Nephrotic-range proteinuria and hyperglycemia associated with clonidine therapy

Glycosuria, hyperglycemia, and nephrotic-range proteinuria developed in a 68-year-old patient after clonidine was added to a stable antihypertensive regimen, which included metoprolol, of three years' duration. He later became glucose-intolerant with fasting hyperglycemia. Clonidine has been reported to transiently impair glucose tolerance. Persistent diabetes in a previously normoglycemic patient following clonidine has not been reported, and it supports the possibility that clonidine and metoprolol may have additive effects in suppressing endogenous insulin secretion.     

Nephrotic-range proteinuria, the major risk factor for early atherosclerosis in juvenile-onset systemic lupus erythematosus

OBJECTIVE: To determine the presence of early carotid atherosclerosis and associated risk factors in patients with juvenile-onset systemic lupus erythematosus (SLE). METHODS: The carotid intima-media wall thickness (IMT) was measured by B-mode ultrasound in patients with SLE onset before the age of 16 years and in sex- and age-matched healthy control subjects. Risk factors for atherosclerosis were determined at the time of the ultrasound scan and included traditional cardiovascular and SLE-related risk factors. RESULTS: Twenty-six patients with juvenile-onset SLE and 26 healthy controls were studied. The mean (+/- SD) IMT of the SLE patients was significantly higher than that of the control group (0.57+/-0.05 mm and 0.54+/-0.03 mm, respectively; P = 0.006). The results of IMT measurement were not correlated with the patients' age, disease duration, SLE Disease Activity Index (SLEDAI) score, Systemic Lupus International Collaborating Clinics/American College of Rheumatology (SLICC/ACR) Damage Index (DI) score, laboratory indicators of lupus activity, or cumulative prednisone dose. Patients with nephrotic-range (NR) proteinuria (> or = 3.5 gm/24 hours; n = 6) had a significantly higher IMT than did those without (n = 20) (P = 0.02). Patients with NR proteinuria also had significantly higher SLEDAI scores, SLICC/ACR DI scores, and systolic and diastolic blood pressures, and significantly higher levels of total cholesterol, low-density lipoprotein cholesterol, apolipoprotein B, and fibrinogen. No difference in any of the above variables, including the IMT, was observed when SLE patients without NR proteinuria were compared with healthy controls. CONCLUSION: These patients with juvenile-onset SLE had ultrasonographic evidence of premature atherosclerosis. The risk of early atherosclerosis may be higher in patients with NR proteinuria.     

Angiotensin converting enzyme inhibition and renal insufficiency in patients with bilateral renovascular disease

A 70 year old patient with malignant hypertension due to bilateral renal artery disease developed acute renal failure within 36 hrs of starting an angiotensin converting enzyme (ACE) inhibitor. Review of the consecutive series of 14 patients with bilateral renal artery disease who had also been given ACE inhibitors showed that functional renal sufficiency was common but not invariable under these circumstances. Although renal function returned towards pretreatment levels in most cases when ACE inhibitors were withdrawn, the speed with which acute renal failure may occasionally develop suggests that renal artery disease should be excluded before prescribing ACE inhibitors for hypertensive patients with undiagnosed renal impairment.     

Atherosclerotic renovascular disease

Atherosclerotic renovascular disease is a combination of renal artery stenosis and renal ischemia. Blood pressure does not rise until the stenosis is 60% or greater. Disease of both large and small blood vessels is often accompanied by the loss of glomerular filtration rate. Activation of the renin-angiotensin-aldosterone system leads to vasoconstriction and salt retention. Risk factors for atherosclerotic renovascular disease include long-standing hypertension, diabetes, smoking and dyslipidemia. The prevalence of the condition in patients with hypertension resistant to two medications is 20%. As yet, there is no single ideal screening test or evidence-based recommended screening algorithm. Magnetic resonance angiography and computed tomography angiography are noninvasive and have high sensitivity and specificity, but also have high costs associated with them. The captopril renal scan has low sensitivity and specificity in people with renal disease (the population most likely to require the test). Doppler ultrasonography has high sensitivity and specificity in experienced hands, and the renal resistance index, which can easily be added to this test, can identify those with microvascular disease who may not benefit from revascularization. The best determinant of patient outcome is not the degree of renal artery stenosis but the degree of renal parenchymal disease. To date, renal revascularization has not been associated with improved renal survival compared with medical treatment alone. Today, the approach to atherosclerotic renovascular disease is determined by the patient's blood pressure and renal function; possibly, in the future, it will be determined by the result of the renal resistance index as part of a screening algorithm. If the blood pressure is uncontrollable or the renal function is deteriorating, the patient should be considered for renal revascularization initially, with a percutaneous endovascular stent. The management of hypertension involves the use of combinations of antihypertensive agents at doses sufficient to control blood pressure. Medical management also includes aggressive lipid-lowering therapy.     

