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D S Silverberg

Publications and source records attributed to D S Silverberg.

At least 19 recordsLinked to original sources
PubMed2004

Correction of anemia in patients with congestive heart failure increases resting energy expenditure.

BACKGROUND & AIM: Congestive heart failure (CHF) and anemia were reported to affect resting energy expenditure (REE). The aim of this study was to evaluate the effect of the correction of anemia on REE in subjects with CHF. PATIENTS AND METHODS: Nine anemic patients with compensated CHF and CRF were studied before and after correction of anemia. REE was studied by an open circuit indirect calorimeter, body composition by dual-energy-X-ray absorption and total body and extracellular water by multi-frequency bioelectrical impedence. Four anemic and 5 non-anemic CHF patients who did not receive any new treatment served as controls. RESULTS: After the correction of their anemia patients tended to increase weight (P<0.06), but no significant changes were observed in body composition. Daily caloric intake increased significantly (P<0.02). Ejection fraction increased (P<0.05) and pulse rate decreased significantly (P<0.001). REE and REEPP were in the normal range before correction but increased significantly afterwards (1402+/-256 vs. 1496+/-206 kcal/d, and 101+/-9 vs. 109+/-8, P<0.023 and P<0.006, respectively). CONCLUSION: Correction of anemia in patients with CHF increases their REE. This can be related either to improved tissue oxygenation and/or to increased caloric intake.

Aged↗
PubMed2003

Anemia in chronic kidney disease and congestive heart failure.

Anemia is seen in chronic kidney insufficiency (CKI), dialysis patients, congestive heart failure (CHF), and renal transplantation. Anemia can lead to progressive cardiac damage as well as progressive renal damage. It is not generally appreciated that CHF itself may be a very common contributor to both the production of anemia as well as to the progression of the renal failure. Correction of the anemia with erythropoietin and, as necessary, intravenous iron, may prevent the deterioration of both the heart and the kidneys. We suggest that there is a triangular relationship, a vicious circle, between CHF, CKI and anemia where each of these three can both cause and be caused by the other. We call this syndrome the cardio-renal anemia (CRA) syndrome. All physicians, especially cardiologists and internists who treat CKI and CHF, should be made aware of the dangers of anemia in CKI and CHF and should work with nephrologists to correct it.

Anemia↗
PubMed2003

The cardio renal anemia syndrome: correcting anemia in patients with resistant congestive heart failure can improve both cardiac and renal function and reduce hospitalizations.

Anemia (Hemoglobin of < 12 to 13 g/dl) is frequently encountered in patients with congestive heart failure (CHF). This anemia may be partly due to hemodilution, partly to the associated reduction in renal function, and partly to the use of ACE inhibitors and aspirin. However, there is evidence that CHF alone--through excessive cytokine production may also reduce the bone marrow and cause anemia. In several recent studies anemia has been found to be associated with a more severe degree of CHF, a higher rate of death, renal failure, hospitalization and evidence of malnutrition. In both uncontrolled and controlled studies correction of anemia with erythropoietin with or without the addition of i.v. iron has been attempted. The correction of anemia has been associated with a marked improvement in New York Heart Association (NYHA) functional cardiac class and Left Ventricular Ejection Fraction, a marked reduction in the need for hospitalization and high dose oral and i.v. diuretics, and an improvement in exercise capacity, peak exercise oxygen utilization and quality of life. The serum creatinine, which had been increasing steadily before treatment, stabilized with the correction of anemia. All this suggests that control of anemia in CHF could become a valuable addition to the therapeutic armamentarium of CHF and might also play a major role in the prevention of progressive renal failure.

Anemia↗
PubMed2002

The correction of anemia in severe resistant heart failure with erythropoietin and intravenous iron prevents the progression of both the heart and the renal failure and markedly reduces hospitalization.

