Do Placebos Primarily Affect Subjective as Opposed to Objective Measures? A Meta-Analysis of Placebo Responses in Insomnia RCTs.

INTRODUCTION: Little is known about the relative magnitude of placebo responses on objective and subjective measures of sleep continuity. To address this issue, the pre-post effects of placebos on objective and subjective measures (i.e., polysomnography [PSG] and sleep diaries) were evaluated meta-analytically. The guiding hypothesis was that large responses would be observed on sleep diary measures and small responses would be observed on PSG measures. METHODS: PubMed searches, 1967-2016, yielded 329 possible articles, 17 of which met the inclusion and exclusion criteria for the present analysis (including 879 subjects with PSG data, 1,209 subjects with diary data, and six studies with both PSG and sleep diary data). Average change and weighted effect sizes (ESs) were computed via modeling for sleep latency (SL), wake after sleep onset (WASO) and total sleep time (TST). RESULTS: Pre-to-post change on PSG measures were: SL -13.7 min., ES = -0.37; WASO -14.3 min., ES = -0.36; and TST 29.8 min., ES = 0.50. Pre-to-post change on sleep diary measures were: SL -13.5 min., ES = -0.36; WASO -13.3 min., ES = -0.20; and TST 25.5 min., ES = 0.36. The modeled average objective subjective difference per sleep continuity measure was less than 5 minutes. The modeled average objective subjective difference per sleep continuity measure (in effect sizes) was less than 0.17. DISCUSSION: The observed outcomes of this analysis suggest that placebos produce comparable effects on objective and subjective measures of sleep continuity. Thus, objective measures do not appear to protect against placebo responses. This being the case and given the importance of the subjective experience of illness severity and recovery, such data suggests that prospectively sampled sleep continuity data (sleep diaries) may be the optimal data for clinical trials, particularly when only one measure is possible.

Meal timing relative to DLMO: Associations with BMI and body fat.

BACKGROUND: Timing of eating relative to the dim light melatonin onset (DLMO) may serve as a modifiable risk factor for adverse cardiometabolic outcomes. The primary aim of this study was to examine whether the timing of eating relative to DLMO is associated with body mass index (BMI), body fat, and diet in healthy adults without the confound of sleep deprivation. METHODS: Healthy men and women (N = 97), ages 18-50, with a habitual sleep duration of ≥6.5 hours and ≤8.5 hours completed 7 days of actigraphy and daily sleep and food diaries. Participants underwent a dual-energy X-ray absorptiometry scan and blood draws to assess DLMO in the clinical research unit. RESULTS: A shorter duration between DLMO and the average clock time of the last meal (last meal-DLMO) was related to a higher number of meals consumed, b = 0.25, SEb = 0.06, P< .001, longer feeding duration, b = 0.84, SEb = 0.06, P< .001, greater carbohydrate intake, b = 9.08, SEb = 3.55, P= .01, and greater sugar intake, b = 4.73, SEb = 1.83, P= .01. Last meal-DLMO was not associated with BMI in the full sample; however, among those with later DLMO (after 10:30 PM) last meal-DLMO was related to higher BMI, b = 0.92, SEb = 0.36, P= .02. CONCLUSION: These results suggest that timing of last meal relative to DLMO may serve as a marker of circadian misalignment and that eating the last meal closer to DLMO may negatively impact dietary habits.

Circadian Rhythm Sleep-Wake Phase Disorders.

This article reviews delayed and advanced sleep-wake phase disorders. Diagnostic procedures include a clinical interview to verify the misalignment of the major nocturnal sleep episode relative to the desired and social-normed timing of sleep, a 3-month or greater duration of the sleep-wake disturbance, and at least a week of sleep diary data consistent with the sleep timing complaint. Treatment options include gradual, daily shifting of the sleep schedule (chronotherapy); shifting circadian phase with properly timed light exposure (phototherapy); or melatonin administration. Future directions are discussed to conclude the article.

Weight and Eating Concerns in Women's Reproductive Health.

PURPOSE OF REVIEW: Women's weight status affects their reproductive functioning, and, likewise, women's lifetime weight trajectories are influenced by reproductive events. We examine the relationship between polycystic ovary syndrome (PCOS), pregnancy, the postpartum period, and gynecological cancers with weight, body image, and other psychiatric issues. RECENT FINDINGS: Women with overweight or obesity are at higher risk for PCOS, and the mood and anxiety symptoms often comorbid with PCOS are linked to weight as well as the core symptoms of the disorder. Excessive gestational weight gain can influence one's body image and mood, and it predicts lasting effects on postpartum weight retention. Finally, overweight and obesity are related to several gynecological cancers. These diseases also impact mood, anxiety, and poor body image. Weight management interventions may be of some benefit in improving the disease states and pregnancy outcomes discussed here, but feasibility, logistics, and costs are issues that remain in delivering such interventions.

Associations among rotating night shift work, sleep and skin cancer in Nurses' Health Study II participants.

