Prediagnosis dietary pattern and survival in patients with multiple myeloma.

Inflammation and endogenous growth factors are important in multiple myeloma (MM) pathogenesis. Although diets that modulate these biologic pathways may influence MM patient survival, studies have not examined the association of dietary patterns with MM survival. We conducted pooled prospective survival analyses of 423 MM patients from the Nurses' Health Study (1986-2016) and the Health Professionals Follow-up Study (1988-2016) using Cox regression models. We used data from repeated food frequency questionnaires (FFQ) to compute dietary patterns as of the last prediagnosis FFQ, including the Alternate Healthy Eating Index (AHEI)-2010, alternate Mediterranean Diet, Dietary Approaches to Stop Hypertension, Prudent, Western and empirical dietary inflammatory patterns and empirical dietary indices for insulin resistance and hyperinsulinemia. During follow-up, we documented 295 MM-related deaths among 345 total deaths. MM-specific mortality was 15-24% lower per one standard deviation (SD) increase (e.g., toward healthier habits) in favorable dietary pattern scores. For example, the multivariable-adjusted hazard ratio [HR] and 95% confidence interval [CI] per 1-SD increase in AHEI-2010 score were 0.76, 0.67-0.87 (p < 0.001). In contrast, MM-specific mortality was 16-24% higher per 1-SD increase (e.g., toward less healthy habits) in "unhealthy" diet scores; for example, the multivariable-adjusted HR, 95% CI per 1-SD increase in Western pattern score were 1.24, 1.07-1.44 (p = 0.005). Associations were similar for all-cause mortality. In conclusion, our consistent findings for multiple dietary patterns provide the first evidence that MM patients with healthier prediagnosis dietary habits may have longer survival than those with less healthy diets.

Birth month, birth season, and overall and cardiovascular disease mortality in US women: prospective cohort study.

OBJECTIVES: To evaluate the associations between birth month, birth season, and overall and cardiovascular disease mortality, and to examine the role of familial and socioeconomic factors in these associations. DESIGN: Prospective cohort study. SETTING: Nurses' Health Study, established in 1976, an ongoing prospective cohort study in the United States. PARTICIPANTS: Female registered nurses who reported information on date of birth at study enrolment (n=116 911, 1976-2014, followed for 38 years). EXPOSURE: Birth month and astronomical birth season (based on solstices and equinoxes as boundaries of the season categories). MAIN OUTCOME MEASURES: Age and various multivariable adjusted hazard ratios and 95% confidence intervals for the association between birth months (using November as the reference), astronomical birth season (using autumn as the reference), and overall and cardiovascular disease specific mortality were assessed using Cox proportional hazards models. RESULTS: Among study participants, 43 248 overall deaths were documented during 4 136 364 person years of follow-up since enrolment, including 8360 cardiovascular disease related deaths. In fully adjusted multivariable analyses, no significant association was observed between birth month, birth season, and overall mortality. Compared with women born in November, increased cardiovascular disease mortality was observed among those born from March to July (hazard ratio for March, 1.09, 95% confidence interval 0.98 to 1.21; April, 1.12, 1.00 to 1.24; May, 1.08, 0.98 to 1.20; June, 1.07, 0.96 to 1.19; and July 1.08, 0.98 to 1.20). Those born in April had the highest cardiovascular disease mortality, and those born in December had the lowest (December, 0.95, 0.85 to 1.06). The relative difference between the lowest and highest risk month was 17.89%. Women born in spring (1.10, 1.04 to 1.17) and summer (1.09, 1.03 to 1.16) had a higher cardiovascular disease mortality than women born in the autumn. Adjustment for familial and socioeconomic factors did not change these results. The relative difference between the lowest and highest risk season was 10.00%. CONCLUSION: Participants born in the spring and summer (especially those born in March-July) had a slight but significant increase in cardiovascular disease specific mortality. However, no seasonal birth month effect was observed among women for overall mortality. Familial and socioeconomic factors did not appear to alter these associations. Further studies are required to confirm these findings and reveal mechanisms of these seasonal birth month effects in cardiovascular disease mortality.

Reproductive health sequelae among women who survived Ebola virus disease in Liberia.

