Ketamine for the treatment of depression in patients receiving hospice care: a retrospective medical record review of thirty-one cases.

BACKGROUND: Depression is prevalent in patients receiving hospice care. Standard antidepressant medications do not work rapidly enough in this setting. Evidence suggests that ketamine rapidly treats treatment refractory depression in the general population. Ketamine׳s role for treating depression in the hospice population warrants further study. METHODS: A retrospective medical record review of 31 inpatients receiving hospice care who received ketamine for depression on a clinical basis was conducted. The primary outcome measure was the Clinical Global Impression Scale, which was used retrospectively to rate subjects׳ therapeutic improvement, global improvement, and side effects from ketamine over 21 days. Additionally, time to onset of therapeutic effect was analyzed. RESULTS: Using the Clinical Global Impression Scale, ketamine was found to be significantly therapeutically effective through the first week after ketamine dosing (p < 0.05), with 93% of patients showing positive results for days 0-3 and 80% for days 4-7 following ketamine dosing. Patients experienced global improvement during all 4 studied time periods following ketamine dosing (p < 0.05). Significantly more patients had either no side effects or side effects that did not significantly impair functioning at each of the 4 assessed time periods following ketamine dosing (p < 0.05). Additionally, significantly more patients experienced their first therapeutic response during days 0-1 following ketamine dosing (p < 0.001) than during any other time period. CONCLUSIONS: These data suggest that ketamine may be a safe, effective, and rapid treatment for clinical depression in patients receiving hospice care. Blinded, randomized, and controlled trials are required to substantiate these findings and support further clinical use of this medication in hospice settings.

The impact of additional support services on caregivers of hospice patients and hospice social workers.

Family caregivers often suffer higher levels of physical and emotional distress when caring for a chronically or terminally ill family member. Providing this kind of care to a loved one at the end of life contributes to increased stress, health problems, and a decreased quality of life. The Hospice Caregiver Support Project provided support services to caregivers identified by the hospice social worker as needing this support and/or assistance. Results from the project show that offering additional services relieved caregiver stress by allowing the caregiver time away from their caregiving role and reducing feelings of guilt and worry, and increased hospice social worker satisfaction with their ability to respond to the needs of hospice patients and caregivers.

Daily oral ketamine for the treatment of depression and anxiety in patients receiving hospice care: a 28-day open-label proof-of-concept trial.

BACKGROUND: Depression and anxiety are prevalent and undertreated in patients receiving hospice care. Standard antidepressants do not work rapidly or often enough to benefit most of these patients. Ketamine has many properties that make it an interesting candidate for rapidly treating depression and anxiety in patients receiving hospice care. To test this hypothesis, a 28-day, open-label, proof-of-concept trial of daily oral ketamine administration was conducted in order to evaluate the tolerability, potential efficacy, and time to potential efficacy in treating depression and anxiety in patients receiving hospice care. METHODS: In this open-label study, 14 subjects with symptoms of depression or depression mixed with anxiety warranting psychopharmacological intervention received daily oral doses of ketamine hydrochloride (0.5 mg/kg) over a 28-day period. The primary outcome measure was the Hospital Anxiety and Depression Scale (HADS), which was used to rate overall depression and anxiety symptoms at baseline, and on days 3, 7, 14, 21, and 28. RESULTS: Over the 28-day trial there was significant improvement in both depressive symptoms (F5,35=8.03, p=0.002, η(2)=0.534) and symptoms of anxiety (F5,35=14.275, p<0.001, η(2)=0.67) for the eight subjects that completed the trial. One hundred percent of subjects completing the trial responded to ketamine for both anxiety and depression. A significant response in depressive symptoms occurred by day 14 for depression (mean Δ=3.5, d=1.14, 95% CI=1.09-5.9, p=0.01) and day 3 for anxiety (mean Δ=2.4, d=0.67, 95% CI=1.0-3.7, p=0.004). These improvements remained significant through day 28 for both depression (mean Δ=4.0, d=1.34, 95% CI=2.3-5.9, p=0.001) and anxiety (mean Δ=6.09, d=1.34, 95% CI=3.6-8.6, p<0.001). Side effects were rare, the most common being diarrhea, trouble sleeping, and trouble sitting still. CONCLUSIONS: Patients who received daily oral ketamine experienced a robust antidepressant and anxiolytic response with few adverse events. The response rate for depression is similar to those found with IV ketamine; however, the time to response is more protracted. The findings of the potential efficacy of oral ketamine for depression and the response of anxiety symptoms are novel. Further investigation with randomized, controlled clinical trials is necessary to firmly establish the efficacy and safety of oral ketamine for the treatment of depression and anxiety in patients receiving hospice care or other subject populations.

