Radon decay product particle radioactivity and oxidative stress biomarkers in patients with COPD.

Radon decay products include α-radiation emitting radionuclides that attach to airborne particles that have potential to promote oxidative tissue damage after inhalation. To assess associations between α-particle radioactivity (α-PR) with urinary biomarkers of oxidative tissue damage, 140 patients with chronic obstructive pulmonary disease (COPD) had up to four 1-week seasonal assessments (N = 413) of indoor (home) and ambient (central site) PM2.5 and black carbon (BC). Following environmental sampling, urine samples were analyzed for total and free malondialdehyde (MDA), biomarkers of lipid oxidation, and 8-hydroxyl-2'-deoxyguanosine (8-OHdG), a biomarker of DNA oxidative damage. Particle radioactivity was measured as α-activity on PM2.5 filter samples. Linear mixed-effects regression models adjusted for urinary creatinine and other personal characteristics were used to assess associations. Indoor α-PR was associated with an increase in 8-OhdG (8.53%; 95% CI: 3.12, 14.23); total MDA (5.59%; 95% CI: 0.20, 11.71); and free MDA (2.17%; 95% CI: 2.75, 7.35) per interquartile range (IQR) of α-PR [median 1.25 mBq/m3; IQR 0.64], similar adjusting for PM2.5 or BC. The ratio of indoor/ambient α-PR was positively associated with each biomarker and associations with ambient α-PR were positive but weaker than with indoor concentrations. These findings are consistent with a contribution of radon decay products as measured by α-PR to oxidative stress in patients with COPD, with a greater contribution of indoor radon decay products.

Prediagnosis Smoking Cessation and Overall Survival Among Patients With Non-Small Cell Lung Cancer.

Importance: Lung cancer remains the leading cause of cancer-related death globally; non-small cell lung cancer (NSCLC) accounts for 85% of all lung cancer cases, and cigarette smoking is the factor most significantly associated with its risk. However, little is known about the association of years since prediagnosis smoking cessation and cumulative smoking with overall survival (OS) following a lung cancer diagnosis. Objective: To characterize the association of years since smoking cessation before diagnosis and cumulative smoking pack-years with OS in patients with NSCLC in a lung cancer survivor cohort. Design, Setting, and Participants: The cohort study involved patients with NSCLC who were recruited to the Boston Lung Cancer Survival Cohort at Massachusetts General Hospital (Boston, Massachusetts) between 1992 and 2022. Patients' smoking history and baseline clinicopathological characteristics were prospectively collected through questionnaires, and OS following lung cancer diagnosis was regularly updated. Exposures: Duration of smoking cessation before a lung cancer diagnosis. Main Outcomes and Measures: The primary outcome was the association of detailed smoking history with OS following a lung cancer diagnosis. Results: Of 5594 patients with NSCLC (mean [SD] age, 65.6 [10.8] years; 2987 men [53.4%]), 795 (14.2%) were never smokers, 3308 (59.1%) were former smokers, and 1491 (26.7%) were current smokers. Cox regression analysis suggested that former smokers had 26% higher mortality (hazard ratio [HR], 1.26; 95% CI, 1.13-1.40; P < .001) and current smokers had 68% higher mortality (HR, 1.68; 95% CI, 1.50-1.89; P < .001) compared with never smokers. Log2-transformed years since smoking cessation before diagnosis were associated with significantly lower mortality among ever smokers (HR, 0.96; 95% CI, 0.93-0.99; P = .003). Subgroup analysis, stratified by clinical stage at diagnosis, revealed that former and current smokers had even shorter OS among patients with early-stage disease. Conclusions and Relevance: In this cohort study of patients with NSCLC, quitting smoking early was associated with lower mortality following a lung cancer diagnosis, and the association of smoking history with OS may have varied depending on clinical stage at diagnosis, potentially owing to the differing treatment regimens and efficacy associated with smoking exposure following diagnosis. Detailed smoking history collection should be incorporated into future epidemiological and clinical studies to improve lung cancer prognosis and treatment selection.

Restless legs syndrome severity in the National RLS Opioid Registry during the COVID-19 pandemic.

OBJECTIVE/BACKGROUND: No research has yet assessed the impact of the coronavirus disease 2019 (COVID-19) pandemic on restless legs syndrome (RLS). We hypothesized that RLS symptom severity would be increased during the COVID-19 pandemic in a sample of patients with diagnosed RLS. PATIENTS/METHODS: The National RLS Opioid Registry is a longitudinal observational study of patients using opioid medications for treatment of RLS. Questionnaires assessing RLS symptom severity, medication dosages, sleep disturbance, depression, and anxiety are administered at baseline and at recurring 6-month surveys. Survey responses from the outset of the pandemic in April/May 2020 were compared to responses completed by other participants in January/February 2020 (between-subjects analysis), as well as responses by the same participants at baseline, approximately six months later in September 2020 through February 2021, and approximately one year later in March through June 2021 (within-subjects analyses). RESULTS: These analyses provide evidence for higher RLS symptom severity scores at the outset of the COVID-19 pandemic in the US. Symptom severity scores were still elevated on subsequent questionnaires completed over six months into the pandemic but had returned towards baseline by the spring of 2021. Participants with increases in RLS severity were significantly more likely than others to see increases in sleep disturbance, depression, and anxiety. CONCLUSIONS: This is the first study demonstrating increased RLS symptom severity during the earliest stage of the COVID-19 pandemic. These findings warrant similar investigations in other patient populations and suggest that clinicians should attend to RLS symptoms during times of socioeconomic and/or political uncertainty.