In vivo β-adrenergic receptor responsiveness: ethnic differences in the relationship with symptoms of depression and fatigue

BACKGROUND

Depressive symptoms and fatigue frequently overlap in clinical samples and the general population. The link of depressive symptoms and fatigue with increased risk of cardiovascular disease has been partly explained by shared biological mechanisms including sympathetic overactivity. Prolonged sympathetic overactivity downregulates the responsiveness of the β-adrenergic receptor (β-AR), a receptor that mediates several end-organ sympathetic responses.

PURPOSE

The authors studied whether depression and fatigue are related to reduced β-AR responsiveness within the human body (in vivo) in an ethnically diverse sample of African and Caucasian Americans.

METHODS

The chronotropic25 dose (CD25) was used to determine in vivo β-AR responsiveness in 93 healthy participants. Psychometric measures included the Center of Epidemiological Studies-Depression Scale and the Multidimensional Fatigue Symptom Inventory.

RESULTS

Hierarchical regression analyses (adjusted for age, gender, body mass index, blood pressure, smoking, and ethnicity) revealed that mental fatigue was significantly related to reduced β-AR responsiveness (i.e., higher CD25 values) in the whole sample. Moderation analyses indicated significant ethnicity × depression/fatigue interactions. Depressive symptoms, total fatigue, emotional fatigue, mental fatigue, and physical fatigue were related to reduced β-AR responsiveness in Caucasian American but not in African Americans.

CONCLUSIONS

Our findings suggest that symptoms of depression and fatigue are related to decreased in vivo β-AR responsiveness in Caucasian Americans. The lack of this association in African Americans highlights the importance for considering ethnicity as a potential moderator in research focusing on associations between psychological variables and cardiovascular function.

Racism and ambulatory blood pressure in a community sample

OBJECTIVE

Racism has been identified as a psychosocial stressor that may contribute to disparities in the prevalence of cardiovascular disease. The goal of the present article was to investigate the relationship of perceived racism to ambulatory blood pressure (ABP) in a sample of American-born Blacks and Latinos.

METHODS

Participants included English-speaking Black or Latino(a) adults between the ages of 24 and 65. They completed daily mood diaries and measures of perceived racism, socioeconomic status, and hostility. Participants were outfitted with ABP monitors; 357 provided data on waking hours only, and 245 provided data on both waking and nocturnal ABP.

RESULTS

Perceived racism was positively associated with nocturnal ABP even when controlling for personality factors and socioeconomic status.

CONCLUSIONS

The results suggest that racism may influence cardiovascular disease risk through its effects on nocturnal BP recovery.

Depression and heart failure in patients with a new myocardial infarction

BACKGROUND

Heart failure (HF) is a disabling chronic illness that is increasing in prevalence. Despite advances in its medical treatment, little is known about its psychosocial correlates. This investigation compared the prevalence of depression in patients with and without HF who were hospitalized with myocardial infarction (MI) and also at high psychosocial risk.

METHODS

Baseline data from the 2444 participants in the ENRICHD clinical trial were used. Within 28 days of the MI, all patients were assessed for depression using Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria, for HF based upon left ventricular dysfunction or history of HF and for demographic and medical confounders.

RESULTS

Eight hundred forty-seven patients (34.7%) met the criteria for HF. Major depression was observed in 43% in the HF group compared with 36% in the non-HF group (P < .001). Multivariate modeling showed a 38% increase in odds of HF for patients with major depression, after adjustment for sociodemographic factors and medical comorbidities (adjusted OR 1.38, 95% CI 1.09-1.76).

CONCLUSIONS

These findings suggest that in patients with new MI who are at psychosocial risk, major depression is more prevalent in those who also have HF. Because major depression undermines adherence and lowers quality of life, special efforts to diagnose and treat it in post-MI patients with HF appear warranted.

Families dealing with advanced heart failure: a challenge and an opportunity

The epidemic nature of heart failure (HF), along with its pathophysiological and psychosocial complexities, results in the disease impacting both the patient and the family unit equally yet very differently. The degree of health and wellness of the patient with HF is most often quantified with percentages of coronary artery occlusion and ejection fraction, numbers of interventions, and levels of various laboratory values. Measures of psychosocial wellness of the patient have been minimally addressed, and the needs of the family unit have been essentially disregarded. This author proposes a family-centered approach built on the Friedman Family Assessment Model and Resiliency Model of Family Stress, Coping, and Adaptation to address the unique needs of the family dealing with advanced HF. This author also challenges advanced practice nurses dealing with patients and families with HF in any setting to consider further research in this area where so little information is available.