Echocardiographic Parameters During Long and Short Interdialytic Intervals in Hemodialysis Patients.

BACKGROUND: The long interdialytic interval in thrice-weekly hemodialysis is associated with excess cardiovascular risk. However, the mechanisms behind these adverse consequences are not fully understood. This study investigated the interdialytic changes in right and left ventricular function during the 2- and 3-day intervals. STUDY DESIGN: Observational study with 2 random crossover sequences of recordings: 3-day followed by 2-day interval or vice versa. SETTINGS & PARTICIPANTS: 41 stable patients with end-stage renal disease on standard thrice-weekly hemodialysis therapy. PREDICTOR: 3-day (long) versus 2-day (short) interdialytic interval. OUTCOME: Interdialytic change in echocardiographic indexes of left and right ventricular function. MEASUREMENTS: 2-dimensional echocardiographic and tissue Doppler imaging studies were performed with a Vivid 7 cardiac ultrasound system at the start and end of the 3- and 2-day interdialytic intervals. RESULTS: During both intervals studied, elevations in cardiac output, stroke volume, left ventricular mass index, and peak early diastolic velocities of the left ventricle were evident. Interdialytic weight gain (3.0±1.7 vs 2.4±1.3 [SD] kg) and inferior vena cava diameter increase (0.54±0.3 vs 0.25±0.3) were higher during the 3-day versus the 2-day interval (P<0.001). Left ventricular systolic and diastolic function indexes were generally no different between interdialytic intervals. In contrast, interdialytic increases in left and right atrial volume, right ventricular systolic pressure (RVSP; 15.3±10.2 vs 4.7±5.2mmHg; P<0.001), and tricuspid regurgitation maximum velocity (0.46±0.45 vs 0.14±0.33m/s; P=0.001) were significantly greater during the 3- versus the 2-day interval. Multivariable analysis suggested that changes in interdialytic weight gain, right ventricle diastolic function, and pulmonary vascular resistance were determinants of the change in RVSP. LIMITATIONS: Observational study design. CONCLUSIONS: Excess volume accumulation over the long interdialytic interval in hemodialysis patients results in higher left and right atrial enlargement and RVSP elevation, which clinically corresponds to pulmonary circulation overload, providing one plausible pathway for the excess mortality risk during this period.

Hemodiafiltration does not have additional benefits over hemodialysis on arterial stiffness, wave reflections and central aortic pressures.

BACKGROUND/AIMS: The hypothesis that dialytic modality affects arterial stiffness was never investigated. This study includes comparative evaluation of hemodiafiltration versus hemodialysis on arterial function during first and second weekly dialysis sessions. METHODS: 24 patients receiving hemodiafiltration and another 24 age- and sex-matched controls receiving hemodialysis were included. Patients were evaluated before and after first and second weekly dialysis sessions. Applanation tonometry of peripheral arteries was applied to determine aortic and brachial pulse wave velocity and heart rate-adjusted augmentation index (AIx(75)). RESULTS: Hemodiafiltration and hemodialysis reduced AIx(75), but not aortic and brachial pulse wave velocity. Intradialytic reductions in AIx(75) did not differ between hemodiafiltration and hemodialysis in first and mid-week dialysis. In multivariate linear regression, predictors of intradialytic reduction in AIx(75) were changes in body weight and central aortic systolic blood pressure, but not dialytic modality. CONCLUSION: This study showed that hemodiafiltration has similar effects with hemodialysis on wave reflections and stiffness.

Diverse effects of interdialytic intervals on central wave augmentation in haemodialysis patients.