The captopril test for identifying renovascular disease in hypertensive patients

To develop a screening test for identifying renovascular hypertension, the blood pressure and plasma renin activity responses to an oral test dose of captopril were studied in 246 quietly seated hypertensive patients. The following criteria were developed that exploit the hyperresponsiveness of renin secretion in renovascular hypertensive patients: a 60-minute post-captopril plasma renin activity of 12 ng/ml per hour or more and an absolute plasma renin activity increase of 10 ng/ml per hour or more, along with a 150 percent increase in plasma renin activity (or a 400 percent increase if the baseline plasma renin activity was below 3 ng/ml per hour). Retrospectively, the test identified, among 200 hypertensive patients without evidence of renal dysfunction, all 56 patients with proved renovascular disease. In this group, false-positive results occurred only in two of 112 patients with essential hypertension and in six with secondary hypertension. Nine untreated patients had blood pressure levels of less than 160/100 mm Hg. The test was neither as sensitive nor specific in the 46 patients with renal insufficiency. This study demonstrates that the renin response to oral captopril is a useful screening test for identifying patients with unilateral or bilateral renovascular disease. Since the test also characterizes the renin dependency of the hypertension, it may have other diagnostic and therapeutic uses.     

The prevalence of peripheral vascular disease in sulfonylurea treated diabetic patients with proteinuria

The aim of this study was to assess the prevalence and the possible risk-factors for the development of peripheral vascular disease (PVD) in sulfonylurea-treated diabetic patients with proteinuria. Fifty non-insulin-dependent diabetics (NIDDs) with proteinuria (greater than 500 mg/24 h), with age less than or equal to 75 years and duration of diabetes greater than or equal to 5 years, and forty-eight NIDDs without proteinuria, matched for age, sex, body mass index (BMI), duration of diabetes and glycaemic control, were studied using Doppler ultrasound. Risk factors analysed included smoking, hypertension and metabolic indices (cholesterol, HDL-C, triglycerides). The prevalence of PVD was 44% in the proteinuric disease group compared to 14.6% in those without proteinuria (p less than 0.01). Among the risk factors analysed, hypertension and triglyceride concentration were significantly higher in the proteinuric diabetics (p less than 0.01), while HDL-C levels were found to be significantly lower in this group (p less than 0.05). We conclude that the prevalence of PVD was significantly higher in NIDDs with proteinuria. Furthermore, proteinuric patients had higher blood pressure and low HDL-C.     

Duplex scanning in renovascular disease

This review describes our experience with renal duplex sonography (RDS) in the elderly as a screening study for renovascular disease and as an intraoperative completion study to define technical error after operative renal artery repair. Methods of patient preparation, technical aspects of renal duplex interrogation and the comparison of RDS results with angiography in the elderly are presented in detail. In the hands of an experienced sonologist, RDS examination performed according to these methods and techniques correlates highly with angiography. We believe renal duplex sonography is the preferred screening test for main renal artery stenosis and occlusion in the elderly population.     

The benefit of renal artery stenting in patients with atheromatous renovascular disease and advanced chronic kidney disease

