Increased urine semaphorin-3A is associated with renal damage in hypertensive patients with chronic kidney disease: a nested case-control study

BACKGROUND

Semaphorins are guidance proteins implicated in several processes such as angiogenesis, organogenesis, cell migration, and cytokine release. Experimental studies showed that semaphorin-3a (SEMA3A) administration induces transient massive proteinuria, podocyte foot process effacement and endothelial cell damage in healthy animals. While SEMA3A signaling has been demonstrated to be mechanistically involved in experimental diabetic glomerulopathy and in acute kidney injury, to date its role in human chronic kidney disease (CKD) has not been investigated.

METHODS

To test the hypothesis that SEMA3A may play a role in human CKD, we performed a cross-sectional, nested, case-control study on 151 matched hypertensive patients with and without CKD. SEMA3A was quantified in the urine (USEMA) by ELISA. Glomerular filtration rate was estimated (eGFR) by the CKD-EPI formula and albuminuria was measured as albumin-to-creatinine ratio (ACR).

RESULTS

USEMA levels were positively correlated with urine ACR (p = 0.001) and serum creatinine (p < 0.001). USEMA was higher in patients with both components of renal damage as compared to those with only one and those with normal renal function (p < 0.007 and <0.001, respectively). The presence of increased USEMA levels (i.e. top quartile) entailed a fourfold higher risk of combined renal damage (p < 0.001) and an almost twofold higher risk of macroalbuminuria (p = 0.005) or of reduced eGFR, even adjusting for confounding factors (p = 0.002).

CONCLUSIONS

USEMA is independently associated with CKD in both diabetic and non diabetic hypertensive patients. Further studies may help clarify the mechanisms underlying this association and possibly the pathogenic changes leading to the development of CKD.

Use of nifedipine in the treatment of hypertension

Hypertension is an important modifiable risk factor for cardiovascular disease; its prevention and treatment currently represent major health concerns around the world, especially in western countries. Effective, well-tolerated drugs such as dihydropyridine calcium channel blockers, to be used either alone or in combination treatments, play a key role in reducing cardiovascular morbidity and mortality. The extended-release formulation of nifedipine given once daily provides a relatively constant concentration profile and has proved to be effective in reducing blood pressure values. In the International Nifedipine gastrointestinal therapeutic system Study: Intervention as a Goal in Hypertension Treatment (INSIGHT) study, it was demonstrated that nifedipine confers cardiovascular protection as effectively as diuretics in high-risk patients, with a smaller incidence of adverse metabolic consequences. Furthermore, two INSIGHT substudies demonstrated that nifedipine prevents the progression of carotid atherosclerosis and reduces the worsening of coronary calcifications, supporting the use of calcium channel blockers in hypertensive patients--especially those at high cardiovascular risk. This review discusses the existing clinical evidence supporting the use of nifedipine in the treatment of hypertension.

Kidney dysfunction and related cardiovascular risk factors among patients with type 2 diabetes

BACKGROUND

Kidney dysfunction is a strong predictor of end-stage renal disease and cardiovascular (CV) events. The main goal was to study the clinical correlates of diabetic kidney disease in a large cohort of patients with type 2 diabetes mellitus (T2DM) attending 236 Diabetes Clinics in Italy.

METHODS

Clinical data of 120 903 patients were extracted from electronic medical records by means of an ad hoc-developed software. Estimated glomerular filtration rate (GFR) and increased urinary albumin excretion were considered. Factors associated with the presence of albuminuria only, GFR < 60 mL/min/1.73 m(2) only or both conditions were evaluated through multivariate analysis.

RESULTS

Mean age of the patients was 66.6 ± 11.0 years, 58.1% were male and mean duration of diabetes was 11.1 ± 9.4 years. The frequency of albuminuria, low GFR and both albuminuria and low GFR was 36.0, 23.5 and 12.2%, respectively. Glycaemic control was related to albuminuria more than to low GFR, while systolic and pulse pressure showed a trend towards higher values in patients with normal kidney function compared with those with both albuminuria and low GFR. Multivariate logistic analysis showed that age and duration of disease influenced both features of kidney dysfunction. Male gender was associated with an increased risk of albuminuria. Higher systolic blood pressure levels were associated with albuminuria, with a 4% increased risk of simultaneously having albuminuria and low GFR for each 5 mmHg increase.

