Anderson, Paul J.

AbstractBackgroundAlthough racial and ethnic identities are associated with a multitude of disparate medical outcomes, surveillance of these subpopulations in the occupational clinic setting could benefit enormously from a more detailed and nuanced recognition of racial and ethnic identity.MethodsThe research group designed a brief questionnaire to capture several dimensions of this identity and collected data from patients seen for work‐related conditions in four occupational medicine clinics from May 2019 through March 2020. Responses were used to calculate the sensitivity and specificity of extant racial/ethnic identity data within our electronic health records system, and were compared to participants' self‐reported industry and occupation, coded according to North American Industry Classification System and Standard Occupational Classification System listings.ResultsOur questionnaire permitted collection of data that defined our patients' specific racial/ethnic identity with far greater detail, identified patients with multiple ethnic identities, and elicited their preferred language. Response rate was excellent (94.2%, n = 773). Non‐White participants frequently selected a racial/ethnic subcategory (78.1%–92.2%). Using our race/ethnicity data as a referent, the electronic health record (EHR) had a high specificity (>87.1%), widely variable sensitivity (11.8%–82.2%), and poorer response rates (75.1% for race, 82.5% for ethnicity, as compared to 93.8% with our questionnaire). Additional analyses revealed some industries and occupations disproportionately populated by patients of particular racial/ethnic identities.ConclusionsOur project demonstrates the usefulness of a questionnaire which more effectively identifies racial/ethnic subpopulations in an occupational medicine clinic, permitting far more detailed characterization of their occupations, industries, and diagnoses.

Objective To identify novel genes and pathways associated with acute mountain sickness (AMS). Background The uniform, rapid transfer of adults from McMurdo Station (sea level, SL) in Antarctica to the South Pole (SP, 2835m) provides a unique opportunity to study changes in gene expression related to the body's adaptation to hypobaric hypoxia. Methods Venous blood was drawn at SL and after 2 d at SP in 98 subjects (age 37±9 y, 70% male). Peripheral blood mononuclear cells (PBMCs) were isolated and microarray analysis of the mRNA isolated from these cells was performed (Affymetrix HG U133 Plus 2 microarray chip). Analysis and the computation of expression fold changes and phenotypic regression were performed using the Bioconductor package in R. Pathway analysis was performed using MetaCore™. Results ~3200 probe sets with sig. p‐values (p<0.05) and fold changes for each subject were used in a binary logistic regression with the presence or absence of AMS during the 2 d at altitude. Corresponding p‐values and z‐values were entered into MetaCore™ for pathways analysis. Identified pathways included smooth muscle contraction, calcium signaling, and acetylcholine regulation of nerve impulses. Conclusions Probe sets associated with the presence of AMS had a significant representation in pathways involving aspects of the autonomic nervous system including smooth muscle contraction and nerve signaling. NSF B‐179‐M.

Objective To identify novel genes that change expression in healthy adults exposed to hypobaric hypoxia. Background The uniform and rapid transfer of adults from McMurdo Station (sea level, SL) in Antarctica to the South Pole (2835m, SP) provides a unique opportunity to study the changes in gene expression related to the body's adaptation to high altitude. We hypothesized that a large number of genes would change expression and that many of these genes would be associated with inflammatory processes. Methods Peripheral venous blood was drawn at SL and after 2 d at SP in 98 subjects (age 37±9 y, 70% male). Peripheral blood mononuclear cells (PBMCs) were isolated and microarray analysis of the mRNA isolated from these cells was performed (Affymetrix HG U133 Plus 2 microarray chip). Analysis and the computation of expression fold changes was performed using the Bioconductor package in R. Pathway analysis was performed using MetaCore™. Results 1118 probe sets with significant p‐values (p<0.05) and fold changes were identified and entered into MetaCore™. Several pathways including oxidative phosphorylation, cytoskeletal remodeling, and platelet aggregation were identified as having significant representation in the restricted data set. Conclusion Several pathways indicating significantly increased activity in PBMCs were identified. This is indicative of an increased inflammatory response. NSF B‐179‐M.

AbstractThis study aimed to evaluate the influence of physical activity on incidence of acute mountain sickness (AMS) by continuous activity monitoring in a free-living sample of South Pole workers over the initial 72 h at altitude exposure of 2,840 m (9,318 ft). Body Media activity monitors were worn by 47 healthy participants. AMS was defined by the Lake Louise symptom questionnaire. Venous blood samples were taken at sea level and approximately 48 h after high altitude exposure. AMS incidence was 34% (n=16/47) over the first 48 h and 40% (n=19/47) over 72 h. On day 2 at high altitude, individuals with AMS demonstrated a significantly greater increase in the percent change in physical activity metrics from baseline: total energy expenditure 19±13 vs. 5±7%, total steps 65±51 vs. 10±18%, metabolic equivalent of tasks 21±13 vs. 7±13%, and time spent performing moderate to vigorous physical activity 114±79 vs. 26±27% for individuals with AMS vs. no AMS, respectively, p<0.05. In addition, erythropoietin and vascular endothelial growth factor were 1.69 and 1.75 times higher, respectively, in those with AMS. In conclusion, workers who engaged in increased physical activity and activity intensity during initial exposure to the South Pole were more susceptible to developing AMS.

