losartan-potassium and Lung-Diseases--Obstructive

In patients with cardiovascular disease, partial correction of anaemia with epoetin improves quality of life and exercise capacity, and reduces left ventricular hypertrophy. The currently recommended haemoglobin in these patients is 11-12 g/dl. The optimal haemoglobin in patients with diabetes mellitus does not differ from that in non-diabetic patients; however, haemoglobin should be increased slowly. There is no difference in the recommended haemoglobin between children and adults. However, epoetin sensitivity is lower in children who, therefore, typically need the same absolute dose of epoetin as adults. Epoetin treatment may delay the progression of chronic renal failure (CRF) in paediatric patients. Elderly patients obtain similar benefits from epoetin as younger adults; moreover, there are no differences in the doses of epoetin required or the optimal haemoglobin. There are very few data available on the effects of epoetin in patients with CRF and chronic obstructive pulmonary disease. At present, a haemoglobin of 11 g/dl seems appropriate. In sickle-cell anaemia patients with CRF, a high haemoglobin could precipitate painful crises; consequently, the recommended haemoglobin is the pre-CRF concentration of 6-9 g/dl. There is no convincing evidence of any effect of previous epoetin treatment on the long-term outcome of renal transplantation. In patients with a failing or failed transplant, the required dose of epoetin may be higher than in pre-transplantation patients. In such cases, transplant nephrectomy might be considered.

Topics: Adult; Aged; Anemia; Anemia, Sickle Cell; Child; Diabetic Nephropathies; Erythropoietin; Humans; Kidney Failure, Chronic; Kidney Transplantation; Lung Diseases, Obstructive

Theophylline, a drug that has been used for several decades, has several different actions at a cellular level, including inhibition of phosphodiesterase isoenzymes, antagonism of adenosine, enhancement of catecholamine secretion, and modulation of calcium fluxes. Recently, theophylline was found to have several immunomodulatory and anti-inflammatory properties, and thus interest in its use in patients with asthma has been renewed. The use of theophylline in the treatment of asthma and chronic obstructive pulmonary disease has diminished with the advent of new medications, but theophylline remains beneficial, especially in the patient with difficult refractory symptoms. In the future, theophylline may be used as treatment for bradyarrhythmias after cardiac transplantation, prophylactic medication to reduce the severity of nephropathy associated with intravenous administration of contrast material, therapy for breathing problems during sleep, and treatment for leukemias.

Topics: Apnea; Apoptosis; Asthma; Calcium Channels; Capillary Leak Syndrome; Catecholamines; Erythropoietin; Humans; Immunity; Kidney; Leukemia, Lymphocytic, Chronic, B-Cell; Lung Diseases, Obstructive; Phosphoric Diester Hydrolases; Receptors, Purinergic P1; Theophylline

If one reviews the literature with zeal, it is increasingly apparent that few organs escape recruitment when IBD is chronic or progressive. Insights into mucosal pathophysiology have helped with understanding the more frequent extraintestinal manifestations, but the mechanisms attendant to the development of less common events (e.g. acute pancreatitis, concurrent gluten sensitive enteropathy, or active pulmonary disease) remain either poorly studied or obscure. It is particularly interesting, however, to read reports of abnormal pulmonary function, generally of the obstructive type, correlated to measurements of abnormal intestinal permeability in patients with either active pulmonary sarcoid or pulmonary involvement in Crohn's disease. It has been further speculated that similarities in the mucosal immune system of the lung and intestine are responsible for evidence of bronchial hyperreactivity in patients with active IBD. Finally, it is important to recognize that extensions of the inflammatory process are not restricted to the development of organ-based events but may be responsible for some of the most frequent systemic abnormalities detected in IBD patients. It is now also well confirmed that the cytokine environment in IBD can support activated coagulation and, in some clinical situations, overt vascular thrombosis. The cerebrovascular complications of IBD are well recognized and range from peripheral venous thrombosis to central stroke syndromes and pseudotumor cerebri. Reports of focal white matter lesions in the brains of patients with IBD or an increased incidence of polyneuropathy may be other clinical examples of regional microvascular clotting. Microvascular injury appears to be more ubiquitously present, with reports ranging from a speculated primary causative role (e.g., granulomatous vasculitis in the mesenteric circulation) to the utility of nailbed vasospasm, in Crohn's disease, as a clinical marker for disease activity. It is also reported that IL-6 suppression of erythropoietin production is a major feature of the chronic anemia seen in active IBD. Moreover, the capacity of peripheral monocytes from active IBD patients to secrete TNF and IL-8 is reported predictive for the degree of therapeutic response from recombinant erythropoietin. These collected observations constitute another excellent example of the symmetry between basic science and clinical utility. It is from the context of applied basic science that many future therapies wi