Comparison of international medical graduates with US medical students and residents after a four-week course in palliative medicine: a pilot study.

BACKGROUND: The need for doctors who have skills in pain management and palliative medicine is greatest in low and moderate resource countries where patients most frequently present to their health care system with advanced illness and greater than 80% of the global deaths occur. While medical students trained in the United States are required to have training in palliative medicine, international medical graduates (IMGs), who have completed medical school outside North America, may not have the same exposure to palliative medicine training as U.S. physicians. The goal of this study was to evaluate whether a four-week course in palliative medicine could bring IMG attitudes, concerns, competence, and knowledge to the level of U.S. trainees. METHODS: As part of a prospective cohort study, 21 IMGs from 14 countries participated in a four-week course in palliative medicine. Attitudes, concerns, self-reported competence, and knowledge were assessed pre-course and post-course. The course was evaluated weekly and at the end of the four-week program. The data from the IMGs was compared to data from U.S. medical students and residents using the same assessment tools. RESULTS: After the course, IMGs had significantly decreased concern about ethical and legal issues in palliative medicine to the level of U.S.-trained residents and a significant increase in knowledge and self-rated competence equivalent to the level of U.S. trainees. CONCLUSIONS: A four-week course in palliative medicine can improve the levels of concern, knowledge and self-assessed competence in IMGs to the level of US trainees.

PAL-MED CONNECT ®: a telephone consultation hotline for palliative medicine questions.

BACKGROUND: Community physicians are often ill-prepared for the management of complex symptoms. With a shortage of board certified physicians in palliative medicine to assist, the result is a lack of access to critical pain and symptom management expertise to care for seriously ill Californians. We report on a palliative medicine telephone hotline available to health care professionals. METHODS: San Diego Hospice and The Institute for Palliative Medicine received a grant to provide a telephone hotline for health care professionals to assist in answering clinical questions relating to palliative care. An extensive marketing campaign was initiated to publicize the service. Information from the calls was collected over a 2.5-year period. The data included referral source, geographic area, diagnosis, and reason for call. Satisfaction surveys were sent following each call. RESULTS: During the first 2.5 years of operation 498 calls were recorded. Although marketing was directed within the state of California, the majority of calls originated outside the state after the first year (66%). Approximately 43% of calls came from physicians, followed by 22% from registered nurses, 15% from nurse practitioners, and 6% from pharmacists. Nearly half of the calls were received from repeat callers. The most frequent topics for callers were related to pain and symptom management (29%), followed by hospice care (21%), medication dosing, and general palliative care (14% each). Ninety-five percent of the callers completed the satisfaction survey with 89% likely to use the service again. CONCLUSIONS: The hotline proved to be a valuable resource for health care providers caring for patients requiring palliative care as evidenced by the steady increase in the number of calls over the initial 2.5 years of operation. Future research on how the information directly impacted patient care might generate data to support the continuation of this service via partnerships with other organizations.

Development and evaluation of a palliative medicine curriculum for third-year medical students.