CONCLUSIONS

In this large cohort of patients with T2DM, reduced GFR and increased albuminuria showed, at least in part, different clinical correlates. A worse CV risk profile is associated with albuminuria more than with isolated low GFR.

Is it time to revise the normal range of serum uric acid levels?

The actual reference range of serum uric acid has been assessed according to its variations among healthy individuals. i.e. those without clinical evidence of gout. By this approach, serum uric acid values between 3.5 and 7.2 mg/dL in adult males and postmenopausal women and between 2.6 and 6.0 mg/dL in premenopausal women have been identified as normal in many countries. However, this definition of normal range of serum uric acid in the general population is inevitably influenced by what we consider as "normal", since the absence of gout flares does not necessarily imply the absence of uric acid-related damage. Indeed, a growing body of evidence indicates that silent deposition of monosodium urate crystals as a result of hyperuricaemia may occur and lead to early destructive skeletal changes. In addition, a growing body of evidences demonstrates that uric acid might play a pathophysiological role in many "cardio-nephro-metabolic" disorders, which seems to be independent of the deposition of monosodium urate crystals, since it is evident also for serum uric acid concentrations below the saturation point for monosodium urate. Taken together, these findings strongly suggest to carefully reconsider the concept of "asymptomaticity" for chronic hyperuricemia and to consequently revise the normal range of serum uric acid levels also considering the progressive worldwide increase of circulating levels of uric acid, which could lead to a "shift to right" (i.e. toward higher values) of normal range. In the light of the new scientific knowledge on the pathophysiological role of uric acid in human disease, a threshold value < 6.0 mg/dL (< 360 µmol/L) seems to better identify true "healthy subjects" and should reasonably be considered for all subjects.

Antihypertensive treatment and renal protection: the role of drugs inhibiting the renin-angiotensin-aldosterone system

The prevalence of chronic kidney disease, currently estimated to vary between 8 and 12 % in the general population, is steadily rising due to aging and to the ongoing epidemic of hypertension and type 2 diabetes. Even in its early stages, chronic kidney disease entails a greater risk for cardiovascular mortality, and its prevention and treatment is rapidly becoming a key medical issue for many health care systems worldwide. Adequate blood pressure control and reduction of urine protein excretion, preferably obtained by the use of renin-angiotensin-aldosterone system inhibitors, have traditionally been considered the mainstay of therapeutic strategies in patients with renal disease. Given the pivotal role of renin-angiotensin-aldosterone system activity in the pathogenesis and progression of renal and cardiovascular damage, a more profound inhibition of the system, either by the use of multiple agents or by a single agent at high dosage has recently been advocated, especially in the presence of proteinuria. Recent trials, however have failed to confirm the usefulness of this therapeutic approach, at least in unselected patients. This article will critically review the current literature and will discuss the clinical implications of targeting the renin-angiotensin-aldosterone system in order to provide the greatest renal protection.

The liver and the kidney: two critical organs influencing the atherothrombotic risk in metabolic syndrome

The increased atherothrombotic risk in patients with metabolic syndrome (MetS) has been classically explained by the multiplicative effect of systemic concomitant pro-atherosclerotic factors. In particular, centripetal obesity, dyslipidaemia, glucose intolerance, hypertension (differently combined in the diagnosis of the disease) would be expected to act as classical cardiovascular risk conditions underlying accelerated atherogenesis. In order to better understand specific atherosclerotic pathophysiology in MetS, emerging evidence focused on the alterations in different organs that could serve as both pathophysiological targets and active players in the disease. Abnormalities in adipose tissue, heart and arteries have been widely investigated in a variety of basic research and clinical studies in MetS. In this narrative review, we focus on pathophysiological activities of the liver and kidney. Considering its key role in metabolism and production of soluble inflammatory mediators (such as C-reactive protein [CRP]), the liver in MetS has been shown to be altered both in its structure and function. In particular, a relevant amount of the fat accumulated within this organ has been shown to be associated with different degrees of inflammation and potential insulin resistance. In humans, non-alcoholic fatty liver disease (NAFLD) has been described as the hepatic manifestation of MetS. In an analogous manner, epidemiological evidence strongly suggested a "guilty" association between MetS and chronic kidney disease (CKD). Some biomarkers of hepatic (such as C-reactive protein, TNF-alpha or other cytokines) and renal diseases (such as uric acid) associated with MetS might be particularly useful to better manage and prevent the atherothrombotic risk.