OBJECTIVE: To estimate the incidence of failed pregnancy and menstrual irregularities among Liberian women who had survived Ebola virus disease (EVD) and to identify host-specific and disease-specific factors associated with these outcomes. METHODS: A cross-sectional questionnaire-based study was conducted between August 10, 2016, and February 7, 2017. The study population comprised 111 women aged 18-45 years who had survived EVD and were enrolled in the Longitudinal Liberian Ebola Survivor study based at the Eternal Love Winning Africa Hospital, Monrovia, Liberia. Self-reported data on outcomes related to pregnancy and menstrual changes since recovery from EVD were collected. RESULTS: In all, 29 (26.1%) of the participants had become pregnant since surviving EVD. Of the 23 women whose pregnancies continued to term, 10 (43.4%) reported live birth, 11 (47.8%) reported spontaneous abortion, and two (8.7%) reported stillbirth. Of the 105 women who reported having regular menstruation before EVD, 27 (29.0%) reported experiencing irregular menstruation for unknown reasons after EVD. In bivariate logistic models, no associations were found between failed pregnancy or irregular menstruation and any of the factors of interest. CONCLUSIONS: Adverse pregnancy outcomes and irregular menstruation were frequently reported among EVD survivors in Liberia.

Night shift work before and during pregnancy in relation to depression and anxiety in adolescent and young adult offspring.

We investigated the relationship between maternal history of nightshift work before and shift work during pregnancy and offspring risk of depression and anxiety, among mothers participating in the Nurses Health Study II and in their offspring enrolled in the Growing Up Today Study 2 between 2004 and 2013. Case definitions were based on offspring self-reports of physician/clinician-diagnosed depression and/or anxiety, regular antidepressant use and depressive symptoms assessed using the Center for Epidemiologic Studies Depression Scale. Multivariable-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using generalized estimating equation models. We found no associations between maternal nightshift work before pregnancy or during pregnancy and offspring mental health disorders (e.g., nightshift work before pregnancy: depression (based on physician/clinician diagnosis): ORever nightwork = 1.14; 95% CI, 0.88-1.47; either depression or anxiety: ORever nightwork = 0.93; 95% CI, 0.81-1.08; nightshift work during pregnancy: depression: ORever nightwork = 1.14; 95% CI, 0.68-1.94; depression or anxiety: ORever nightwork =1.17; 95% CI, 0.70-1.98) and no dose-response relationship with longer history of nightshift work (all PTrend >0.10). Stratifying by maternal chronotype revealed a higher risk of depression for offspring whose mothers worked nightshifts before pregnancy and reported being definite morning chronotypes (a proxy for circadian strain) (ORever nightwork = 1.95; 95% CI, 1.17, 3.24 vs. ORever nightwork = 0.93; 95% CI, 0.68, 1.28 for any other chronotype; PInteraction = 0.03). Further studies replicating our findings and refined understanding regarding the interplay of nightshift work and chronotype and its potential influences on offspring mental health are needed.

Shift Work, Chronotype, and Melatonin Rhythm in Nurses.

BACKGROUND: Previous studies associated night-shift work with melatonin disruption, with mixed evidence regarding the modulating effects of chronotype (i.e., diurnal preference). METHODS: One hundred and thirty active nurses (84 rotating-shift and 46 day-shift workers) in the Nurses' Health Study II wore a head-mounted light meter and collected spontaneous urine voids over 3 days. 6-Sulfatoxymelatonin (aMT6s), the major urinary metabolite of melatonin, was assessed. RESULTS: Rotating-shift workers on night shifts had more light exposure and lower urinary melatonin levels during the night, and urinary melatonin rhythms with smaller peaks [11.81 ng/mg-creatinine/h, 95% confidence interval (CI), 9.49-14.71 vs. 14.83 ng/mg-creatinine/h, 95% CI, 11.72-18.75] and later peak onset (5.71 hours, 95% CI, 4.76-6.85 vs. 4.10 hours, 95% CI, 3.37-4.99), compared with day-shift workers. Furthermore, evening chronotypes' melatonin rhythms had later peak onset compared with morning types (4.90 hours, 95% CI, 3.94-6.09 vs. 3.64 hours, 95% CI, 2.99-4.43). However, among day-shift workers, morning chronotypes had melatonin rhythms with greater mean levels, larger peaks, and earlier peak onset compared with evening chronotypes; patterns were similar comparing evening versus morning chronotypes among rotating-shift workers on night shifts. The interaction of rotating-shift work and chronotype was significant across all parameters (P < 0.05). CONCLUSIONS: As expected, rotating-shift workers on night shifts had greater light exposure and lower urinary melatonin levels during the night compared with day-shift workers. Intriguingly, melatonin rhythms were dependent on both chronotype and rotating-shift work type, and better alignment of rotating-shift work and chronotype appeared to produce less disrupted melatonin rhythms. IMPACT: The joint effects of shift-work type and chronotype require attention in future studies.

Night Shift Work Before and During Pregnancy and Offspring Weight Outcomes Through Adolescence.

OBJECTIVE: This study aimed to investigate associations between maternal history of rotating night shift nursing work before pregnancy and number of night shifts worked during pregnancy with offspring weight outcomes from early life through adolescence. METHODS: More than 4,000 children, enrolled in the second phase of the Growing Up Today Study between 2004 and 2013, and their mothers participating in the Nurses' Health Study II were included in our analyses. RESULTS: Children of women with and without a history of rotating night shift work before pregnancy were similar in birth weight and body size at age 5. However, for mothers with night shift work before pregnancy, their children had a modestly elevated risk of having overweight or obesity (relative risk = 1.11; 95% CI: 1.02-1.21), which was stronger for persistently having overweight or obesity during adolescence and early adulthood. Longer duration of rotating night shift work was not associated with any of these weight outcomes. Weight outcomes of children of women with versus without night shift work during pregnancy were similar, regardless of frequency of night shifts worked during pregnancy (all P > 0.09). CONCLUSIONS: Overall, nurses' night shift work before or during pregnancy did not affect offspring weight outcomes. Future larger studies should explore these associations in more detail.

Photoperiod during maternal pregnancy and lifetime depression in offspring.

Experimental studies indicate that perinatal light exposure has enduring effects on affective behaviors in rodents; however, insufficient research has explored this hypothesis in humans. We examined photoperiod (i.e., day length) metrics during maternal pregnancy in relation to lifetime depression in the longitudinal Nurses' Health Study (NHS) and NHS II. 160,723 participants reported birth date and birth state (used to derive daily photoperiod based on published mathematical equations), and clinician-diagnosed depression and antidepressant use throughout adulthood. Logistic regression was used to estimate odds ratios (OR) (and 95% confidence intervals [CI]) for depression (defined as clinician diagnosis and antidepressant use) across quintiles of two exposures during maternal pregnancy: 1) total photoperiod (total number of daylight hours) and 2) differences between minimum/maximum photoperiod; each trimester of pregnancy was examined separately. Total photoperiod during maternal pregnancy was not associated with depression overall or by trimester of pregnancy. However, larger differences between minimum/maximum photoperiod during maternal pregnancy were related to lower odds of depression (multivariable [MV]-adjusted OR: 0.86, 95% CI: 0.83, 0.90 comparing extreme quintiles of exposure; p-trend<0.0001); this association appeared specific to the second trimester of pregnancy (MV-adjusted p-trends = 0.03, <0.0001, and 0.3 across the three trimesters, respectively). In addition, birth at higher latitude (where larger differences in minimum/maximum photoperiod exist) was associated with a significant reduction in the lifetime risk of depression. These findings are consistent with an emerging hypothesis in which perinatal light exposure may influence risk of depression, and they might be understood through the conceptual framework of adaptive developmental plasticity.

Rotating night shift work and colorectal cancer risk in the nurses' health studies.

Animal and human data have suggested that shift work involving circadian disruption may be carcinogenic for humans, but epidemiological evidence for colorectal cancer remains limited. We investigated the association of rotating night shift work and colorectal cancer risk in two prospective female cohorts, the Nurses' Health Study (NHS) and NHS2, with 24 years of follow-up. In total, 190,810 women (NHS = 77,439; NHS2 = 113,371) were included in this analysis, and 1,965 incident colorectal cancer cases (NHS = 1,527; NHS2 = 438) were reported during followup (NHS: 1988-2012, NHS2: 1989-2013). We used Cox proportional hazards models adjusted for a wide range of potential confounders. We did not observe an association between rotating night work duration and colorectal cancer risk in these cohorts (NHS: 1-14 years: Hazard Ratio (HR) 1.04, 95% CI: 0.94, 1.16; 15+ years: HR 1.15, 95% CI: 0.95, 1.39; Ptrend = 0.14 and NHS2: 1-14 years: HR 0.81, 95% CI: 0.66, 0.99; 15+ years: HR 0.96, 95% CI: 0.56, 1.64 and Ptrend = 0.88). In subsite analysis in NHS, rectal cancer risk increased after long-term (15+ years) rotating night shift work (proximal colon cancer: HR 1.00, 95% CI: 0.75, 1.34, Ptrend = 0.90; distal colon cancer: HR 1.27, 95% CI: 0.87, 1.85, Ptrend = 0.32; rectal cancer: HR 1.60, 95% CI: 1.09, 2.34, Ptrend = 0.02). We found no overall evidence of an association between rotating night shift work and colorectal cancer risk in these two large cohorts of nurses. Risk for rectal cancer significantly increased with shift work duration, suggesting that long-term circadian disruption may play a role in rectal cancer development.

Prospective study of chronotype and incident depression among middle- and older-aged women in the Nurses' Health Study II.

BACKGROUND: Prior cross-sectional studies have suggested that being a late chronotype is associated with depression and depressive symptoms, but prospective data are lacking. METHODS: We examined the association between chronotype and incident depression (defined as self-reported physician/clinician-diagnosed depression or antidepressant medication use) in 32,470 female participants of the Nurses' Health Study II cohort who self-reported their chronotype (early, intermediate or late) and were free of depression at baseline in 2009 (average age: 55 yrs). Women updated their depression status on biennial questionnaires in 2011 and 2013. We used multivariable (MV)-adjusted Cox proportional hazards models to estimate hazard ratios (HR) and 95% confidence intervals (95%CI) for incident depression across chronotype categories (i.e., early, intermediate, and late chronotypes). RESULTS: Across a follow-up period of 4 years, we observed 2,581 cases of incident depression in this cohort. Compared to intermediate chronotypes, early chronotypes had a modestly lower risk of depression after MV adjustment (MVHR = 0.88, 95%CI = 0.81-0.96), whereas late chronotypes had a similar risk of 1.06 (95%CI = 0.93-1.20); the overall trend across chronotype categories was statistically significant (ptrend<0.01). Results were similar when we restricted analyses to women who reported average sleep durations (7-8 h/day) and no history of rotating night shift work at baseline. CONCLUSIONS: Our results suggest that chronotype may influence the risk of depression in middle-to older-aged women. Additional studies are needed to confirm these findings and examine roles of both environmental and genetic factors to further our understanding of the role of chronotype in the etiology of mood disorders.

Patterns of late-life depressive symptoms and subsequent declines in cognitive domains.

BACKGROUND: Depression frequently co-occurs with cognitive decline, but the nature of this association is unclear. We examined relations of late-life depressive symptom patterns to subsequent domain-specific cognitive changes. METHODS: Depressive symptoms were measured at up to 3 timepoints among 11,675 Nurses' Health Study participants prior to cognitive testing. Depressive symptom patterns were categorized as non-depressed, variable or persistent, based on published severity cutpoints. Outcomes were global, verbal, and executive function-attention composite scores. RESULTS: Participants with persistent depressive symptoms had worse executive function-attention decline compared with non-depressed participants (multivariable-adjusted mean difference = -0.03 units/year, 95% CI: -0.05, -0.01; p = 0.003); this difference was comparable with 8 years of aging. However, being in the persistent versus non-depressed group was not significantly related to verbal (p = 0.71) or global score (p = 0.09) decline. By contrast, compared with the non-depressed group, those with variable depressive symptoms had worse verbal memory decline (multivariable-adjusted mean difference = -0.01 units/year, 95% CI: -0.02, -0.002; p = 0.03); this group showed no differences for global or executive function-attention decline. CONCLUSIONS: A variable pattern of depressive symptom severity related to subsequent decline in verbal memory, while a persistent pattern related to decline in executive function-attention. Findings could signal differences in underlying neuropathologic processes among persons with differing depression patterns and late-life cognitive decline. Copyright © 2016 John Wiley & Sons, Ltd.