Both Congestive Heart Failure (CHF) and Chronic Renal Failure (CRF) are increasing steadily in the community. We propose that there is a vicious circle established whereby CHF and CRF both cause anemia and the anemia then worsens both the CHF and CRF causing more anemia and so on. We call this the Cardio Renal Anemia (CRA) syndrome. By the combination of active treatment of the CHF and control of the anemia with subcutaneous erythropoietin and intravenous iron, the progression of both the CHF and the CRF can be slowed or stopped in most cases, the quality of life improved and the need for recurrent hospitalization reduced. This will involve cooperation between internists, cardiologists, and nephrologists to allow early and maximal therapy of both the CHF and the anemia.

Aged↗
PubMed2001

The effect of correction of mild anemia in severe, resistant congestive heart failure using subcutaneous erythropoietin and intravenous iron: a randomized controlled study.

OBJECTIVES: This is a randomized controlled study of anemic patients with severe congestive heart failure (CHF) to assess the effect of correction of the anemia on cardiac and renal function and hospitalization. BACKGROUND: Although mild anemia occurs frequently in patients with CHF, there is very little information about the effect of correcting it with erythropoietin (EPO) and intravenous iron. METHODS: Thirty-two patients with moderate to severe CHF (New York Heart Association [NYHA] class III to IV) who had a left ventricular ejection fraction (LVEF) of < or =40% despite maximally tolerated doses of CHF medications and whose hemoglobin (Hb) levels were persistently between 10.0 and 11.5 g% were randomized into two groups. Group A (16 patients) received subcutaneous EPO and IV iron to increase the level of Hb to at least 12.5 g%. In Group B (16 patients) the anemia was not treated. The doses of all the CHF medications were maintained at the maximally tolerated levels except for oral and intravenous (IV) furosemide, whose doses were increased or decreased according to the clinical need. RESULTS: Over a mean of 8.2+/-2.6 months, four patients in Group B and none in Group A died of CHF-related illnesses. The mean NYHA class improved by 42.1% in A and worsened by 11.4% in B. The LVEF increased by 5.5% in A and decreased by 5.4% in B. The serum creatinine did not change in A and increased by 28.6% in B. The need for oral and IV furosemide decreased by 51.3% and 91.3% respectively in A and increased by 28.5% and 28.0% respectively in B. The number of days spent in hospital compared with the same period of time before entering the study decreased by 79.0% in A and increased by 57.6% in B. CONCLUSIONS: When anemia in CHF is treated with EPO and IV iron, a marked improvement in cardiac and patient function is seen, associated with less hospitalization and renal impairment and less need for diuretics.

Aged↗
PubMed2001

Are sleep-related breathing disorders important contributing factors to the production of essential hypertension?

About 50% of all patients with essential hypertension have obstructive sleep apnea (OSA), and another 40% of essential hypertension patients are habitual snorers, but without OSA. There is now convincing evidence that both OSA and habitual snoring are independent risk factors for essential hypertension, and that treatment of OSA will reduce the blood pressure. There is also some evidence that treatment of habitual snoring will also reduce the blood pressure. If this is the case, then we postulate a unifying hypothesis: that these two sleep-related breathing disorders (SRBD) (OSA and habitual snoring) are very common contributing factors to what is called "essential hypertension." The many epidemiologic, clinical, hematologic, biochemical, and physiologic findings seen in essential hypertension could also be due to the associated SRBD. A routine search for SRBD by asking a few simple questions of all patients (especially those with hypertension) and their bed partners could increase the number of patients detected and treated significantly. Successful treatment of SRBD would improve sleep quality and the associated excessive daytime sleepiness, and thus improve the quality of life. In addition, there is a good chance that the hypertension will improve as well.

Blood Pressure↗
PubMed2001

The pathological consequences of anaemia.