Relationship between inter-arm difference in systolic blood pressure and arterial stiffness in community-dwelling older adults

A significant inter-arm difference in systolic blood pressure (IADSBP) has recently been associated with worse cardiovascular outcomes. The authors hypothesized that part of this association is mediated by arterial stiffness, and examined the relationship between significant IADSBP and carotid-femoral pulse wave velocity (CF-PWV) in a sample from the Baltimore Longitudinal Study of Aging. Of 1045 participants, 50 (4.8%) had an IADSBP ≥10 mm Hg at baseline, and 629 had completed data from ≥2 visits (for a total of 1704 visits during 8 years). CF-PWV was significantly higher in patients with an IADSBP ≥10 mm Hg (7.3±1.9 vs 8.2±2, P=.002). Compared with others, patients with IADSBP ≥10 mm Hg also had higher body mass index, waist circumference, and triglycerides; higher prevalence of diabetes; and lower high-density lipoprotein (HDL) cholesterol (P<.001 for all). A significant association with IADSBP ≥10 mm Hg was observed for CF-PWV in both cross-sectional (odds ratio [OR], 1.19; 95% confidence interval [CI], 1.06-1.87; P=.01) and longitudinal (OR, 1.15; 95% CI, 1.03-1.29; P=.01) multivariate analyses. Female sex, Caucasian race, high body mass index (plus diabetes and low HDL cholesterol only cross-sectionally) were other independent correlates of IADSBP ≥10 mm Hg. Significant IADSBP is associated with increased arterial stiffness in community-dwelling older adults.

Serum uric acid and blood pressure in children at cardiovascular risk

OBJECTIVES

Hyperuricemia has been shown to be a strong correlate of hypertension in children. However, the complex interaction between serum uric acid (UA), systemic blood pressure (BP), and possibly confounding factors has been elucidated only in part.

METHODS

We evaluated office BP as well as clinical and biohumoral parameters in a cross-sectional cohort of 501 children (280 boys and 221 girls) aged between 6 and 18 years (mean = 10.8 years) consecutively referred for cardiovascular risk assessment.

RESULTS

Overall, 156 (31.1%) were normotensive, 122 (24.4%) showed transient hypertension, 87 (17.4%) had prehypertension, and 136 (27.1%) had hypertension. Altogether 33.3% and 40.5% of the study group were overweight or obese, respectively. There was a trend toward greater weight and waist circumference and higher BMI, Homeostasis Model Assessment index, and UA levels as the BP categories rose. Moreover, the prevalence of pubertal children, obesity, and waist-to-height ratio above 0.50 progressively increased from lower to upper BP categories. After adjusting for puberty, gender, BMI (z-score), Homeostasis Model Assessment index, and renal function, UA was found to be directly related to systolic and diastolic BP values (P = .03). Using normotensive children for comparison, the risk of showing prehypertension or hypertension increased by at least 50% for each 1 mg/dL UA increase (P < .01), whereas it doubled for children in the top gender-specific UA quartile (P < .03).

CONCLUSIONS

Increased UA levels showed an independent predictive power for the presence of higher BP levels among a cohort of children at relatively high cardiovascular risk.

