The combined effect of motivational interviewing and wearable fitness trackers on motivation and physical activity in inactive adults: A randomized controlled trial.

Despite overwhelming adoption of wearable fitness trackers (WFT), it is unclear if they affect physical activity (PA) engagement or PA motivation. We hypothesized that combining a WFT with an effective intervention, motivational interviewing (MI), would positively influence both motivation and PA. A 12-week randomized controlled trial was conducted in 40 adults who did not meet PA recommendations. The four conditions were: a PA education (Educational control, n = 10), a WFT (WFT, n = 10), bi-weekly MI sessions (MI, n = 10), or both interventions (WFT+, n = 10). Motivation and PA were measured through an online survey and actigraphy pre- and post-intervention. Both the WFT+ and MI groups improved autonomous forms and decreased controlled forms of motivation. They also had higher basic psychological needs scores when compared to the Education group post-intervention. We detected no changes in PA. High autonomous motivation at baseline predicted higher post-intervention PA in the WFT+ group but predicted lower post-intervention PA in the WFT group. Results suggests that MI alone or with a WFT can improve basic psychological needs and autonomous forms of motivation for PA, but not PA participation. Individual differences in motivation at baseline may moderate the effect of a WFT on PA. This study was registered at clinicaltrials.gov (NCT490014).

Educational attainment of same-sex and opposite-sex dizygotic twins: An individual-level pooled study of 19 twin cohorts.

Comparing twins from same- and opposite-sex pairs can provide information on potential sex differences in a variety of outcomes, including socioeconomic-related outcomes such as educational attainment. It has been suggested that this design can be applied to examine the putative role of intrauterine exposure to testosterone for educational attainment, but the evidence is still disputed. Thus, we established an international database of twin data from 11 countries with 88,290 individual dizygotic twins born over 100 years and tested for differences between twins from same- and opposite-sex dizygotic pairs in educational attainment. Effect sizes with 95% confidence intervals (CI) were estimated by linear regression models after adjusting for birth year and twin study cohort. In contrast to the hypothesis, no difference was found in women (ß = -0.05 educational years, 95% CI -0.11, 0.02). However, men with a same-sex co-twin were slightly more educated than men having an opposite-sex co-twin (ß = 0.14 educational years, 95% CI 0.07, 0.21). No consistent differences in effect sizes were found between individual twin study cohorts representing Europe, the USA, and Australia or over the cohorts born during the 20th century, during which period the sex differences in education reversed favoring women in the latest birth cohorts. Further, no interaction was found with maternal or paternal education. Our results contradict the hypothesis that there would be differences in the intrauterine testosterone levels between same-sex and opposite-sex female twins affecting education. Our findings in men may point to social dynamics within same-sex twin pairs that may benefit men in their educational careers.

Autonomous motivation and action planning are longitudinally associated with physical activity during adolescence and early adulthood.

We examined the associations of autonomous motivation, controlled motivation, and physical activity (PA) planning with PA participation over six years across the adolescent-to-adult transition. Participants from the NEXT Generation Health Study, a nationally representative cohort study of U.S. 10th graders (N=2785), completed surveys yearly from 2010 to 2016 (four years post-high school). This study used data from Waves 2 (W2) through 7 (W7). Data were analyzed using growth models accounting for the complex survey design and controlling for sex, race/ethnicity, and body mass index. A piecewise growth model with two pieces (Piece 1: W2-W4; Piece 2: W4-W7) indicated that PA declined during late adolescence (W2-W4) (b=-0.31, ß=-0.22, p<.001), but did not decline after the transition into early adulthood (W4-W7) (b=-0.08, ß=-0.04, p=.052). Autonomous motivation was positively associated with PA at all waves (b=0.23-0.33, ß=1.90-4.37, p<.001). Controlled motivation was only positively associated with PA at W3 (12th grade) (b=0.13, ß=1.54, p=.011). PA planning varied significantly between individuals and significantly predicted PA (b=0.44, ß=0.21, p<.001). Although PA decreased significantly during late adolescence, PA did not decrease significantly after transitioning into early adulthood (one to four years post-high school). Elevated autonomous motivation and PA planning were consistently and significantly associated with higher PA, suggesting that these may be useful intervention targets during this adolescent-to-adult transition.

C-reactive protein from dried blood spots: Application to household air pollution field studies.