Many patients with chronic diseases such as chronic renal failure, chronic inflammatory bowel disease and rheumatoid arthritis are anaemic. Recently congestive heart failure (CHF) has also been found to be associated with anaemia. In all these diseases this anaemia or chronic disease is at least partially due to excessive production of cytokines and leukotrines that interfere both with the effect of erythropoietin (EPO) at the bone marrow and the release of stored iron in the reticuloendothelial system. Treating this anaemia with subcutaneous EPO and IV iron improves the weakness, fatigue, cachexia, nutritional state, mood, cognitive function and quality of life. In the case of CHF it also improves cardiac function and patient functional class, prevents deterioration of renal function and markedly reduces hospitalization. Very few agents in medicine improve so many aspects of the patient so well and so quickly. Unfortunately (for the suffering patient) this anaemia is often ignored and goes untreated.

Anemia↗
PubMed2001

Apnoea characteristics across the night in severe obstructive sleep apnoea: influence of body posture.

Several studies have reported changes in apnoea characteristics across the night in patients with obstructive sleep apnoea (OSA). However, the effect of body posture on these changes has not been evaluated. The purpose of this study was to assess how body posture influences sleep apnoea characteristics across the night in severe OSA. Polysomnograms of 30 patients with severe OSA who had > or = 30 apnoeic episodes in the lateral position and 30 in the supine position during Stage 2 sleep, in the early, middle and late sleep periods were analysed. For each of the 30 events in each body position, the following variables were evaluated: apnoea duration; minimum saturation; change in saturation; duration of arousal; maximum snoring loudness and change in cardiac frequency. Although at any time during the night, apnoeas in the supine posture were more severe than those in the lateral position, a time effect across the night was found only for apnoea duration, change in cardiac frequency and duration of arousal. Body position did not affect the time trend for these variables across the night. The best fit for the changes of these three variables across the night was a quadratic time trend. It was concluded that in severe obstructive sleep apnoea during Stage 2 sleep, body position does not significantly affect the time trends of apnoea characteristics across the night. These data provide support for the participation of sleep-dependent mechanisms (homeostatic and circadian) in the determination of apnoea characteristics across the night.

Adult↗
PubMed2001

The effect of i.v. iron alone or in combination with low-dose erythropoietin in the rapid correction of anemia of chronic renal failure in the predialysis period.

BACKGROUND: It is now more and more evident that anemia of predialysis chronic renal failure (CRF) should be actively treated, since long-standing anemia may cause irremediable damage to the heart. The most common form of treatment of this anemia is subcutaneous erythropoietin (EPO). iron (Fe) deficiency can also contribute to anemia in predialysis CRF, and intravenous iron (i.v. Fe) can frequently improve it. It is possible, therefore, that the combination of EPO and i.v. Fe may have an additive effect, and cause a rapid improvement in anemia with relatively small doses of EPO. PURPOSE: The purpose of this study was an initial study: to assess the ability of a combination of low-dose EPO and i.v. Fe, given weekly for 5 doses, to correct the anemia of predialysis CRF patients compared to the use of i.v. Fe alone in a randomized study. In the follow-up study: to assess the ability of the maintenance of adequate iron stores for one year to achieve and maintain the target Hct of 35% with the minimum dose of EPO. Initial study: METHOD: Ninety predialysis CRF patients (creatinine clearance 10-40 ml/min/1.73 m2 received either: Group A (45 patients): 200 mg i.v. Fe as Fe sucrose (Venofer, Vifor Int.) once per week for 5 doses in combination with 2,000 international units (IU) EPO (Eprex, Cilag-Janssen), subcutaneously given simultaneously also for 5 doses. Group B (45 patients): the same dose of i.v. Fe as in Group A but without EPO. RESULTS: The mean increase in hematocrit (Hct) and hemoglobin (Hb) by one week after the last dose was greater in group A, 4.54 +/- 2.64% (p < 0.01) and 1.37 +/- 0.84 g% (p < 0.01), respectively, than in Group B, 2.74 +/- 2.72% (p < 0.05) and 0.91 +/- 0.78 g% (p < 0.05), respectively. 80% of those in Group A had an increase in Hct of 3 vol% or more compared to 48.9% in Group B (p < 0.01). 40% of those in Group A reached the target Hct of 35% compared to 28.9% in Group B (p > 0.05). Follow-up study: During a 12-month follow-up period, enough i.v. iron was given to maintain the Hct at 35%, while keeping the serum ferritin at < 400 ug/l and % Fe Sat at < 40%. If the i.v. Fe alone was not capable of maintaining the target Hct, EPO was given in increasing doses. Eighteen patients required dialysis. Of the 72 patients who did not require dialysis, 24 (33.3%) maintained the target Hct with i.v. Fe alone, without EPO. All the remaining 48 patients (66.7%) continued to receive EPO in addition to the i.v. Fe, and 47 achieved and maintained the target Hct with a mean EPO dose of 2,979 +/- 1,326 IU/week. CONCLUSION: The combination of low-dose EPO and i.v. Fe had a rapid and additive effect on the correction of anemia in CRF predialysis patients. Maintaining adequate iron stores with i.v. Fe during a subsequent maintenance phase allowed the target Hct of 35% to be reached and maintained with low-dose EPO in two-thirds of the predialysis patients and with no EPO at all in one-third.

