Additional file 1: Table S1. of Relationship between sleep characteristics and measures of body size and composition in a nationally-representative sample

Questions on sleep habits and sleep disorders in the sleep disorder questionnaire, NHANES 2005–2006. Table S2. Population distribution by sleep characteristic in the analytic sample, NHANES 2005–2006. Table S3. Spearman correlation coefficient a among sleep variables, NHANES 2005–2006. Table S4. Spearman correlation coefficient a among measurements of adiposity, by sex, NHANES 2005–2006. Table S5. Study participant characteristics by snoring, NHANES 2005–2006. Table S6. Study participant characteristics by sleep quality, NHANES 2005–2006. Table S7. Multivariate a associations between sleep characteristics and measurements of adiposity in men, NHANES 2005–2006. (DOCX 51 kb

Time to First Morning Cigarette and Risk of Chronic Obstructive Pulmonary Disease: Smokers in the PLCO Cancer Screening Trial

<div><p>Background</p><p>Time to first cigarette (TTFC) after waking is an indicator of nicotine dependence. The association between TTFC and chronic obstructive pulmonary disease (COPD), the third leading cause of death in the United States, has not yet been reported.</p><p>Methods</p><p>We investigated the cross-sectional association between TTFC and prevalent COPD among 6,108 current smokers in the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial. COPD was defined as a self-reported diagnosis of emphysema, chronic bronchitis, or both. Current smokers in PLCO reported TTFC, the amount of time they typically waited before smoking their first cigarette of the day after waking, in four categories: ≤5, 6-30, 31-60, or >60 minutes. We used logistic regression models to investigate the association between TTFC and prevalent COPD with adjustments for age, gender, race, education, and smoking (cigarettes/day, years smoked during lifetime, pack-years, age at smoking initiation), and prior lung cancer diagnosis.</p><p>Results</p><p>COPD was reported by 19% of these 6,108 smokers. Individuals with the shortest TTFC had the greatest risk of COPD; compared to those with the longest TTFC (>60 minutes) the adjusted odds ratios (OR) and 95% confidence intervals (CI) for COPD were 1.48 (95% CI, 1.15-1.91), 1.64 (95% CI, 1.29-2.08), 2.18 (95% CI, 1.65-2.87) for those with TTFC 31-60 minutes, 6-30 minutes, and ≤5 minutes, respectively (P-trend <0.0001). The association between TTFC and emphysema was similar to that for bronchitis, albeit the ORs were slightly stronger for chronic bronchitis; comparing TTFC ≤5 minutes to >60 minutes, the adjusted OR (95% CI) was 2.29 (1.69-3.12) for emphysema and 2.99 (1.95-4.59) for chronic bronchitis.</p><p>Conclusions</p><p>Current smokers with shorter TTFC have increased risk of COPD compared to those with longer TTFC, even after comprehensive adjustment for established smoking covariates. Future epidemiologic studies, including prospective designs, should incorporate TTFC to better assess disease risk and evaluate the potential utility of TTFC as a COPD screening tool for smokers in the clinical setting.</p></div

Sleep Duration and Cancer in the NIH-AARP Diet and Health Study Cohort

<div><p>Background</p><p>Very few studies have examined sleep duration in relation to cancer incidence with the exception of breast cancer.</p><p>Methods</p><p>We assessed the associations between sleep duration and incidences of total and 18 site-specific cancers in the NIH-AARP Health and Diet Study cohort, with 173,327 men and 123,858 women aged 51–72 years at baseline. Self-reported sleep duration categories were assessed via questionnaire. We used multivariable Cox proportional hazards regression to estimate hazard ratios (HR) and 95% confidence intervals (CI), using 7–8 hours/night as the reference.</p><p>Results</p><p>We observed a significantly increased risk of stomach cancer among male short sleepers (multivariable HR_{5-6 vs. 7–8 hours} = 1.29; 95%CI: 1.05, 1.59; <i>P</i>_trend = 0.03). We also observed suggestive associations in either short or long sleepers, which did not reach overall significance (<i>P</i>_trend >0.05), including increased risks in male short sleepers for cancers of head and neck (HR_{<5vs.7-8 hours} = 1.39; 95%CI:1.00–1.95), bladder (HR_{5-6vs.7-8 hours} = 1.10; 95%CI:1.00–1.20), thyroid (HR_{<5 vs. 7–8 hours} = 2.30; 95%CI:1.06, 5.02), Non-Hodgkin Lymphoma (NHL) (HR_{5-6vs.7-8 hours} = 1.17; 95%CI:1.02–1.33), and myeloma (HR_{<5vs.7-8 hours} = 2.06; 95%CI:1.20–3.51). In women, the suggestive associations include a decreased total cancer risk (HR_{<5vs.7-8 hours} = 0.9; 95%CI:0.83–0.99) and breast cancer risk (HR_{<5vs.7-8 hours} = 0.84; 95%CI:0.71–0.98) among short sleepers. A decreased ovarian cancer risk (HR_{≥ 9 vs. 7–8 hours} = 0.50; 95%CI:0.26–0.97) and an increased NHL risk (HR_{≥ 9 vs. 7–8 hours} = 1.45; 95%CI:1.00–2.11) were observed among long sleepers.</p><p>Conclusion</p><p>In an older population, we observed an increased stomach cancer risk in male short sleepers and suggestive associations with short or long sleep duration for many cancer risks in both genders.</p></div

