Weight stigma and acculturation in relation to hair cortisol among Asian Americans with overweight and obesity: A cross-sectional study

Weight stigma as a stressor: A preliminary multi-wave, longitudinal study testing the biobehavioral pathways of the cyclic obesity/weight-based stigma (COBWEBS) model

Higher weight individuals often face significant weight stigma. According to the Cyclic Obesity/Weight-Based Stigma (COBWEBS) model, weight stigma operates as a stressor that increases the stress hormone cortisol and promotes comfort eating, thus resulting in weight gain. Such weight gain is harmful as it exposes individuals to further stigmatization. Thus far, no study has yet tested the mechanistic pathways of the COBWEBS model and prospective longitudinal studies are severely lacking. To fill this gap, the current study tested the biobehavioral pathways of the COBWEBS model using a 4-wave yearlong longitudinal study comprising 348 higher weight individuals. Using a structural equation modeling framework, we tested three cross lagged panel models for the putative mediator, comfort eating. The models examined either synchronous and/or lagged effects across weight stigma, perceived stress, comfort eating, weight, and future weight stigma. The best fitting model revealed significant associations between baseline weight stigma, perceived stress, and comfort eating within the same month. However, comfort eating did not significantly predict weight four months later. Weight status and baseline weight stigma both predicted future weight stigma as expected. Additionally, a separate path model with hair cortisol found that weight stigma predicted perceived stress four months later, but stress did not predict aggregate cortisol levels from months 10 and 11. Hair cortisol also did not predict later weight. This preliminary work lays the foundation for identifying modifiable targets of weight stigma, thereby offering potential avenues to reduce weight stigma's harm on higher weight individuals.

A systematic review of hair cortisol in healthy adults measured using immunoassays: Methodological considerations and proposed reference values for research

Hair cortisol concentration (HCC) has shown remarkable promise as a stable, non-invasive measure of systemic cortisol; however, despite methodological advances, the value that would typically be seen in healthy adults has not been established. Therefore, we sought to review the relevant literature to determine a reference value for HCC in healthy (i.e., non-clinical) adults. To this end, we conducted a systematic review of the PubMed, Scopus, and CINAHL databases for studies that measured healthy adult HCC using immunoassay methods, given that these are the most widely accessible analytical tools. To be eligible, studies were required to have been published in English, to have provided relevant descriptive statistics (i.e., means and standard deviations), and to have used a healthy adult human sample. We found 17 studies that met our inclusion criteria; the reports involved 1348 participants with a mean age of about 38 years. Since we identified a large amount of between-study heterogeneity, we completed a random-effect meta-regression analysis and found that test kit vendor was the only significant variable of the model. As a result, when using methodologies from traditional finite mixture distributions to determine reference values for mean and elevated HCC in individual healthy adults, we calculated these estimates for each of the major test kit vendors. Future work will need to determine whether our estimated reference values need to be modified, and these efforts will be greatly assisted by studies that account for potential moderating factors, such as age, sex, and ethnicity.

Cross-sectional relation of long-term glucocorticoids in hair with anthropometric measurements and their possible determinants: A systematic review and meta-analysis

BACKGROUND

Long-term glucocorticoids (HairGC) measured in scalp hair have been associated with body mass index (BMI), waist circumference (WC), and waist-hip-ratio (WHR) in several cross-sectional studies. We aimed to investigate the magnitude, strength, and clinical relevance of these relations across all ages.

METHODS

We performed a systematic review and meta-analysis (PROSPERO registration CRD42020205187) searching for articles relating HairGC to measures of obesity. Main outcomes were bivariate correlation coefficients and unadjusted simple linear regression coefficients relating hair cortisol (HairF) and hair cortisone (HairE) to BMI, WC, and WHR.

RESULTS

We included k = 146 cohorts (n = 34,342 individuals). HairGC were positively related to all anthropometric measurements. The strongest correlation and largest effect size were seen for HairE-WC: pooled correlation 0.18 (95%CI 0.11-0.24; k = 7; n = 3,158; I²  = 45.7%) and pooled regression coefficient 11.0 cm increase in WC per point increase in 10-log-transformed HairE (pg/mg) on liquid-chromatography-(tandem) mass spectrometry (LC-MS) (95%CI 10.1-11.9 cm; k = 6; n = 3,102). Pooled correlation for HairF-BMI was 0.10 (95%CI 0.08-0.13; k = 122; n = 26,527; I²  = 51.2%) and pooled regression coefficient 0.049 kg/m² per point increase in 10-log-transformed HairF (pg/mg) on LC-MS (95%CI 0.045-0.054 kg/m² ; k = 26; n = 11,635).

