Chronic respiratory symptoms following deployment-related occupational and environmental exposures among US veterans.

OBJECTIVES: Characterise inhalational exposures during deployment to Afghanistan and Southwest Asia and associations with postdeployment respiratory symptoms. METHODS: Participants (n=1960) in this cross-sectional study of US Veterans (Veterans Affairs Cooperative Study 'Service and Health Among Deployed Veterans') completed an interviewer-administered questionnaire regarding 32 deployment exposures, grouped a priori into six categories: burn pit smoke; other combustion sources; engine exhaust; mechanical and desert dusts; toxicants; and military job-related vapours gas, dusts or fumes (VGDF). Responses were scored ordinally (0, 1, 2) according to exposure frequency. Factor analysis supported item reduction and category consolidation yielding 28 exposure items in 5 categories. Generalised linear models with a logit link tested associations with symptoms (by respiratory health questionnaire) adjusting for other covariates. OR were scaled per 20-point score increment (normalised maximum=100). RESULTS: The cohort mean age was 40.7 years with a median deployment duration of 11.7 months. Heavy exposures to multiple inhalational exposures were commonly reported, including burn pit smoke (72.7%) and VGDF (72.0%). The prevalence of dyspnoea, chronic bronchitis and wheeze in the past 12 months was 7.3%, 8.2% and 15.6%, respectively. Burn pit smoke exposure was associated with dyspnoea (OR 1.22; 95% CI 1.06 to 1.47) and chronic bronchitis (OR 1.22; 95% CI 1.13 to 1.44). Exposure to VGDF was associated with dyspnoea (OR 1.29; 95% CI 1.14 to 1.58) and wheeze (OR 1.18; 95% CI 1.02 to 1.35). CONCLUSION: Exposures to burn pit smoke and military occupational VGDF during deployment were associated with an increased odds of chronic respiratory symptoms among US Veterans.

Heritability and individuality of the plasma sodium concentration: a twin study in the United States veteran population.

Little is known about the population genetics of water balance. A recent meta-genome-wide association study on plasma sodium concentration identified novel loci of high biological plausibility, yet heritability of the phenotype has never been convincingly shown in European ancestry. The present study linked the Vietnam Era Twin Registry with the Department of Veterans Affairs VistA patient care clinical database. Participants (n = 2,370, 59.6% monozygotic twins and 40.4% dizygotic twins) had a median of seven (interquartile range: 3-14) plasma sodium determinations between October 1999 and March 2017. Heritability of the mean plasma sodium concentration among all twins was 0.41 (95% confidence interval: 0.35-0.46) and 0.49 (95% confidence interval: 0.43-0.54) after exclusion of 514 twins with only a single plasma sodium determination. Heritability among Caucasian (n = 1,958) and African-American (n = 268) twins was 0.41 (95% confidence interval: 0.34-0.47) and 0.36 (95% confidence interval: 0.17-0.52), respectively. Exclusion of data from twins who had been prescribed medications known to impact systemic water balance had no effect. The ability of the present study to newly detect substantial heritability across multiple racial groups was potentially a function of the cohort size and relatedness, exclusion of sodium determinations confounded by elevated plasma glucose and/or reduced glomerular filtration rate, transformation of plasma sodium for the independent osmotic effect of plasma glucose, and use of multiple laboratory determinations per individual over a period of years. Individual-level plasma sodium concentration exhibited longitudinal stability (i.e., individuality); the degree to which individual-level means differed from the population mean was substantial, irrespective of the number of determinations. In aggregate, these data establish the heritability of plasma sodium concentration in European ancestry and corroborate its individuality.

Assessing equity in the uptake of remote foot temperature monitoring in a large integrated US healthcare system.