Blood pressure variability and multiple organ damage in primary hypertension

Organ damage (OD) is an indicator of increased cardiovascular risk. Blood pressure variability (BPV) is related to greater incidence of events, regardless of the severity of hypertension. We investigated the relationship between ambulatory blood pressure monitoring (ABPM)-derived indices of BPV and the presence of multiple OD in primary hypertension (PH). One hundred and sixty-nine untreated patients with PH were evaluated. Systolic (SBP) and diastolic blood pressure (DBP) variability were assessed as the crude and weighted (w.) standard deviation (s.d.), and average real variability (ARV) of the mean value of 24-h, awake and asleep ABPM recordings. Left ventricular mass index, intima-media thickness, estimated-glomerular filtration rate and urinary albumin excretion were assessed as indices of cardiac, vascular and renal damage, respectively. Risk profile progressively increased starting from patients without OD to patients with only one sign of OD, and then to those with multiple OD. In addition to greater severity of the organ involvement, the only variables that were found to significantly differ between subjects with multiple and single OD were office SBP (160 ± 14 vs 154 ± 11 mm  Hg, P=0.0423) and DBP (101 ± 7 vs 97 ± 8  mm Hg, P=0.0291), ambulatory arterial stiffness index (AASI) (0.60 ± 0.10 vs 0.50 ± 0.17, P=0.0158) and indices of BPV (24-h SBP s.d., 23 ± 5 vs 20 ± 6  mm  Hg, P=0.0300; awake SBP s.d., 22 ± 6 vs 19 ± 6  mm  Hg, P=0.0366; 24-h SBP w.s.d., 20 ± 5 vs 17 ± 5  mm  Hg, P=0.0385; and 24-h SBP ARV, 18 ± 4 vs 15 ± 5  mm  Hg, P=0.0420). All the above mentioned BPV parameters turned out to be determinants of multiple OD, regardless of several confounding variables, including BP levels. Therefore, in hypertensive patients increased SBP variability is associated with multiple signs of OD, regardless of BP values.

Serum uric acid and cardio-renal diseases

OBJECTIVES

In this article, the results of clinical and experimental studies that examine the association of hyperuricemia and gout with hypertension and kidney disease are presented and discussed.

METHODS

Key papers for inclusion were identified by a PubMed search, and articles were selected according to their relevance for the topic, according to the authors' judgment.

RESULTS AND CONCLUSIONS

Increasing evidence supports a causal role for Uric acid (UA) in hypertension. Further larger studies are needed to confirm the possible beneficial role of UA lowering drugs and/or xantine-oxidase (XO) inhibitors. Overall, clinical evidence suggests a relationship of UA level with incident chronic kidney disease (CKD). In addition, the results of clinical trials using urate lowering therapy provide some promising evidence that lowering UA levels may retard the progression of CKD. Reviewed data indicate the need for large, well designed studies in these patients to evaluate XO inhibitors or uricosuric drugs in cardio-renal diseases and further elucidate the role of UA in the development and progression of CKD.

C-reactive protein and target organ damage in untreated patients with primary hypertension

High sensitivity C-reactive protein (hs-CRP) has been recognized as a risk factor for cardiovascular disease. Asymptomatic organ damage is known to precede cardiovascular events in hypertension. The aim of the present study was to investigate the relationship between hs-CRP and signs of organ damage, namely left ventricular mass index (LVMI), albuminuria, and carotid atherosclerosis in a group of hypertensive patients. One hundred and eighty-two untreated patients with primary hypertension were studied. HS-CRP was measured by immunonephelometry. LVMI was assessed by echocardiography, albuminuria was measured as albumin to creatinine ratio, and carotid atherosclerosis by ultrasonography. Patient stratification according to quartiles of hs-CRP showed a significant trend toward higher age, prevalence of left ventricular hypertrophy, and carotid plaques. Moreover, there was a significant correlation among hs-CRP quartiles and left ventricular mass index, carotid cross-sectional area, carotid plaques, and albuminuria. Multiple regression analysis showed that, after adjusting for established cardiovascular risk factors (ie, age, duration of hypertension, smoking habit, body mass index (BMI), 24-hour systolic and diastolic blood pressures, glucose, creatinine, uric acid, triglycerides, total and low-density lipoprotein cholesterol), hs-CRP remained a strong correlate of target organ damage. These results support the importance of chronic microinflammation in the development of atherosclerotic disease in hypertension.

