Index of cardiometabolic health: a new method of measuring allostatic load using electronic health records

Allostatic Load in Childhood, Adolescence, and Young Adulthood: Are Assumptions of Measurement Invariance Warranted?

OVERVIEW

Allostatic load represents the cumulative toll of chronic mobilization of the body's stress response systems, as indexed by biomarkers. Higher levels of stress and disadvantage predict higher levels of allostatic load, which, in turn, predict poorer physical and mental health outcomes. To maximize the efficacy of prevention efforts, screening for stress- and disadvantage-associated health conditions must occur before middle age-that is, during childhood, adolescence, and young adulthood. However, this requires that models of allostatic load display properties of measurement invariance across age groups. Because most research on allostatic load has featured older adults, it is unclear if these requirements can be met.

METHODS

To address this question, we fit a series of exploratory and confirmatory analytic models to data on eight biomarkers using a nationally representative sample of N = 4260 children, adolescents, and young adults drawn from the National Health and Nutrition Examination Survey dataset.

RESULTS

Exploratory and confirmatory models indicated that, consistent with allostatic load theory, a unidimensional model was a good fit to the data. However, this model did not display properties of measurement invariance; post-hoc analyses suggested that the biomarkers included in the final confirmatory model were most strongly intercorrelated among young adults and most weakly intercorrelated among adolescents.

CONCLUSIONS

These results underscore the importance of testing assumptions about measurement invariance in allostatic load before drawing substantive conclusions about stress, disadvantage, and health by directly comparing levels of allostatic load across different stages of development, while underscoring the need to expand investigations of measurement invariance to samples of longitudinal data.

Uses of Social Determinants of Health Data to Address Cardiovascular Disease and Health Equity: A Scoping Review

Background Cardiovascular disease is the leading cause of morbidity and mortality worldwide. Prior research suggests that social determinants of health have a compounding effect on health and are associated with cardiovascular disease. This scoping review explores what and how social determinants of health data are being used to address cardiovascular disease and improve health equity. Methods and Results After removing duplicate citations, the initial search yielded 4110 articles for screening, and 50 studies were identified for data extraction. Most studies relied on similar data sources for social determinants of health, including geocoded electronic health record data, national survey responses, and census data, and largely focused on health care access and quality, and the neighborhood and built environment. Most focused on developing interventions to improve health care access and quality or characterizing neighborhood risk and individual risk. Conclusions Given that few interventions addressed economic stability, education access and quality, or community context and social risk, the potential for harnessing social determinants of health data to reduce the burden of cardiovascular disease remains unrealized.

Differential associations between everyday versus institution-specific racial discrimination, self-reported health, and allostatic load among black women: implications for clinical assessment and epidemiologic studies

PURPOSE

Black women have the highest estimated allostatic load (AL). AL and self-perceived health are strong health predictors and have been linked to racial discrimination. Research suggests that everyday and institution-specific racial discrimination may predict different AL and self-reported health (SRH) outcomes. Furthermore, discrepancies between AL and self-perceived health could widen disparities. We estimated associations between everyday versus institution-specific racial discrimination with AL and SRH.

METHODS

Data are from a San Francisco Bay Area community sample of 208 black women aged 30-50 years. Participation involved a questionnaire, self-interview, blood draw, and anthropometric measurements. Adjusted generalized linear regression models estimated associations of racial discrimination with AL and SRH.

RESULTS

After adjusting for age, socioeconomic position, and medication use, institution-specific discrimination was negatively associated with AL (i.e., better health), whereas everyday experiences showed no association. Those reporting very-high (vs. moderate) institution-specific discrimination had lower AL (β = -1.31 [95% CI: -2.41, -0.20]; AL range: 0-15). No racial discrimination-SRH association was found.

CONCLUSIONS

For black women, (1) institution-specific racial discrimination may be differentially embodied compared with everyday experiences and (2) institutional racism may contribute to physiologic stress-regulation regardless of self-perceived health status. Potential factors that may contribute to an inverse racial discrimination-AL association, and future research, are discussed.