OBJECTIVE: To assess the impact, retention, and magnitude of effect of a required didactic and experiential palliative care curriculum on third-year medical students' knowledge, confidence, and concerns about end-of-life care, over time and in comparison to benchmark data from a national study of internal medicine residents and faculty. DESIGN: Prospective study of third-year medical students prior to and immediately after course completion, with a follow-up assessment in the fourth year, and in comparison to benchmark data from a large national study. SETTING: Internal Medicine Clerkship in a public accredited medical school. PARTICIPANTS: Five hundred ninety-three third-year medical students, from July 2002 to December 2007. MAIN OUTCOME MEASURES: Pre- and postinstruction performance on: knowledge, confidence (self-assessed competence), and concerns (attitudes) about end-of-life care measures, validated in a national study of internal medicine residents and faculty. Medical student's reflective written comments were qualitatively assessed. INTERVENTION: Required 32-hour didactic and experiential curriculum, including home hospice visits and inpatient hospice care, with content drawn from the AMA-sponsored Education for Physicians on End-of-life Care (EPEC) Project. RESULTS: Analysis of 487 paired t tests shows significant improvements, with 23% improvement in knowledge (F(1,486)=881, p<0.001), 56% improvement in self-reported competence (F(1,486)=2,804, p<0.001), and 29% decrease in self-reported concern (F(1,486)=208, p<0.001). Retesting medical students in the fourth year showed a further 5% increase in confidence (p<0.0002), 13% increase in allaying concerns (p<0.0001), but a 6% drop in knowledge. The curriculum's effect size on M3 students' knowledge (0.56) exceeded that of a national cross-sectional study comparing residents at progressive training levels (0.18) Themes identified in students' reflective comments included perceived relevance, humanism, and effectiveness of methods used to teach and assess palliative care education. CONCLUSIONS: We conclude that required structured didactic and experiential palliative care during the clinical clerkship year of medical student education shows significant and largely sustained effects indicating students are better prepared than a national sample of residents and attending physicians.

Psychiatry resident education in palliative care: opportunities, desired training, and outcomes of a targeted educational intervention.

OBJECTIVES: To assess the educational offerings provided to psychiatry residents in palliative care as well as their concomitant interest in learning more about this subspecialty. To measure the pre- and post-levels of competence, concern, and knowledge exhibited by psychiatry residents when completing a formalized clinical rotation in hospice and palliative care, with additional comparisons to family and internal medicine residents completing the same clinical rotation. METHODS: Fifty-two Psychiatry Program Directors and 98 psychiatry residents completed an online survey assessing the current course offerings and level of interest in palliative care. Thirty psychiatry residents were additionally evaluated before and after completion of a clinical rotation in hospice and palliative care. RESULTS: Few programs offered any formalized training in palliative care, although nearly all psychiatry residents reported interest in this area. A clinical rotation in palliative care significantly increased psychiatry residents' competence and knowledge while simultaneously decreasing their concerns about practice in this area; most were at levels comparable to family and internal medicine residents completing the same rotation. Psychiatry residents' knowledge of pain assessment, pain management, and generalized non-pain management were also enhanced during the rotation. CONCLUSIONS: Results indicate that training opportunities in palliative care are lacking for psychiatry residents in the United States although residents report strong interest in this area. This study finds psychiatry residents can benefit as much as other disciplines from receiving palliative care training. The need to offer such training within psychiatry residencies is highlighted and the welcoming of psychiatrists into palliative care is suggested.

The hospice caregiver support project: providing support to reduce caregiver stress.

INTRODUCTION: The vast majority (80%) of care provided to hospice patients is given by informal and unpaid caregivers, who are often family members. They may be responsible for everything from management of the household and finances to medical and personal care. Providing this kind of care to a loved one at the end of life can contribute to increased stress, health problems, and decreased quality of life. METHODS: Hospice social workers referred caregivers identified as needing additional support into a special project that funded services not covered by hospice and that the family could not afford to purchase. There were no restrictions on the types of services that could be requested. The Pearlin role overload measure (ROM) was administered and the family selected a service provider from an approved list of agencies. Upon completion of the service period, the ROM was re-administered. Use of the hospice respite benefit by any hospice patient during this study was compared with use before the project began. RESULTS: Self-reported caregiver stress, as measured by the Pearlin ROM pre- and post-services, decreased by 52% (t(122) = 10.254; p < 0.0001). Use of the hospice respite benefit requested by any hospice patient caregiver decreased during the project period (χ(2), p < 0.02), and when respite was requested fewer days were used as compared with the same time period prior to the project (χ(2), p < 0.0043). CONCLUSION: The project results show that offering such services relieved caregiver stress, reduced use of respite, and reduced the number of respite days used.