BACKGROUND: Increased arterial stiffness is a common finding and independent predictor of mortality in end-stage renal disease (ESRD) patients. A long interdialytic interval was associated with increased risk of cardiovascular death in patients receiving conventional haemodialysis (HD). This is the first study to examine the effects of a long (3-day) versus short (2-day) interdialytic period on arterial elasticity in HD patients. METHODS: Seventy ESRD patients receiving standard HD three times per week were studied at the start and end of a 3-day and a 2-day interdialytic interval. At each time point, applanation tonometry of peripheral arteries was performed to assess arterial stiffness and wave reflection parameters. Aortic and brachial pulse wave velocities (PWV) were recorded as measures of arterial stiffness and augmentation index (AIx) as a measure of wave reflections. RESULTS: AIx, heart-rate-adjusted AIx and augmentation pressure were significantly increased during both interdialytic intervals, whereas aortic and brachial PWVs remained unchanged. The interdialytic increases in all the three AIx parameters were significantly higher during the 3-day interval in comparison to the 2-day interval (P < 0.001 for all comparisons). In contrast, no significant differences in interdialytic changes of aortic (P = 0.355) and brachial (P = 0.319) PWVs were noted between the two intervals. Mixed linear model analysis revealed that central aortic systolic blood pressure (SBP) and body weight, but not aortic or brachial PWV, were independent determinants of the change in heart-rate-adjusted AIx throughout the study. CONCLUSIONS: AIx is increased between HD sessions, whereas arterial elasticity is not. This interdialytic increase in central wave augmentation is more pronounced during the 3-day interval, suggesting a mechanism possibly involved in the elevated cardiovascular risk of HD patients at this time point.

Hypertension and symptomatic hypokalemia in a patient with simultaneous unilateral stenoses of intrarenal arteries and mesangioproliferative glomerulonephritis.

We present the case of a young patient with hypertension and unprovoked symptomatic hypokalemia. His workup uncovered secondary aldosteronism, moderate proteinuria, and, quite unusually, concurrent chronic hepatitis B. Detailed investigations, including renal angiography, renal vein sampling, and kidney biopsy, showed unilateral renin hypersecretion due to intrarenal arterial stenoses and mesangioproliferative glomerulonephritis, presumed to be secondary to hepatitis B infection. Targeted pharmacotherapy reversed all clinical manifestations, normalizing blood pressure and serum potassium level and achieving full remission of proteinuria and loss of hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg), and a dramatic decrease in viral load.

Hemodialysis reduces augmentation index but not aortic or brachial pulse wave velocity in dialysis-requiring patients.

BACKGROUND/AIMS: Arterial stiffening characterizes the vasculature of end-stage renal disease (ESRD) patients and is a strong predictor of their cardiovascular morbidity and mortality. Previous studies evaluating the effect of hemodialysis on large artery elasticity gave contradictory results. This study aimed to investigate the impact of hemodialysis on arterial stiffness and wave reflections on chronic hemodialysis patients. METHODS: A total of 51 stable ESRD patients on maintenance hemodialysis were evaluated before and after the first and second dialysis session of the week. Arterial stiffness was assessed by measuring aortic and brachial pulse wave velocity (PWV). Central arterial pressure waveform parameters were estimated by radial artery applanation tonometry. Heart rate-adjusted augmentation index [AIx(75)] was used as measure of wave reflections. RESULTS: During both dialysis sessions systolic blood pressure (SBP) and pulse pressure (PP) at brachial artery and central aorta were reduced. AIx(75) was decreased in first and second weekly dialysis session (27.5 ± 1.2 vs. 21.0 ± 1.5, p < 0.001 and 24.7 ± 1.2 vs. 20.5 ± 1.5, p < 0.001, respectively). In contrast, aortic and brachial PWV remained unchanged during both dialysis sessions. Changes in AIx(75) during hemodialysis were associated with changes in central aortic SBP, PP and ejection duration. CONCLUSIONS: This study shows that hemodialysis does not acutely affect arterial stiffness, but reduces wave reflections from periphery. This dissociation between effects of hemodialysis on PWV and AIx(75) may reflect differential impact on large and small branches of the arterial tree.

Effect of thiazolidinediones on albuminuria and proteinuria in diabetes: a meta-analysis.