RAAS inhibition and renal protection

Chronic kidney disease has become a major public health problem worldwide mainly as a consequence of the emerging epidemic of hypertension, diabetes, and obesity. It is currently estimated that nearly 15% of the general population has some degree of renal damage, a figure that reaches 50% in at-risk subgroups. Renin-angiotensin-aldosterone system (RAAS) inhibitors represent the agents of choice to control hypertension and reduce urinary albumin excretion, thereby delaying renal function deterioration. Greater blockade of the RAAS either by the combined use of multiple drugs or by supramaximal doses of single agents may provide greater renal protection. Furthermore, it has been proposed especially in the presence of proteinuria. However, at this time there is insufficient evidence to routinely recommend this therapeutic approach in patients with chronic kidney disease. The present article examines the currently available evidence and practical implications of pharmacological disruption of RAAS activity for renal protection.

Direct renin inhibition: from pharmacological innovation to novel therapeutic opportunities

Nowadays, social and economic burden related to cardiovascular and renal diseases still remains extremely high, although there has been a dramatic improvement of diagnostic options and therapeutic strategies reported in the last 30 years. The progressively higher attention towards integrated pharmacological strategies, which are able to interfere with different pathophysiological mechanisms, has certainly led to better control of cardiovascular and renal diseases. In view of the large involvement of the renin-angiotensin system (RAS) in the vast majority of pathophysiological mechanisms leading to the development and progression of cardiovascular and renal diseases, it can be easily understood why it has been long viewed as the 'ideal' target for the pharmacological treatment of several clinical conditions. Recently, besides the well known therapeutic approaches for RAS blockade, based on the use of ACE inhibitors, angiotensin II type 1 receptor antagonists (angiotensin receptor blockers [ARBs]) and aldosterone antagonists, both the scientific and medical community have focused their attention on a novel therapeutic option. In 2007, aliskiren, the first compound of a new drug class, the direct renin inhibitors (DRIs), has become available for clinical use, being a novel and innovative therapeutic option. Aliskiren is able to interfere with the enzymatic activity of renin by blocking the catalytic site of the molecule and inducing an 'upstream' RAS blockade. This leads to a modulation of the biological properties of renin, thus resulting in the missed cleavage of angiotensinogen to angiotensin I. Aliskiren has demonstrated antihypertensive efficacy comparable or even superior to that of other classes of antihypertensive drugs, both in monotherapy and in combination therapies. Its safety and tolerability are comparable with those of other antihypertensive drug classes and almost similar to placebo. In addition, it has been demonstrated to reduce progression of cardiac and renal organ damage in addition to ACE inhibitors or ARBs. An ambitious and large clinical trial programme specifically designed for this innovative antihypertensive drug will evaluate the efficacy of aliskiren in terms of reduced incidence of major cardiovascular and renal outcomes in patients with hypertension and cardiovascular disease, besides the use of optimal (standard) therapeutic strategies, including ACE inhibitors and ARBs.

Cardiovascular and renal effects of hyperuricaemia and gout

A number of epidemiological studies have reported an association between serum uric acid levels and a wide variety of high-risk conditions including hypertension, insulin resistance, and kidney and cerebro-cardiovascular disease. All things considered, serum uric acid may induce cardiovascular and kidney events both directly and indirectly by promoting other well-known mechanisms of damage. While asymptomatic hyperuricemia is currently not considered to be an indication for urate lowering therapy, there is growing evidence indicating a linear relationship between pharmacological reduction in serum uric acid and incidence of cardiovascular and renal events.

Sub-clinical organ damage in hypertension and obesity

BACKGROUND

The development of sub-clinical organ damage precedes and predicts the occurrence of cardiovascular (CV) events in hypertensive as well as in obese patients.

AIM AND METHODS

We investigated the prevalence and clinical correlates of organ damage (OD), namely carotid atherosclerosis (US scan) and urine albumin to creatinine ratio (three non-consecutive first morning samples) in a group of 164 obese patients and in an age- and gender-matched group of non-obese hypertensive patients.