Background : Around 16% of all patients who present with atheromatous renovascular disease (ARVD) in the United States undergo revascularization. Historically, patients with advanced chronic kidney disease (CKD) have been considered least likely to show improvement in renal functional terms, or survival. We aimed to investigate whether differences in outcomes after revascularization compared to medical management might be observed in ARVD patients if stratified by their CKD classes. Methods : Two prospective cohorts, a UK center with a traditionally conservative approach, and a German center who undertook a proactive revascularization approach, were compared. An improvement in renal function was defined as > 20% renal improvement at one year's follow‐up. To improve validity and comparability, revascularized patients in the UK center were also used within analyses, Results : 347 (UK conservative group), 89 (UK revascularized group), and 472 (German center) patients were included in the analysis. When subdivided by CKD stage, patient ages between the two centers were comparable. Improvements in renal function were observed in twice as many patients who underwent revascularization as compared to medical treatment, particularly in the latter CKD stages, 15.2 (German revascularization) vs. 0% in CKD 1–2, 12.2 (UK), and 32.8 (German) revascularization vs. 14.1% in CKD3, and 53.1 and 53.8 vs. 28.3 in patients with CKD 4–5. The improvements in eGFR were 10.2 (16) and 8.1 (12.5) ml/min/year in the German and UK revascularized groups, respectively, vs. ?0.05 (6.8) ml/min/year in the medical cohort in CKD 4–5. Improvements in blood pressure control were noted at 1 year overall and within each CKD category. Multivariate analysis revealed that revascularization independently reduced the risk of death by 45% in all patients combined (RR 0.55, P = 0.013). Conclusions : Although this study has significant methodological limitations, it does shows that percutaneous renal revascularization can improve renal function in advanced CKD (stages 4–5), and that this can provide a survival advantage in prospective analysis. © 2009 Wiley‐Liss, Inc.     

Primary Superior Lumbar Hernia with Nephrotic-range Orthostatic Proteinuria

Lumbar hernias are extremely rare. The posterolateral abdominal wall has two susceptible areas - the superior (Grynfeltt-Lesshaft''s triangle) and the inferior (Petit''s triangle) lumbar triangles - that cause superior and inferior lumbar hernias, respectively. We herein report a 67-year-old woman with nephrotic-range proteinuria caused by primary superior lumbar hernia. Superior lumbar hernias should be considered as a differential disease causing massive orthostatic proteinuria in adults. The present case highlights the importance of considering lumbar hernia in patients with flank swelling and the potential complications that may result from a missed diagnosis.     

Plasma renin activity in patients with renovascular hypertension

Changes of plasma renin activity (PRA) were studied in 45 patients with renovascular hypertension. Peripheral PRA was assayed by Serebovskaya's modification of Pickens' biological method; in 13 patients it was additionally assayed in blood samples taken from both renal veins. In some of the patients who were not surgically treated PRA was followed up over a period of 1 to 5 years. The interrelation between PRA and the sex and age of the patients, the duration and the severity of the disease, the clinical and the morphological type of renovascular hypertension, as well as uni- or bilateral involvement of the renal artery is discussed. PRA was increased during the early stage of renovascular hypertension, while later it became normal. PRA of renal vein blood samples, from the kidney with a constricted renal artery, reflects more exactly the dynamics of the changes in the pressor system of the kidney. The assay of PRA is of special importance in the evaluation of the indications for surgical treatment and of the effect of reconstructive surgery.     

Diagnosis and management of renovascular disease and renovascular hypertension

Renovascular disease is a common but complex disorder, the most common causes of which are fibromuscular dysplasia and atherosclerosis. Clinically, it can present as asymptomatic renal artery stenosis, renovascular hypertension, or ischemic nephropathy. Assessing the clinical index of suspicion remains essential in determining an appropriate diagnostic strategy. For diagnosis in patients with suspected fibromuscular disease, it may be reasonable to proceed directly to renal angiography; however, for most patients with suspected atherosclerotic disease, there are a number of noninvasive tests available that can aid in decision making. The choice of the most appropriate initial test should be based on patient characteristics, clinical presentation, and local expertise. Treatment options include medical, surgical, or percutaneous approaches. Generally, in patients with fibromuscular disease, percutaneous intervention provides durable improvement or cure of hypertension. In patients with atherosclerotic disease, the data are less consistent, and there does appear to be a group of patients who will respond well to medical management alone. As technology advances, the diagnostic and treatment paradigms will continue to evolve.     

The captopril test in the detection of renovascular disease in hypertensive patients

A number of reports share the conclusion that the captopril test is an adequate screening procedure for the detection of renovascular disease among hypertensive patients. Therefore, we prospectively studied the value of this test in 149 consecutive hypertensive patients. The test was considered positive if plasma renin activity, after an oral dose of 25 mg of captopril, rose by more then 4.44 ng.L-1.s-1 (16.0 ng/mL per hour). The sensitivity of the test was 39%, the specificity was 96%, the positive predictive value was 81%, and the negative predictive value was 79%. No clinically important cutoff point identifying patients with renal artery stenosis could be detected in the values of baseline and stimulated plasma renin activity nor in baseline blood pressure or changes after captopril testing. The low sensitivity makes the captopril test unfit to be used as a screening procedure in an unselected hypertensive population.