Everyday discrimination and nocturnal blood pressure dipping in black and white americans.

OBJECTIVE: To investigate whether an association exists between experiences of everyday discrimination and blood pressure (BP) dipping in a biracial sample of black and white adults. Attenuated nocturnal BP dipping is closely linked to cardiovascular morbidity and mortality. Self-reported experiences of everyday discrimination have also been associated with negative cardiovascular health outcomes. METHODS: Seventy-eight hypertensive and normotensive women and men (n = 30 black and 48 white) reported on their experiences of everyday discrimination (Everyday Discrimination Scale) and underwent two separate 24-hour ambulatory BP monitoring (ABPM) sessions approximately 1 week apart. RESULTS: Correlation analysis revealed that higher endorsement of everyday discrimination was significantly associated with less diastolic BP (DBP) and systolic BP (SBP) dipping (p < .05). Subsequent hierarchical regression analyses indicated that everyday discrimination explained 8% to 11% of the variance in SBP and DBP dipping above and beyond other demographic and life-style-related factors, including race, age, 24-hour BP, body mass index, and current socioeconomic status. The relationship between discrimination and dipping was significantly stronger on the second night of monitoring. Finally, analyses revealed that everyday discrimination mediated the relationship between race and BP dipping. CONCLUSIONS: These findings suggest that experiences of everyday discrimination are associated with less nocturnal SBP and DBP dipping above and beyond the effect of known covariates. The use of multiple ABPM sessions may facilitate the detection of relationships between psychological variables and BP dipping.

Influence of education and neighborhood poverty on pressor responses to phenylephrine in African-Americans and Caucasian-Americans.

Although neighborhood disadvantage has been linked to the development of cardiovascular disease, the mechanism through which living in impoverished neighborhoods is associated with poor cardiovascular health is not well understood. Additionally, it is not clear whether individual socioeconomic status (SES) interacts with neighborhood factors to influence cardiovascular outcomes. Using multilevel modeling, we examined the interaction between neighborhood poverty and individual SES on pressor responses to an alpha agonist, phenylephrine (PE), in an adult sample of 105 African-Americans and 106 Caucasian-Americans. Neighborhood poverty was assessed using census block data gathered from the Census Bureau. Education and occupation were used to assess individual SES. Pressor responsiveness was calculated as the systolic and diastolic blood pressure (BP) response to a 100-microg PE bolus administered intravenously. There was a significant interaction between education and neighborhood poverty on pressor responses. Higher education was associated with smaller BP responses to PE; but only in individuals who lived in neighborhoods in which less than 5% of the residents lived below the poverty line. Occupation was unrelated to pressor responses to PE. These results suggest that neighborhood characteristics play an important role in cardiovascular functioning.

Racial differences in the impact of social support on nocturnal blood pressure.

OBJECTIVE: To investigate whether black and white adults benefit similarly from perceived social support in relation to blood pressure (BP) dipping during sleep. METHODS: The Interpersonal Support Evaluation List (ISEL, 12-item version), which measures the perceived availability of several types of functional social support, was examined for interactive effects with race on dipping of mean arterial pressure (MAP), systolic blood pressure (SBP), and diastolic blood pressure (DBP) derived from 24-hour ambulatory blood pressure monitoring (ABPM). The sample consisted of 156 young to middle-aged adults (61 blacks, 95 whites; mean age = 35.7 years). RESULTS: Mean ISEL scores did not differ between racial groups. Controlling for age, body mass index (BMI), resting BP, and socioeconomic status (SES), the interaction of social support by race yielded associations with nighttime dipping in MAP and DBP (p < .001) as well as SBP (p < .01). As ISEL scores increased among white participants, the extent of dipping increased in MAP, SBP, and DBP (p < .01), explaining 10%, 10%, and 8% of the variance, respectively. Conversely, black participants exhibited associations between increasing ISEL scores and decreasing levels of dipping in MAP, SBP, and DBP (p < .05), accounting for 9%, 8%, and 8% of the variance, respectively. CONCLUSION: As perceived social support increased, white adults received cardiovascular benefits as suggested by enhanced nocturnal dipping of BP, but black adults accrued risks as evidenced by blunted declines in BP during sleep.

