Clinton D. Brown

Depression is an important contributor to low medication adherence in hemodialyzed patients and transplant recipients

End-stage renal disease (ESRD) is a growing public health concern and non-adherence to treatment has been associated with poorer health outcomes in this population. Depression, likely to be the most common psychopathology in such patients, is associated with increased morbidity and mortality. We compared psychological measures and self-reported medication adherence of 94 kidney transplant recipients to those of 65 patients receiving hemodialysis in a major medical center in Brooklyn, New York. Compared to the transplant group, the hemodialysis cohort was significantly more depressed as determined by the Beck Depression Inventory score. They also had a significantly lower adherence to medication as reported on the Medication Therapy Adherence Scale. Using hierarchical multiple regression analysis, the variance in depression was the only statistically significant predictor of medication adherence beyond gender and mode of treatment, accounting for an additional 12% of the variance. Our study strongly suggests that a depressive affect is an important contributor to low medication adherence in patients with ESRD on hemodialysis or kidney transplant recipients.

Depression and anxiety in urban hemodialysis patients.

Depression is well established as a prevalent mental health problem for people with ESRD and is associated with morbidity and mortality. However, depression in this population remains difficult to assess and is undertreated. Current estimates suggest a 20 to 30% prevalence of depression that meets diagnostic criteria in this population. The extent of other psychopathology in patients with ESRD is largely unknown. The aim of this study was to expand the research on psychiatric complications of ESRD and examine the prevalence of a broad range of psychopathology in an urban hemodialysis center and their impact on quality of life. With the use of a clinician-administered semistructured interview in this randomly selected sample of 70 predominately black patients, >70% were found to have a psychiatric diagnosis. Twenty-nine percent had a current depressive disorder: 20% had major depression, and 9% had a diagnosis of dysthymia or depression not otherwise specified. Twenty-seven percent had a current major anxiety disorder. A current substance abuse diagnosis was found in 19%, and 10% had a psychotic disorder. The mean Beck Depression Inventory score was 12.1 +/- 9.8. Only 13% reported being in current treatment by a mental health provider, and only 5% reported being prescribed psychiatric medication by their physician. A total of 7.1% had compound depression or depression coexistent with another psychiatric disorder. The construct of depression was also disentangled from the somatic effects of poor medical health by demonstrating a unique relationship between depressive affect and depression diagnosis, independent of health status. This study also suggests the utility of cognitive variables as a meaningful way of understanding the differences between patients who have ESRD with clinical depression or other diagnoses and those who have no psychiatric comorbidity. The findings of both concurrent and isolated anxiety suggest that the prevalence of psychopathology in patients with ESRD might be higher than previously expected, and the disorders may need to be treated independently. In addition, the data suggest that cognitive behavioral therapeutic techniques may be especially advantageous in this population of patients who are treated with many medications.

Sleep Duration among Black and White Americans: Results of the National Health Interview Survey

INTRODUCTION Epidemiologic studies have shown the importance of habitual sleep duration as an index of health and mortality risks. However, little has been done to ascertain ethnic differences in sleep duration in a national sample. This study compares sleep duration in a sample of black and white participants in the National Health Interview Survey (NHIS). METHOD Data were collected from 29,818 Americans (age range 18-85 years) who participated in the 2005 NHIS. The NHIS is a cross-sectional household interview survey that uses a multistage area probability design, thus permitting representative sampling of U.S. households. During face-to-face interviews conducted by trained interviewers from the U.S. Census Bureau, respondents provided demographic data and information about physician-diagnosed chronic conditions, estimated habitual sleep duration and functional capacity, and rated their mood. RESULTS Fishers exact test results indicated that blacks were less likely than whites to report sleeping 7 hours (23% vs. 30%; chi2 = 94, p < 0.0001). Blacks were more likely to experience both short sleep (< or = 5 hours) (12% vs. 8%, chi2 = 44, p < 0.0001) and long sleep (> or = 9 hours) (11% vs. 9%, chi2 = 23, p < 0.0001). Logistic regression analysis, adjusting for differences in sociodemographic factors, depression, functional capacity and medical illnesses, demonstrated that black ethnicity was a significant predictor of extreme sleep duration (Wald = 46, p < 0.0001; OR = 1.35, 95% CI: 1.24-1.47). DISCUSSION Independent of several sociodemographic and medical factors, blacks had more prevalent short and long sleep durations, suggesting greater variation in habitual sleep time. Therefore, blacks might be at increased risks of developing medical conditions associated with short and long sleep.