Adult↗
PubMed2001

Aggressive therapy of congestive heart failure and associated chronic renal failure with medications and correction of anemia stops or slows the progression of both diseases.

The prevalence of congestive heart failure (CHF) is increasing rapidly in the community. We and others have shown that the prevalence and severity of both anemia and chronic renal failure (CRF) increase steadily with increasing severity of CHF. We have also shown that CHF patients may be resistant to standard drug therapy for CHF as long as the associated anemia is not corrected, and that correction of the anemia with subcutaneous erythropoietin and intravenous iron sucrose (Venofer: Vifor International, St. Gallen, Switzerland) may improve both the CHF and CRF and markedly reduce hospitalizations without causing side effects. We report here our experience with correcting anemia in this manner in 126 cases of anemic-resistant CHF patients. As in our previous studies, correction of the anemia improved both CHF and CRF, and reduced hospitalizations. Our studies suggest that correction of even mild anemia in CHF may be an important addition to the treatment of patients with the combination of CHF and CRF.

Aged↗
PubMed2000

The use of subcutaneous erythropoietin and intravenous iron for the treatment of the anemia of severe, resistant congestive heart failure improves cardiac and renal function and functional cardiac class, and markedly reduces hospitalizations.

OBJECTIVES: This study evaluated the prevalence and severity of anemia in patients with congestive heart failure (CHF) and the effect of its correction on cardiac and renal function and hospitalization. BACKGROUND: The prevalence and significance of mild anemia in patients with CHF is uncertain, and the role of erythropoietin with intravenous iron supplementation in treating this anemia is unknown. METHODS: In a retrospective study, the records of the 142 patients in our CHF clinic were reviewed to find the prevalence and severity of anemia (hemoglobin [Hb] <12 g). In an intervention study, 26 of these patients, despite maximally tolerated therapy of CHF for at least six months, still had had severe CHF and were also anemic. They were treated with subcutaneous erythropoietin and intravenous iron sufficient to increase the Hb to 12 g%. The doses of the CHF medications, except for diuretics, were not changed during the intervention period. RESULTS: The prevalence of anemia in the 142 patients increased with the severity of CHF, reaching 79.1% in those with New York Heart Association class IV. In the intervention study, the anemia of the 26 patients was treated for a mean of 7.2 +/- 5.5 months. The mean Hb level and mean left ventricular ejection fraction increased significantly. The mean number of hospitalizations fell by 91.9% compared with a similar period before the study. The New York Heart Association class fell significantly, as did the doses of oral and intravenous furosemide. The rate of fall of the glomerular filtration rate slowed with the treatment. CONCLUSIONS: Anemia is very common in CHF and its successful treatment is associated with a significant improvement in cardiac function, functional class, renal function and in a marked fall in the need for diuretics and hospitalization.