The relationship between heart rate variability and inflammatory markers in cardiovascular diseases.

INTRODUCTION: Recent evidence implicates a cholinergic anti-inflammatory pathway. Because vagus nerve activity mediates some heart rate variability (HRV), this qualitative review examines the literature concerning circulating cytokines and HRV in cardiovascular function in humans. This qualitative review examines the literature concerning circulating cytokines and HRV in cardiovascular function in humans. METHODS: Thirteen studies on HRV, inflammation, and cardiovascular function were located by electronic library search and descriptively reviewed. RESULTS: The relationship between HRV and inflammation was studied in healthy controls, patients with acute or stable coronary heart disease (CHD), patients with metabolic syndrome or impaired glucose tolerance and patients with kidney failure. Investigations focused mainly on Interleukin-6 (IL-6) and C-reactive peptide (CRP). The majority of reviewed studies reported that parasympathetic nervous system tone as inferred from heart rate variability is inversely related to inflammatory markers (r values between -0.2 and -0.4). The relationships with inflammatory markers were similar whether derived from ECG signals as short as 5-30min or from 24-h ECG readings for HRV analyses. While inflammatory markers appear to be related to HRV, it is a mistake to assume that the traditional "vagal measures" of HRV (such as high frequency heart rate variability) are the driving factors. Indeed, low frequency heart rate variability, a complex measure reflecting both parasympathetic and sympathetic activity, is the more commonly associated measure linked to inflammatory markers. DISCUSSION: Heart rate variability is inversely correlated with inflammatory markers in healthy individuals as well as in those with cardiovascular diseases.

Relationship between heart rate variability, interleukin-6, and soluble tissue factor in healthy subjects.

Decreased heart rate variability (HRV) has been associated with an increased risk of atherosclerosis. We hypothesized that a decrease in frequency domains of resting HRV would be associated with elevated plasma levels of interleukin (IL)-6 and soluble tissue factor (sTF) both previously shown to prospectively predict atherothrombotic events in healthy subjects. Subjects were 102 healthy and unmedicated black and white middle-aged men and women. We determined IL-6 and sTF antigen in plasma and HRV measures from surface electrocardiogram data using spectral analysis. All statistical analyses controlled for age, gender, ethnicity, smoking status, blood pressure, and body mass index. Low amounts of low frequency (LF) power (beta=-0.31, p=0.007) and high frequency (HF) power (beta=-0.36, p=0.002) were associated with increased amounts of IL-6, explaining 7% and 9% of the variance, respectively. Interactions between LF power and IL-6 (p=0.002) and between HF power and IL-6 (p=0.012) explained 8% and 5%, respectively, of the variance in sTF. Post hoc analyses showed associations between IL-6 and sTF when LF power (beta=0.51, p<0.001) and HF power (beta=0.48, p<0.001) were low but not when LF power and high HF power were high. The findings suggest that systemic low-grade inflammatory activity is associated with a decrease in HRV. Furthermore, there was a positive relationship between plasma levels of IL-6 and sTF antigen when HRV was low. Inflammation and related hypercoagulability might particularly contribute to atherothrombotic events in a setting of decreased HRV.

Relation of autonomic activity to plasminogen activator inhibitor-1 plasma concentration and the role of body mass index.