Course of Depression and Anxiety Diagnosis in Patients Treated with Hemodialysis: A 16-month Follow-up

BACKGROUND AND OBJECTIVES There is growing identification of the need to seriously study the psychiatric presentations of end-stage renal disease patients treated with hemodialysis. This study reports on the course of depression and anxiety diagnoses and their impact on quality of life and health status. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS The 16-mo course of psychiatric diagnoses in 50 end-stage renal disease patients treated with hemodialysis was measured by structured clinical interview. RESULTS Three different pathways were identified: one subset of patients not having a psychiatric diagnosis at either baseline or 16-mo follow-up (68% for depression, 51% for anxiety), one group having an intermittent course (21% for depression, 34% for anxiety), and one group having a persistent course (11% for depression, 15% for anxiety), with diagnoses at both time 1 and time 2. For depression, the people with the persistent course showed marked decreases in quality of life and self-reported health status compared with the nondepressed and intermittently depressed cohorts. The most powerful predictor of depression at time 2 is degree of depressive affect at time 1(P < 0.05). CONCLUSIONS Patients at risk for short- and long-term complications of depression can be potentially identified by high levels of depressive affect even at a single time point. As nearly 20% of the sample had chronic depression or anxiety, identifying a psychiatric diagnosis in hemodialysis patients and then offering treatment are important because, in the absence of intervention, psychiatric disorders are likely to persist in a substantial proportion of patients.

Effects of different exercise training intensities on lipoprotein cholesterol fractions in healthy middle-aged men.

Exercise training has been associated with decreases in total cholesterol and increases in high-density lipoprotein (HDL) cholesterol. The effect of the intensity of the exercise on alterations in cholesterol and lipoprotein fractions has not been defined and is the subject of this study. We divided 49 healthy men (aged 44 +/- 8 years) into four groups and evaluated them before and after 12 weeks of cycle ergometer exercise training at (1) an intensity of 65% of maximal achieved heart rate, (2) 75% maximal heart rate, (3) 85% maximal heart rate, and (4) a 12-week nonexercise control period. Pre- and post-training evaluations included maximal ergometer exercise ECG examinations with measurement of maximal minute oxygen consumption and serum total cholesterol, HDL cholesterol, and triglyceride levels. Low-density (LDL) and very low-density lipoprotein (VLDL) cholesterol levels were calculated. Dietary histories were obtained before and after the training period, and body weight and percentage of body fat were measured. Post-training oxygen uptake was significantly increased (training effect) in the groups exercising to 65%, 75%, and 85% maximal heart rate. Results of within-group analysis showed significant increases in the HDL cholesterol fractions in the 75% and 85% groups but not in the 65% group or the control group. Significant decreases in calculated LDL fractions occurred only in the 75% exercise-trained group with maximal heart rate. Aerobic exercise training favorably alters plasma lipoprotein profiles. A minimum training intensity equal to 75% maximal heart rate is required to the increase HDL cholesterol level.

Sleep Duration and the Risk of Diabetes Mellitus: Epidemiologic Evidence and Pathophysiologic Insights

Evidence from well-defined cohort studies has shown that short sleep, through sleep fragmentation caused by obstructive sleep apnea (OSA) or behavioral sleep curtailment because of lifestyle choices, is associated with increased incidence of diabetes. In this report, we review epidemiologic and clinical data suggesting that OSA is involved in the pathogenesis of altered glucose metabolism. Evidence suggesting increased risk of developing diabetes resulting from curtailed sleep duration is also considered. Proposed mechanisms explaining associations between short sleep and diabetes are examined and clinical management of OSA among patients with diabetes is discussed.

Obstructive sleep apnea and dyslipidemia: evidence and underlying mechanism

IntroductionOver the past half century, evidence has been accumulating on the emergence of obstructive sleep apnea (OSA), the most prevalent sleep-disordered breathing, as a major risk factor for cardiovascular disease. A significant body of research has been focused on elucidating the complex interplay between OSA and cardiovascular risk factors, including dyslipidemia, obesity, hypertension, and diabetes mellitus that portend increased morbidity and mortality in susceptible individuals.ConclusionAlthough a clear causal relationship of OSA and dyslipidemia is yet to be demonstrated, there is increasing evidence that chronic intermittent hypoxia, a major component of OSA, is independently associated and possibly the root cause of the dyslipidemia via the generation of stearoyl-coenzyme A desaturase-1 and reactive oxygen species, peroxidation of lipids, and sympathetic system dysfunction. The aim of this review is to highlight the relationship between OSA and dyslipidemia in the development of atherosclerosis and present the pathophysiologic mechanisms linking its association to clinical disease. Issues relating to epidemiology, confounding factors, significant gaps in research and future directions are also discussed.