RESULTS

There was a significantly greater prevalence and severity of OD in obese patients as compared to non-obese hypertensive patients. In particular obese patients more frequently had microalbuminuria (16 vs 7%, χ(2) 5.8, P=0.0157) and carotid abnormalities (53 vs 10%, χ(2) 69.5, P<0.0001) as well as higher urinary albumin excretion rate (-0.05 ± 0.52 vs -0.28 ± 0.43log ACR, P<0.0001) and carotid intima-media thickness (0.955 ± 0.224 vs 0.681 ± 0.171, <0.0001). Notably, the coexistence of hypertension and obesity did not entail a greater prevalence and severity of OD. Moreover, after adjusting for potentially confounding factors including blood pressure levels, diagnosis of diabetes, and lipid profile, morbidly obese patients showed a 5-fold, and 22-fold higher risk of having microalbuminuria, and carotid atherosclerosis, respectively.

CONCLUSIONS

Sub-clinical OD is highly prevalent in obese patients, even in the absence of high blood pressure. Hypertension and obesity seem to exert an independent, possibly non-additive role on the occurrence of organ damage.

Combined use of urinary neutrophil gelatinase-associated lipocalin (uNGAL) and albumin as markers of early cardiac damage in primary hypertension

BACKGROUND

Neutrophil Gelatinase-Associated Lipocalin (NGAL) is an early and specific marker of acute kidney dysfunction. Recent evidences suggest that NGAL may also be involved in chronic vascular remodeling during the development of atherosclerosis. Albuminuria, a powerful predictor of cardiovascular events, is thought to reflect widespread subclinical vascular abnormalities. We investigated the relationship between urinary NGAL (uNGAL), albuminuria and left ventricular mass (LVM) in patients with primary hypertension.

METHODS

A total of 120 untreated, non diabetic patients with primary hypertension (mean age 47 ± 9 years) were studied. uNGAL was measured by a chemiluminescent microparticle method, optimized on a fully automated analytical platform (ARCHITECT, Abbott Diagnostics Inc, Rome, IT). Albuminuria was measured by immunonephelometry on an Immage Immunochemistry System (Beckman Coulter, Inc., Fullerton, California, USA) and expressed as albumin/creatinine ratio (ACR). LVM was assessed by echocardiography and indexed to body surface area (LVM/BSA).

RESULTS

No significant correlation was found between uNGAL and ACR; however, both variables were directly related to clinic systolic blood pressure (rho=0.241, p=0.0085 and rho=0.248, p=0.0068 respectively), left ventricular relative wall thickness (rho=0.251, p=0.0156 and rho=0.263, p=0.0013 respectively), and LVM/BSA (rho=0.285, p=0.0062 and rho=0.213, p=0.0410 respectively). The uNGAL and ACR simultaneous increase above their respective median values was associated with higher LVM/BSA values (p=0.0109) and with a higher prevalence of left ventricular hypertrophy (LVH) (p=0.0017). Furthermore, logistic regression analysis showed that the risk of presenting LVH increased more than 4-fold when uNGAL and ACR were both above the median value, even after adjustment for age, gender and blood pressure values.

CONCLUSIONS

The simultaneous increase in uNGAL and ACR excretion is significantly associated with the increase of LVM in low risk patients with primary hypertension. This association is clinically significant for the early assessment of cardiac damage in hypertension.

Chronic kidney disease in the hypertensive patient: an overview of the I-DEMAND study

The kidney has been recognized as a sensor of cardiovascular risk. However, evaluation of urinary albumin excretion and estimated glomerular filtration rate is still too often overlooked in clinical practice. The I-DEMAND (Italy-Developing Education and awareness on MicroAlbuminuria in patients with hyperteNsive Disease) study was designed to assess the prevalence of microalbuminuria and its clinical correlates among Italian hypertensive patients. A total of 4151 patients from 87 specialized care centres were included in the study. Overall, this study demonstrated that approximately one-half of the enrolled patients had chronic kidney disease, with albuminuria being present in one-quarter of the individuals. The presence of renal abnormalities was more prevalent in patients with concomitant cardiovascular risk factors. This article discusses the main results of the study and its potential implications in clinical practice.