Household air pollution (HAP) is estimated to be an important risk factor for cardiovascular disease, but little clinical evidence exists and collecting biomarkers of disease risk is difficult in low-resource settings. Among 54 Nicaraguan women with woodburning cookstoves, we evaluated cross-sectional associations between 48-hour measures of HAP (eg, fine particulate matter, PM2.5 ) and C-reactive protein (CRP) via dried blood spots; secondary analyses included seven additional biomarkers of systemic injury and inflammation. We conducted sub-studies to calculate the intraclass correlation coefficient (ICC) in biomarkers collected over four consecutive days in Nicaragua and to assess the validity of measuring biomarkers in dried blood by calculating the correlation with paired venous-drawn samples in Colorado. Measures of HAP were associated with CRP (eg, a 25% increase in indoor PM2.5 was associated with a 7.4% increase in CRP [95% confidence interval: 0.7, 14.5]). Most of the variability in CRP concentrations over the 4-day period was between-person (ICC: 0.88), and CRP concentrations were highly correlated between paired dried blood and venous-drawn serum (Spearman ρ = .96). Results for secondary biomarkers were primarily consistent with null associations, and the sub-study ICCs and correlations were lower. Assessing CRP via dried blood spots provides a feasible approach to elucidate the association between HAP and cardiovascular disease risk.

Exposure to household air pollution from biomass cookstoves and self-reported symptoms among women in rural Honduras.

Household air pollution from combustion of solid fuels is an important risk factor for morbidity and mortality, causing an estimated 2.6 million premature deaths globally in 2016. Self-reported health symptoms are a meaningful measure of quality of life, however, few studies have evaluated symptoms and quantitative measures of exposure to household air pollution. We assessed the cross-sectional association of self-reported symptoms and exposures to household air pollution among women in rural Honduras using stove type (traditional [n = 76]; cleaner-burning Justa [n = 74]) and 24-hour average personal and kitchen fine particulate matter (PM2.5) concentrations. The odds of prevalent symptoms were higher among women using traditional stoves vs Justa stoves (e.g. headache: odds ratio = 2.23; 95% confidence interval = 1.13-4.39). Associations between symptoms and measured PM2.5 were generally consistent with the null. These results add to the evidence suggesting reduced exposures and better health-related quality of life among women using cleaner-burning biomass stoves.

Household air pollution from biomass-burning cookstoves and metabolic syndrome, blood lipid concentrations, and waist circumference in Honduran women: A cross-sectional study.

BACKGROUND: Household air pollution from cooking with solid fuels affects nearly 3 billion people worldwide and is responsible for an estimated 2.5 million premature deaths and 77 million disability-adjusted life years annually. Investigating the effect of household air pollution on indicators of cardiometabolic disease, such as metabolic syndrome, can help clarify the pathways between this widespread exposure and cardiovascular diseases, which are increasing in low- and middle-income countries. METHODS: Our cross-sectional study of 150 women in rural Honduras (76 with traditional stoves and 74 with cleaner-burning Justa stoves) explored the effect of household air pollution exposure on cardiovascular disease risk factors. Household air pollution was measured by stove type and 24-h average kitchen and personal fine particulate matter [PM2.5] mass and black carbon concentrations. Health endpoints included non-fasting total cholesterol, high-density lipoprotein, calculated low-density lipoprotein, triglycerides, waist circumference to indicate abdominal obesity, and presence of metabolic syndrome (defined by current modified international guidelines: waist circumference ≥ 80 cm plus any two of the following: triglycerides > 200 mg/dL, HDL < 50 mg/dL, systolic blood pressure ≥ 130 mmHg, diastolic blood pressure ≥ 85 mmHg, or glycated hemoglobin > 5.6%). RESULTS: Forty percent of women met the criteria for metabolic syndrome. The prevalence ratio [PR] for metabolic syndrome (versus normal) per interquartile range increase in kitchen PM2.5 and kitchen black carbon was 1.16 (95% confidence interval [CI]: 1.01-1.34) per 312 µg/m3 increase in PM2.5, and 1.07 (95% CI: 1.03-1.12) per 73 µg/m3 increase in black carbon. There is suggestive evidence of a stronger effect in women ≥ 40 years of age compared to women < 40 (p-value for interaction = 0.12 for personal PM2.5). There was no evidence of associations between all other exposure metrics and health endpoints. CONCLUSIONS: The prevalence of metabolic syndrome among our study population was high compared to global estimates. We observed a suggestive effect between metabolic syndrome and exposure to household air pollution. These results for metabolic syndrome may be driven by specific syndrome components, such as blood pressure. Longitudinal research with repeated health and exposure measures is needed to better understand the link between household air pollution and indicators of cardiometabolic disease risk.