Background Minnesota has an ethnically diverse labor force, with the largest number of refugees per capita in the United States. In recent years, Minnesota has been and continues to be a major site for immigrant and refugee resettlement in the United States, with a large population of both immigrant and native born Hmong, Hispanic, and East Africans. This study seeks to evaluate the injury risk among the evolving minority workforce in the Minnesota Twin Cities region. Methods A retrospective cohort study identifying work‐related injuries following pre‐employment examinations was performed using electronic health records from a large multi‐clinic occupational medicine practice. Preplacement examinations and subsequent work‐related injuries were pulled from the electronic health record using representative ICD‐10 codes for surveillance examinations and injuries. This study included patient records collected over a 2‐year period from January 1, 2015, through December, 2016. The patients in this cohort worked in a wide‐array of occupations including production, assembly, construction, law enforcement, among others. Results Hispanic minority workers were twice as likely to be injured at work compared with White workers. Hispanics were 2.89 times more likely to develop back injuries compared with non‐Hispanic workers, and 1.86 times more likely to develop upper extremity injuries involving the hand, wrist, or elbow. Conclusion Clinical practice data shows that Hispanic workers are at increased risk for work‐related injuries in Minnesota. They were especially susceptible to back and upper extremity injuries. Lower injury rates in non‐Hispanic minority workers, may be the result of injury underreporting and require further investigation.

Anderson, Paul J., Christina M. Wood-Wentz, Kent R. Bailey, and Bruce D. Johnson. Objective versus self-reported sleep quality at high altitude. High Alt Med Biol . 24:144–148, 2023. Background: Previous studies have found little relationship between polysomnography and a diagnosis of acute mountain sickness (AMS) using the Lake Louise Symptom Questionnaire (LLSQ). The correlation between sleep question responses on the LLSQ and polysomnography results has not been explored. We compared LLSQ sleep responses and polysomnography data from our previous study of workers rapidly transported to the South Pole. Methods: Sixty-three subjects completed a 3-hour flight from sea level to the South Pole (3200 m, 9800 ft). Participants completed limited overnight polysomnography on their first night and completed LLSQ upon awakening. We compared polysomnography results at the South Pole with sleep question responses on the LLSQ to assess their degree of correspondence. Results: Twenty-two (30%) individuals reported no sleep problems whereas 20 (32%) reported some problems and 20 (33%) individuals reported poor sleep and 1 reported no sleep ( n = 1). Median sleep efficiency was (94%) among response groups and mean overnight oxygen saturation was 81%. Median apnea hypopnea index (AHI; events/hour) was 10.2 in those who reported no problems sleeping, 5.1 in those reporting some problems sleeping, and 13.7 in those who reported poor sleep. These differences were not statistically significant. Conclusion: Self-reported sleep quality varied but there were no associated significant differences in sleep efficiency, overnight oxygen saturation, nor AHI. Studies that explore the role of objective sleep quality in the development of AMS should remove the sleep question on the LLSQ from AMS scoring algorithms.

Objectives Overweight and obesity are increasing in individuals over age 60 years. This systematic review quantifies the effect of exercise on body mass index (BMI), waist circumference (WC) and lipids in overweight and obese individuals over the age of 60 years. Settings Nine randomised controlled trials conducted in Brazil, Great Britain, Iceland, Japan and the USA compared aerobic and/or resistance exercise with a control group. Participants Final analysis reviewed 1166 participants over the age of 60 years for 3–9 months. Primary outcome measures This study reviewed the effects of exercise on BMI, WC and low-density lipoprotein (LDL). Results Exercise produced a significant reduction in BMI (−1.01 kg/m 2 , 95% CI −2.00 to −0.01) and WC (−3.09 cm, 95% CI −4.14 to −2.04) but not LDL cholesterol (−0.31 mg/dL, 95% CI −0.81 to 0.19). Analyses revealed substantial heterogeneity likely due to the type and intensity of exercise. Data on adverse effects were minimal. The overall level of evidence is moderate due to imprecision and heterogeneity. Conclusions Exercise in overweight and obese older individuals improves anthropometric measures such as BMI and WC. The effect of exercise on serum lipids is unclear.

Introduction Each year, the US Antarctic Program rapidly transports scientists and support personnel from sea level (SL) to the South Pole (SP, 2835 m) providing a unique natural laboratory to quantify the incidence of acute mountain sickness (AMS), patterns of altitude related symptoms and the field effectiveness of acetazolamide in a highly controlled setting. We hypothesized that the combination of rapid ascent (3 hr), accentuated hypobarism (relative to altitude), cold, and immediate exertion would increase altitude illness risk. Methods Medically screened adults (N = 246, age = 37 ± 11 yr, 30% female, BMI = 26 ± 4 kg/m 2 ) were recruited. All underwent SL and SP physiological evaluation, completed Lake Louise symptom questionnaires (LLSQ, to define AMS), and answered additional symptom related questions (eg, exertional dyspnea, mental status, cough, edema and general health), during the 1st week at altitude. Acetazolamide, while not mandatory, was used by 40% of participants. Results At SP, the barometric pressure resulted in physiological altitudes that approached 3400 m, while T ° C averaged -42, humidity 0.03%. Arterial oxygen saturation averaged 89% ± 3%. Overall, 52% developed LLSQ defined AMS. The most common symptoms reported were exertional dyspnea-(87%), sleeping difficulty-(74%), headache-(66%), fatigue-(65%), and dizziness/lightheadedness-(46%). Symptom severity peaked on days 1-2, yet in >20% exertional dyspnea, fatigue and sleep problems persisted through day 7. AMS incidence was similar between those using acetazolamide and those abstaining (51 vs. 52%, P = 0.87). Those who used acetazolamide tended to be older, have less altitude experience, worse symptoms on previous exposures, and less SP experience. Conclusion The incidence of AMS at SP tended to be higher than previously reports in other geographic locations at similar altitudes. Thus, the SP constitutes a more intense altitude exposure than might be expected considering physical altitude alone. Many symptoms persist, possibly due to extremely cold, arid conditions and the benefits of acetazolamide appeared negligible, though it may have prevented more severe symptoms in higher risk subjects.