Aged↗
PubMed2000

Association of body position with severity of apneic events in patients with severe nonpositional obstructive sleep apnea.

STUDY OBJECTIVE: To compare the severity of sleep apneic events occurring in the supine posture vs the severity of sleep apneic events occurring in the lateral posture in patients with severe obstructive sleep apnea (OSA). DESIGN: A retrospective analysis of apneic event variables in a group of 30 OSA patients who underwent a complete polysomnographic evaluation in our sleep disorders unit. PATIENTS: Thirty patients with severe OSA (respiratory disturbance index [RDI] = 70.1+/-18.2) who were nonpositional patients (NPP), ie, in whom the ratio of the supine RDI to the lateral RDI is < 2 (supine RDI = 85.7+/-11.7, lateral RDI = 64.8+/-17.3), and who had > or =30 apneic events in the lateral position and 30 apneic events in the supine position during sleep stage 2 were included in the study. MEASUREMENTS: For the 30 apneic events in each body position, the following variables were evaluated: apnea duration (ApDur), minimum desaturation (MinDes), Delta desaturation (Delta-Des), duration of arousal (DurArous), maximum snoring loudness (MaxSL), and Delta heart rate (Delta-HR). In addition, three other variables assessed as a ratio of ApDur (Rate-D = Delta-Des/ApDur, R-HR =Delta-HR/ApDur, and R-Arous = DurArous/ApDur) were also calculated. RESULTS: For all variables evaluated, apneic events occurring in the supine posture were significantly more severe than those apneic events occurring in the lateral posture during sleep stage 2. ApDur of both body postures correlated significantly with DurArous, Delta-HR, and MaxSL, but not with Delta-Des and MinDes. ApDur correlated linearly with DurArous for both postures. The slopes of the two regression lines were similar (p = 0.578) but the regression line intercept for the supine apneas was significantly higher than that of lateral apneas (p<0.0001). In addition, the average number of supine apneic events that did not end with an arousal was smaller than the average number of lateral apneic events not ending with an arousal (4.4+/-6.0 vs. 10.5+/-6.7, respectively; p< 0.0001). Also, only 4 of 900 (0.44%) apneic events analyzed in the lateral posture ended with an awakening (> 15 s), whereas in the supine posture, there were 37 (4.1%) such events (p<0.001). CONCLUSIONS: These results show that even in patients with severe OSA who have a high number of apneic events in the supine and lateral posture, the apneic events occurring in the supine position are more severe than those occurring while sleeping in the lateral position. Thus, it is not only the number of apneic events that worsen in the supine sleep position but, probably no less important, the nature of the apneic events themselves.

Apnea↗
PubMed1999

Intravenous iron for the treatment of predialysis anemia.

This article, based on our own studies and those of others, presents evidence to show that the anemia of chronic renal failure in the predialysis period is, to a significant extent, caused by iron deficiency and can be improved in most cases by the administration of intravenous (i.v.) but not oral iron. We estimate that in approximately 30% of all predialysis patients with anemia, a target hematocrit (Hct) of 35% can be reached and maintained by giving i.v. iron alone without exceeding currently acceptable limits of serum ferritin (500 microg/liter) or the percentage of iron saturation (40%). If, in addition, subcutaneous erythropoietin (EPO-usually in only low doses-is added, the combination has an additive effect on the Hct response, and almost all anemic predialysis patients can reach and maintain the target Hct of 35% over a one-year period. Therefore, the advantage of maintaining adequate iron stores with i.v. iron is that if EPO is needed, lower doses will be required to achieve the target Hct than if EPO were used alone. This not only avoids the high cost of EPO therapy but also its associated side-effects, especially hypertension. Using Venofer, a ferric hydroxide sucrose complex, as our i.v. iron supplement, we have seen no anaphylactic reactions in over 20,000 infusions over a four-year period in 360 hemodialysis, 123 predialysis, and 58 peritoneal dialysis patients.