Exposure to household air pollution from biomass cookstoves and blood pressure among women in rural Honduras: A cross-sectional study.

Growing evidence links household air pollution exposure from biomass cookstoves with elevated blood pressure. We assessed cross-sectional associations of 24-hour mean concentrations of personal and kitchen fine particulate matter (PM2.5 ), black carbon (BC), and stove type with blood pressure, adjusting for confounders, among 147 women using traditional or cleaner-burning Justa stoves in Honduras. We investigated effect modification by age and body mass index. Traditional stove users had mean (standard deviation) personal and kitchen 24-hour PM2.5 concentrations of 126 µg/m3 (77) and 360 µg/m3 (374), while Justa stove users' exposures were 66 µg/m3 (38) and 137 µg/m3 (194), respectively. BC concentrations were similarly lower among Justa stove users. Adjusted mean systolic blood pressure was 2.5 mm Hg higher (95% CI, 0.7-4.3) per unit increase in natural log-transformed kitchen PM2.5 concentration; results were stronger among women of 40 years or older (5.2 mm Hg increase, 95% CI, 2.3-8.1). Adjusted odds of borderline high and high blood pressure (categorized) were also elevated (odds ratio = 1.5, 95% CI, 1.0-2.3). Some results included null values and are suggestive. Results suggest that reduced household air pollution, even when concentrations exceed air quality guidelines, may help lower cardiovascular disease risk, particularly among older subgroups.

Study protocol for a stepped-wedge randomized cookstove intervention in rural Honduras: household air pollution and cardiometabolic health.

BACKGROUND: Growing evidence links household air pollution exposure from biomass-burning cookstoves to cardiometabolic disease risk. Few randomized controlled interventions of cookstoves (biomass or otherwise) have quantitatively characterized changes in exposure and indicators of cardiometabolic health, a growing and understudied burden in low- and middle-income countries (LMICs). Ideally, the solution is to transition households to clean cooking, such as with electric or liquefied petroleum gas stoves; however, those unable to afford or to access these options will continue to burn biomass for the foreseeable future. Wood-burning cookstove designs such as the Justa (incorporating an engineered combustion zone and chimney) have the potential to substantially reduce air pollution exposures. Previous cookstove intervention studies have been limited by stove types that did not substantially reduce exposures and/or by low cookstove adoption and sustained use, and few studies have incorporated community-engaged approaches to enhance the intervention. METHODS/DESIGN: We conducted an individual-level, stepped-wedge randomized controlled trial with the Justa cookstove intervention in rural Honduras. We enrolled 230 female primary cooks who were not pregnant, non-smoking, aged 24-59 years old, and used traditional wood-burning cookstoves at baseline. A community advisory board guided survey development and communication with participants, including recruitment and retention strategies. Over a 3-year study period, participants completed 6 study visits approximately 6 months apart. Half of the women received the Justa after visit 2 and half after visit 4. At each visit, we measured 24-h gravimetric personal and kitchen fine particulate matter (PM2.5) concentrations, qualitative and quantitative cookstove use and adoption metrics, and indicators of cardiometabolic health. The primary health endpoints were blood pressure, C-reactive protein, and glycated hemoglobin. Overall study goals are to explore barriers and enablers of new cookstove adoption and sustained use, compare health endpoints by assigned cookstove type, and explore the exposure-response associations between PM2.5 and indicators of cardiometabolic health. DISCUSSION: This trial, utilizing an economically feasible, community-vetted cookstove and evaluating endpoints relevant for the major causes of morbidity and mortality in LMICs, will provide critical information for household air pollution stakeholders globally. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT02658383 , posted January 18, 2016, field work completed May 2018. Official title, "Community-Based Participatory Research: A Tool to Advance Cookstove Interventions." Principal Investigator Maggie L. Clark, Ph.D. Last update posted July 12, 2018.

Interactions Between Diet and Exposure to Secondhand Smoke on Glycated Hemoglobin Levels Among US Children: Results From NHANES 2007-2012.