Long-Term Renal and Cardiovascular Outcomes in Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) Participants by Baseline Estimated GFR

BACKGROUND AND OBJECTIVES CKD is common among older patients. This article assesses long-term renal and cardiovascular outcomes in older high-risk hypertensive patients, stratified by baseline estimated GFR (eGFR), and long-term outcome efficacy of 5-year first-step treatment with amlodipine or lisinopril, each compared with chlorthalidone. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS This was a long-term post-trial follow-up of hypertensive participants (n=31,350), aged ≥55 years, randomized to receive chlorthalidone, amlodipine, or lisinopril for 4-8 years at 593 centers. Participants were stratified by baseline eGFR (ml/min per 1.73 m(2)) as follows: normal/increased (≥90; n=8027), mild reduction (60-89; n=17,778), and moderate/severe reduction (<60; n=5545). Outcomes were cardiovascular mortality (primary outcome), total mortality, coronary heart disease, cardiovascular disease, stroke, heart failure, and ESRD. RESULTS After an average 8.8-year follow-up, total mortality was significantly higher in participants with moderate/severe eGFR reduction compared with those with normal and mildly reduced eGFR (P<0.001). In participants with an eGFR <60, there was no significant difference in cardiovascular mortality between chlorthalidone and amlodipine (P=0.64), or chlorthalidone and lisinopril (P=0.56). Likewise, no significant differences were observed for total mortality, coronary heart disease, cardiovascular disease, stroke, or ESRD. CONCLUSIONS CKD is associated with significantly higher long-term risk of cardiovascular events and mortality in older hypertensive patients. By eGFR stratum, 5-year treatment with amlodipine or lisinopril was not superior to chlorthalidone in preventing cardiovascular events, mortality, or ESRD during 9-year follow-up. Because data on proteinuria were not available, these findings may not be extrapolated to proteinuric CKD.

Cardiovascular disease risk reduction with sleep apnea treatment

Cardiovascular diseases are the leading cause of death among adults in developed countries. An increase in prevalent cardiovascular risk factors (e.g., obesity, hypertension and diabetes) has led to a concerted effort to raise awareness of the need to use evidence-based strategies to help patients at risk of developing cardiovascular disease and to reduce their likelihood of suffering a stroke. Sleep apnea has emerged as an important risk factor for the development of cardiovascular disease. Epidemiologic and clinical evidence has prompted the American Heart Association to issue a scientific statement describing the need to recognize sleep apnea as an important target for therapy in reducing cardiovascular disease risks. This article examines evidence supporting associations of sleep apnea with cardiovascular disease and considers evidence suggesting cardiovascular risk reductions through sleep apnea treatment. Perspectives on emerging therapeutic approaches and promising areas of clinical and experimental research are also discussed.

Linking sleep duration and obesity among black and white US adults

AIMS The effect of race/ethnicity on the risk of obesity associated with short or long sleep durations is largely unknown. This study assessed whether the sleep-obesity link differentially affects black and whites. METHODS Analysis was based on data obtained from 29,818 adult American respondents from the 2005 National Health Interview Survey, a cross-sectional household interview survey. RESULTS Multivariate-adjusted odds ratios for obesity associated with short sleep (≤6 h) among blacks and whites were 1.98 (95% CI: 1.69-2.30) and 1.20 (95% CI: 1.10-1.31), respectively, and with long sleep (≥9 h) for blacks and whites were 1.48 (95% CI: 1.14-1.93) and 0.77 (95% CI: 0.67-0.89), respectively (all p < 0.001). CONCLUSION Race/ethnicity may have significantly influenced the likelihood of reporting obesity associated with short and long sleep durations. Relative to white respondents, an excess of 78% of black respondents showed increased obesity odds associated with short sleep. Black long sleepers also showed increased odds for obesity, but white long sleepers may be at a reduced obesity risk.