Administration, Oral↗
PubMed1999

The sleep supine position has a major effect on optimal nasal continuous positive airway pressure : relationship with rapid eye movements and non-rapid eye movements sleep, body mass index, respiratory disturbance index, and age.

STUDY OBJECTIVES: To evaluate the impact of sleep position on optimal nasal continuous positive airway pressure (nCPAP [op-nCPAP]) in obstructive sleep apnea (OSA) patients and to investigate how rapid eye movements (REM) and Non-REM (NREM) sleep, body mass index (BMI), respiratory disturbance index (RDI), and age are related to this effect. DESIGN: Retrospective analysis. SETTING: Sleep Disorders Unit at Loewenstein Hospital Rehabilitation Center. PATIENTS: Eighty-three consecutive adult OSA patients who underwent a complete nCPAP titration. From this group, 60 patients who spent at least 30 min in both the supine (Sup) and lateral (Lat) positions and 46 patients who had data on both positions during REM and NREM sleep were included in the analysis. RESULTS: In most OSA patients (52; 86.7%), the recommended op-nCPAP was obtained when the patients slept in the Sup posture. The mean op-nCPAP was significantly higher in the Sup posture (10.00 +/- 2.20 cm H(2)O) than it was in the Lat posture (7.61 +/- 2.69 cm H(2)O). The op-nCPAP was significantly higher in the Sup position than it was in the Lat position in both REM and NREM sleep, as well as in the severe BMI group (BMI >/= 30) and in the less obese group (BMI < 30). Similarly, in the severe (RDI >/= 40) and less severe groups (RDI < 40), as well as in both age groups (< and > 60 years of age), the op-nCPAP was significantly higher in the Sup posture than it was in the Lat posture. Irrespective of the four parameters mentioned, the actual differences in op-nCPAP between the two body postures were almost identical, ranging between 2.31 and 2.66 cm H(2)O. CONCLUSIONS: For most OSA patients, the op-nCPAP level is significantly higher in the Sup position than it is in the Lat position. This is true for REM and NREM sleep, for obese and nonobese patients, for patients with different degrees of severity, and for young and old OSA patients. Since the op-nCPAP was highest in the Sup posture during REM sleep, no nCPAP titration should be considered complete without the patient having slept in the Sup posture during REM sleep.

Adult↗
PubMed1998

The effect of body posture on sleep-related breathing disorders: facts and therapeutic implications.

The aggravating effect of the supine body position on breathing abnormalities during sleep was recognized from the earliest studies on sleep breathing disorders. Most of the anatomical and physiological correlates of this phenomenon appear to be due to the effect of gravity on the upper airway. Although few articles have been published on this topic, it has been shown in a large population of obstructive sleep apnoea (OSA) patients that more than half of them are Positional Patients, i.e. they have at least twice as many apnoeas/hypopnoeas during sleep in the supine posture as in the lateral position. This positional phenomenon is influenced by factors such as Respiratory Disturbances Index (RDI), Body Mass Index (BMI), age and sleep stages. The sleep supine posture not only increases the frequency of the abnormal breathing events but also their severity. This sleep posture also has a detrimental effect on snoring, as well as on the optimal CPAP pressure. Positional Therapy, i.e. the avoidance of the supine posture during sleep, is a simple behavioural therapy for many mild to moderate OSA patients. Unfortunately, only a few studies, including only a few patients, have investigated this form of therapy. Although the results of these studies are promising, the lack of a reliable long-term evaluation of its efficacy is perhaps an important reason why this form of therapy has not been widely accepted. Since mild to moderate OSA patients are the majority of the OSA patients and since without treatment, a large percentage of them will develop a more severe form of the disease, a thorough evaluation with a major emphasis on the long-term effectiveness of this form of therapy is urgently needed.