BACKGROUND: Because of the major clinical and economic burden of diabetic nephropathy, new therapeutic tools to delay its progression are needed. Recent studies suggest that thiazolidinediones have renal benefits. We aimed to evaluate the effect of thiazolidinediones on urinary albumin and protein excretion in patients with diabetes mellitus. STUDY DESIGN: Systematic review and meta-analysis by searching MEDLINE/PubMed, EMBASE, and Cochrane CENTRAL databases (1991 to September 2009). SETTING & POPULATION: Patients with diabetes mellitus. SELECTION CRITERIA FOR STUDIES: Randomized controlled trials. INTERVENTION: Thiazolidinediones (rosiglitazone and pioglitazone) compared with placebo or other antidiabetic agents. OUTCOMES: Weighted (WMDs) and standardized mean differences (SMDs) for changes in urine albumin or protein excretion between the thiazolidinedione and control groups. RESULTS: Of 171 originally identified articles, 15 studies (5 with rosiglitazone and 10 with pioglitazone) involving 2,860 patients were included in the analysis. In participants with baseline normo- or microalbuminuria, the WMD of proportional changes between the thiazolidinedione and control groups in urinary albumin excretion measured using time-specified collections was -64.8% (95% CI, -75.6 to -53.9) and the WMD of changes in albumin-creatinine ratio was -24.8% (95% CI, -39.6 to -10.0). Overall, in participants with normo- and microalbuminuria, thiazolidinedione treatment was associated with a significant decrease in urinary albumin excretion (SMD, -0.6 units of standard deviation [SD]; 95% CI, -0.8 to -0.4). Similarly, thiazolidinediones were associated with a significant decrease in urinary protein excretion in patients with proteinuria (SMD, -1.1 units of SD; 95% CI, -1.8 to -0.4). LIMITATIONS: Significant heterogeneity across included studies in several subgroup analyses; patient-level data not available. CONCLUSIONS: Treatment with thiazolidinediones significantly decreases urinary albumin and protein excretion in patients with diabetes. This finding calls for clinical trials with hard renal outcomes to elucidate the potential benefits of thiazolidinediones on diabetic nephropathy.

Beneficial effects of oral magnesium supplementation on insulin sensitivity and serum lipid profile.

BACKGROUND: Epidemiological studies have associated low dietary Mg2+ intake with insulin resistance (IR) and increased risk for metabolic syndrome; however, the effect of Mg2+ supplementation on IR has not been adequately investigated. This study aimed to investigate the effects of oral Mg2+ supplementation on insulin sensitivity (IS) and serum lipids.
MATERIAL/METHODS: Forty-eight patients with mild uncomplicated hypertension participated in the study. Among them, 24 subjects were assigned to 600 mg of pidolate Mg2+ daily in addition to lifestyle recommendations for a 12-week period, and another 24 age- and sex-matched controls were only given lifestyle recommendations. At baseline and study-end, blood sampling for determination of fasting glucose and insulin levels, serum lipids and other standard laboratory tests, as well as an oral glucose tolerance test (OGTT) for estimation of IS indices, were performed in all subjects.
RESULTS: In the Mg2+ supplementation group the OGTT-derived IS indices of Stumvoll, Matsuda and Cedercholm in were increased between baseline baseline and study-end. In contrast, none of these parameters were changed in the control group. Reductions in total cholesterol, LDL-cholesterol and triglyceride levels, along with a parallel increase in HDL-cholesterol levels, were evident at study-end in the intervention group, but not in the control group.
CONCLUSIONS: This study suggests that oral Mg2+ supplementation improves IS and lipid profile in mildly hypertensive patients. These potential beneficial effects of Mg2+ on associated metabolic factors could be helpful for patients with hypertension in terms of overall cardiovascular risk reduction.

Effects of renin-angiotensin system blockers on renal outcomes and all-cause mortality in patients with diabetic nephropathy: an updated meta-analysis.