Racial discrimination, educational attainment, and biological dysregulation among midlife African American women

OBJECTIVE

To examine the association between self-reported racial discrimination and allostatic load, and whether the association differs by socioeconomic position.

METHODS

We recruited a purposive cross-section of midlife (ages 30-50) African American women residing in four San Francisco Bay area counties (n = 208). Racial discrimination was measured using the Experience of Discrimination scale. Allostatic load was measured as a composite of 15 biomarkers assessing cardiometabolic, neuroendocrine, and inflammatory activity. We calculated four composite measures of allostatic load and three system-specific measures of biological dysregulation. Multivariable regression was used to examine associations, while adjusting for relevant confounders.

RESULTS

In the high education group, reporting low (b = -1.09, P = .02, 95% CI = -1.99, -0.18) and very high (b = -1.88, P = .003, 95% CI = -3.11, -0.65) discrimination was associated with lower allostatic load (reference=moderate). Among those with lower education, reporting low (b = 2.05, P = .008, 95% CI = 0.55,3.56) discrimination was associated with higher allostatic load. Similar but less consistent associations were found for poverty status. Associations were similar for cardiometabolic functioning, but not for neuroendocrine or inflammatory activity.

CONCLUSIONS

Racial discrimination may be an important predictor of cumulative physiologic dysregulation. Factors associated with educational attainment may mitigate this association for African American women and other groups experiencing chronic social stress.

Elevated allostatic load in individuals presenting at psychiatric emergency services

OBJECTIVE

Individuals requiring psychiatric emergency services are often highly distressed and intoxicated. To provide an objective and comprehensive measure of their stress-related physiological dysregulations, we indexed allostatic load with 14 biomarkers collected within 24 h of patients' admission to the largest psychiatric hospital in the Canadian province of Quebec.

METHODS

This study (N = 278) combines data for emergency patients (n = 76; 65.8% women; M age = 44.97, SE = 1.6) and hospital workers who served as sex- and age-matched controls (n = 202; 70.8% women; M age = 40.10, SE = 0.83). Sex-specific allostatic load indices summarized neuroendocrine (cortisol), immune (tumor necrosis factor-α, interleukin-6, c-reactive protein), metabolic (insulin, glycosylated hemoglobin, total cholesterol, high-density lipoprotein, low-density lipoprotein, triglycerides, body mass index), and cardiovascular (heart rate, systolic and diastolic blood pressure) functioning. Well-validated questionnaires assessed substance (ab)use.

RESULTS

Individuals presenting at psychiatric emergency showed elevated allostatic load, drug abuse, and tobacco use compared to controls. Elevated allostatic load in emergency patients was driven by elevated cortisol, interleukin-6, systolic blood pressure, and heart rate; however, allostatic load was not explained by substance (ab)use or demographic variables. Sub-group analyses revealed that emergency patients primarily diagnosed with bipolar, depressive, or anxiety disorders showed higher allostatic load than those diagnosed with personality disorder(s).

CONCLUSIONS

This study demonstrates that individuals presenting at psychiatric emergency services show physiological dysregulations associated with chronic stress. Future research should explore the clinical utility of allostatic load in predicting comorbidities among psychiatric patients.

Assessment of cumulative health risk in the World Trade Center general responder cohort

BACKGROUND

Multiple comorbidities have been reported among rescue/recovery workers responding to the 9/11/2001 WTC disaster. In this study, we developed an index that quantifies the cumulative physiological burden of comorbidities and predicts life expectancy in this cohort.

METHODS

A machine learning approach (gradient boosting) was used to model the relationship between mortality and several clinical parameters (laboratory test results, blood pressure, pulmonary function measures). This model was used to construct a risk index, which was validated by assessing its association with a number of health outcomes within the WTC general responder cohort.

RESULTS

The risk index showed significant associations with mortality, self-assessed physical health, and onset of multiple chronic conditions, particularly COPD, hypertension, asthma, and sleep apnea.

CONCLUSION

As an aggregate of several clinical parameters, this index serves as a cumulative measure of physiological dysregulation and could be utilized as a prognostic indicator of life expectancy and morbidity risk.