INTRODUCTION: Antioxidant-rich diets may lessen the adverse metabolic responses triggered by exposure to secondhand smoke (SHS), but no studies have investigated these potential interactions. OBJECTIVE: To examine the interaction between diet and exposure to SHS on glycated hemoglobin (HbA1c) levels among 2551 children, ages 12-19 years, who participated in the 2007-2012 National Health and Nutrition Examination Survey (NHANES). METHODS: Exposure to SHS was assessed by 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), cotinine, and self-report. Weighted linear regression models evaluated the cross-sectional association between exposure to SHS and HbA1c levels. Additive interaction was assessed by introducing product terms (with SHS) of individual nutrients (dietary fiber, eicosapentaenoic acid [EPA], docosahexaenoic acid [DHA], vitamin C, and vitamin E) to separate models. RESULTS: Over half of the children had NNAL or cotinine levels above the limit of detection (56% and 71%, respectively). The median HbA1c level was 5.2% (95% confidence interval: 5.17%, 5.23%). The interaction results suggest that the effects of exposure to SHS and certain dietary nutrients (EPA, DHA, vitamin C) on HbA1c levels may not be independent. For example, although there was only a slight difference in adjusted mean HbA1c levels across NNAL categories among children with high EPA intakes, the adjusted mean HbA1c level was 0.09% higher for high NNAL as compared to low NNAL among children with low EPA intakes. CONCLUSIONS: Further research is needed to inform public health strategies for limiting increases in HbA1c levels among children. Messages may need to focus both on reducing exposure to SHS and improving diets to obtain the maximum benefit. IMPLICATIONS: Our results suggest that the effects of exposure to SHS and diet on HbA1c levels may not be independent. For example, although there was little effect of exposure to SHS on HbA1c levels among children with high EPA intakes, high exposure to SHS was associated with an increase in HbA1c levels among children with low EPA intakes. Further research is necessary; however, based on these joint effects, strategies for limiting increases in HbA1c levels that focus both on reducing exposure to SHS and improving diets may achieve the largest public health benefits.

Cognitive decline and the PPAR-γ Pro12Ala genotype: variation by sex and ethnicity.

Objective: We investigated the association between the peroxisome proliferator-activated receptor (PPAR)-gamma Pro12Ala polymorphism and cognitive decline in older adults. Methods: Participants from a population-based cohort of older Hispanic and non-Hispanic white adults (n = 492) were administered the Mini Mental State Examination (MMSE), a multi-domain cognitive screening tool, and the Behavioral Dyscontrol Scale (BDS), a measure of executive cognitive function, at baseline and at follow-up, an average of 22 months later. Multiple linear regression was used to investigate the association between the two cognitive test scores and the Pro12Ala polymorphism. Results: At baseline, presence of the Ala12 allele was not significantly associated with MMSE score (P = 0.62) nor with BDS score (P = 0.85). Heterogeneity was present for cognitive decline as measured by the MMSE among ethnic, sex and Ala12 allele status (P = 0.04 for three-way interaction term). Stratification by the cross-classification of sex and ethnicity revealed significantly greater declines in MMSE score among male Hispanic carriers of the Ala12 allele compared to male Hispanic non-carriers (decline = 4.0 versus 1.6 points; P = 0.02). A significant difference in decline between Ala12 carriers and non-carriers was not present among the other sex/ethnic groups. Conclusions: Carriers of the PPAR-γ Ala12 allele showed greater cognitive decline compared to non-carriers as detected by the MMSE but the risk varied across sex and ethnic groups. Male Ala12 carriers of Hispanic origin may be a high-risk group for cognitive decline.

Education in Twins and Their Parents Across Birth Cohorts Over 100 years: An Individual-Level Pooled Analysis of 42-Twin Cohorts.