Serum uric acid levels predict new-onset type 2 diabetes in hospitalized patients with primary hypertension: the MAGIC study

OBJECTIVE

Recent studies suggest that uric acid may predict the development of diabetes in the general population. Whether this association holds true in primary hypertension and is independent of renal function and metabolic syndrome is not clear at present.

RESEARCH DESIGN AND METHODS

In a prospective, observational study, 758 untreated hypertensive patients were evaluated at baseline and followed-up for 11 years.

RESULTS

A total of 8,332 person-years of follow-up revealed that slightly elevated uric acid levels (i.e., ≥318 μmol/l for women and ≥420 μmol/l for men) at baseline were associated with a significantly higher risk of developing diabetes (hazard ratio 3.65 [95% CI 1.99-6.69], P < 0.0001), even after adjustment for several confounding factors such as metabolic syndrome (2.78 [1.35-5.70], P = 0.0054).

CONCLUSIONS

Uric acid is an independent predictor of diabetes in primary hypertension.

[Antihypertensive therapy in hypertensive patients with metabolic syndrome]

A growing body of evidence indicates that the metabolic syndrome and hypertension are interrelated at an epidemiological as well as pathophysiological level. Due to the high prevalence of concomitant signs of subclinical organ damage and the high risk of cardiorenal complications, hypertensive patients with metabolic syndrome are to be considered at high risk. Although the management of this condition must begin with the implementation of a healthy lifestyle and dietary habits, these measures are usually insufficient to adequately control blood pressure values and reduce the cardiovascular risk in the long term. Therefore, in the presence of persistent blood pressure values above 140/90 mmHg, pharmacological antihypertensive therapy is often required to reach the recommended target of less than 130/80 mmHg. In the absence of specific, compelling indications to the contrary, inhibitors of the renin-angiotensin system and calcium-channel blockers should be preferred over diuretics and beta-blockers. However, diuretics, preferably at a low dosage, are often necessary to obtain satisfactory blood pressure control. The combination of diuretics and beta-blockers should be avoided, if possible, in patients with prediabetes or diabetes.

Microalbuminuria is a predictor of chronic renal insufficiency in patients without diabetes and with hypertension: the MAGIC study

BACKGROUND AND OBJECTIVES

Increased urinary albumin excretion is a known risk factor for cardiovascular events and clinical nephropathy in patients with diabetes. Whether microalbuminuria predicts long-term development of chronic renal insufficiency (CRI) in patients without diabetes and with primary hypertension remains to be documented.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We conducted an 11.8-year follow-up of 917 patients who did not have diabetes and had hypertension and were enrolled in the Microalbuminuria: A Genoa Investigation on Complications (MAGIC) cohort between 1993 and 1997. Urinary albumin-to-creatinine ratio (ACR) was assessed at baseline in untreated patients in a core laboratory. Microalbuminuria was defined as ACR > or =22 mg/g in men and ACR > or =31 mg/g in women.

RESULTS

A total of 10,268 person-years of follow-up revealed that baseline microalbuminuria was associated with an increased risk for developing CRI (relative risk [RR] 7.61; 95% confidence interval [CI] 3.19 to 8.16; P < 0.0001), cardiovascular events (composite of fatal and nonfatal cardiac and cerebrovascular events; RR 2.11; 95% CI 1.08 to 4.13; P < 0.028), and cardiorenal events (composite of former end points; RR 3.21; 95% CI 1.86 to 5.53; P < 0.0001). Microalbuminuria remained significantly related to CRI (RR 12.75; 95% CI 3.62 to 44.92; P < 0.0001) and cardiorenal events (RR 2.58; 95% CI 1.32 to 5.05; P = 0.0056) even after adjustment for several baseline covariates.

CONCLUSIONS

Microalbuminuria is an independent predictor of renal and cardiovascular complications in patients without diabetes and with primary hypertension.