Dataset Information

Bedtime Variability and Metabolic Health in Midlife Women: The SWAN Sleep Study.

ABSTRACT:

Study objectives

Circadian misalignment, as seen in shift workers, can disrupt metabolic processes. Associations between sleep timing in nonshift workers and metabolic health are unknown. We examined sleep timing and indices of metabolic health in a community sample of midlife women.

Methods

Caucasian (n = 161), African American (n = 121) and Chinese (n = 56) non-shift-working women aged 48-58 y who were not taking insulin-related medications, participated in the Study of Women's Health Across the Nation (SWAN) Sleep Study and were subsequently examined approximately 5.39 (standard deviation = 0.71) y later. Daily diary-reported bedtimes were used to calculate four measures of sleep timing: mean bedtime, bedtime variability, bedtime delay and bedtime advance. Body mass index (BMI) and insulin resistance (homeostatic model assessment-insulin resistance, HOMA-IR) were measured at two time points. Linear regressions evaluated whether sleep timing was associated with BMI and HOMA-IR cross-sectionally and prospectively.

Results

In cross-sectional models, greater variability in bedtime and greater bedtime delay were associated with higher HOMA-IR (? = 0.128; P = 0.007, and ? = 0.110; P = 0.013, respectively) and greater bedtime advance was associated with higher BMI (? = 0.095; P = 0.047). Prospectively, greater bedtime delay predicted increased HOMA-IR at Time 2 (? = 0.152; P = 0.003). Results were partially explained by shifted sleep timing on weekends.

Conclusion

Frequent shifts in sleep timing may be related to metabolic health among non-shift working midlife women.

Commentary

A commentary on this article appears in this issue on page 269.

SUBMITTER: Taylor BJ

PROVIDER: S-EPMC4712396 | biostudies-literature | 2016 Feb

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Bedtime Variability and Metabolic Health in Midlife Women: The SWAN Sleep Study.

Taylor Briana J BJ Matthews Karen A KA Hasler Brant P BP Roecklein Kathryn A KA Kline Christopher E CE Buysse Daniel J DJ Kravitz Howard M HM Tiani Alaina G AG Harlow Sioban D SD Hall Martica H MH

Sleep 20160201 2

<h4>Study objectives</h4>Circadian misalignment, as seen in shift workers, can disrupt metabolic processes. Associations between sleep timing in nonshift workers and metabolic health are unknown. We examined sleep timing and indices of metabolic health in a community sample of midlife women.<h4>Methods</h4>Caucasian (n = 161), African American (n = 121) and Chinese (n = 56) non-shift-working women aged 48-58 y who were not taking insulin-related medications, participated in the Study of Women's ...[more]

PMID: 27091639

Similar Datasets

Project description:ObjectiveTo examine the effects of prescription sleep medications on patient-reported sleep disturbances.DesignRetrospective cohort.SettingLongitudinal cohort of community-dwelling women in the USA.ParticipantsRacially and ethnically diverse middle-aged women who reported a sleep disturbance.InterventionsNew users of prescription sleep medications propensity score matched to women not starting sleep medications.Main outcomes and measuresSelf-reported sleep disturbance during the previous 2 weeks-difficulty initiating sleep, waking frequently and early morning awakening-using a 5-point Likert scale, ranging from no difficulty on any night (rating 1) to difficulty on 5 or more nights a week (rating 5). Sleep disturbances were compared at 1 year (primary outcome) and 2 years of follow-up.Results238 women who started sleep medications were matched with 447 non-users. Participants had a mean age of 49.5 years and approximately half were white. At baseline, sleep disturbance ratings were similar: medication users had a mean score for difficulty initiating sleep of 2.7 (95% CI 2.5 to 2.9), waking frequently 3.8 (95% CI 3.6 to 3.9) and early morning awakening 2.8 (95% CI 2.6 to 3.0); non-users ratings were 2.6 (95% CI 2.5 to 2.7), 3.7 (95% CI 3.6 to 3.9) and 2.7 (95% CI 2.6 to 2.8), respectively. After 1 year, ratings for medication users were 2.6 (95% CI 2.4 to 2.8) for initiating sleep, 3.6 (95% CI 3.4 to 3.8) for waking frequently and 2.8 (95% CI 2.6 to 3.0) for early morning awakening; for non-users, the mean ratings were 2.3 (95% CI 2.2 to 2.5), 3.5 (95% CI 3.3 to 3.6) and 2.5 (95% CI 2.3 to 2.6), respectively. None of the 1 year changes were statistically significant nor were they different between medication users and non-users. Two-year follow-up results were consistent, without statistically significant reductions in sleep disturbance in medication users compared with non-users.ConclusionsThese analyses suggest that women who initiated sleep medications rated their sleep disturbances similar after 1 and 2 years. The effectiveness of long-term sleep medication use should be re-examined.