We hypothesized an association between heart rate variability (HRV) and plasminogen activator inhibitor (PAI)-1 that would be affected by body mass index (BMI). We determined PAI-1 antigen in plasma and the low-frequency power, high-frequency power and the low-frequency/high-frequency power ratio from surface electrocardiogram data using spectral analysis in a sample of 116 black and white men and women (mean +/- SE age, 36.8 +/- 0.7 years). Regression equations controlled for age, gender, ethnicity, smoking status, blood pressure, and BMI. We specifically tested whether BMI would moderate or mediate the relationship between HRV and PAI-1. There were bivariate correlations between PAI-1 and low-frequency power (r = -0.24, P = 0.010), high-frequency power (r = -0.41, P < 0.001), and the low-frequency/high-frequency power ratio (r = 0.19, P = 0.042). High-frequency power emerged as an independent predictor of PAI-1 levels (beta = -0.20, P = 0.040; DeltaR = 0.027) after controlling for covariates. The BMI significantly mediated the relationship between PAI-1 levels and low-frequency power (t = -2.77, P = 0.006) and high-frequency power (t = -2.99, P = 0.003). In conclusion, reduced parasympathetic activity (i.e. decreased high-frequency power) accounted for a small but significant amount of the variance in elevated PAI-1 levels. More apparent, higher BMI explained a significant proportion of the variance in the relationship between depressed sympathetic and parasympathetic activity and elevated plasma PAI-1 concentration.

Prediction of continuous positive airway pressure in obstructive sleep apnea.

Continuous positive airway pressure (CPAP) prediction formulas can potentially simplify the treatment of obstructive sleep apnea (OSA). However, they can be difficult to derive and validate. We tested a statistical method to derive and validate a CPAP prediction formula using the same sample population. Seventy-six OSA patients underwent polysomnography and CPAP titration. Anthropometric measures, sleep parameters, and the Epworth sleepiness scale (ESS) were evaluated as predictors. All subsets regression was used to determine the optimum number of variables in the model. The Bayes information criterion was used to find the best-fit model. The model was then evaluated by a tenfold cross-validation procedure. Subjects were obese (BMI 31.3 +/- 5.4) and had significant daytime somnolence (ESS 11.9 +/- 5). Mean respiratory disturbance index (RDI) was 53.5 +/- 31.3. The ESS was not predictive of titrated CPAP. The best-fit model included three variables (CPAP(pred) = 30.8 + RDI x 0.03 - nadir saturation x 0.05 - mean saturation x 0.2). This model explained 67% of the variance. Our data and the literature suggest that a combination of two to three factors is predictive of titrated CPAP: RDI, oxyhemoglobin saturation, and obesity. Except for RDI, the specific factors vary in each population. A CPAP prediction formula that explains a high proportion of the titrated CPAP variance can be easily derived from parameters measured during the diagnostic work-up of OSA patients using a unique statistical model that allows derivation and validation of the formula in the same test population.

Ethnicity, perceived discrimination, and vascular reactivity to phenylephrine.

OBJECTIVES: This study examined relationships among ethnicity, perceived discrimination, and vascular reactivity to phenylephrine (PE). METHODS: Seventy-six white patients and 46 black patients were studied at an inpatient clinical research center in response to a bolus intravenous injection of 100 microg PE. Self-report questionnaires assessed perceived discrimination. RESULTS: After controlling for body surface area, number of cigarettes smoked, and baseline blood pressure, black patients had greater vascular reactivity to PE than white patients (p = .01). There was also a significant relationship between perceived discrimination and diastolic blood pressure responsiveness to PE (p < .05). Path analyses revealed that perceived discrimination mediated the relationship between ethnicity and diastolic pressor responses. Individuals who perceived more discrimination had a larger increase in diastolic blood pressure in response to PE. CONCLUSION: These data suggest perceived discrimination is associated with increased blood pressure responsiveness to PE.

The association of social status and blood pressure with markers of vascular inflammation.

