Heart Rate Variability and Incident Stroke

BACKGROUND AND PURPOSE: Low heart rate variability (HRV), a marker of cardiac autonomic dysfunction, has been associated with increased all-cause and cardiovascular mortality. We examined the association between reduced HRV and incident stroke in a community-based cohort. METHODS: The Atherosclerosis Risk in Communities (ARIC) study measured HRV using 2-minute ECG readings in 12 550 middle-aged adults at baseline (1987-1989). HRV indices were calculated using the SD of RR intervals (SDNN), the mean of all normal RR intervals (meanNN), the root mean square of successive differences of successive RR intervals (RMSSD), low (LF) and high (HF) frequency power, and the LF/HF ratio. All HRV measures were categorized into quintiles. Incident stroke was adjudicated through 2011. Cox regression was used to estimate hazard ratios (HRs) with the lowest HRV quintile as the reference, with and without stratification by prevalent diabetes mellitus. RESULTS: Over a median follow-up of 22 years, 816 (6.5%) participants experienced incident stroke. After covariate adjustment, there was no strong evidence of association between HRV and stroke risk. In stratified analyses, the lowest HRV quintile was associated with higher stroke risk compared with the highest quintile for SDNN (HR, 2.0, 95% confidence interval, 1.1-4.0), RMSSD (HR, 1.7; 95% confidence interval, 0.9-3.2), LF (HR, 1.5; 95% confidence interval, 0.8-3.0), and HF (HR, 1.7; 95% confidence interval, 0.9-3.0) only among people with diabetes mellitus. CONCLUSIONS: Lower HRV was associated with higher risk of incident stroke among middle-aged adults with prevalent diabetes mellitus but not among people without diabetes mellitus

American Indian Alaska Native (AIAN) adolescents and obesity: the influence of social determinants of health, mental health, and substance use

ObjectiveTo explore the prevalence of obesity among American Indian and Alaska Native (AIAN) adolescents aged 12-19 years in association with social determinants of health (SDOH), and mental health and substance use disorders.MethodsGuided by the World Health Organization's Social Determinants of Health Framework, we examined data from the Indian Health Service (IHS) Improving Health Care Delivery Data Project from Fiscal Year 2013, supplemented by county-level data from the U.S. Census and USDA. Our sample included 26,226 AIAN adolescents ages 12-19 years. We described obesity prevalence in relationship to SDOH and adolescents' mental health and substance use disorder status. We then fit a multivariable logit generalized linear mixed model to estimate the relationships after adjusting for other individual and county level characteristics.ResultsWe observed a prevalence of 32.5% for obesity, 13.8% for mental health disorders, and 5.5% for substance use disorders. Females had lower odds of obesity than males (OR = 0.76, p < 0.001), which decreased with age. Having Medicaid coverage (OR = 1.09, p < 0.01), residing in a county with lower education attainment (OR = 1.17, p < 0.05), and residing in a county with higher rates of poverty (OR = 1.51, p < 0.001) were each associated with higher odds of obesity. Residing in a county with high access to a grocery store (OR = 0.73, p < 0.001) and residing in a county with a higher proportion of AIANs (OR = 0.83, p < 0.01) were each associated with lower odds of obesity. Those with mental health disorders had higher odds of obesity (OR = 1.26, p < 0.001); substance use disorders were associated with decreased odds of obesity (OR = 0.73, p < 0.001).ConclusionsOur findings inform future obesity prevention and treatment programs among AIAN youth; in particular, the need to consider mental health, substance use, and SDOH

Social determinants of obesity in American Indian and Alaska Native peoples aged ≥ 50 years.

ObjectiveAmerican Indian and Alaska Native peoples (AI/ANs) have a disproportionately high rate of obesity, but little is known about the social determinants of obesity among older AI/ANs. Thus, our study assessed social determinants of obesity in AI/ANs aged ≥ 50 years.DesignWe conducted a cross-sectional analysis using multivariate generalized linear mixed models to identify social determinants associated with the risk of being classified as obese (BMI ≥ 30.0 kg/m2). Analyses were conducted for the total study population and stratified by median county poverty level.SettingIndian Health Service (IHS) data for AI/ANs who used IHS services in FY2013.Participants27,696 AI/ANs aged ≥ 50 years without diabetes.ResultsMean BMI was 29.8 ± 6.6 with 43% classified as obese. Women were more likely to be obese than men, and younger ages were associated with higher obesity risk. While having Medicaid coverage was associated with lower odds of obesity, private health insurance was associated with higher odds. Living in areas with lower rates of educational attainment and longer drive times to primary care services were associated with higher odds of obesity. Those who lived in a county where a larger percentage of people had low access to a grocery store were significantly less likely to be obese.ConclusionsOur findings contribute to the understanding of social determinants of obesity among older AI/ANs and highlight the need to investigate AI/AN obesity, including longitudinal studies with a life course perspective to further examine social determinants of obesity in older AI/ANs

Associations Between Rurality, pre-pregnancy Health Status, and Macrosomia in American Indian/Alaska Native Populations.

