Sleep in the elderly. What is normal?

Sleep is a basic biologic function that changes with normal aging and in many pathologic states. Some of the changes with aging are so profound that it is difficult to separate normal aging from disease. The problem is made worse by the difficulty of recognizing many common sleep disorders. Complaints of poor sleep or daytime somnolence are common in all adults but are more prevalent in elderly individuals. This article addresses normal sleep and the changes expected with aging, and reviews the more common sleep diseases in the elderly population, such as insomnia, sleep-disordered breathing, periodic limb movements of sleep, and the rapid eye movement sleep-behavior disorder.     

Does the plasma endothelin-1 concentration reflect atherosclerosis in the elderly?

BACKGROUND AND OBJECTIVE: Recently, attention has been focused on endothelin-1 (ET-1) as an indicator of atherosclerosis. However, normal levels of ET-1 are frequently found in elderly patients. We investigated the relationships between echocardiographic findings and ET-1 in 117 inpatients for rehabilitation. METHODS: The patients were 34 men and 83 women, 83.4 +/- 0.8 years old (mean +/- SE), with the following diseases: cerebrovascular diseases (n = 83), cardiovascular diseases of New York Heart Association Class I or II (n = 57), diabetes mellitus (n = 11) and hyperlipidemia (n = 12). Ejection fraction (EF) and left ventricular mass index (LVMI) were calculated by echocardiographic studies. RESULTS: The average ET-1 was within the normal range, but a significant positive correlation was observed between age and ET-1 (ET-1 = 1.8 +/- 0.1 pg/ml, r = 0. 248, p < 0.01). Moreover, plasma ET-1 was positively correlated to total cholesterol and to low density lipoprotein cholesterol in patients with a history of hypertension (n = 41, r = 0.318 and r = 0. 314, both p < 0.05). Gender was not a significant factor. There was no significant difference in ET-1 between patients with mild renal dysfunction (n = 54) and patients with normal renal function (n = 63) (blood urea nitrogen = 30.9 +/- 2.4 vs. 15.1 +/- 0.5 mg/dl, serum creatinine = 1.03 +/- 0.06 vs. 0.59 +/-0.02 mg/dl, ET-1 = 1.7 +/- 0.1 vs. 1.8 +/- 0.1 pg/ml), or between patients with (n = 50) and without (n = 67) left ventricular hypertrophy (LVMI = 146 +/- 6 vs. 83 +/- 2 g/m(2), ET-1 = 1.8 +/- 0.1 vs. 1.8 +/- 0.1 pg/ml). There was no difference in ET-1 between patients with EF <50% (n = 27) and EF >/=50% (n = 90) (ET-1 = 1.8 +/- 0.2 vs. 1.7 +/- 0.1 pg/ml). CONCLUSION: There were no significant relationships between echocardiographic findings and ET-1 in elderly subjects without overt heart failure. However, in patients with a history of hypertension, measuring ET-1 may be useful for estimating the extent of atherosclerosis.     

Low plasma levels of brain natriuretic peptide in severe acute heart failure: Merely a case?

Brain natriuretic peptide (BNP) is commonly used for diagnosis and prognosis of patients with congestive heart failure (HF). High levels of BNP are associated with high probability of cardiogenic dyspnea and higher risk of subsequent cardiovascular events. We describe a case of acute HF (worsening chronic HF) in a 74-year-old male with low plasma BNP levels on admission, in whom a rapid and consistent increase in the marker's concentration occurred after administration of diuretics and vasodilators, despite a prompt clinical and hemodynamic improvement. Reports of cardiogenic dyspnea with moderate increase or normal plasma levels of BNP have been recently published: does this signify a pitfall for BNP as a useful diagnostic and prognostic tool? Clinical implications of our observation are discussed, and we conclude that neurohumoral biomarkers do not obviate the need for a careful physical and instrumental examination of patient.     

Correlations of plasma levels of brain natriuretic peptide and Meprin-α with the severity of coronary-artery stenosis

<正>Objective To explore the relationship of the severity of coronary-artery stenosis with plasma levels of brain natriuretic peptide(BNP)and Meprin-α.Methods Totally237 patients in our hospital were divided into control group(CON group),stable angina group(SA group)and acute coronary syndrome group(ACS group),according     

Factors that influence the serum of atrial natriuretic peptide and brain natriuretic peptide concentrations--is there a specific marker for senile patients?

