The new Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition defines somatic symptom and related disorders as long-standing somatic symptoms that are associated with disproportionate thoughts, feelings, and behaviors, irrespective of whether or not a medical cause for these symptoms can be determined. In this Special Section of Psychosomatic Medicine, several articles address diagnostic issues and the central nervous system correlates of somatic symptom and related disorder and document new developments in its treatment.

The purpose of this study was to describe fatigue and the utility of the Multidimensional Fatigue Symptom Inventory-Short Form (MFSI-SF) to assess fatigue among Latino cancer patients. Twenty-two female and thirteen male Latino cancer patients participated in one of seven focus groups that took place in the southern California USA-Mexico border region. Participants were asked to describe their fatigue experiences; participants also completed the MFSI-SF and provided feedback about the items. Content analyses indicate that there are gender differences in the salience of the challenges that fatigue poses. Men tended to focus on physical symptoms, whereas women tended to focus on the impairment in role fulfillment. Findings have implications for intervention and health education efforts in Latino cancer patients.

Background

Obstructive sleep apnea (OSA) is a prevalent disorder with multiple consequences including negative effects on neurocognitive function. Several domains of cognitive function are impaired in OSA patients, but the mechanisms through which this sleep disorder results in impairment are not clear. Given the well-known effects of cortisol on cognitive function, in particular memory, the dysregulating effects of OSA on cortisol levels are hypothesized as a potential pathway leading to cognitive impairment.

Methods

Fifty-five participants with OSA (mean apnea-hypopnea index [AHI], 30.3) were assessed over 2 days. Over a 24-h period, blood samples were collected every 2h to examine cortisol levels. The following night, sleep was monitored with polysomnography (PSG). Participants were given a battery of neurocognitive tests, which assessed seven cognitive domains.

Results

OSA severity assessed by oxygen desaturation index (ODI) was associated with 24-h cortisol levels. AHI, ODI, and nighttime cortisol levels were associated with global deficit scores (GDS) in cognitive functioning, particularly in domains of learning, memory, and working memory (P<.05 for all). Hierarchical linear regression analysis revealed that nighttime cortisol accounted for 9-16% of variance in learning (P=.018), memory (P=.003), and working memory (P=.016) domains, though apnea severity did not significantly predict any additional variance.

Conclusions

In our sample of patients with OSA, nocturnal cortisol levels were associated with neuropsychologic functioning above and beyond the influence of covariates and apnea severity. These findings suggest that OSA-related alterations in cortisol activity may partially explain the pathophysiology of neuropsychologic impairments in sleep apnea.

Fatigue is an important and often underemphasized symptom in patients with obstructive sleep apnea (OSA). Sleep fragmentation, i.e., arousals and disruptions in sleep architecture, is common in patients with OSA and may potentially contribute to their fatigue. We hypothesized that arousal frequency and changes in sleep architecture contribute to the fatigue experienced by patients with OSA. Seventy-three patients with diagnosed but untreated OSA (AHI ≥ 15) were enrolled in this study. A baseline polysomnogram was obtained, and fatigue was measured with the Multidimensional Fatigue Symptom Inventory-short form (MFSI-sf). We evaluated the association between fatigue and arousals and various polysomongraphic variables, including sleep stages and sleep efficiency. Significant correlations between MFSI-sf subscale scores and various arousal indices were noted. Emotional fatigue scores were associated with total arousal index (r = 0.416, p = .021), respiratory movement arousal index (r = 0.346, p = .025), and spontaneous movement arousal index (r = 0.378, p = .025). Physical fatigue scores were associated with total arousal index (r = 0.360, p = .033) and respiratory movement arousal index (r = 0.304, p = .040). Percent of stage 1 sleep and REM sleep were also associated with physical and emotional fatigue scores. Hierarchal linear regression analysis demonstrated that emotional fatigue scores were independently associated with spontaneous movement arousals after controlling for age, body mass index, depression, and sleep apnea severity. These findings suggest that arousals may contribute to the fatigue seen in patients with OSA.

