clock relative to social (ie, local) clock time and the timing of sleep can vary greatly among individuals. Whether the timing of these processes is stable within an individual is not well-understood. We examined the stability of circadian-controlled melatonin timing, sleep timing, and their interaction across ~ 100 days in 15 students at a single university. At three time points ~ 35-days apart, circadian timing was determined from the dim-light melatonin onset (DLMO). Sleep behaviors (timing and duration) and chronotype (ie, mid-sleep time on free days corrected for sleep loss on school/work days) were determined via actigraphy and analyzed in ~ 1-month bins. Melatonin timing was stable, with an almost perfect relationship strength as determined via intraclass correlation coefficients ([ICC]=0.85); average DLMO timing across all participants only changed from the first month by 21 minutes in month 2 and 5 minutes in month 3. Sleep behaviors also demonstrated high stability, with ICC relationship strengths ranging from substantial to almost perfect (ICCs = 0.65-0.85). Average DLMO was significantly associated with average chronotype (r  = 0.53, P <.01), with chronotype displaying substantial stability across months (ICC = 0.61). These findings of a robust stability in melatonin timing and sleep behaviors in young adults living in real-world settings holds promise for a better understanding of the reliability of previous cross-sectional reports and for the future individualized strategies to combat circadian-associated disease and impaired safety (ie, “chronomedicine”).

    Caloric and Macronutrient Intake Differ with Circadian Phase and between Lean and Overweight Young Adults

    No full text
    The timing of caloric intake is a risk factor for excess weight and disease. Growing evidence suggests, however, that the impact of caloric consumption on metabolic health depends on its circadian phase, not clock hour. The objective of the current study was to identify how individuals consume calories and macronutrients relative to circadian phase in real-world settings. Young adults (n = 106; aged 19 &plusmn; 1 years; 45 females) photographically recorded the timing and content of all calories for seven consecutive days using a smartphone application during a 30-day study. Circadian phase was determined from in-laboratory assessment of dim-light melatonin onset (DLMO). Meals were assigned a circadian phase relative to each participant&rsquo;s DLMO (0&deg;, ~23:17 h) and binned into 60&deg; bins. Lean (n = 68; 15 females) and non-lean (n = 38, 30 females) body composition was determined via bioelectrical impedance. The DLMO time range was ~10 h, allowing separation of clock time and circadian phase. Eating occurred at all circadian phases, with significant circadian rhythmicity (p &lt; 0.0001) and highest caloric intake at ~300&deg; (~1900 h). The non-lean group ate 8% more of their daily calories at an evening circadian phase (300&deg;) than the lean group (p = 0.007). Consumption of carbohydrates and proteins followed circadian patterns (p &lt; 0.0001) and non-lean participants ate 13% more carbohydrates at 240&deg; (~1500 h) than the lean group (p = 0.004). There were no significant differences when caloric intake was referenced to local clock time or sleep onset time (p &gt; 0.05). Interventions targeting the circadian timing of calories and macronutrients for weight management should be tested
    corecore