To evaluate factors that influence of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) levels in elderly people, we measured those levels in 54 men and 148 women (84.4 +/- 0.5 years old), and looked for associations of ANP and BNP with clinical factors and echocardiographic variables [left ventricular mass index and atrial to-early peak transmitral velocity ratio (A/E)]. ANP and BNP levels were 1.6 and 6.5 times higher than average. Sex was not a significant factor. We also looked for a link between cardiac rhythms and levels of ANP and BNP. Patients with atrial fibrillation had significantly higher levels of ANP and BNP than did patients with sinus rhythm. ANP and BNP levels were abnormally high in patients with left ventricular hypertrophy (LVH). We could measured A/E in 161 of 202 subjects; 154 of 157 subjects with normal LV systolic function had A/E > 1 which indicates abnormally low in LV diastolic function. Moreover, abnormally high LV diastolic stress might have been present, because 124 of 202 subjects had aortic regurgitation. We divided the patients into two groups: those 65 to 75 years old, and those over 75 years old. The older patients had significantly higher levels of ANP and BNP even without LVH and without a difference in renal function. Furthermore, the older patients had significantly higher levels of BNP even without LVH, with normal renal function, with sinus rhythm, with normal LV systolic function, and in NYHA Class I or II. These data indicate that ANP and BNP levels in people with senility may be associated with the cardiac rhythm and with abnormally low renal function, myocardial hypertrophy, abnormally high cardiac volume, and abnormally low diastolic function.     

Is measurement of plasma brain natriuretic peptide levels a useful test to detect for surgical timing of valve disease?

BACKGROUND: The optimal timing of valve surgery is very important. In patients who are severely symptomatic, the marked improvement in symptomatic status observed following successful valve surgery. However, in patients with no or only mild symptoms, the decision is more difficult. The aim of this retrospective study was to determine whether the measurement of plasma brain natriuretic peptides (BNP) levels is useful to decide surgical timing for valve disease. METHODS: Fifty-one patients with valve disease underwent single valve surgery (mitral stenosis, MS, 13; mitral regurgitation, MR, 16; aortic stenosis, AS, 14; aortic regurgitation, AR, 8 patients). Blood samples, echocardiographic and cardiac catheterization data were obtained before operation and echocardiographic examination were performed after 1-year of operations. RESULTS: In patients subjected to single heart valve surgery, plasma BNP mean levels were 214.6+/-48.5 pg/ml. In plasma BNP levels, there was only significant difference between MS and AS group (MS 67.5+/-9.7 vs. AS 314.3+/-112.0 pg/ml, P=0.04). There were no relationships between plasma BNP levels and pre-operative cardiac functions. After 1-year of the valve surgery, NYHA functional class was reduced in 36 patients (70.6%) and plasma BNP levels before the surgery significantly correlated with post-operative NYHA functional class. CONCLUSIONS: In this retrospective study, patients with high plasma BNP levels significantly impaired the improvement of clinical symptoms after surgery. We have suggested that plasma BNP levels is useful for detecting asymptomatic valvular disease, and is a clinical marker useful in determining the optimal surgical timing.     

B-type natriuretic peptide assays for detecting heart failure in the elderly: same value as those in the younger?

Establishing a diagnosis of heart failure in elderly patients is notoriously difficult, especially in those who experience slowly progressive breathlessness, have multiple co-morbidity, and when, as in primary care echocardiography is not routinely (or readily) available. B-type natriuretic peptides measurements are useful in the diagnostic assessment of such patients, although the evidence in the very old (i.e. those aged 75 years and over) is less clear than for younger patients. Conflicting results in literature regarding B-type natriuretic peptides are mainly caused by differences in assays, the applied 'gold standard' for heart failure, and the population studied. Moreover, there is no consensus as to whether similar cut-off points should be applied across age-groups. Numerous studies showed that plasma levels of B-type natriuretic peptide are elevated in the elderly, including the 'healthy' ones. Age-related myocardial fibrosis and subtle diastolic dysfunction that are not detectable by current techniques, and reduced renal clearance have been suggested as reasons for this phenomenon. Importantly, B-type natriuretic peptides are not specific for heart failure, but reflect haemodynamic myocardial stress independent of the underlying pathology, and thus are more 'markers' of the general cardiac state. Cut-points differ widely when comparing studies in patients with acute versus chronic dyspnoea. In patients with acute dyspnoea age-dependent cut-points should be used, while in patients with chronic dyspnoea (that is, slowly progressive breathlessness) at least thresholds below which heart failure can be excluded seem rather independent of age. Especially in the primary care setting where elderly patients with slowly progressive dyspnoea are investigated, the excellent exclusionary capacities of B-type natriuretic peptides are of great help to select those that require echocardiography to establish or eventually reject a diagnosis of heart failure.     

Does brain natriuretic peptide have a direct renal effect in human hypertensives?