OBJECTIVE: Low socioeconomic status (SES) is associated with low-grade inflammation. Vascular inflammation often accompanies high blood pressure (BP) and has clinical implications for future vascular diseases, including atherosclerosis. Elevated plasma levels of soluble intercellular adhesion molecule-1 (sICAM-1) and endothelin-1 (ET-1) are reliable indicators of vascular inflammation. We examined the associations among BP, social status, and sICAM-1 and ET-1 levels in 121 European American and African American men and women. METHODS: Social status of the subjects was determined by using the Hollingshead Two Factor Index of Social Position scale, and plasma sICAM-1 and ET-1 levels were assessed using immunoassays. RESULTS: Correlation analyses revealed positive correlations among plasma sICAM-1 levels, BP, and social status. Levels of ET-1 were also significantly correlated with BP (p < .01) and social status (p < .001). When subjects were categorized into three social classes, sICAM-1 levels were significantly higher in the lowest social class as compared with the upper (p < .05) or middle (p < .01) class. The levels of ET-1 were higher in the low (p < .01) and middle (p < .05) social classes as compared with the upper class. Multiple hierarchic regression analyses revealed that even after controlling for demographic and health characteristics (gender, ethnicity, age, body mass index, and smoking) and systolic BP, social status accounted for additional variance of sICAM-1 or ET-1 levels. CONCLUSION: These results suggest that low-social-status individuals may incur risk for future vascular diseases through vascular inflammation.

Effects of continuous positive airway pressure versus supplemental oxygen on 24-hour ambulatory blood pressure.

Obstructive sleep apnea (OSA) is associated with recurrent episodes of nocturnal hypoxia and increased risk for development of systemic hypertension. Prior studies have been limited, however, in their ability to show reduction in blood pressure after continuous positive airway pressure (CPAP) therapy, and the effect of supplemental oxygen alone on blood pressure in OSA has not been evaluated. We performed a randomized, double-blind, placebo-controlled study comparing the effects of 2 weeks of CPAP versus sham-CPAP versus supplemental nocturnal oxygen on 24-hour ambulatory blood pressure in 46 patients with moderate-severe OSA. We found that 2 weeks of CPAP therapy resulted in a significant reduction in daytime mean arterial and diastolic blood pressure and nighttime systolic, mean, and diastolic blood pressure (all Ps <0.05). Although nocturnal supplemental oxygen therapy improved oxyhemoglobin saturation, it did not affect blood pressure. We conclude that CPAP therapy reduces both daytime and nighttime blood pressure in patients with OSA, perhaps through mechanisms other than improvement of nocturnal oxyhemoglobin saturation.

Depressive symptoms are associated with increased systemic vascular resistance to stress.

OBJECTIVE: The deleterious effects of major depressive disorder on cardiovascular (CV) functioning are well known. However, the etiologic mechanisms underlying this association are incompletely understood. In the current study, subjects with varying degrees of depressive symptoms performed a stress task while CV reactivity was measured. We hypothesized that high levels of depressive symptoms would be associated with altered CV reactivity. METHODS: Ninety-one healthy volunteer subjects performed reactivity testing while measures of impedance cardiography and autonomic nervous system function were obtained. Subjects completed the Center for Epidemiological Studies Depression Scale (CES-D) and were categorized into either the high depressive (i.e., CES-D > or =16) or low depressive (i.e., CES-D <16) symptoms group. RESULTS: Task performance was associated with increases in systemic vascular resistance (SVR) (p = .001), mean arterial pressure (p = .001), and heart rate (p = .005), and decreases in cardiac output (p = .001), heather index (p = .001), and stroke volume (p = .05). After controlling for screening mean arterial pressure, an interaction effect of stress by mood group on SVR (p = .01) was observed; subjects with high amounts of depressive symptoms manifested significantly greater SVR at baseline and in response to a stressor task than did subjects with low amounts of depressive symptoms. CONCLUSIONS: These results suggest a mechanism that may partially explain the increased CV morbidity associated with depressive symptoms. In future studies, it may be useful to examine if treatment of depressive symptoms alters CV reactivity.