BACKGROUND: In contrast to previous studies, recent data questioned the ability of renin-angiotensin-aldosterone system (RAAS) blockers to delay progression of diabetic nephropathy. This study evaluated the effect of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin-receptor blockers (ARBs) in patients with diabetic nephropathy. METHODS: A systematic literature search of MEDLINE/PubMed and EMBASE databases was performed to identify randomized trials published up to June 2007 comparing the effects of ACEIs or ARBs with placebo and/or a regimen not including a RAAS blocker on the incidence of end-stage renal disease (ESRD), doubling of serum creatinine (DSC), or death from any cause in patients with diabetic nephropathy. Treatment effects were summarized as relative risks (RRs) using the Mantel-Haenszel fixed-effects model. RESULTS: Of the 1,028 originally identified studies, 24 fulfilled the inclusion criteria (20 using ACEIs and 4 using ARBs). Use of ACEIs was associated with a trend toward reduction of ESRD incidence (RR 0.70; 95% confidence interval (CI) 0.46-1.05) and use of ARBs with significant reduction of ESRD risk (RR 0.78; 95% CI 0.67-0.91). Both drug classes were associated with reduction in the risk of DSC (RR 0.71; 95% CI 0.56-0.91 for ACEIs and RR 0.79; 95% CI 0.68-0.91 for ARBs) but none affected all-cause mortality (RR 0.96; 95% CI 0.85-1.09 for ACEIs and RR 0.99; 95% CI 0.85-1.16 for ARBs). CONCLUSION: Treatment of patients with diabetic nephropathy with a RAAS blocker reduces the risks of ESRD and DSC, but does not affect all-cause mortality. These findings are added to the evidence of a renoprotective role of RAAS blockers in such patients.

Effects of statins on blood pressure: a review of the experimental and clinical evidence.

The "pleiotropic" effects of statins have been the centre of a considerable research activity. Among the numerous experimental and clinical studies of this field, some focused on the effects of statins on blood pressure (BP), while others reported data on BP together with other parameters. Some of the animal or human studies do not show an association between statin treatment and BP changes, whereas others usually report mild but significant reductions. Among the latter, all clinical studies using ambulatory BP recordings show a significant drop in both systolic and diastolic BP in hypertensive patients. In addition, accumulating evidence has identified a number of statin actions that may be involved in BP lowering. Overall, current evidence suggests that statins can be associated with a mild beneficial effect on BP, but further research is needed to clarify the exact magnitude of this action, as well as its clinical relevance.

Statins and blood pressure: is there an effect or not?

In addition to the lipid-lowering effects of statins, several basic and clinical studies in recent years have examined the effects of these agents on other cardiovascular parameters. Some of these studies investigated the general impact of a statin on blood pressure (BP) among various other factors, while others were specifically designed to determine this effect. Data from animal studies are conflicting but the majority of human studies in the field report a beneficial effect, and most available statin compounds are reported to lower BP levels. Recent clinical studies using ambulatory BP measurements support these findings. Although the exact actions of statins involved in this effect are unknown, several possible mechanisms can be hypothesized. This review summarizes existing data on the effect of statins on BP, aiming to give an overview of the current knowledge and to provide perspectives for future research in the field.

A cost-effectiveness analysis of angiotensin-converting enzyme inhibitors and angiotensin receptor blockers in diabetic nephropathy.

The aim of this study was to estimate the cost-effectiveness of renin-angiotensin-aldosterone system blockers in patients with diabetic nephropathy. A cost-effectiveness analysis was performed based on a meta-analysis of studies investigating the effect of angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) as part of a treatment regimen on the incidence of end-stage renal disease (ESRD) in patients with diabetic nephropathy. The primary outcome was the cost to prevent 1 patient from developing ESRD. Cost analysis was performed from a third-party payer perspective in 2006 US dollars. As part of a treatment regimen, ARBs significantly reduced the incidence of ESRD and doubling of serum creatinine concentration (P<.05) but not total mortality. The cost to prevent 1 patient from developing ESRD was $31,729 (95% confidence interval, $19,443-$85,442; P<.01), $189,190 (P=.13) and $51,585 (P=.068) for patients receiving ARBs, ACE inhibitors, or either of them, respectively. This study demonstrates that blocking the RAAS, which delays the progression to ESRD, appears to be cost-effective. The current analysis favors ARBs in terms of cost-effectiveness.

Blood pressure and serum potassium levels in hypertensive patients receiving or not receiving antihypertensive treatment.