Adjusted Odds Ratio for COPD according to Time to First Cigarette (TTFC) among current smokers in PLCO.

<p>COPD cases responded affirmatively to question(s) regarding diagnosis of emphysema (on study baseline questionnaire, follow-up questionnaire in 2006, or both), chronic bronchitis (on study baseline questionnaire), or both. ORs and 95% CIs were determined using logistic regression with adjustments for age, gender (except in gender-stratified analyses), race, education, cigarettes/day, years smoked during lifetime, pack-years, age at smoking initiation, and lung cancer diagnosis prior to follow-up questionnaire. TTFC was categorical (>60 minutes as reference) with the exception of P-trend assessment where TTFC was treated as an ordinal variable.</p><p>PLCO, Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial. P-value for interaction between TTFC*gender interaction term. Significant P-values (P<0.05) in bold.</p><p>^a N = 6,106; 2 participants were excluded due to missing data on emphysema endpoint.</p><p>^b N = 6,070; 38 participants were excluded due to missing data on bronchitis endpoint.</p><p>Adjusted Odds Ratio for COPD according to Time to First Cigarette (TTFC) among current smokers in PLCO.</p

Association between night time sleep duration and cancer incidence in women.

<p>Association between night time sleep duration and cancer incidence in women.</p

Characteristics of Current Smokers in the PLCO Study, by COPD Status.

<p>COPD cases responded affirmatively to question(s) regarding diagnosis of emphysema (on study baseline questionnaire, follow-up questionnaire in 2006, or both), chronic bronchitis (on study baseline questionnaire), or both. Baseline data were substituted for missing follow-up questionnaire data for the following variables (number of participants) for race (218), age at smoking initiation (108), pack-years (299), cigarettes per day (65), smoking duration (262). PLCO, Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial. Some values do not sum to 100 due to missing data.</p><p>^a Report prior to PLCO follow-up questionnaire in 2006</p><p>^b Self-report of emphysema and chronic bronchitis was not mutually exclusive; 201 participants reported a diagnosis of both emphysema and chronic bronchitis, thus the sum of reports of emphysema and chronic bronchitis are greater than the total 1,136 COPD cases.</p><p>Characteristics of Current Smokers in the PLCO Study, by COPD Status.</p

Time to first cigarette (TTFC) upon waking and risk of chronic obstructive pulmonary disease (COPD) among current smokers.

<p>Odds Ratios for each category of TTFC (≤5, 6–30, and 31–60 minutes, compared to the reference group of smokers with TTFC >60 minutes) were calculated by logistic regression, adjusted for age, gender (except in gender-stratified analyses), race, education, cigarettes/day, years smoked during lifetime, pack-years, age at smoking initiation, and lung cancer diagnosis prior to follow-up questionnaire. (A) OR for COPD, emphysema, and chronic bronchitis. (B) OR for COPD by age at smoking initiation. (C) OR for COPD by typical number of cigarettes smoked per day. (D) OR for COPD by pack-years. (E) OR for COPD by total smoking duration in years. Categories of smoking covariates were collapsed for visual representation of results; refer to <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0125973#pone.0125973.t002" target="_blank">Table 2</a> for further details.</p