Journal Article↗
PubMed1998

Comparison of a vegetable-based (soya) and an animal-based low-protein diet in predialysis chronic renal failure patients.

There is some experimental evidence to suggest that progression of chronic renal failure (CRF) is slower on diets based on soya protein than on diets based on animal protein. We have compared the effect of a soya-based vegetarian low-protein diet (VPD) and an animal-based low-protein diet (APD) in 15 patients with CRF. 15 patients with CRF (51Cr-EDTA-measured glomerular filtration rate 15-50 ml/min/1.73 m2) were studied. In a randomized crossover trial, the patients were given each diet (each containing 0.75 g protein and 32 kcal per kilogram body weight) for a 6-month period. Nine patients completed the trial, 2 others dropped out because they could not tolerate the VPD, 3 because of unrelated medical complications, and 1 for technical reasons. The caloric intake was higher and the protein, phosphate and essential amino acid intake lower on the VPD than on the APD. The compliance with the suggested caloric intake was better with the VPD than with the APD (97 vs. 88% of recommended intake), as was the compliance with the suggested protein intake (94 vs. 112% of recommended intake) and with the suggested phosphate intake (102 vs. 116%). The mean glomerular filtration rate, as judged by 51Cr-EDTA, was similar after 6 months on each diet and remained unchanged throughout the entire year of the study. The rate of fall of glomerular filtration, as measured by the slope of 1/serum creatinine was slowed by 73% during the 1-year study period as compared with the prestudy period. Nutritional status (as measured by body mass index, midarm circumference, and lean body mass and percent body fat), serum transferrin, cholesterol and albumin, and total lymphocyte count were similar on the two diets. The serum albumin level on both diets, however, was significantly higher on the two diets than during the prediet period. Blood urea nitrogen, urine urea nitrogen, protein catabolic rate, and 24-hour urine creatinine and phosphate were lower on the VPD than on the APD. The 24-hour protein excretion was similar on the two diets. The two low-protein diets resulted in a slowing in the progression of CRF. A VPD is well tolerated in CRF and is associated with lower protein and phosphate intakes and a higher caloric intake than an APD and may, therefore, be used as a safe alternative or partial substitute for the usual APD in CRF.

Adult↗
PubMed1997

Sleep related breathing disorders are common contributing factors to the production of essential hypertension but are neglected, underdiagnosed, and undertreated.

There is now strong evidence from animal studies and, in humans, from epidemiological studies as well as from retrospective and prospective intervention studies, that obstructive sleep apnea (OSA) can cause persistent hypertension not only during sleep but during waking hours as well. There is also some evidence that habitual snoring alone, even without OSA, can do the same. Many of the hitherto unexplained epidemiological, clinical, biochemical, hematological, and physiological abnormalities seen in essential hypertension (EH) could be explained by the accompanying sleep related breathing disorders (SRBD). Many cases of resistant hypertension are probably due to SRBD. Recent studies show that SRBD are extremely common in EH but that the vast majority of patients with these sleep disorders are being missed by physicians who are treating the accompanying hypertension, even when the patients already have blatant symptoms of OSA. Recent investigations have shown that the probable reason for this underdiagnosis of OSA is lack of physician knowledge about the condition. This lack of knowledge is prevalent not only among family physicians, but among hypertension specialists and researchers in the field of hypertension as well. OSA is a common, easily diagnosed, and eminently treatable condition that is associated not only with disturbed sleep, loud snoring and excessive daytime sleepiness (which greatly increases the risk of traffic accidents), but also with hypertension, especially resistant hypertension, a broad range of cardiovascular problems, decreased sexual functioning, memory deficits, difficulty concentrating, and changes in personality and mood. It deserves much more attention by physicians treating hypertension than it is currently getting.

Animals↗