ObjectivesTo examine the relationships between pre-pregnancy diabetes mellitus (DM), gestational diabetes mellitus (GDM), pre-pregnancy body mass index (BMI) and county-level social determinants of health, with infant macrosomia within a sample of American Indian/Alaska Native (AI/AN) women receiving Indian Health Service (IHS) care.MethodsThe sample included women-infant dyads representing 1,136 singleton births from fiscal year 2011 (10/1/2019-9/30/2011). Data stemmed from the IHS Improving Health Care Delivery Data Project. Multivariate generalized linear mixed models were fitted to assess the association of macrosomia with pre-pregnancy health status and social determinants of health.ResultsNearly half of the women in the sample were under age 25 years (48.6%), and most had Medicaid health insurance coverage (76.7%). Of those with a pre-pregnancy BMI measure, 66.2% were overweight or obese. Although few women had pre-pregnancy DM (4.0%), GDM was present in 12.8% of women. Most women had a normal term delivery (85.4%). Overweight, obesity, pre-pregnancy DM, and county-level rurality were all significantly associated with higher odds of infant macrosomia

Social Determinants of Health and Body Mass Index in American Indian/Alaska Native Children.

Objective: To examine the associations between social determinants of health (SDOH) and prevalent overweight/obesity status and change in adiposity status among American Indian and Alaska Native (AI/AN) children. Methods: The study sample includes 23,950 AI/AN children 2-11 years of age, who used Indian Health Service (IHS) from 2010 to 2014. Multivariate generalized linear mixed models were used to examine the following: (1) cross-sectional associations between SDOH and prevalent overweight/obesity status and (2) longitudinal associations between SDOH and change in adiposity status over time. Results: Approximately 49% of children had prevalent overweight/obesity status; 18% had overweight status and 31% had obesity status. Prevalent severe obesity status was 20% in 6-11-year olds. In adjusted cross-sectional models, children living in counties with higher levels of poverty had 28% higher odds of prevalent overweight/obesity status. In adjusted longitudinal models, children 2-5 years old living in counties with more children eligible for free or reduced-priced lunch had 15% lower odds for transitioning from normal-weight status to overweight/obesity status. Conclusions: This work contributes to accumulating knowledge that economic instability, especially poverty, appears to play a large role in overweight/obesity status in AI/AN children. Research, clinical practice, and policy decisions should aim to address and eliminate economic instability in childhood

Heart Rate Variability and Incident Stroke

BACKGROUND AND PURPOSE: Low heart rate variability (HRV), a marker of cardiac autonomic dysfunction, has been associated with increased all-cause and cardiovascular mortality. We examined the association between reduced HRV and incident stroke in a community-based cohort. METHODS: The Atherosclerosis Risk in Communities (ARIC) study measured HRV using 2-minute ECG readings in 12 550 middle-aged adults at baseline (1987-1989). HRV indices were calculated using the SD of RR intervals (SDNN), the mean of all normal RR intervals (meanNN), the root mean square of successive differences of successive RR intervals (RMSSD), low (LF) and high (HF) frequency power, and the LF/HF ratio. All HRV measures were categorized into quintiles. Incident stroke was adjudicated through 2011. Cox regression was used to estimate hazard ratios (HRs) with the lowest HRV quintile as the reference, with and without stratification by prevalent diabetes mellitus. RESULTS: Over a median follow-up of 22 years, 816 (6.5%) participants experienced incident stroke. After covariate adjustment, there was no strong evidence of association between HRV and stroke risk. In stratified analyses, the lowest HRV quintile was associated with higher stroke risk compared with the highest quintile for SDNN (HR, 2.0, 95% confidence interval, 1.1-4.0), RMSSD (HR, 1.7; 95% confidence interval, 0.9-3.2), LF (HR, 1.5; 95% confidence interval, 0.8-3.0), and HF (HR, 1.7; 95% confidence interval, 0.9-3.0) only among people with diabetes mellitus. CONCLUSIONS: Lower HRV was associated with higher risk of incident stroke among middle-aged adults with prevalent diabetes mellitus but not among people without diabetes mellitus

Archaeological assessment reveals Earth’s early transformation through land use

Humans began to leave lasting impacts on Earth's surface starting 10,000 to 8000 years ago. Through a synthetic collaboration with archaeologists around the globe, Stephens et al. compiled a comprehensive picture of the trajectory of human land use worldwide during the Holocene (see the Perspective by Roberts). Hunter-gatherers, farmers, and pastoralists transformed the face of Earth earlier and to a greater extent than has been widely appreciated, a transformation that was essentially global by 3000 years before the present.Science, this issue p. 897; see also p. 865Environmentally transformative human use of land accelerated with the emergence of agriculture, but the extent, trajectory, and implications of these early changes are not well understood. An empirical global assessment of land use from 10,000 years before the present (yr B.P.) to 1850 CE reveals a planet largely transformed by hunter-gatherers, farmers, and pastoralists by 3000 years ago, considerably earlier than the dates in the land-use reconstructions commonly used by Earth scientists. Synthesis of knowledge contributed by more than 250 archaeologists highlighted gaps in archaeological expertise and data quality, which peaked for 2000 yr B.P. and in traditionally studied and wealthier regions. Archaeological reconstruction of global land-use history illuminates the deep roots of Earth's transformation and challenges the emerging Anthropocene paradigm that large-scale anthropogenic global environmental change is mostly a recent phenomenon