OBJECTIVE: Serum potassium has a fundamental role in blood pressure (BP) regulation, and there is evidence highlighting the importance of potassium homeostasis in hypertension. The aim of this study was to determine the relationship between serum potassium levels and office BP in untreated essential hypertensives and the effect of antihypertensive medication on serum potassium levels. SETTING AND PARTICIPANTS: In a retrospective analysis, we collected data for consecutive patients first visiting our Hypertension Clinic from 1999-2004. From this population, we first selected patients who were not taking any antihypertensive medication. Patients who had conditions that could affect potassium metabolism, such as history of arrhythmias treated with digitalis, diabetes mellitus under insulin treatment, and hypo- and hyperthyroidism, were excluded from the study. From the remaining patients, those who had impaired renal function (serum creatinine > or = 1.6 mg/dL for men and > or = 1.4 mg/dl for women) and patients with secondary forms of hypertension were also excluded. The final population consisted of 817 subjects. Multivariate linear regression analysis was applied, and models were created associating serum potassium with systolic BP, diastolic BP, mean BP, or pulse pressure. The population for the second part of the study consisted of patients first visiting our Hypertension Clinic who were on one antihypertensive agent. This second group included 757 patients, 218 of whom were on beta-blockers, 42 on diuretics, 187 on angiotensin-converting enzyme (ACE) inhibitors, 287 on calcium channel blockers (CCBs), and 28 on angiotensin receptor blockers (ARBs). RESULTS: After adjusting for age, gender, and body mass index, significant negative correlations were found between serum potassium levels and systolic BP (R = -0.093, p = 0.007), diastolic BP (R = -0.078, p = 0.03), mean BP (R = -0.122, p = 0.002), and pulse pressure (R = -0.071, p = 0.044). The levels of potassium were found to be significantly lower among patients receiving diuretics than those receiving one of the other four drug categories of antihypertensive (p < 0.05 for beta-blockers, ACE inhibitors, and CCBs; p < 0.001 for ARBs). In addition, hypokalemia was found to be significantly more prevalent in the group using diuretics than the other groups. CONCLUSIONS: The observed reverse relation between serum potassium and BP supports a close pathophysiological connection between serum potassium and essential hypertension. Moreover, diuretic therapy is a significant cause of hypokalemia and requires systematic monitoring.

Changes in Kidney Function in a Population With Essential Hypertension in Real Life Settings.

INTRODUCTION: Hypertension has been identified as one of the commonest modifiable determinants for chronic kidney disease progression. A variety of antihypertensive drugs are available and their effect on kidney function has been investigated by a large number of randomized controlled trials. Observational studies, although scarcely been used, outpatient can reflect everyday practice, where drug exposures vary over time, and may provide an alternative for detecting longitudinal changes in kidney function. MATERIALS AND METHODS: We applied mixed model repeated measures analysis to investigate the effect of antihypertensive drug categories and their combinations on kidney function change over time in a cohort of 779 patients with essential hypertension, using the data from a Greek hypertension outpatient clinic. Antihypertensive drugs were grouped in 5 categories. Their effect was evaluated and their combinations with and without renin-angiotensin-system inhibitors (RASI) to each other. In addition, the combination of RASI with calcium channel blockers (CCBs) was studied. RESULTS: Diuretics, RASI, CCBs, and beta-blockers had a significant renoprotective and blood pressure lowering effect. Combinations with RASI had a smaller beneficial effect on kidney function compared to CCBs (0.75 mL/min/1.73 m2 per year of drug use versus 0.97 mL/min/1.73 m2). There was no additional effect when combining RASI with CCBs. However, the lowering effect on systolic blood pressure was greater (-0.83 mm Hg per year of drug use, P < .001). CONCLUSIONS: RASI were found to have a smaller, although significant, renoprotective effect. There was no additional effect on kidney function when combining RASI with CCBs.

Actions of peroxisome proliferator-activated receptors-gamma agonists explaining a possible blood pressure-lowering effect.

The metabolic syndrome is a cluster of disturbances such as type 2 diabetes mellitus, hypertension, central obesity, dyslipidemia, and others for which insulin resistance and compensatory hyperinsulinemia have been proposed to be the underlying disorders. Several possible mechanisms linking insulin resistance and compensatory hyperinsulinemia with hypertension have been described, such as renal sodium reabsorption enhancement, sympathetic nervous system activation, and blunted insulin-mediated vasodilation caused by endothelial dysfunction. Peroxisome proliferator-activated receptors-gamma agonists or thiazolidinediones (TZD) are a class of agents for the treatment of type 2 diabetes mellitus that act through improvement of insulin sensitivity. In parallel to their antihyperglycemic action, these drugs were found to exert beneficial effects on other components of the metabolic syndrome. For example all TZD have been shown to reduce blood pressure (BP) levels in both animal and human studies. In addition a considerable number of in vitro and in vivo studies report actions of TZD on the cardiovascular system that could explain this blood pressure-lowering effect of TZD, such as restoration of blunted endothelium-mediated vasodilation, attenuation of sympathetic overactivity, inhibition of intracellular Ca(2+) increase, and proliferation of vascular smooth muscle cells and others. This review summarizes the current evidence about these actions of TZD that could positively influence BP, representing possible mechanisms of BP amelioration.