Topics: Anemia; Animals; Brain Diseases; Bronchial Hyperreactivity; Cerebrovascular Disorders; Crohn Disease; Cytokines; Disease Models, Animal; Erythropoietin; Humans; Inflammatory Bowel Diseases; Interleukin-6; Lung Diseases; Lung Diseases, Obstructive; Sarcoidosis; Thrombosis

Topics: Altitude; Circadian Rhythm; Erythrocyte Volume; Erythropoietin; Hematocrit; Hemoglobins; Humans; Hypoxia; Lung Diseases, Obstructive; Polycythemia; Smoking; Testosterone

Topics: Altitude; Biological Transport; Chronic Disease; Erythropoietin; Heart Diseases; Hemoglobins, Abnormal; Humans; Hypoxia; Lung Diseases; Lung Diseases, Obstructive; Oxygen; Oxygen Consumption; Polycythemia

Erythropoietin (EPO) controls red cell production. Hypoxaemia, reduced blood oxygen-carrying capacity and increased affinity of haemoglobin (Hb) for oxygen are the primary stimuli for EPO secretion. The effect of hyperoxaemia (arterial oxygen tension (Pa,O2) > 13.3 kPa) on EPO secretion has not been thoroughly studied and is not fully understood. The primary purpose of this study was to evaluate EPO production in patients with acute respiratory failure as well as to determine the effect of hyperoxaemia on EPO secretion in patients with and without anaemia. A prospective clinical study was carried out in a 14-bed general (medical and surgical) intensive care unit in a university hospital. Twenty-one patients with acute or acute on chronic respiratory failure, requiring mechanical ventilation, were included in this study. The patients were divided into two groups; group I comprised patients who developed anaemia, and group II patients who did not. EPO levels and haematological parameters were measured in venous blood under three oxygenation conditions: hypoxaemia, hyperoxaemia and normoxaemia. All patients exhibited high EPO levels during hypoxaemia (mean value 108.7 +/- 27 mU.mL-1 (+/- SD)). During hyperoxaemia, EPO levels decreased in both groups (mean value 21.6 +/- 15.2 mU.mL-1 in group I, 36.8 +/- 19 mU.mL-1 in group II). During normoxaemia, EPO levels increased again in group I patients, but in group II patients EPO production remained stable. In conclusion, hyperoxaemia inhibits erythropoietin secretion in spite of anaemia and low arterial oxygen tension. Hyperoxaemia may be a contributing factor to anaemia in intensive care unit patients under oxygen therapy.