Prediction of Long-term Cognitive Decline Following Postoperative Delirium in Older Adults.

BACKGROUND: Increasing evidence suggests that postoperative delirium may result in long-term cognitive decline among older adults. Risk factors for such cognitive decline are unknown. METHODS: We studied 126 older participants without delirium or dementia upon entering the Successful AGing After Elective Surgery (SAGES) study, who developed postoperative delirium and completed repeated cognitive assessments (up to 36 months of follow-up). Pre-surgical factors were assessed preoperatively and divided into nine groupings of related factors ("domains"). Delirium was evaluated at baseline and daily during hospitalization using the Confusion Assessment Method diagnostic algorithm, and cognitive function was assessed using a neuropsychological battery and the Informant Questionnaire for Cognitive Decline in the Elderly (IQCODE) at baseline and 6-month intervals over 3 years. Linear regression was used to examine associations between potential risk factors and rate of long-term cognitive decline over time. A domain-specific and then overall selection method based on adjusted R2 values was used to identify explanatory factors for the outcome. RESULTS: The General Cognitive Performance (GCP) score (combining all neuropsychological test scores), IQCODE score, and living alone were significantly associated with long-term cognitive decline. GCP score explained the most variation in rate of cognitive decline (13%), and six additional factors-IQCODE score, cognitive independent activities of daily living impairment, living alone, cerebrovascular disease, Charlson comorbidity index score, and exhaustion level-in combination explained 32% of variation in this outcome. CONCLUSIONS: Global cognitive performance was most strongly associated with long-term cognitive decline following delirium. Pre-surgical factors may substantially predict this outcome.

Urinary Melatonin in Relation to Postmenopausal Breast Cancer Risk According to Melatonin 1 Receptor Status.

Background: Urinary melatonin levels have been associated with a reduced risk of breast cancer in postmenopausal women, but this association might vary according to tumor melatonin 1 receptor (MT1R) expression.Methods: We conducted a nested case-control study among 1,354 postmenopausal women in the Nurses' Health Study, who were cancer free when they provided first-morning spot urine samples in 2000 to 2002; urine samples were assayed for 6-sulfatoxymelatonin (aMT6s, a major metabolite of melatonin). Five-hundred fifty-five of these women developed breast cancer before May 31, 2012, and were matched to 799 control subjects. In a subset of cases, immunohistochemistry was used to determine MT1R status of tumor tissue. We used multivariable-adjusted conditional logistic regression to estimate the relative risk (RR) of breast cancer [with 95% confidence intervals (CI)] across quartiles of creatinine-standardized urinary aMT6s level, including by MT1R subtype.Results: Higher urinary melatonin levels were suggestively associated with a lower overall risk of breast cancer (multivariable-adjusted RR = 0.78; 95% CI = 0.61-0.99, comparing quartile 4 vs. quartile 1; Ptrend = 0.08); this association was similar for invasive vs. in situ tumors (Pheterogeneity = 0.12). There was no evidence that associations differed according to MT1R status of the tumor (e.g., Pheterogeneity for overall breast cancer = 0.88).Conclusions: Higher urinary melatonin levels were associated with reduced breast cancer risk in this cohort of postmenopausal women, and the association was not modified by MT1R subtype.Impact: Urinary melatonin levels appear to predict the risk of breast cancer in postmenopausal women. However, future research should evaluate these associations with longer-term follow-up and among premenopausal women. Cancer Epidemiol Biomarkers Prev; 26(3); 413-9. ©2016 AACR.

Rotating night shift work, sleep, and colorectal adenoma in women.