An economic evaluation of the 2003 European Society of Hypertension-European Society of Cardiology guidelines for the management of mild-to-moderate hypertension in Greece.

BACKGROUND: In the 2003 European Society of Hypertension-European Society of Cardiology (ESH-ESC) guidelines, it is concluded that the major classes of antihypertensive agents are suitable for the initiation and maintenance of antihypertensive therapy. The aim of this study was to compare the cost-effectiveness of each one of the major antihypertensive agents as monotherapy in the management of mild-to-moderate hypertension in Greece, when following the 2003 ESH-ESC guidelines. METHODS: We performed a cost-effectiveness analysis based on numbers needed to treat. A decision analysis model was developed to compare chlorthalidone, propranolol, amlodipine, enalapril and losartan. Clinical inputs were derived from a meta-analysis and randomized controlled trials and cost data from public sources. The evaluation of the cost of managing hypertension includes the cost of drug therapy, monitoring, treating side effects, poor compliance and switching. All costs were calculated from a public insurance system perspective, in 2004 Euros. Future costs and clinical benefits were discounted at 5%. The time frame was 5 years. Extensive sensitivity analyses were also performed. RESULTS: The cost (in Euros) of uncomplicated hypertension treatment for 5 years was 485.87, 567.66, 851.44, 607.45, and 1279.88 for chlorthalidone, propranolol, amlodipine, enalapril, and losartan, respectively. The estimated total cost (in Euros) to prevent one death was 60230.71, 70369.96, 105596.72, 75301.40, and 158659.35, respectively. CONCLUSIONS: In mild-to-moderate uncomplicated hypertension chlorthalidone is the most cost-effective agent. If it was the drug of choice to initiate treatment of uncomplicated hypertension, it would probably save the public insurance system organizations a great amount of expenses for benefit of the insured patients.

The effect of rosiglitazone on urine albumin excretion in patients with type 2 diabetes mellitus and hypertension.

BACKGROUND: Thiazolidinediones are antidiabetic agents that improve insulin sensitivity (IS). Accumulating data indicate that these agents provide beneficial effects beyond glycemic control, such as improvement in vascular function. The aim of this study was to determine the effect of rosiglitazone on urine albumin excretion (UAE) in patients with type 2 diabetes mellitus (DM) and hypertension. METHODS: The study involved 20 subjects with type 2 DM who were already on 15 mg glibenclamide daily but were achieving poor glycemic control and who had either poorly controlled or newly diagnosed hypertension. In these patients, rosiglitazone (4 mg daily) was added to the existing therapeutic regimen for 26 weeks. At baseline and the end of the treatment, subjects gave a 24-h urine collection for direct measurement of albumin and a spot specimen for determination of the albumin-to-creatinine ratio (ACR). Subjects also had a hyperinsulinemic euglycemic clamp and an ambulatory blood pressure (BP) monitoring. RESULTS: At the end of the study, UAE was significantly reduced versus baseline, as measured either directly in the 24-h collection (22.4 +/- 4.6 v 13.8 +/- 3.0 mg/day, P < .05) or with ACR (20.9 +/- 3.8 v 14.0 +/- 2.8 mg/g, P < .05). The percentage changes in UAE (DeltaALB for the 24-h collection and DeltaACR for ACR) correlated with the respective changes in IS (r = -0.64, P < .01 for DeltaALB and r = -0.48, P < .05 for DeltaACR), systolic BP (r = 0.63, P < .01 and r = 0.58, P < .01 respectively), and diastolic BP (r = 0.56, P < .05 and r = 0.50, P < .05 respectively). CONCLUSIONS: In this study, treatment of type 2 diabetic hypertensive patients with rosiglitazone significantly decreased UAE. Lowering of BP and improvement of IS should play roles in this UAE reduction.