Topics: Adult; Aged; Analysis of Variance; Anemia; Blood Gas Analysis; Erythropoietin; Female; Humans; Hyperoxia; Linear Models; Lung Diseases, Obstructive; Male; Middle Aged; Monitoring, Physiologic; Prospective Studies; Pulmonary Gas Exchange; Respiration, Artificial; Respiratory Insufficiency; Sensitivity and Specificity

Presence of elevated plasma levels of erythropoietin (EPO) has been reported both in polycythaemic and normocythaemic patients with chronic obstructive pulmonary disease (COPD). The present study aimed to elucidate in what extent prolonged erythropoietin half-life time (T1/2EPO) is involved in the pathogenesis of elevated plasma EPO levels in patients with COPD. Seven normocythaemic patients (5 men and 2 women) with CODP and 6 healthy controls (4 males and 2 females) were examined. In all examined subjects half-life time of erythropoietin was determined after i.v. administration of EPO in a dose of 50 U/kg b.m. In COPD patients the T1/2EPO value was 5.98 +/- 0.67 hours and did not differ from that found in healthy controls (5.87 +/- 0.35 h). Results obtained in this study suggest participation of factors other than prolonged half-time of erythropoietin in the pathogenesis of polycythaemia in patients with COPD.

Topics: Erythropoietin; Female; Half-Life; Humans; Injections, Intravenous; Lung Diseases, Obstructive; Male; Middle Aged; Polycythemia

Chronic hypoxemia is associated with development of secondary polycythemia. To evaluate effects of transient hypoxemia on serum EPO activity in patients with chronic lung disease, we studied six oxygen-dependent patients who underwent either a 4-h oxygen withdrawal or their routine therapy, in a randomized, blinded fashion, on two separate days. Serum EPO did not differ at baseline between study days. Erythropoietin levels did not change significantly over time during normoxic conditions. Under hypoxic conditions, serum EPO levels rose over 4 h with the change from baseline first becoming significant at 2 h. The log of serum EPO response showed an inverse correlation with the level of arterial oxygen saturation. We conclude that patients with chronic lung disease are able to produce EPO in response to acute hypoxemic stress. Transient episodes of hypoxemia, such as occur during sleep or exercise, may result in increased red blood cell production stimulated by this EPO response.

Topics: Acute Disease; Animals; Biological Assay; Erythropoietin; Female; Humans; Hypoxia; Lung Diseases, Obstructive; Male; Mice; Oxygen; Oxygen Inhalation Therapy; Time Factors

The relations between serum-erythropoietin (se-EPO), blood hemoglobin and lung function were investigated in patients with chronic obstructive pulmonary disease (COPD). In a randomized, double-blind, placebo-controlled design, the hypothesis was tested that se-EPO might increase after treatment with a calcium antagonist. In 18 patients with COPD, median se-EPO (19.2 mU ml-1) was in the low normal range. The correlations between se-EPO and blood hemoglobin (p = -0.63, p = 0.024) and between se-EPO and lung function indices were negative (n.s.) and the correlation between blood hemoglobin and lung function indices (n.s.) were positive. The hypothesis is proposed that the normal hemoglobin found in most patients with COPD is a result of a balance between a trend towards a decreased red cell mass, as found in chronic diseases, and a trend towards an increased red cell mass due to the erythropoietic effect of EPO. Se-EPO was not changed by the calcium antagonist, isradipine.

Topics: Aged; Calcium Channel Blockers; Dihydropyridines; Double-Blind Method; Erythropoietin; Forced Expiratory Volume; Hematocrit; Hemoglobins; Humans; Isradipine; Lung Diseases, Obstructive; Middle Aged; Respiratory Mechanics; Vital Capacity

The mechanisms controlling erythropoietin (EPO) synthesis by the kidney in patients with chronic obstructive lung disease (COLD) or congestive left heart failure (CLHF) remain incompletely understood. Renal dysfunction occurs as a consequence of decreased renal blood flow (RBF) in these diseases. Because alterations in renal haemodynamics may affect EPO synthesis and red blood cell production, we investigated the potential relationships between renal function and plasma EPO synthesis in patients with COLD or CLHF. Thirty-two patients with COLD and 13 with CLHF underwent determination of renal physiology parameters, plasma EPO levels and haemoglobin levels. Plasma EPO concentrations were increased in patients with COLD or CLHF as compared to normal subjects, and were inversely correlated to haemoglobin concentrations. In patients with COLD or CLHF, plasma EPO was negatively correlated with both RBF and renal oxygen delivery (ROD) and positively correlated with filtration fraction. Plasma EPO was not correlated with glomerular filtration rate, fractional excretion of sodium, PO2 or PCO2. Among the patients with COLD, those with polycythemia (haemoglobin > 150 g L-1) had lower plasma EPO and higher RBF and ROD values than those with normocythemia (haemoglobin < or = 150 g L-1). Taken together, our data suggest that in patients with COLD or CLHF the critical determinant for EPO production is impairment of renal haemodynamics.

Topics: Adult; Aged; Erythropoietin; Female; Heart Failure; Humans; Kidney; Lung Diseases, Obstructive; Male; Middle Aged; Oxygen; Regional Blood Flow

The aim of this study was to assess the erythropoietic response to hypoxaemia in patients with diffuse idiopathic pulmonary fibrosis (DIPF), and to speculate on the underlying mechanisms. Patients on an established chronic respiratory failure due to DIPF or chronic obstructive pulmonary disease (COPD) were studied. The erythropoietic response to hypoxaemia in both conditions was assessed. We studied 18 patients with DIPF and 29 patients with COPD in respiratory failure in a stable stage, free from acute infection and congestive heart failure. Blood gases, erythrocytic parameters, as well the serum levels of iron, ferritin and erythropoietin were determined. All the DIPF patients studied, apart from two, had normal or subnormal haematocrit values. The patients with COPD had an inconsistant response to hypoxaemia; 12 had normal or subnormal haematocrit values and the remaining 17 were erythraemic. The mean value of erythropoietin (EPO) in both DIPF and COPD patients was significantly higher than normal. In conclusion, patients with DIPF exhibit a lack of erythropoietic response to hypoxaemia, despite the augmented erythropoietin levels. This may reflect a defective bone marrow erythropoietic response in DIPF patients. It is suggested that the pathophysiology of DIPF underlies this mechanism.

Topics: Adult; Aged; Aged, 80 and over; Blood Gas Analysis; Erythropoiesis; Erythropoietin; Female; Ferritins; Hematocrit; Humans; Hypoxia; Iron; Lung Diseases, Obstructive; Male; Middle Aged; Pulmonary Fibrosis; Reference Values; Regression Analysis

Factors which could influence serum erythropoietin (s-EPO) levels in patients with chronic pulmonary diseases were investigated, paying special attention to the role of changes in acid-base balance (PaCO2, HCO3- and base excess levels) in EPO production. Data from 30 patients with chronic pulmonary diseases (chronic pulmonary emphysema, chronic bronchitis and post-tuberculosis status) were obtained in the morning and were analyzed with a stepwise forward multiple regression analysis, evaluating the statistical significance of seven factors which may potentially influence s-EPO levels: arterial pH, PaCO2, PaO2, HCO3-, base excess (BE), SaO2 and hemoglobin (Hb). Significant simple correlations (P < 0.01) of log(s-EPO) were obtained with PaO2 (r = -0.66), PaCO2 (r = 0.59), HCO3- (r = 0.67), BE (r = 0.71) and SaO2 (r = -0.77). The stepwise forward multiple regression analysis revealed that significant correlate variables for the outcome variable of log(s-EPO) were SaO2 and BE, with r = 0.823 (P < 0.0001). In patients with chronic pulmonary diseases it was shown that SaO2 was a negative correlate and BE was a positive correlate of s-EPO levels. It was speculated that s-EPO levels in the morning reflected daytime hypoxemia (SaO2) and nocturnal desaturation evoked by hypopnea during sleep (indicated as BE) in these patients.