Whether monozygotic (MZ) and dizygotic (DZ) twins differ from each other in a variety of phenotypes is important for genetic twin modeling and for inferences made from twin studies in general. We analyzed whether there were differences in individual, maternal and paternal education between MZ and DZ twins in a large pooled dataset. Information was gathered on individual education for 218,362 adult twins from 27 twin cohorts (53% females; 39% MZ twins), and on maternal and paternal education for 147,315 and 143,056 twins respectively, from 28 twin cohorts (52% females; 38% MZ twins). Together, we had information on individual or parental education from 42 twin cohorts representing 19 countries. The original education classifications were transformed to education years and analyzed using linear regression models. Overall, MZ males had 0.26 (95% CI [0.21, 0.31]) years and MZ females 0.17 (95% CI [0.12, 0.21]) years longer education than DZ twins. The zygosity difference became smaller in more recent birth cohorts for both males and females. Parental education was somewhat longer for fathers of DZ twins in cohorts born in 1990-1999 (0.16 years, 95% CI [0.08, 0.25]) and 2000 or later (0.11 years, 95% CI [0.00, 0.22]), compared with fathers of MZ twins. The results show that the years of both individual and parental education are largely similar in MZ and DZ twins. We suggest that the socio-economic differences between MZ and DZ twins are so small that inferences based upon genetic modeling of twin data are not affected.

Twin's Birth-Order Differences in Height and Body Mass Index From Birth to Old Age: A Pooled Study of 26 Twin Cohorts Participating in the CODATwins Project.

We analyzed birth order differences in means and variances of height and body mass index (BMI) in monozygotic (MZ) and dizygotic (DZ) twins from infancy to old age. The data were derived from the international CODATwins database. The total number of height and BMI measures from 0.5 to 79.5 years of age was 397,466. As expected, first-born twins had greater birth weight than second-born twins. With respect to height, first-born twins were slightly taller than second-born twins in childhood. After adjusting the results for birth weight, the birth order differences decreased and were no longer statistically significant. First-born twins had greater BMI than the second-born twins over childhood and adolescence. After adjusting the results for birth weight, birth order was still associated with BMI until 12 years of age. No interaction effect between birth order and zygosity was found. Only limited evidence was found that birth order influenced variances of height or BMI. The results were similar among boys and girls and also in MZ and DZ twins. Overall, the differences in height and BMI between first- and second-born twins were modest even in early childhood, while adjustment for birth weight reduced the birth order differences but did not remove them for BMI.

Maternal Risk of Cardiovascular Disease Is Associated With Higher BMI Among Preschool-Aged Children: A Cross-Sectional Study.

Childhood obesity is an ongoing concern in the United States. Higher weight status in early childhood is associated with higher weight status at older ages. The Maternal Obesity Matters (MOMs) Study investigated associations between maternal risk of cardiovascular disease (CVD) and child BMI z-scores (BMIz) among preschool-aged children. This cross-sectional exploratory study included mothers and their 3- to 5-year-old children in Colorado, United States. Maternal nonfasting blood samples, blood pressure, and maternal and child anthropometrics were collected. Maternal CVD risk was assessed on a scale of 0-5 using five health measures. Multivariate regression tested associations between maternal CVD risk and child BMIz. Each 1-point increase in maternal CVD risk was associated with a 0.18 increase in child BMIz, controlling for maternal employment. Intervening upon maternal health may be an important strategy for addressing childhood obesity.

Association of Physical Domain Participation with POTFF Domains in Special Forces Operators.

BACKGROUND: The purpose of this study was to evaluate the effectiveness of the physical domain (PD) to improve performance in all the POTFF domains (physical, psychological, social/family, and spiritual) among Special Forces (SF) Operators. METHODS: This was a cross-sectional study of active SF Operators assigned to the United States Army Special Operations Command (USASOC). Recruitment began in October 2016. Testing began on 1 January 2017, and concluded on 28 February 2020. Participants completed physical testing, blood draws, and questionnaires to determine domain metrics. Means, medians, and proportions were compared by level of participation in the PD. RESULTS: A total of 231 Soldiers participated; n=63 in the control group, n=93 in the <4 days PD/week (PD <4) group, and n=66 in the >4 days PD/week (PD =4) group. The average age was 31 years (range 21-47 y). The average time in the Special Operations Forces (SOF) was 4 years (range 0-19 y). The PD =4 group showed significantly greater overall upper (p=.01) and lower (p=0) body strength, power (p=.01), and positive affect (p=.04). The PD =4 group also had significantly lower anxiety (p=.03), stress (p=.04), and depression (p=.02) than the control group. CONCLUSION: The PD and psychological domain metrics were most associated with PD participation. This finding is consistent with the goals of the PD, which are to increase physical and mental capabilities and decrease injury recovery time.