PURPOSE: This study aims to investigate the associations of rotating night shift work history and sleep duration with risk of colorectal adenoma. METHODS: We evaluated 56,275 cancer-free participants of the Nurses' Health Study II, who had their first colonoscopy or sigmoidoscopy between 1991 and 2011; rotating night shift work and sleep duration were reported by mailed questionnaire. Multivariable-adjusted logistic regression was used to estimate relative risks (RR) of colorectal adenoma, with 95% confidence intervals (CI), across categories of rotating night shift work history (none, 1-4, 5-9, and ≥10 years) and sleep duration (≤5, 6, 7, 8, and ≥9 h/day). RESULTS: We found no association between duration of rotating night shift work and occurrence of colorectal adenoma (p-trend across shift work categories = 0.5). Women with the longest durations of rotating night shift work (≥10 years) had a similar risk of adenoma compared to women without a history of rotating night shift work (multivariable-adjusted RR = 0.96, 95% CI = 0.83-1.11). Similarly, there were no associations of shorter or longer sleep durations with adenoma risk (p-trend = 0.2 across sleep durations of ≤5 through 7 h/day and p-trend = 0.5 across sleep durations of 7 through ≥9 h/day). Results were similar when we examined associations according to adenoma location and subtype. CONCLUSIONS: Our results do not support an association between rotating night shift work or sleep duration and risk of colorectal adenoma in women.

Association of urinary melatonin levels and aging-related outcomes in older men.

BACKGROUND: Circadian disruptions can contribute to accelerated aging, and the circadian system regulates cognitive and physical functions; therefore, circadian markers (eg, melatonin) may be associated with key aspects of healthy aging and longevity. OBJECTIVE: To evaluate urinary melatonin levels in relation to cognitive function, physical function, and mortality among 2,821 older men in the Osteoporotic Fractures in Men Study DESIGN: Cohort study. MEASUREMENTS: In 2003-2005, participants provided first-morning spot urine samples, which were assayed for 6-sulfatoxymelatonin (the primary melatonin metabolite in urine); cognitive and physical function assessments were completed twice, at baseline and an average of 6.5 years later. Participant deaths were confirmed by central review of death certificates over a mean of 9.2 years of follow up. RESULTS: In multivariable-adjusted regression models, we observed a significant trend of better Digit Vigilance Test scores (ie, decreased time to completion) at baseline across increasing melatonin quartiles (p-trend = 0.01); however, mean time-to-completion scores did not significantly differ comparing extreme quartiles (group means: 547.1 seconds (95% CI: 533.6, 560.6) versus 561.3 seconds (95% CI: 547.8, 574.9)), and there were no associations of urinary melatonin levels with other cognitive test scores, or any cognitive change scores over time. Furthermore, melatonin levels were not related to physical function scores (p-trends = 0.4 for walking speed, 0.7 for chair stands, and 0.6 for grip strength in fully-adjusted models) or mortality risk (p-trend = 0.3 in the fully-adjusted model). CONCLUSION: We found little evidence of associations between urinary melatonin levels and key measures of healthy aging and mortality in this cohort of older men. Further research should explore the relation of melatonin, particularly if assessed earlier in life, and other circadian markers with healthy aging outcomes.

Association Between Rotating Night Shift Work and Risk of Coronary Heart Disease Among Women.

IMPORTANCE: Prospective studies linking shift work to coronary heart disease (CHD) have been inconsistent and limited by short follow-up. OBJECTIVE: To determine whether rotating night shift work is associated with CHD risk. DESIGN, SETTING, AND PARTICIPANTS: Prospective cohort study of 189,158 initially healthy women followed up over 24 years in the Nurses' Health Studies (NHS [1988-2012]: N = 73,623 and NHS2 [1989-2013]: N = 115,535). EXPOSURES: Lifetime history of rotating night shift work (≥3 night shifts per month in addition to day and evening shifts) at baseline (updated every 2 to 4 years in the NHS2). MAIN OUTCOMES AND MEASURES: Incident CHD; ie, nonfatal myocardial infarction, CHD death, angiogram-confirmed angina pectoris, coronary artery bypass graft surgery, stents, and angioplasty. RESULTS: During follow-up, 7303 incident CHD cases occurred in the NHS (mean age at baseline, 54.5 years) and 3519 in the NHS2 (mean age, 34.8 years). In multivariable-adjusted Cox proportional hazards models, increasing years of baseline rotating night shift work was associated with significantly higher CHD risk in both cohorts. In the NHS, the association between duration of shift work and CHD was stronger in the first half of follow-up than in the second half (P=.02 for interaction), suggesting waning risk after cessation of shift work. Longer time since quitting shift work was associated with decreased CHD risk among ever shift workers in the NHS2 (P<.001 for trend). [table: see text] CONCLUSIONS AND RELEVANCE: Among women who worked as registered nurses, longer duration of rotating night shift work was associated with a statistically significant but small absolute increase in CHD risk. Further research is needed to explore whether the association is related to specific work hours and individual characteristics.