Topics: Acid-Base Equilibrium; Adult; Aged; Blood Gas Analysis; Circadian Rhythm; Erythropoietin; Female; Forced Expiratory Volume; Humans; Lung Diseases, Obstructive; Male; Middle Aged; Regression Analysis; Vital Capacity

Since erythropoietin (Epo) presents a diurnal rhythm in its circulating serum levels and it is reported increased in patients with chronic obstructive pulmonary disease (COPD), the circadian rhythm of Epo was investigated in a group of 40 normocytemic patients with chronic obstructive pulmonary disease compared with 40 clinically healthy subjects.. Venous blood samples were drawn in each subject during the span of a whole day every four hours, starting from midnight, for the determination of serum Epo levels by RIA. Statistical analysis was carried out by chronograms and by means of the "cosinor" method.. The control group presents a significant (p < 0.001) circadian rhythm in serum Epo levels, with maximum in the afternoon, whereas no rhythm (p > 0.05) is detected in the patient group. This has significantly (p < 0.05) higher mean daily levels and lower diurnal variations of serum Epo than the control group; a significant (p < 0.05) difference exists between the two groups regarding the peaks of rhythms.. These data confirm the presence of circadian rhythm in serum Epo levels and suggest that the COPD, by daytime hypoxemia with associated severe nocturnal desaturation, is associated with increased serum Epo levels both by day and by night, so that the physiological circadian rhythm is lost in these patients.

Topics: Adult; Aged; Circadian Rhythm; Erythropoietin; Female; Humans; Lung Diseases, Obstructive; Male; Middle Aged

Patients with chronic obstructive pulmonary disease (COPD) are characterized by compensatory polycythaemia probably induced by increased erythropoietin (EPO) secretion in the kidneys.. As the regulatory mechanisms of erythropoietin secretion in chronic obstructive pulmonary disease are scarcely known we studied plasma EPO levels in 14 patients with COPD (pO2 = 61.9 +/- 1.4 mm Hg, Hct = 47.8 +/- 1.1%) under basal conditions, after two hours of isobaric oxygen breathing and two and four hours after discontinued oxygen breathing. The control group consisted of 12 healthy subjects (pO2 = 87.5 +/- 2.2 mm Hg, Hct = 43.7 +/- 1.6%). Under basal conditions patients with COPD showed significantly higher plasma erythropoietin levels as compared with healthy controls. Oxygen breathing was followed by a significant decline of plasma EPO levels both in patients with COPD as in the control group. This decline was significantly more marked and of longer duration in COPD patients than in healthy controls.. 1. Patients with chronic obstructive pulmonary disease are characterized by significantly higher plasma EPO levels as compared with healthy subjects. 2. The renal oxygen sensor function involved in the regulation of EPO secretion seems to be altered in COPD patients.

Topics: Erythropoietin; Humans; Lung Diseases, Obstructive; Male; Middle Aged; Oxygen Inhalation Therapy

Deliberate self-administration of recombinant human erythropoietin (rHuEpo) in a patient without anemia has never been documented. The case of a 62-year-old man who worked in an allied health care field and surreptitiously injected the drug, causing his hematocrit to increase to a dangerously high level is presented. Resultant complications of the misuse of erythropoietin in this patient included worsening hypertension, exacerbation of chronic lung disease and development of new onset angina. Medical management consisted of endotracheal intubation with mechanical ventilation, intravenous hydration, and serial phlebotomy. The unusual possibility of erythropoietin abuse must be added to the differential diagnosis with a patient with unexplained polycythemia. This case highlights the potential abuse of biological growth factors that may mask medical conditions.