Depression and polypharmacy are risk factors for activity limitation in type 2 diabetes.

OBJECTIVES: Individuals with type 2 diabetes are at risk for deficits in instrumental activities of daily living (IADL: e.g., managing medication, preparing healthy meals). Understanding which demographic and health factors contribute to decreased frequency of IADL performance is especially important to prevent age-related functional decline in type 2 diabetes. This study examined the relationships among demographic and health variables and frequency of IADL performance in adults with type 2 diabetes. METHODS: For this cross-sectional study, we collected health, demographic, and activity information via self-report and electronic health record review from safety-net primary care patients with type 2 diabetes (n = 93). We used regression models to determine which factors were associated with IADL performance in three subscales (domestic, leisure/work, outdoor) and the overall score. RESULTS: Depression was associated with decreased frequency of IADL performance for domestic, leisure/work, and outdoor activities. Each additional daily medication was associated with decreased frequency of domestic and outdoor IADL performance. DISCUSSION: Depression and taking more daily medication were predictors of decreased IADL performance for adults with type 2 diabetes. Our findings suggest regular screening for depression and polypharmacy is important in the primary care of diabetes; especially as these are potentially modifiable risk factors.

Household air pollution from wood-burning cookstoves and C-reactive protein among women in rural Honduras.

Household air pollution from solid fuel combustion was estimated to cause 2.31 million deaths worldwide in 2019; cardiovascular disease is a substantial contributor to the global burden. We evaluated the cross-sectional association between household air pollution (24-h gravimetric kitchen and personal particulate matter (PM2.5) and black carbon (BC)) and C-reactive protein (CRP) measured in dried blood spots among 107 women in rural Honduras using wood-burning traditional or Justa (an engineered combustion chamber) stoves. A suite of 6 additional markers of systemic injury and inflammation were considered in secondary analyses. We adjusted for potential confounders and assessed effect modification of several cardiovascular-disease risk factors. The median (25th, 75th percentiles) 24-h-average personal PM2.5 concentration was 115 µg/m3 (65,154 µg/m3) for traditional stove users and 52 µg/m3 (39, 81 µg/m3) for Justa stove users; kitchen PM2.5 and BC had similar patterns. Higher concentrations of PM2.5 and BC were associated with higher levels of CRP (e.g., a 25% increase in personal PM2.5 was associated with a 10.5% increase in CRP [95% CI: 1.2-20.6]). In secondary analyses, results were generally consistent with a null association. Evidence for effect modification between pollutant measures and four different cardiovascular risk factors (e.g., high blood pressure) was inconsistent. These results support the growing evidence linking household air pollution and cardiovascular disease.

Association of body mass index with peripheral arterial disease in older adults: the Cardiovascular Health Study.

The authors hypothesized that the absence of cross-sectional associations of body mass index (BMI; weight (kg)/height (m)(2)) with peripheral arterial disease (PAD) in prior studies may reflect lower weight among persons who smoke or have poor health status. They conducted an observational study among 5,419 noninstitutionalized residents of 4 US communities aged ≥ 65 years at baseline (1989-1990 or 1992-1993). Ankle brachial index was measured, and participants reported their history of PAD procedures. Participants were followed longitudinally for adjudicated incident PAD events. At baseline, mean BMI was 26.6 (standard deviation, 4.6), and 776 participants (14%) had prevalent PAD. During 13.2 (median) years of follow-up through June 30, 2007, 276 incident PAD events occurred. In cross-sectional analysis, each 5-unit increase in BMI was inversely associated with PAD (prevalence ratio (PR) = 0.92, 95% confidence interval (CI): 0.85, 1.00). However, among persons in good health who had never smoked, the direction of association was opposite (PR = 1.20, 95% CI: 0.94, 1.52). Similar results were observed between BMI calculated using weight at age 50 years and PAD prevalence (PR = 1.30, 95% CI: 1.11, 1.51) and between BMI at baseline and incident PAD events occurring during follow-up (hazard ratio = 1.32, 95% CI: 1.00, 1.76) among never smokers in good health. Greater BMI is associated with PAD in older persons who remain healthy and have never smoked. Normal weight maintenance may decrease PAD incidence and associated comorbidity in older age.

Association Between COVID-19 Exposure and Self-reported Compliance With Public Health Guidelines Among Essential Employees at an Institution of Higher Education in the US.