Systemic infusion of brain natriuretic peptide (BNP) stimulates natriuresis and diuresis but has variable effects on the renal vasculature. In this study, we investigated whether BNP has any direct effects on the kidney in hypertensive patients. Three stepwise increasing doses of BNP (60, 120, and 180 pmol/min) or placebo were infused into the renal artery of 26 hypertensive patients. Renal blood flow was determined with the 133Xenon washout technique. Before and after infusion of BNP, arterial and venous blood samples were taken for cGMP, renin, and creatinine concentration. Intra-arterial blood pressure and heart rate were monitored continuously. Intrarenal BNP infusion did not induce significant changes in renal blood flow despite increases in circulating levels of cGMP. The latter, however, was not associated with changes in the cGMP gradient across the kidney. In addition, we did not find any BNP-related changes in the secretion of active renin and in creatinine extraction. At the highest dose, heart rate increased after BNP infusion without a change in mean intra-arterial blood pressure. In conclusion, this study suggests that at least in hypertensive subjects, BNP has no direct intrarenal hemodynamic effects and that the rise in circulating cGMP without changes in net renal extraction of this second messenger is related to a primary extrarenal target of BNP.     

Measuring plasma B-type natriuretic peptide in heart failure: good to go in 2004?

Elevated plasma brain natriuretic (BNP) concentrations correlate with increased cardiac filling pressures. Therefore, increased BNP has been proposed as a marker for asymptomatic ventricular dysfunction, as an aid in the diagnosis of cardiac dyspnea, as an end point to assess the efficacy of heart failure therapy, and as a prognostic marker in heart failure. An understanding of the utility of BNP requires an appreciation of the sensitivity, specificity, and diagnostic accuracy of BNP in each of these clinical situations. At this time, there is strong evidence for the value of BNP in the evaluation of dyspnea of uncertain cause. Further population studies will need to be performed to refine the application of BNP to community cohorts and to determine its clinical value and cost-effectiveness as a screening tool in the early diagnosis of ventricular dysfunction. To make optimal use of BNP for the assessment of heart failure therapy and prognosis in individual patients, physicians will require additional information on the biological variability of BNP. Studies comparing the sensitivity, specificity, and predictive value of the available BNP and N-terminal pro-BNP assays need to be conducted in each of these clinical settings.     

Why is plasma renin activity lower in populations of African origin?

Plasma renin activity is significantly lower in black people compared with whites independent of age and blood pressure status. The lower PRA appears to be due to a reduction in the rate of secretion of renin but the exact mechanistic events underlying such differences in renin release between blacks and whites are still not fully understood. Nevertheless, given the paramount importance of the renin-angiotensin system in the control of sodium balance, a most likely explanation is that the lower renin is a consequence of differences in renal sodium handling between blacks and whites. The lower PRA does not reflect differences in dietary sodium intake but the evidence available suggests that the low PRA could be part of the corrective mechanisms designed to maintain sodium balance in the presence of an increased tendency for sodium retention in black people. While it is possible that several factors may contribute to the reduced PRA, more recent investigation at the molecular level suggests that the lower PRA may arise from gene variation in the renal epithelial sodium channel. The functional significance of the lower PRA in relation to the different pattern of cardiovascular and renal disease between blacks and whites remains unclear. Moreover, direct investigations of pre-treatment renin status in hypertensive blacks in relation to blood pressure response have demonstrated that the pre-treatment PRA is not a good index of subsequent blood pressure response to pharmacological treatment. Nevertheless, the blood pressure reduction to short term sodium restriction is greater in blacks compared with whites and, in the black subjects, the greater reduction in blood pressure to sodium restriction appears to be related, at least in part, to the decreased responsiveness of the renin-angiotensin system. Journal of Human Hypertension (2001) 15, 17-25     

The definition of anemia: what is the lower limit of normal of the blood hemoglobin concentration?

The diagnosis of anemia is an important aspect of the practice of hematology. The first step is to decide whether the patient is, in fact, anemic. Unless earlier blood counts are available, and they often are not, the physician must make his or her decision on the basis of the population distribution of hemoglobin values. How likely is it that the patient's hemoglobin value lies below the normal distribution; that is, "the lower limit"?     

Diagnostic and clinical perspectives of fusion imaging in cardiology: is the total greater than the sum of its parts?

Positron emission tomography, cardiovascular magnetic resonance and multislice computed tomography have contributed to changing our pathophysiological understanding of many conditions. Clinically, they have provided new tools for the identification of preclinical disease and a better understanding of how disease progresses. The application of these imaging modalities to preclinical disease and the use of these techniques in patients with overt cardiovascular disease are reviewed.