Topics: Angina Pectoris; Bloodletting; Delusions; Diagnosis, Differential; Drug Overdose; Erythropoietin; Fluid Therapy; Hematocrit; Humans; Hypertension; Lung Diseases, Obstructive; Male; Middle Aged; Polycythemia; Respiration, Artificial; Self Medication; Substance-Related Disorders

1. To clarify the relationship between nocturnal oxygen desaturation and erythropoietin production in patients with chronic obstructive pulmonary disease, we determined arterial oxygen saturation and serum immunoreactive erythropoietin levels over 24 h in eight patients with chronic obstructive pulmonary disease and in nine normal subjects. 2. In the normal subjects, there was a significant circadian variation in serum erythropoietin levels with the highest mean deviation from the geometric mean at 22.00 hours and the nadir at 05.00 hours. 3. The three patients with chronic obstructive pulmonary disease with the most marked nocturnal desaturation (lowest arterial oxygen saturation < 57%) and most marked daytime hypoxaemia (daytime arterial partial pressure of oxygen < 6 kPa) had raised nocturnal serum erythropoietin levels. In two of these patients, the serum erythropoietin level was raised throughout the 24 h and erythrocyte mass was also raised. In the other patient, the serum erythropoietin level was not raised in five daytime samples and erythrocyte mass was normal. 4. The other five patients with chronic obstructive pulmonary disease with less severe nocturnal hypoxaemia (lowest arterial oxygen saturation range 78-86%) had serum erythropoietin levels (range 14-36 m-i.u./ml) which were indistinguishable from normal (range 12-44 m-i.u./ml) and showed circadian changes which were not significantly different (P = 0.35) from those in the normal subjects. 5. Thus, mild nocturnal oxygen desaturation is not associated with elevation of serum erythropoietin levels, whereas daytime hypoxaemia with associated severe nocturnal desaturation is associated with increased serum erythropoietin levels both by day and by night.

Topics: Aged; Chronic Disease; Circadian Rhythm; Erythropoietin; Female; Humans; Hypoxia; Lung Diseases, Obstructive; Male; Oxygen; Sleep

The serum concentration of erythropoietin in 79 cases with various blood diseases, uremia, chronic obstructive pulmonary disease etc was determined. At comparable degrees of anemia, patients with myelodysplastic syndrome and aplastic anemia had the highest levels of erythropoietin in our study. The high level of erythropoietin titer in patients with aplastic anemia should be taken as the nom for renal synthesis and release of this hormone. The erythropoietin level in patients with uremic anemia was lower than the level in patients with anemia of other causes but still higher than that of the normal controls. Patients suffering from polycystic kidney disease with or without uremia had a high level of erythropoietin due to local hypoxia of remnant kidney tissue resulting from the pressure of cystic formation. Different methods are used to determine the erythropoietin level, which varies with the stage and etiology of the diseases. There are other stimulating or inhibitory factors of erythropoiesis when the assay is processed. Transfusion and administration of certain drugs also influence the growth of erythroid cells, thus the serum titers of erythropoietin differed markedly between patients at comparable hemoglobin concentration.

Topics: Adolescent; Adult; Aged; Anemia, Aplastic; Child; Erythropoietin; Female; Hemoglobins; Humans; Lung Diseases, Obstructive; Male; Middle Aged; Uremia

In order to investigate the mechanism of polycythemia in chronic obstructive pulmonary disease (COPD), serum and urinary levels of erythropoietin and medullary erythroid progenitors were studied in 21 patients; nine were nonpolycythemic (hematocrit, 39 +/- 4 percent; red blood cell [RBC] mass, 28 +/- 5 ml/kg; forced expiratory volume in one second [FEV1], 0.6 +/- 0.1 L), and 12 patients were polycythemic (hematocrit, 52 +/- 7 percent; RBC mass, 46 +/- 7 ml/kg; FEV1, 0.9 +/- 0.3 L). Hypoxia was severe in both groups, with mean arterial oxygen pressure of 47 mm Hg. The following parameters of tissue oxygenation were not significantly different between the two groups: arterial and mixed-venous oxygen saturations; cardiac output; oxygen utilization coefficient; 2, 3-diphosphoglycerate, and carboxyhemoglobin level. The level of erythropoietin was measured by bioassay in vitro. The level was increased in the serum of 85 percent (18) and in the urine of 38 percent (8) of the patients. There was no significant difference between the nonpolycythemic and polycythemic groups. Without exogenous erythropoietin, none of the subjects showed spontaneous colonies of erythroid progenitors. The addition of one unit of erythropoietin induced a similar normal proliferation of erythroid progenitors in both groups. The absence of adaptative polycythemia in the nonpolycythemic group with severe hypoxia was seemingly related neither to a quantitative deficit of erythropoietin nor to a lack of sensitivity of erythroid progenitors to its action.