Importance: Detailed analysis of infection rates paired with behavioral and employee-reported risk factors is vital to understanding how transmission of SARS-CoV-2 infection may be exacerbated or mitigated in the workplace. Institutions of higher education are heterogeneous work units that supported continued in-person employment during the COVID-19 pandemic, providing a test site for occupational health evaluation. Objective: To evaluate the association between self-reported protective behaviors and prevalence of SARS-CoV-2 infection among essential in-person employees during the first 6 months of the COVID-19 pandemic in the US. Design, Setting, and Participants: This cross-sectional study was conducted from July 13 to September 2, 2020, at an institution of higher education in Fort Collins, Colorado. Employees 18 years or older without symptoms of COVID-19 who identified as essential in-person workers during the first 6 months of the pandemic were included. Participants completed a survey, and blood and nasal swab samples were collected to assess active SARS-CoV-2 infection via quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) and past infection by serologic testing. Exposure: Self-reported practice of protective behaviors against COVID-19 according to public health guidelines provided to employees. Main Outcomes and Measures: Prevalence of current SARS-CoV-2 infection detected by qRT-PCR or previous SARS-CoV-2 infection detected by an IgG SARS-CoV-2 testing platform. The frequency of protective behavior practices and essential workers' concerns regarding contracting COVID-19 and exposing others were measured based on survey responses. Results: Among 508 participants (305 [60.0%] women, 451 [88.8%] non-Hispanic White individuals; mean [SD] age, 41.1 [12.5] years), there were no qRT-PCR positive test results, and only 2 participants (0.4%) had seroreactive IgG antibodies. Handwashing and mask wearing were reported frequently both at work (480 [94.7%] and 496 [97.8%] participants, respectively) and outside work (465 [91.5%] and 481 [94.7%] participants, respectively). Social distancing was reported less frequently at work (403 [79.5%]) than outside work (465 [91.5%]) (P < .001). Participants were more highly motivated to avoid exposures because of concern about spreading the infection to others (419 [83.0%]) than for personal protection (319 [63.2%]) (P < .001). Conclusions and Relevance: In this cross-sectional study of essential workers at an institution of higher education, when employees reported compliance with public health practices both at and outside work, they were able to operate safely in their work environment during the COVID-19 pandemic.

Using Ecological Momentary Assessment to Examine the Effects of Duty Status on Acute Stress and Tiredness in Firefighters: A Pilot Study.

OBJECTIVE: Characterize firefighters' acute stress and tiredness by duty status (ie, "off night/day," "on night/day"). METHODS: Thirty nine career firefighters completed three, eight-day smartphone-based ecological momentary assessment periods with seven surveys per day assessing stress and tiredness. Mixed-effects location scale models examined duty status effects on stress and tiredness. RESULTS: Firefighters' lowest stress and tiredness levels were when off-duty (ß = 16.27 and ß = 24.71, respectively) and their highest levels were when on-duty (ß = 24.47 and ß = 32.18, respectively). Within-subject effects of duty status accounted for a larger proportion of variability in stress and tiredness for all duty types, except for stress when "on-duty night/off-duty day." CONCLUSIONS: Firefighters had more similar stress and tiredness outcomes when they were on-duty and less similar outcomes when off-duty. This could be due to firefighters having more similar experiences when they are on- versus off-duty.

Genetic and environmental influences on human height from infancy through adulthood at different levels of parental education.

Genetic factors explain a major proportion of human height variation, but differences in mean stature have also been found between socio-economic categories suggesting a possible effect of environment. By utilizing a classical twin design which allows decomposing the variation of height into genetic and environmental components, we tested the hypothesis that environmental variation in height is greater in offspring of lower educated parents. Twin data from 29 cohorts including 65,978 complete twin pairs with information on height at ages 1 to 69 years and on parental education were pooled allowing the analyses at different ages and in three geographic-cultural regions (Europe, North America and Australia, and East Asia). Parental education mostly showed a positive association with offspring height, with significant associations in mid-childhood and from adolescence onwards. In variance decomposition modeling, the genetic and environmental variance components of height did not show a consistent relation to parental education. A random-effects meta-regression analysis of the aggregate-level data showed a trend towards greater shared environmental variation of height in low parental education families. In conclusion, in our very large dataset from twin cohorts around the globe, these results provide only weak evidence for the study hypothesis.