Association of psychosocial stressors with metabolic syndrome severity among African Americans in the Jackson Heart Study

Highlights

• High global stress is related to significantly greater MetS severity.

• High major life event stress was related to significantly greater MetS severity.

• Women report higher global and life event stress than men.

• Men significantly increase their MetS severity at medium levels of stress.

• Women significantly increase their MetS severity at high levels of stress.

Abstract

Introduction

Using Jackson Heart Study (JHS) data, we assessed the association between perceived psychosocial stressors and metabolic syndrome (MetS) severity in African American adults.

Methods

Participants included 3870 African American JHS participants aged 21–95 years (63.1% women; mean age 53.8 ± 13.0). Psychosocial stressors assessed included: major life events (MLEs); global stress; and weekly stress inventory. Each stress measure was classified into tertiles (low, medium, and high). Associations of psychosocial stressors with a sex- and race/ethnic-specific MetS severity Z-score were examined after adjustment for demographics and MetS risk factors (i.e., nutrition, physical activity, smoking status, and alcohol consumption).

Results

Independent of lifestyle factors, participants who reported high (versus low) perceived global stress and MLEs had significantly greater MetS severity (p = .0207 and p = .0105, respectively). Weekly stress was not associated with MetS severity. Compared to men, women reported significantly higher global stress and MLEs (p < 0.0001). A significant interaction between sex and MLEs (p = .0456) demonstrated men significantly increased their MetS severity at medium levels of stress, whereas women’s MetS severity was significantly increased at high levels of MLEs.

Conclusions

In the total sample, higher reported global stress and MLEs were associated with increased risk of MetS severity, while weekly stress was not. Men’s and women’s stress responses to MLEs were differentially associated with MetS severity, with male MetS severity increasing significantly at lower levels of MLEs relative to women’s MetS severity. These data may have implications for targeting stress-related factors in interventions to improve cardiometabolic health in African American adults.

Introduction

Metabolic syndrome (MetS) is a risk factor for the development of cardiovascular disease (CVD) and type 2 diabetes. Individuals with MetS are twice as likely to develop CVD (Gami et al., 2007; Mottillo et al., 2010) and up to 5 times more likely to develop type 2 diabetes (Ford et al., 2008). Common features of MetS include abdominal adiposity, hypertension, hyperglycemia, and dyslipidemia (Grundy et al., 2005a). In 2012, a nationally representative sample demonstrated the prevalence of MetS in the U.S. was 34.7%, with slightly higher rates among African Americans (AA; 35.5%) than the general population (Aguilar et al., 2015). These rates are consistent with previously published MetS prevalence in the Jackson Heart Study (JHS) with 28.3–36.4% of participants having MetS (Gurka et al., 2016).

While development of MetS is attributed to known risk factors (e.g., poor diet, physical inactivity, smoking, low education) (Cameron et al., 2004; Irwin et al., 2002), adverse psychosocial factors may also contribute to MetS development and severity. Previously published JHS work indicated AA women with depression had worse MetS severity over an 8-year period relative to AA women who were not depressed (Gurka et al., 2016). Additionally, chronic stress has been identified as a possible risk factor for MetS, as it has been posited that psychosocial stress and neuroendocrine activation exert causal effects on MetS development (Björntorp, 1996; Hjemdahl, 2002; Kaur, 2014; Rosmond, 2005). For example, the “Bjorntorp hypothesis” states that chronic stress can activate the HPA axis, which increases cortisol levels leading to an increase in visceral fat deposition, which in turn promotes development of MetS (Björntorp, 1996, Björntorp, 2001). Yet, our group and others have demonstrated that AA tend to have less visceral adiposity relative to their non-Hispanic white counterparts (Cardel et al., 2011; Wagner and Heyward, 2000). Thus, there may be additional factors driving development of MetS in AA beyond that of excess visceral adiposity. The “Weathering Hypothesis” suggests that the health of AA deteriorates prematurely relative to non-Hispanic whites as a result of chronic exposure to social and environmental risk factors (Das, 2013; Thorpe et al., 2016). However, limited research has been conducted investigating the influence of psychosocial stressors on MetS outcomes in large samples of AA. Additionally, most research has focused on development or incidence, rather than severity, of MetS resulting from psychosocial stressors.

Thus, this study used JHS data to examine the associations of psychosocial stressors with severity of MetS among AA adults and whether relationships differed by sex. The hypothesis was that AA adults, particularly women, would have a higher MetS severity and that these relationships would be associated with psychosocial stressors.