The objective of this study is to examine the diurnal variability of C-reactive protein (CRP) in obstructive sleep apnea (OSA). Participants included 44 women and men with untreated OSA (mean apnea/hypopnea index = 37.5, SD ± 28) and 23 healthy adults with no OSA. Sleep was monitored with polysomnography in the University of California San Diego General Clinical Research Center. Over a 24-h period, blood was collected every 2 h, and CRP levels were determined. Adjusting for age, gender, and body mass index, a significant group by time interaction showed that patients with OSA had higher CRP levels during the daytime (8:00 a.m.–8:00 p.m.) versus the nighttime (10:00 p.m. until 6:00 p.m.; p < 0.001). Non-apneics showed no significant change in CRP levels during the 24 h. The findings indicate that sleep apnea patients have disproportionately elevated CRP levels in the day versus the nighttime, possibly as a result of carryover effects of nighttime arousal into the daytime.

Objective

Living in adverse neighborhood conditions has been linked with greater prevalence of cardiovascular disease (CVD). We aimed to learn whether perceived neighborhood problems are related to attenuated nocturnal blood pressure (BP) dipping, a risk factor for CVD morbidity.

Method

A sample of 133 adults (71 male, 62 female; 80 White, 53 Black) underwent 24-hr ambulatory blood pressure monitoring. The neighborhood problem scale (NPS) was used to assess neighborhood environmental stressors.

Results

Nocturnal dipping in systolic (SBP), diastolic (DBP) and mean arterial (MAP) blood pressure was reduced in individuals with higher NPS scores (p < .05). Hierarchical regression analyses revealed that neighborhood problems explained 4%-6% of the variance in SBP, DBP, and MAP dipping (p < .05) even after adjusting for several theoretical confounders such as social status, age, gender, race, body mass index (BMI), smoking, exercise, depression and discrimination.

Conclusion

Neighborhood problems may contribute to attenuated BP dipping beyond the effect of known risk factors.

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.

Although objective and subjective indicators of socioeconomic status (SES) are linked to cardiovascular disease (CVD), little is known about their relationship to endothelial dysfunction, which often precedes CVD. This study examined how objective and subjective SES relate to brachial artery flow-mediated dilation (FMD). FMD was assessed in 72 healthy adults (mean age 36 years). The MacArthur Scale of Subjective Social Status assessed perceived social standing in the USA (SSS-USA) and local community (SSS-Community). Objective SES measures included income and the Hollingshead Two-Factor Index of Social Position (education, occupation). Adjusted regressions revealed that SSS-Community positively correlated with FMD (p < 0.05) and explained 8% of the variance. No other SES measures were significant for FMD. The association between FMD and SSS-Community remained significant (p < 0.01) after adjustment for objective SES and other covariates. Lower subjective social status in one’s community may be linked to CVD via impaired vasodilation.

Patients with obstructive sleep apnea (OSA) have been described to have increased levels of inflammatory cytokines (particularly TNF-α) and have severely disturbed sleep architecture. Serum inflammatory markers, even in normal individuals, have been associated with abnormal sleep architecture. Not much is known about the role the TNF receptor plays in the inflammation of OSA nor if it is associated with changes in sleep architecture or arousals during the night. We hypothesized that the TNF receptor might play an important role in the inflammation as well as sleep architecture changes in patients with OSA. Thirty-six patients with diagnosed (AHI > 15) but untreated OSA were enrolled in this study. Baseline polysomnograms as well as TNF-α and soluble TNF receptor I (sTNF-RI) serum levels were obtained on all patients. We evaluated the association between serum levels of TNF-α and sTNF-RI with various polysomongraphic characteristics, including sleep stages and EEG arousals. sTNF-RI levels were significantly correlated with snore arousals (r value 0.449, p value 0.009), spontaneous movement arousals (r value 0.378, p value 0.025), and periodic limb movement arousals (r value 0.460, p value 0.008). No statistically significant correlations were observed with TNF-α to any polysomnographic variables. To control for statistical significance with multiple comparisons, a MANOVA was performed with TNF-α and sTNF-RI as dependent variables and sleep architecture measures and arousals as independent variables. The model for sTNF-RI was statistically significant (F value 2.604, p value 0.03), whereas the model for TNF-α was not, suggesting sleep quality significantly affects sTNF-RI. Hierarchal linear regression analysis demonstrated that sTNF-RI was independently associated with spontaneous movement arousal index scores after controlling for age, body mass index, and sleep apnea severity. These findings suggest that sTNF-RI is associated with arousals during sleep, but not with other measures in patients with OSA.