OBJECTIVE: We assessed equity in the uptake of remote foot temperature monitoring (RTM) for amputation prevention throughout a large, integrated US healthcare system between 2019 and 2021, including comparisons across facilities and between patients enrolled and eligible patients not enrolled in RTM focusing on the Reach and Adoption dimensions of the Reach, Effectiveness, Adoption, Implementation, and Maintenance (RE-AIM) framework. MATERIAL AND METHODS: To assess whether there was equitable use of RTM across facilities, we examined distributions of patient demographic, geographic, and facility characteristics across facility RTM use categories (e.g., no RTM use, and low, moderate, and high RTM use) among all eligible patients (n = 46,294). Second, to understand whether, among facilities using RTM, there was equitable enrollment of patients in RTM, we compared characteristics of patients enrolled in RTM (n = 1066) relative to a group of eligible patients not enrolled in RTM (n = 27,166) using logistic regression and including all covariates. RESULTS: RTM use increased substantially from an average of 11 patients per month to over 40 patients per month between 2019 and 2021. High-use RTM facilities had higher complexity and a lower ratio of patients per podiatrist but did not have consistent evidence of better footcare process measures. Among facilities offering RTM, enrollment varied by age, was inversely associated with Black race (vs. white), low income, living far from specialty care, and being in the highest quartiles of telehealth use prior to enrollment. Enrollment was positively associated with having osteomyelitis, Charcot foot, a partial foot amputation, BMI≥30 kg/m2, and high outpatient utilization. CONCLUSIONS: RTM growth was concentrated in a small number of higher-resourced facilities, with evidence of lower enrollment among those who were Black and lived farther from specialty care. Future studies are needed to identify and address barriers to uptake of new interventions like RTM to prevent exacerbating existing ulceration and amputation disparities.

Evaluation of the Effectiveness of Remote Foot Temperature Monitoring for Prevention of Amputation in a Large Integrated Health Care System.

OBJECTIVE: We evaluated the effectiveness of remote foot temperature monitoring (RTM) in the Veterans Affairs health care system. RESEARCH DESIGN AND METHODS: We conducted a retrospective cohort study that included 924 eligible patients enrolled in RTM between 2019 and 2021 who were matched up to 3:1 to 2,757 nonenrolled comparison patients. We used conditional Cox regression to estimate adjusted cause-specific hazard ratios (aHRs) and corresponding 95% CIs for lower-extremity amputation (LEA) as the primary outcome and all-cause hospitalization and death as secondary outcomes. RESULTS: RTM was not associated with LEA incidence (aHR 0.92, 95% CI 0.62-1.37) or all-cause hospitalization (aHR 0.97, 95% CI 0.82-1.14) but was inversely associated (reduced risk) with death (aHR 0.63, 95% CI 0.49-0.82). CONCLUSIONS: This study does not provide support that RTM reduces the risk of LEA or all-cause hospitalization in individuals with a history of diabetic foot ulcer. Randomized controlled trials can overcome important limitations.

Comparative venous thromboembolic safety of oral and transdermal postmenopausal hormone therapies among women Veterans.

OBJECTIVE: Hormone therapy (HT) is used by menopausal women to treat vasomotor symptoms. Venous thromboembolism (VTE) is an important risk of HT use, and more knowledge on the comparative safety of different estrogenic compounds is useful for women who use HT for these symptoms. The objective was to compare the risk of VTE among users of oral conjugated equine estrogen (CEE), oral estradiol (E2), and transdermal E2, in a cohort of women veterans. METHODS: This retrospective cohort study included all women veterans aged 40 to 89 years, using CEE or E2, without prior VTE, between 2003 and 2011. All incident VTE events were adjudicated. Time-to-event analyses using a time-varying HT exposure evaluated the relative VTE risk between estrogen subtypes, with adjustment for age, race, and body mass index, with stratification for prevalent versus incident use of HT. RESULTS: Among 51,571 users of HT (74.5% CEE, 12.6% oral, and 12.9% transdermal E2 at cohort entry), with a mean age of 54.0 years, the incidence of VTE was 1.9/1,000 person-years. Compared with CEE use, in the multivariable regression model, there was no difference in the risk of incident VTE associated with oral E2 use (hazard ratio 0.96, 95% CI 0.64-1.46) or with transdermal E2 use (hazard ratio 0.95, 95% CI 0.60-1.49). Results were unchanged when restricting to incident users of HT. CONCLUSIONS: Among women veterans, the risk of VTE was similar in users of oral CEE, oral E2, and transdermal E2. These findings do not confirm the previously observed greater safety of transdermal and oral E2 over CEE.