Project description:BACKGROUND:Little is known about the extent of exposure to metals and metal mixtures among midlife women. OBJECTIVES:We assessed exposure to multiple metals in the Study of Women's Health Across the Nation (SWAN), a multi-site, multi-racial/ethnic cohort of women at midlife. METHODS:We measured urinary concentrations of 21 metals (arsenic, barium, beryllium, cadmium, cobalt, chromium, cesium, copper, mercury, manganese, molybdenum, nickel, lead, platinum, antimony, tin, thallium, uranium, vanadium, tungsten and zinc) using high-resolution inductively coupled plasma-mass spectrometry among 1335 white, black, Chinese and Japanese women aged 45-56?years?at the third SWAN annual visit (1999-2000). Least squared geometric mean concentrations were compared across race/ethnicity, education, financial hardship, smoking, secondhand smoking, seafood intake and rice intake groups. Overall exposure patterns of multiple metals were derived using k-means clustering method. RESULTS:The percentage of women with detectable concentrations of metals ranged from 100% for arsenic, cesium, molybdenum and zinc, to less than 5% for platinum; 15 metals had detection rates of 70% or more. Asian women, both Chinese and Japanese, had higher urinary concentrations of arsenic, cadmium, copper, mercury, molybdenum, lead and thallium, compared with other race/ethnic groups, independent of sociodemographic, lifestyle, dietary, and geographic characteristics. Seafood and rice intake were important determinants of urinary arsenic, cesium, mercury, molybdenum and lead levels. Two distinct overall exposure patterns- "high" vs. "low" -- were identified. Women in the "high" overall exposure pattern were more likely to be Asians, current smokers, and to report high consumption of seafood and rice. Black women were less likely to have the high exposure pattern. CONCLUSIONS:Metal exposure of midlife women differs by racial/ethnic, sociodemographic, lifestyle, dietary, and geographic characteristics. Asian women may be experiencing the highest exposures to multiple metals compared with other racial/ethnic groups in the United States.

Project description:Aims/hypothesisDiabetogenic effects of per- and polyfluoroalkyl substances (PFAS) have been suggested. However, evidence based on prospective cohort studies is limited. We examined the association between serum PFAS concentrations and incident diabetes in the Study of Women's Health Across the Nation Multi-Pollutant Study (SWAN-MPS).MethodsWe included 1237 diabetes-free women aged 45-56 years at baseline (1999-2000) who were followed up to 2017. At each follow-up visit, women with incident diabetes were identified by the presence of one or more of the following conditions: (1) use of a glucose-lowering medication at any visit; (2) fasting glucose ≥7 mmol/l on two consecutive visits while not on steroids; and (3) any two visits with self-reported diabetes and at least one visit with fasting blood glucose ≥7 mmol/l. Serum concentrations of 11 PFAS were quantified by online solid-phase extraction-HPLC-isotope dilution-tandem MS. Seven PFAS with high detection rates (>96%) (n-perfluorooctanoic acid [n-PFOA], perfluorononanoic acid [PFNA], perfluorohexane sulfonic acid [PFHxS], n-perfluorooctane sulfonic acid [n-PFOS], sum of perfluoromethylheptane sulfonic acid isomers [Sm-PFOS], 2-[N-methyl-perfluorooctane sulfonamido] acetic acid [MeFOSAA] and 2-[N-ethyl-perfluorooctane sulfonamido] acetic acid) were included in data analysis. Cox proportional hazards models were used to compute HRs and 95% CIs. Quantile-based g-computation was used to evaluate the joint effects of PFAS mixtures.ResultsAfter adjustment for race/ethnicity, site, education, smoking status, alcohol consumption, total energy intake, physical activity, menopausal status and BMI, the HR (95% CI) comparing the lowest with the highest tertile was 1.67 (1.21, 2.31) for n-PFOA (ptrend = 0.001), 1.58 (1.13, 2.21) for PFHxS (ptrend = 0.003), 1.36 (0.97, 1.90) for Sm-PFOS (ptrend = 0.05), 1.85 (1.28, 2.67) for MeFOSAA (ptrend = 0.0004) and 1.64 (1.17, 2.31) for the sum of four common PFAS (n-PFOA, PFNA, PFHxS and total PFOS) (ptrend = 0.002). Exposure to seven PFAS as mixtures was associated with an HR of 2.62 (95% CI 1.12, 6.20), comparing the top with the bottom tertiles for all seven PFAS.Conclusions/interpretationThis study suggests that PFAS may increase diabetes risk in midlife women. Reduced exposure to these 'forever and everywhere chemicals' may be an important preventative approach to lowering population-wide diabetes risk.

Dataset Information

Bedtime Variability and Metabolic Health in Midlife Women: The SWAN Sleep Study.

Study objectives

Methods

Results

Conclusion

Commentary

Publications

Bedtime Variability and Metabolic Health in Midlife Women: The SWAN Sleep Study.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets