Papers by Roberto Bigazzi
American Journal of Hypertension, 1996
Atherosclerosis, 2019
Statistical analysis centre (D. De Bacquer h , G. De Backer h), Central laboratory (L. Raman ax ,... more Statistical analysis centre (D. De Bacquer h , G. De Backer h), Central laboratory (L. Raman ax , J. Sundvall ax), Study centres, organisations, investigators and other research personnel (National Coordinators in each country are indicated by asterisk (D. DeSmedt * bd , J.
Clinical nephrology, Jan 8, 2016
Ultrafiltration (UF) technique is a valuable alternative to pharmacological therapy in the treatm... more Ultrafiltration (UF) technique is a valuable alternative to pharmacological therapy in the treatment of patients with refractory congestive heart failure (HF). The aim of this study was to describe a single-center experience in the treatment of refractory HF patients with peritoneal dialysis (PD). Retrospective study of 5 patients included in a single PD Unit, showing symptoms and signs of severe refractory congestive HF to optimal pharmacological therapy (NYHA class IV). Clinical and laboratory parameters, survival, hospitalization, and peritonitis rates were recorded. Patients were followed for 9.36 (± 6.36) months; population mean age was 62 (± 16) years and Charlson's comorbidity index was 7.2 (± 2.1). After PD therapy, functional class of NYHA significantly improved (class IV to class II in 4 patients). Doppler-echocardiography improved in terms of ejection fraction (EF) or systolic pressure of the pulmonary artery (SPPA) in 3 patients. No patient was readmitted due to HF. ...
Hypertension, 1994
We previously showed that a high salt diet increases glomerular capillary pressure in salt-sensit... more We previously showed that a high salt diet increases glomerular capillary pressure in salt-sensitive hypertensive patients and suggested that this may underlie the greater propensity of these patients to develop renal failure. Because microalbuminuria is considered an initial sign of renal damage, we have tested whether salt-sensitive patients display greater urinary albumin excretion than salt-resistant hypertensive patients. Twenty-two patients were placed on a low sodium intake (20 mEq/d) for 7 days followed by a high sodium diet (250 mEq/d) for 7 more days. Twelve patients were classified as salt sensitive and 10 as salt resistant. Urinary albumin excretion was greater in salt-sensitive than salt-resistant patients (54 +/- 11 versus 22 +/- 5 mg/24 h, P < .01). During the low sodium diet, glomerular filtration rate, renal plasma flow, and filtration fraction were similar between the two groups. During the high sodium intake, glomerular filtration, renal plasma flow, filtration...
American Journal of Hypertension, 1991
Ρ < .05). There was also no difference in intestinal absorption of calcium after 2 and 24 h among... more Ρ < .05). There was also no difference in intestinal absorption of calcium after 2 and 24 h among hy pertensives and normotensives. When hypertensive patients were stratified ac cording to plasma renin activity (PRA) we found that patients with low PRA had higher intestinal absorption of calcium at 2 h (23 ± 2.9 ν 18 ± 0.6%, Ρ < .05) but not at 24 h. Serum total and ionozed calcium, PTH, and l,25(OH) 2 D were not different between patients with low and those with normalhigh PRA. The major derangement of calcium metabolism in patients with essential hypertension is hypercalciuria. This abnormality is more pronounced in pa tients with low PRA, and it may lead to increased vitamin D-dependent intestinal absorption of cal cium.
American Journal of Hypertension, 1995
American Journal of Hypertension, 1994
Microalbuminuria has been shown in approxi mately 40% of patients with essential hyperten sion. P... more Microalbuminuria has been shown in approxi mately 40% of patients with essential hyperten sion. Previous studies have failed to demonstrate any consistent relationship between microalbumin uria and levels of office blood pressure. Because average ambulatory blood pressure correlates with incidence of cardiovascular morbidity and mortal ity better than office blood pressure, we have stud ied whether levels of urinary albumin excretion correlate with average diurnal, nocturnal, or 24-h blood pressure better than with office blood pres sure. Sixty-three patients with essential hyperten sion and 21 healthy volunteers were included in the study. Twenty-four hypertensive patients failed to show the normal nighttime fall in blood pressure of at least 10/5 mm Hg and were defined as "nondippers"; the remaining were defined as "dippers." Office blood pressure was not different between dippers and nondippers. However, night time systolic and diastolic blood pressures were sig nificantly greater in nondippers than in dippers. The median urinary albumin excretion in nondip pers (42 mg/24 h) was significantly greater (P < .001) than in dippers (17.5 mg/24 h), and in normal subjects (8.6 mg/24 h). A significant correlation was present between nighttime systolic and dia stolic blood pressure and urinary albumin excre tion (UAE) and between 24-h systolic blood pres sure and UAE in all hypertensive patients; in addi tion, a significant correlation was present between 24-h diastolic and nighttime diastolic blood pres sure and UAE in nondippers. The increased amount of UAE in nondipper hypertensive patients suggests the presence of greater renal damage than in dippers.
Journal of nephrology
The increasing prevalence of obesity and diabetes mellitus in most industrialized countries, incl... more The increasing prevalence of obesity and diabetes mellitus in most industrialized countries, including China and India, is reaching epidemic proportions and requires intense studies and interventions. Insulin resistance appears to be the most relevant feature of the metabolic syndrome and is often the precursor of diabetes mellitus. Insulin resistance has been associated with endothelial dysfunction, which is considered the initial step in the process of atherosclerosis. In this brief review, we analyze the relationship between insulin resistance, endothelial function and cardiovascular events.
American Journal of Hypertension, 2006
Background: The prevalence of overweight and obesity in the United States has dramatically increa... more Background: The prevalence of overweight and obesity in the United States has dramatically increased. Obesity clusters with a variety of hemodynamic and metabolic disturbances that increase the risk of cardiovascular disease. In this study we evaluated whether overweight subjects with hypertension also manifest hemodynamic and metabolic abnormalities compared with individuals of normal weight. Methods: In a cohort of 129 patients with essential hypertension we measured the relationship between body mass index (BMI), blood pressure (BP), insulin sensitivity, lipid profile, and markers of organ damage including thickness of the carotid artery (IMT) and urine albumin excretion (UAE). A total of 41 normotensive, age-matched, healthy individuals served as control subjects. Results: Hypertensive individuals showed higher levels of serum triglycerides, insulin area-under-the-curve (AUC), UAE, and greater IMT than normotensive subjects. Overweight hypertensive subjects showed higher levels of serum triglycerides, LDL cholesterol, glucose AUC, insulin AUC, UAE, and IMT than hypertensive subjects with normal body weight (BMI Ͻ25). Night-time systolic BP was higher and night-time fall in BP was lower among overweight than among normal-weight hypertensive patients. Simple regression analysis showed that BMI was correlated with age, UAE, BP, insulin and glucose AUC, serum triglycerides, cholesterol, and IMT in hypertensive subjects. However multiple regression analyses showed that BMI significantly correlated only with UAE. Conclusions: The study results show that increased body weight clusters with a variety of hemodynamic and metabolic abnormalities in hypertensive subjects. However multiple regression analyses showed a significant correlation only between BMI and UAE, a marker and predictor of cardiovascular and renal disease.
Hemodialysis, 2011
The prevalence of chronic kidney disease (CKD) is increasing alarmingly mainly as a result of an ... more The prevalence of chronic kidney disease (CKD) is increasing alarmingly mainly as a result of an ongoing epidemic of obesity, metabolic syndrome, and diabetes mellitus. CKD is a well-recognized risk multiplier for development of cardiovascular disease (CVD), and it is widely known that CVD is the leading cause of morbidity and mortality in patients with CKD. Cardiovascular (CV) morbidity and mortality is significantly increased along the continuum of CKD, and it is more than 10 times higher in end-stage renal disease populations than in the general population. Lipid metabolism is profoundly disturbed in CKD, and there is a gradual shift to the uremic lipid profile as kidney function deteriorates, which is further modified by the presence of comorbidities such as diabetes and obesity. Apart from quantitative differences, major qualitative changes in lipoproteins can be observed, such as oxidization and modification to small and dense low-density lipoprotein (LDL), which render the particles more atherogenic. It has been noted that these abnormalities contribute to the development of CV events, and they may lead to the progression of CKD. Lipid-lowering treatment with statins in the general population has achieved important benefits both in reducing CV risk and in the prevention of CVD. Similarly, data from secondary analyses of CKD subgroups of larger prospective trials using statins also suggest an important benefit on CV outcomes and, with more conflicting evidence, on the progression of kidney disease. Preliminary results from a large randomized controlled trial of lipid-lowering therapy in CKD confirm similar benefits of treatment for dyslipidemia in patients with CKD and ESRD. The safety profile of lipid- lowering therapy with statins in CKD is not different from that observed in people with normal renal function. Hence, lipid- lowering therapy with statins should be part of the standard treatment of patients with CKD.
Nutrition, Metabolism and Cardiovascular Diseases, 2008
Insulin resistance (IR) is commonly associated with other cardiovascular risk factors and is cons... more Insulin resistance (IR) is commonly associated with other cardiovascular risk factors and is considered an independent risk factor for cardiovascular disease and events. The hyperinsulinemic euglycemic clamp technique is considered the gold standard for evaluating IR, but this technique is cumbersome and not easily applicable in large studies. Therefore, there are no long-term follow-up published studies on the relationship between IR determined by this technique and cardiovascular outcome. Thirteen years ago we performed a hyperinsulinemic euglycemic clamp in 31 hypertensive patients, 16 of whom manifested IR and 15 had normal insulin sensitivity. Thirteen years later we were able to re-evaluate or obtain medical records for all these patients. Over these years, 11 of the 16 insulin resistant patients developed cardiovascular disease and events, including two cardiovascular deaths, two myocardial infarctions, one angina pectoris, one peripheral vascular disease, and five carotid plaques or stenosis. Moreover, two patients developed new onset diabetes, one proteinuria and two impaired kidney function. Among insulin-sensitive patients, one developed peripheral vascular disease, one new onset diabetes and one proteinuria.
Kidney International, 1999
Association between hyperlipidemia and microalbuminuria in lin-dependent diabetes mellitus (NIDDM... more Association between hyperlipidemia and microalbuminuria in lin-dependent diabetes mellitus (NIDDM) [1]. In both essential hypertension. IDDM and NIDDM patients, microalbuminuria also Background. Some patients with essential hypertension predicts cardiovascular morbidity and mortality [2]. manifest greater than normal urinary albumin excretion Some evidence also indicates that microalbuminuria may (UAE). A few retrospective studies have suggested that there predict cardiovascular events and perhaps early renal is an association between microalbuminuria and cardiovascular risk. The reasons for this association are not well established, damage in patients with essential hypertension. The posand they are the object of this review. sible reasons underlying the association between mi-Results. We found that hypertensive patients with microalcroalbuminuria and increased incidence of cardiovascubuminuria manifest greater levels of blood pressure, particular and renal events are outlined in this review. larly at night. Serum levels of cholesterol, triglycerides, and uric acid in patients with microalbuminuria were higher than levels in those with normal UAE, whereas levels of high-density MICROALBUMINURIA IN ESSENTIAL lipoprotein cholesterol in patients with microalbuminuria were HYPERTENSION: INCIDENCE AND lower than levels in patients with normal UAE. Patients with microalbuminuria manifest a greater incidence of insulin resis-RELATIONSHIP WITH LEVELS OF tance, and thicker carotid arteries. After a follow-up of seven BLOOD PRESSURE years we observed that 12 cardiovascular events occurred The prevalence of microalbuminuria in patients with among 54 (21.3%) patients with microalbuminuria, and only two such events among 87 patients with normal UAE (P Ͻ
Journal of Hypertension, 1991
Hypertension, 1991
African-Americans with essential hypertension are more prone to the development of renal failure ... more African-Americans with essential hypertension are more prone to the development of renal failure and are frequently salt-sensitive as well. Because alterations of intrarenal hemodynamics are important in the progression of renal disease and because salt-sensitive animal models with hypertension manifest a greater propensity to develop glomerulosclerosis in association with a rise in glomerular capillary pressure, we tested whether the renal hemodynamic adaptation to high dietary Na+ intake differs in salt-sensitive and salt-resistant hypertensive patients. We studied 17 black and nine white patients with essential hypertension who were placed on a low Na+ diet (20 meq/day) for 9 days, followed by a high Na+ diet (200 meq/day) for 14 days. During the last 4 days of each diet regimen, they received 30 mg/day of slow-release nifedipine. Eleven blacks were salt-sensitive, and all whites were salt-resistant. During the low Na+ diet period, salt-sensitive and salt-resistant patients had s...
American Journal of Nephrology, 1992
Since calcium plays a modulatory role in the activity of the sympathetic nervous system (SNS), in... more Since calcium plays a modulatory role in the activity of the sympathetic nervous system (SNS), in these studies, we have tested the hypothesis that hypercalcemia may alter renal SNS activity, and, consequently, renal function. Acute hypercalcemia was induced in Sprague-Dawley rats by infusion of calcium 30 mg/kg/2 h in 0.45% saline. A control group of rats received only 0.45% saline. Two more groups of rats received either calcium or 0.45% saline 7-10 days after total renal denervation. Calcium infusion increased serum calcium by 1.8 +/- 0.23 mg/dl in rats with intact renal nerves and by 2.7 +/- 0.48 mg/dl in renal denervated rats. Mean arterial pressure and inulin clearance did not change during calcium or 0.45% saline in rats with intact renal nerves. Renal sympathetic nerve activity (RSNA) decreased by 44% in rats infused with calcium, but it did not change in control animals. Calcium caused a significantly greater rise in urine volume, sodium excretion and fractional excretion of sodium than the infusion of 0.45% saline. Rats with renal denervation manifested greater baseline urine volume, sodium excretion and fractional excretion of sodium than rats with intact renal nerves. Infusion of calcium, however, caused no further rise in urine sodium excretion in these animals. alpha-Methyltyrosine, an inhibitor of norepinephrine (NE) synthesis, also increased natriuresis in rats. Calcium reduced by 27% the NE content in the kidney but not in the heart. Methyltyrosine, on the other hand, reduced NE content in both the heart and the kidney.(ABSTRACT TRUNCATED AT 250 WORDS)
American Journal of Nephrology, 1991
The long-term effects of converting enzyme inhibitors and calcium channel blockers on proteinuria... more The long-term effects of converting enzyme inhibitors and calcium channel blockers on proteinuria and the progression of renal disease in patients with hypertension and chronic renal insufficiency are not well established. We have studied the long-term effects of treating hypertension with an angiotensin-converting enzyme inhibitor, enalapril, and a calcium channel blocker, nicardipine, on urinary albumin excretion (UAE) and on renal function in 16 patients with hypertension and chronic renal insufficiency (creatinine clearance ranging between 17 and 62 ml/ min). After 1 year of treatment, these agents caused a similar decrease in blood pressure. Only enalapril, however, caused a significant decrease in UAE (from 641 ± 98 to 292 ± 47 mg/24 h, p &lt; 0.01), whereas UAE did not change in the group treated with nicardipine (675 ± 78 vs. 601 ± 75 mg/24 h). Creatinine clearance at the beginning of the study was similar in the group treated with enalapril and in the group treated with nicardipine (35 ± 3.6 vs. 40 ± 4.1 ml/min). After 1 year of follow-up, creatinine clearance remained unchanged in both groups of patients. These studies demonstrate that both enalapril and nicardipine can effectively reduce blood pressure in patients with hypertension and chronic renal insufficiency. Enalapril but not nicardipine, however, appears to reduce urinary albumin excretion in these patients. Whether the reduction in UAE has any significant impact on the progression of renal disease remains to be established.Copyright © 1991 S. Karger AG, Basel
The American Journal of Medicine, 1992
Microalbuminuria can be present in 10% to 40% of patients with essential hypertension and is asso... more Microalbuminuria can be present in 10% to 40% of patients with essential hypertension and is associated with an increased incidence of cardiovascular events. The effect of commonly used antihypertensive agents on urinary albumin excretion (UAE) has not been well established. The aim of this study was to evaluate the effects of a converting enzyme inhibitor, a calcium channel blocker, a beta blocker, and a diuretic on UAE and on creatinine clearance in patients with mild to moderate hypertension. We prospectively measured UAE prior to and 4 and 8 weeks after treatment with enalapril, nitrendipine, atenolol, or a diuretic in 48 patients with essential hypertension and microalbuminuria. All these agents were equally effective in reducing arterial pressure. However, enalapril but not the other agents significantly decreased UAE. Eight weeks of therapy with enalapril may reduce UAE in patients with mild to moderate essential hypertension, whereas other agents, such as nitrendipine, atenolol, or diuretics, had no measurable effect on UAE. The clinical and prognostic significance of these observations remains to be established.
American Journal of Kidney Diseases, 1999
Some patients with essential hypertension manifest greater than normal urinary albumin excretion ... more Some patients with essential hypertension manifest greater than normal urinary albumin excretion (UAE). The significance of this association, which is the object of this review, is not well established. Hypertensive patients with microalbuminuria manifest greater levels of blood pressure, particularly at night, and higher serum levels of cholesterol, triglycerides, and uric acid than patients with normal UAE. Levels of high-density lipoprotein cholesterol, on the other hand, were lower in patients with microalbuminuria than in those with normal UAE. Patients with microalbuminuria manifested greater incidence of insulin resistance and thicker carotid arteries than patients with normal UAE. After a follow-up of 7 years, we observed that 12 cardiovascular events occurred among 54 (21.3%) patients with microalbuminuria and only two such events among 87 patients with normal UAE (P F 0.0002). Stepwise logistic regression analysis showed that UAE, cholesterol level, and diastolic blood pressure were independent predictors of the cardiovascular outcome. Rate of creatinine clearance from patients with microalbuminuria decreased more than that from those with normal UAE. In conclusion, these studies suggest that hypertensive individuals with microalbuminuria manifest a variety of biochemical and hormonal derangements with pathogenic potential, which results in hypertensive patients having a greater incidence of cardiovascular events and a greater decline in renal function than patients with normal UAE.
American Journal of Kidney Diseases, 2005
Background: Experimental evidence suggests that aldosterone may contribute to progressive kidney ... more Background: Experimental evidence suggests that aldosterone may contribute to progressive kidney disease. Although angiotensin-converting enzyme (ACE) inhibitors and angiotensin type 1 receptor antagonists (ARBs) suppress the renin-angiotensin system, these agents do not adequately control plasma aldosterone levels. Hence, administration of aldosterone receptor antagonists may provide additional renal benefits to the ACE inhibitors and ARBs. Methods: In the present uncontrolled pilot study, we evaluate the short-term (8 weeks) effects of spironolactone on proteinuria in 42 patients with chronic kidney disease (CKD) already treated with ACE inhibitors and/or ARBs. Results: Spironolactone (25 mg/d for 8 weeks) decreased proteinuria from protein of 2.09 ؎ 0.16 to 1.32 ؎ 0.08 g/24 h after 2 weeks and 1.05 ؎ 0.08 g/24 h after 8 weeks. Four weeks after discontinuation of spironolactone therapy, proteinuria returned to close to baseline values. Baseline proteinuria correlated significantly with plasma aldosterone level (r ؍ 0.81; P < 0.0001). Moreover, baseline aldosterone level correlated significantly with degree of reduction in proteinuria after treatment with spironolactone (r ؍ 0.70; P < 0.0001). Spironolactone caused a significant increase in serum potassium levels (from 4.4 ؎ 0.1 mEq/L [mmol/L] at baseline to 4.8 ؎ 0.1 mEq/L [mmol/L] after 8 weeks of treatment; P < 0.01). Conclusion: This study shows that spironolactone may effectively reduce proteinuria in patients with CKD. Concerns remain in regard to the risk for hyperkalemia in patients with CKD. Prospective randomized trials are necessary to confirm the efficacy and safety of antagonists of aldosterone on proteinuria and progression of CKD.
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Papers by Roberto Bigazzi