Sleep Duration in Relation to Cognitive Function among Older Adults: A Systematic Review of Observational Studies.

CONTEXT: Increasing evidence suggests that circadian and sleep parameters influence cognitive function with aging. OBJECTIVE: To evaluate observational studies of sleep duration and cognition in older adults. DATA SOURCES: A systematic review of OVID Medline and PsycINFO through September 2015, and review of bibliographies from studies identified. STUDY SELECTION: English-language articles reporting observational studies of sleep duration and cognitive function in older populations. DATA EXTRACTION: Data extraction by 2 authors using predefined categories of desired information. RESULTS: Thirty-two studies met our inclusion criteria, with nearly two-thirds published in the past 4 years. One-third of studies indicated that extreme sleep durations were associated with worse cognition in older adults. More studies favored an association with long vs. short sleep durations (35 vs. 26% of studies, respectively). Four studies found that greater changes in sleep duration over time were related to lower cognition. Study design and analytic methods were very heterogeneous across studies; therefore, meta-analysis was not undertaken. LIMITATIONS: We reviewed English-language manuscripts only, with a qualitative summary of studies identified. CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS: Observational studies of sleep duration and cognitive function in older adults have produced mixed results, with more studies suggesting that long (rather than short) sleep durations are related to worse cognition. Studies more consistently indicate that greater changes in sleep duration are associated with poor cognition. Future studies should be prospectively designed, with objective sleep assessment and longer follow-up periods; intervention studies are also needed to identify strategies for promoting cognitive health with aging.

Mismatch of Sleep and Work Timing and Risk of Type 2 Diabetes.

OBJECTIVE: To examine whether a mismatch between chronotype (i.e., preferred sleep timing) and work schedule is associated with type 2 diabetes risk. RESEARCH DESIGN AND METHODS: In the Nurses' Health Study 2, we followed 64,615 women from 2005 to 2011. Newly developed type 2 diabetes was the outcome measure (n = 1,452). A question on diurnal preference ascertained chronotype in 2009; rotating night shift work exposure was assessed regularly since 1989. RESULTS: Compared with intermediate chronotypes, early chronotypes had a slightly decreased diabetes risk after multivariable adjustment (odds ratio 0.87 [95% CI 0.77-0.98]), whereas no significant association was observed for late chronotypes (1.04 [0.89-1.21]). Among early chronotypes, risk of type 2 diabetes was modestly reduced when working daytime schedules (0.81 [0.63-1.04]) and remained similarly reduced in women working <10 years of rotating night shifts (0.84 [0.72-0.98]). After ≥10 years of shift work exposure, early chronotypes had a nonsignificant elevated diabetes risk (1.15 [0.81-1.63], Ptrend = 0.014). By contrast, among late chronotypes, the significantly increased diabetes risk observed among day workers (1.51 [1.13-2.02]) appeared largely attenuated if their work schedules included night shifts (<10 years: 0.93 [0.76-1.13]; ≥10 years: 0.87 [0.56-1.34]; Ptrend = 0.14). The interaction between chronotype and shift work exposure was significant (Pinteraction = 0.0004). Analyses restricting to incident cases revealed similar patterns. CONCLUSIONS: In early chronotypes, type 2 diabetes risk increased with increasing duration of shift work exposure, whereas late types had the highest diabetes risk working daytime schedules. These data add to the growing body of evidence that workers could benefit from shift schedules minimizing interference with chronotype-dependent sleep timing.

The association of body size in early to mid-life with adult urinary 6-sulfatoxymelatonin levels among night shift health care workers.