BACKGROUND: Night shift work and sleep duration have been associated with breast and other cancers. Results from the few prior studies of night shift work and skin cancer risk have been mixed and not fully accounted for other potentially important health-related variables (eg, sleep characteristics). This study evaluated the relationship between rotating night shift work and skin cancer risk and included additional skin cancer risk factors and sleep-related variables. METHODS: The current study used data from 74 323 Nurses' Health Study (NHS) II participants. Cox proportional hazards models were used to estimate multivariable-adjusted HRs and 95% CIs for skin cancers across categories of shift work and sleep duration. RESULTS: Over 10 years of follow-up, 4308 basal cell carcinoma (BCC), 334 squamous cell carcinoma (SCC) and 212 melanoma cases were identified. Longer duration of rotating night shifts was associated with a linear decline in risk of BCC (HR=0.93, 95% CI 0.90 to 0.97 per 5-year increase). Shift work was not significantly associated with either melanoma (HR=1.02, 95% CI 0.86 to 1.21) or SCC (HR=0.92, 95% CI 0.80 to 1.06). A short sleep duration (≤6 hours per day) was associated with lower risks of melanoma (HR=0.68, 95% CI 0.46 to 0.98) and BCC (HR=0.93, 95% CI 0.86 to 1.00) compared with the most common report of 7 hours. SCC was not associated with duration of sleep (HR=0.94, 95% CI 0.83 to 1.06). CONCLUSIONS: Longer duration of rotating night shift work and shorter sleep duration were associated with lower risk of some skin cancers. Further research is needed to confirm and identify the mechanisms underlying these associations.

A "Sleep 101" Program for College Students Improves Sleep Hygiene Knowledge and Reduces Maladaptive Beliefs about Sleep.

Sensitizing young adults about sleep hygiene knowledge and helpful sleep attitudes may have the potential to instill long-lasting healthy sleep practices. Towards these ends, evaluation of psychoeducational program "Sleep 101" tailored to college students was undertaken. Following two weeks of sleep-log recordings, participants were randomly assigned to a Sleep 101 (experimental) condition or a sleep monitoring (control) condition. The Sleep 101 condition was comprised of two 90-minute workshops aimed to educate students about healthy sleep practices, helpful thoughts about sleep, and ways to improve sleep. The sleep monitoring group received a sleep hygiene handout and completed sleep logs for the study duration. Sleep 101 participants endorsed fewer maladaptive beliefs and attitudes about sleep, increased sleep hygiene knowledge, and reduced sleep onset latency compared to the sleep monitoring participants. Brief psychoeducational courses may be a cost-effective way to alleviate current, and/or prevent future, sleep problems in young adults.

Associations between seasonal sleep change and indoor tanning.

Identification of risk factors for indoor tanning may ultimately aid the development of better indoor tanning prevention strategies, which is pertinent given the association between indoor tanning and skin cancer. This study aimed to examine the relationship between seasonal sleep change and indoor tanning. Female tanners (N=139) completed self-report measures including items relating to seasonal sleep changes, seasonal affective disorder (SAD), reasons for tanning, tanning during the winter months, and the Tanning Pathology Scale (TAPS), which measures problematic tanning motives and symptoms of tanning dependence. It was hypothesized that seasonal sleep change and SAD would be associated with greater indoor tanning during the winter, more tanning to improve mood and to relax, and higher scores on the TAPS. Findings indicated that more seasonal sleep change was associated with tanning to improve mood and higher scores on the TAPS. Similarly, the presence of SAD was related to tanning to improve mood, tanning to relax, and more problematic tanning.

Sleep, sleep disturbance, and fertility in women.

Sleep and sleep disturbances are increasingly recognized as determinants of women's health and well-being, particularly in the context of the menstrual cycle, pregnancy, and menopause. At present, however, little is known about whether fertility is affected by sleep quantity and quality. That is, to what degree, and by what mechanisms, do sleep and/or its disturbances affect fertility? The purpose of this review is to synthesize what is known about sleep disturbances in relation to reproductive capacity. A model is provided, whereby stress, sleep dysregulation, and circadian misalignment are delineated for their potential relevance to infertility. Ultimately, if it is the case that sleep disturbance is associated with infertility, new avenues for clinical intervention may be possible.

A prospective study of weight gain associated with chronotype among college freshmen.

A prospective study of chronotype as a predictor of increased weight gain and body mass index (BMI) among college freshman was undertaken. At baseline, 137 college freshmen were characterized as morning, neutral, or evening types using the reduced version of the Morningness-Eveningness Questionnaire. Additionally, information was collected regarding weight, BMI, and health habits (e.g., junk food and alcohol consumption). These additional measures consisted of a descriptive questionnaire, the Pittsburgh Sleep Quality Index, the International Physical Activity Questionnaire, the Gray-Donald Eating Patterns Questionnaire, and the Positive and Negative Affect Scale. Participants included 79 females and 80 males with a mean age of 18.25 (SD = 0.56) yrs. Eight weeks later, participants returned (N = 54) to complete follow-up measures, which were identical to baseline assessments with the exception of the descriptive questionnaire, in which demographic questions were removed. Evening types had a significantly greater BMI gain (p < 0.05) when compared with morning/neutral types. Health behaviors did not differ by chronotype. Future studies should seek to clarify the mechanisms underlying the chronotype-BMI/weight gain relationship.