DISCUSSION

There is a consistent positive association between HairGC and BMI, WC, and WHR, most prominently and clinically relevant for HairE-WC. These findings overall suggest an altered setpoint of the hypothalamic-pituitary-adrenal axis with increasing central adiposity.

Internalized weight bias and cortisol reactivity to social stress

Weight-associated stigmatization and discrimination may induce chronic stress in individuals with obesity. As a consequence, this stressor may cause an imbalance of HPA stress axis leading to increased eating behavior, and ultimately, weight gain. However, the direct link between internalized weight bias and stress response to acute stressors via cortisol secretion has not been investigated so far. Therefore, the purpose of this study was to investigate the interaction between internalized weight stigma as a stressor and cortisol reactivity in an acute psychosocial stress situation induced by the Trier Socials Stress Test for groups (TSST-G). Participants with BMI >30 kg/m² (n = 79) were included in the study. Results reveal that while individuals with low internalized stigma reacted as predicted with an increase in cortisol secretion to acute psychosocial stress, individuals with medium or high internalized stigma did not show a typical cortisol response. However, these findings depend on the several factors, for instance on gender. In sum, acute stress in individuals with internalized weight bias seems to blunt HPA axis reactions to acute psychosocial stress. The study contributes to the understanding of the psychological and endocrinological consequences of internalized weight bias and underlines the importance of interventions to reduce stigmatization.

Deciphering the Association Between Hypothalamus-Pituitary-Adrenal Axis Activity and Obesity: A Meta-Analysis

OBJECTIVE

Both the cortisol awakening response (CAR; corresponding to the state measurement) and hair cortisol concentration (HCC; corresponding to the trait measurement) are considered reliable markers of hypothalamus-pituitary-adrenal axis activity. Because cortisol has long been associated with adiposity, this systematic review and meta-analysis aims to summarize and compare the literature around CAR and HCC and their association with obesity or fat distribution indices.

METHODS

The PubMed, Web of Science (Web of Science Core Collection and Medline), EBSCO Information Services, Embase, and PsycNET databases were searched, and full-text articles investigating the association between CAR or HCC and markers of adiposity in humans were included. Meta-analyses were then performed to compare studies associating CAR or HCC with BMI (a marker of general adiposity) and waist circumference (a marker of fat distribution).

RESULTS

The results of this review highlight inconsistencies in cortisol sampling and CAR computation, which makes comparisons between studies difficult. It was found that adiposity indices are not associated with CAR but that they correlate significantly and positively with HCC. The subgroup analysis hinted to possible age differences in the magnitude of the association between HCC and BMI.

CONCLUSIONS

Trait rather than state measurement of the hypothalamus-pituitary-adrenal axis activity is associated with increased general and abdominal adiposity in humans.

Weight Stigmatization and Binge Eating in Asian Americans with Overweight and Obesity

Weight stigma and binge eating have been found to be associated in Western populations; however, this relationship is understudied among Asian Americans. The aims of the study were to (1) investigate the prevalence of binge eating and its relationship with experienced weight stigma in higher-weight Asian Americans, and (2) examine whether the level of acculturation moderates this relationship. Data were collected from a cross-sectional study with 166 higher-weight Asian American adults living in North Carolina, United States. Demographic data, the frequency of experiencing weight stigma, the severity of binge eating, the levels of acculturation, the perceived racism against Asians, and perceived stress were assessed via self-reported questionnaires. The results indicated that experienced weight stigma was a significant independent predictor over and above the effects of other stressors, such as racism and general stress. The level of acculturation did not influence the relationship between the experienced weight stigma and binge eating after adjusting for relevant covariates. Our findings contribute to the limited literature examining weight stigma and binge eating among Asian American populations, highlighting that higher levels of experienced weight stigma are associated with a greater degree of binge eating.