BACKGROUND: Adult body mass index (BMI) has been associated with urinary melatonin levels in humans; however, whether earlier-life body size is associated with melatonin, particularly among night shift workers, remains unknown. METHODS: We evaluated associations of birth weight, body shape (or somatotype) at ages 5 and 10, BMI at age 18 and adulthood, weight change since age 18, waist circumference, waist to hip ratio, and height with creatinine-adjusted morning urinary melatonin (6-sulfatoxymelatonin, aMT6s) levels among 1,343 healthy women (aged 32-53 at urine collection, 1996-1999) in the Nurses' Health Study (NHS) II cohort. Using multivariable linear regression, we computed least-square mean aMT6s levels across categories of body size, and evaluated whether these associations were modified by night shift work. RESULTS: Adult BMI was inversely associated with aMT6s levels (mean aMT6s levels = 34 vs. 50 ng/mg creatinine, comparing adult BMI ≥ 30 vs. <20 kg/m(2); P trend < 0.0001); however, other measures of body size were not related to aMT6s levels after accounting for adult BMI. Night shifts worked prior to urine collection, whether recent or cumulatively over time, did not modify the association between adult BMI and aMT6s levels (e.g., P interaction = 0.72 for night shifts worked within two weeks of urine collection). CONCLUSIONS: Our results suggest that adult BMI, but not earlier measures of body size, is associated with urinary aMT6s levels in adulthood. These observations did not vary by night shift work status, and suggest that adult BMI may be an important mechanism by which melatonin levels are altered and subsequently influence chronic disease risk.

Antihypertensive medication use and incident breast cancer in women.

The purpose of this study was to evaluate whether antihypertensive medication use, including long-term use, is associated with increased breast cancer incidence in women. We studied 210,641 U.S. registered nurses participating in the Nurses' Health Study (NHS) and Nurses' Health Study II (NHS II). Information on antihypertensive medication use was collected on biennial questionnaires in both cohorts, and breast cancer cases were ascertained during this period. Multivariable-adjusted Cox proportional hazard models were used to estimate relative risks of invasive breast cancer over follow-up (1988-2012 in NHS, 1989-2011 in NHS II) across categories of overall antihypertensive medication use and use of specific classes (diuretics, beta blockers, calcium channel blockers, and angiotensin-converting enzyme inhibitors). During follow-up, 10,012 cases of invasive breast cancer developed (6718 cases in NHS and 3294 in the NHS II). Overall, current use of any antihypertensive medication was not associated with breast cancer risk compared with past/never use in NHS (multivariable-adjusted relative risk = 1.00, 95 % CI = 0.95-1.06) or NHS II (multivariable-adjusted relative risk = 0.94, 95 % CI = 0.86-1.03). Furthermore, no specific class of antihypertensive medication was consistently associated with breast cancer risk. Results were similar when we considered hypertensive women only, and when we evaluated consistency and duration of medication use over time. Overall, antihypertensive medication use was largely unrelated to the risk of invasive breast cancer among women in the NHS cohorts.

Night shift work at specific age ranges and chronic disease risk factors.

OBJECTIVES: We examined the association of night shift work history and age when night shift work was performed with cancer and cardiovascular disease risk factors among 54 724 women in the Nurses' Health Study (NHS) II. METHODS: We calculated age-adjusted and socioeconomic status-adjusted means and percentages for cancer and cardiovascular risk factors in 2009 across categories of night shift work history. We used multivariable-adjusted logistic regression to estimate odds ratios (ORs) and 95% CIs for key risk factors among 54 724 participants (72% ever shift workers). We further examined these associations by age (20-25, 26-35, 36-45 and 46+ years) at which shift work was performed. RESULTS: Ever night shift workers had increased odds of obesity (body mass index ≥30 kg/m(2); OR=1.37, 95% CI 1.31 to 1.43); higher caffeine intake (≥131 mg/day; OR=1.16, 95% CI 1.12 to 1.22) and total calorie intake (≥1715 kcal/day; OR=1.09, 95% CI 1.04 to 1.13); current smoking (OR=1.30, 95% CI 1.19 to 1.42); and shorter sleep durations (≤7 h of sleep/day; OR=1.19, 95% CI 1.15 to 1.24) compared to never night shift workers. These estimates varied depending on age at which night work was performed, with a suggestion that night shift work before age 25 was associated with fewer risk factors compared to night shift work at older ages. CONCLUSIONS: Our results indicate that night shift work may contribute to an adverse chronic disease risk profile, and that risk factors may vary depending on the age at which night shift work was performed.