Topics: Aged; Blood Pressure; Erythropoietin; Female; Hematocrit; Hematopoietic Stem Cells; Humans; Lung Diseases, Obstructive; Male; Middle Aged; Oxygen; Polycythemia; Pulmonary Artery

We studied 20 patients with chronic airflow obstruction, 10 patients without polycythaemia and 10 patients with compensatory polycythaemia having respectively mean red cell mass 24.7 (SD 4.2) and 47.8 (SD 7.5) ml/kg, mean daytime PaO2 7.6 and 6.9 kPa, mean FEV1 0.85 and 0.821. Groups were matched for severity of daytime arterial hypoxaemia but nocturnal arterial oxygen desaturation was more severe in the patients with polycythaemia than in those without. We also studied six additional patients with chronic airflow obstruction and polycythaemia and 19 normal controls. Estimates of serum immunoreactive erythropoietin (siEp) in those without polycythaemia were 19 m-i.u./ml (geometric mean) with 95% confidence range 11-35 m-i.u./ml and stable during 3 months. In those with polycythaemia they were similar and consistent in five and, in the other five, higher on at least one occasion. There was no significant difference between siEp in daytime (12.00 hours to 16.00 hours) and morning (07.00 hours) samples but geometric mean estimates of erythropoietin in paired daytime and morning samples were higher and more variable in patients with polycythaemia than in those without. The geometric mean estimate of siEp in all patients with chronic airflow obstruction and polycythaemia was greater than in normal subjects but, despite secondary polycythaemia, siEp could be in the range for normal subjects. In the patients with polycythaemia we were unable to predict the finding of normal or elevated siEp. Changes in siEp after erythrapheresis (10-26% reduction in packed cell volume) were observed in the 10 patients with polycythaemia and in one without. One month after erythrapheresis, packed cell volume remained below and siEp was above initial pretreatment levels, implying an erythropoietin secretory response and that the development of secondary polycythaemia had induced a fall in siEp.

Topics: Aged; Erythropoietin; Female; Hematocrit; Hemoglobins; Humans; Lung Diseases, Obstructive; Male; Middle Aged; Polycythemia

Serum levels of immunoreactive erythropoietin (Ep) were measured in 48 normal male and female volunteers, ages 20-60 years, to establish a control value for Ep of 18.5 +/- 5.0 (mean +/- SD) mU/ml. Levels of the hormone were also measured sequentially over a 24 h period of time in an additional 17 'normal' volunteers with no diurnal variation. Diurnal levels of immunoreactive Ep were also measured in 30 subjects, with chronic lung disease. These patients, in contrast to normal subjects exhibited a diurnal variation in the level of immunoreactive Ep with peak levels occurring at midnight. The only variable measured which correlated with the serum immunoreactive Ep level in subjects with chronic lung disease was the level of carboxyhaemoglobin (P less than 0.02).

Topics: Adult; Carboxyhemoglobin; Circadian Rhythm; Coal Mining; Erythropoietin; Female; Hematologic Tests; Humans; Lung Diseases, Obstructive; Male; Middle Aged; Pneumoconiosis; Respiratory Function Tests; Smoking

Topics: Aged; Asthma; Bicarbonates; Bloodletting; Carbon Dioxide; Carotid Body; Erythrocyte Count; Erythropoiesis; Erythropoietin; Hematocrit; Humans; Hydrogen-Ion Concentration; Lung Diseases, Obstructive; Male; Middle Aged; Oxygen; Respiration; Reticulocytes; Time Factors