Yuan Lu

Fine particulate matter (PM _2.5 ) is a risk factor for cardiovascular disease (CVD), even at concentrations below U.S. air quality standards. The frequency and severity of wildfires are increasing, causing episodic PM _2.5 spikes. Our study examined whether associations between long-term exposure to PM _2.5 and cardiovascular hospitalizations differed in the presence and absence of wildfire smoke waves. We conducted a cohort study of 65.2 million U.S. Medicare beneficiaries aged ⩾65 years across the contiguous U.S. during 2017–2022. Daily total and wildfire smoke PM _2.5 concentrations were estimated at 1 km and 10 km spatial resolutions, respectively, using validated machine learning models that incorporated satellite, meteorological, emission, and land-use data. Exposure estimates were aggregated to beneficiaries’ residential ZIP codes by population-weighted averaging. Wildfire smoke waves were defined as ⩾2 consecutive days with daily smoke PM _2.5 > 10 µ g m ⁻³ . We applied quasi-Poisson regressions to estimate relative risks (RR) of first hospitalizations for overall CVD, ischemic heart disease, cerebrovascular disease, and hypertension in ZIP-years with and without smoke waves. In the full cohort, an increase in two-year average PM _2.5 from 5 µ g m ⁻³ (WHO annual air quality guideline) to 9 µ g m ⁻³ (current U.S. annual PM _2.5 standard) was associated with increased risks of overall CVD, cerebrovascular, and hypertension hospitalizations, with stronger associations in ZIP-years without smoke waves than in those with smoke waves (overall CVD: RR 1.09, 95% confidence intervals (CI) 1.09–1.10 vs RR 1.04, 95% CI 1.03–1.04; ratio of RR 1.05, 95% CI 1.04–1.06). Similar patterns were observed among beneficiaries residing in ZIP codes with annual PM _2.5 concentrations below 9 µ g m ⁻³ throughout the study period. Smoke wave-related differences in PM _2.5 -CVD associations were greater among males, urban residents, and residents in the western region compared with their counterparts. The association between long-term PM _2.5 exposure and cardiovascular hospitalizations differed by wildfire smoke wave occurrence. These findings suggest that long-term average PM _2.5 may not fully capture episodic high-intensity exposures and may underestimate the cardiovascular morbidity burden in smoke-affected areas, highlighting the need for risk assessments accounting for exposure patterns.

Background: Randomized trials show substantial weight loss with semaglutide and tirzepatide under structured care, but little is known about whether patients in routine practice continue therapy, reach a maintenance dose, and have their weight measured. Objectives: To describe the first year after initiation of semaglutide or tirzepatide for obesity, including care patterns, maintenance-dose attainment, weight documentation, and total body weight loss (TBWL). Methods: This retrospective cohort study used Epic Cosmos, an electronic health record network of >350 US health systems, to identify adults with obesity and without diabetes who initiated injectable semaglutide or tirzepatide in 2024. Outcomes over 12 months included prescribing persistence, discontinuation, switching, add-on therapy, and reinitiation; attainment of Food and Drug Administration (FDA)-labeled maintenance doses; availability of follow-up weight; and TBWL across progressively restricted populations. Results: Among 743,153 adults (60.1% semaglutide; mean age, 48.5 years; 72.5% female), 12-month prescribing persistence was 29.9% for semaglutide and 35.9% for tirzepatide. FDA-labeled maintenance-dose attainment was 28.3% and 55.0%, respectively, and only 8.8% and 16.4% remained prescribing persistent at a maintenance dose with a recorded weight at 12 months. About half of initiators lacked a 12-month weight. Among all initiators, ≥5% TBWL was documented in 25.6% (semaglutide) and 30.4% (tirzepatide), rising to 51.9% and 61.9% among those with recorded weight, 66.1% and 79.5% among those also prescribing persistent, and 82.9% and 87.3% among those further at a maintenance dose. Conclusions: In routine practice, most patients initiating semaglutide or tirzepatide did not remain on therapy, reach a maintenance dose, and have weight documented through the first year. Documented weight loss was greatest among those completing each step of care, suggesting continuation, dose escalation, and monitoring as targets for improvement. CENTRAL ILLUSTRATION: Care Cascade and Weight-Loss Outcomes Among Semaglutide and Tirzepatide Initiators, Standardized to 100 Initiators. Numbers are per 100 initiators and were rounded so that categories at each step sum to the preceding step. At the 12-month dose step, prescribed dose was missing for 1 per 100 semaglutide initiators and <1 per 100 tirzepatide initiators.

Background: Hypertension is the leading modifiable risk factor for ischemic stroke, yet the adequacy of preventative hypertension care in routine clinical practice remains suboptimal, potentially representing missed opportunities for stroke prevention. We evaluated the association between hypertension care delivery and incident ischemic stroke. Methods: We conducted a retrospective, matched, nested case–control study among adults with hypertension using data from a large regional health system (2010–2024). Patients with a first‐ever ischemic stroke were matched 1:2 to controls on age, sex, race and ethnicity, and calendar time. Three care metrics were assessed: (1) outpatient visits with blood pressure measurement per year; (2) number of antihypertensive medication ingredients; and (3) medication intensification score. Conditional logistic regression estimated adjusted odds ratios. Results: The study included 13 476 cases and 26 952 matched controls. Cases had fewer blood pressure visits per year (median, 2.50 versus 3.01), similar number of medication ingredients (2.00 versus 2.00), and lower treatment intensification scores (−0.211 versus −0.125). Compared with ≤1 visit, >5 blood pressure visits per year was associated with lower stroke odds (adjusted odds ratio, 0.55 [95% CI, 0.51–0.59]). Use of 2 to 3 medication ingredients (versus 0) was also associated with reduced stroke odds (adjusted odds ratio, 0.80 [95% CI, 0.75–0.86]), whereas >3 ingredients was not. The highest quartile of treatment intensification showed the strongest association (adjusted odds ratio, 0.47 [95% CI, 0.44–0.51]). Findings were consistent across subgroup and sensitivity analyses. Conclusions: Greater engagement in hypertension care was associated with lower odds of ischemic stroke, suggesting that gaps in routine management may represent missed opportunities for prevention.