The effect of rosiglitazone on novel atherosclerotic risk factors in patients with type 2 diabetes mellitus and hypertension. An open-label observational study.

Thiazolidinediones are antidiabetic agents that decrease insulin resistance. Emerging evidence indicates that they present beneficial effects for the vasculature beyond glycemic control. The aim of this open-label observational study was to determine the effect of the thiazolidinedione rosiglitazone on novel cardiovascular risk factors, namely, lipoprotein(a) [Lp(a)], C-reactive protein (CRP), homocysteine, and fibrinogen in patients with type 2 diabetes and hypertension. A total of 40 type 2 diabetic patients already on treatment with 15 mg of glibenclamide daily and with poorly controlled or newly diagnosed hypertension were included in the study. Twenty of them received 4 mg of rosiglitazone daily as added-on therapy, whereas the rest remained on the preexisting antidiabetic treatment for 26 weeks. At baseline and the end of the study, subjects gave blood tests for the determination of Lp(a), CRP, homocysteine, fibrinogen, serum lipids, apolipoprotein (apo) A-I, and apo B. At the end of the study, rosiglitazone treatment was associated with significant reductions in Lp(a) (10.5 [8.9-54.1] to 9.8 [8.0-42.0] mg/dL, P<.05) and CRP levels (0.33 [0.07-2.05] to 0.25 [0.05-1.84] mg/dL, P<.05) vs baseline. Homocysteine levels were not affected but plasma fibrinogen presented a significant increase (303.5+/-75.1 to 387.5+/-70.4 mg/dL, P<.01) with rosiglitazone. Although no significant changes were observed in the rosiglitazone group for triglycerides, total cholesterol, high-density lipoprotein cholesterol, and low-density lipoprotein (LDL) cholesterol, both apo A-I and apo B presented small significant reductions and the LDL-apo B ratio was significantly increased. None of the above parameters were changed in the control group. In conclusion, rosiglitazone treatment had a beneficial impact on Lp(a), CRP, and LDL particles' lipid content in type 2 diabetic hypertensive patients but not on homocysteine and fibrinogen. The overall effect of rosiglitazone on cardiovascular risk factors seems positive but must be further evaluated.

Arterial stiffness: a novel cardiovascular risk factor in kidney disease patients.

Prospective observational studies have shown that arterial stiffness is a strong and independent predictor of cardiovascular disease in hemodialysis patients. Recent evidence further supports that arterial hardening predicts cardiovascular and all-cause mortality in peritoneal dialysis patients, renal transplant recipients and patients with chronic kidney disease (CKD) not on dialysis. Of note, dissociation of arterial stiffness with blood pressure reduction were related to worsened cardiovascular outcome in kidney disease patients, suggesting that arterial stiffness may not only be a predictor, but also a true risk factor, representing a specific and potentially reversible pattern of outward arterial remodeling in these individuals. On this basis, arterial stiffness has emerged as a novel therapeutic target for cardiovascular risk reduction in patients with CKD; specific interventions, such as renin-angiotensin-system blockade, use of statins, and decrease of calcium- phosphate product may delay the progression of arteriosclerotic process. This article summarizes the accumulated evidence from clinical and epidemiological studies regarding the prognostic significance of arterial stiffening on cardiovascular outcomes and provides insights on possible treatment strategies for arterial stiffness attenuation in patients with CKD.

Ambulatory recording of wave reflections and arterial stiffness during intra- and interdialytic periods in patients treated with dialysis.

BACKGROUND AND OBJECTIVES: Wave reflections and arterial stiffness are independent cardiovascular risk factors in ESRD. Previous studies in this population included only static recordings before and after dialysis. This study investigated the variation of these indices during intra- and interdialytic intervals and examined demographic, clinical, and hemodynamic variables related to arterial function in patients undergoing hemodialysis. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Between February 2013 and May 2014, a total of 153 patients receiving maintenance hemodialysis in five dialysis centers of northern Greece underwent ambulatory BP monitoring with the newly introduced Mobil-O-Graph device (IEM, Stolberg, Germany) over a midweek dialysis session and the subsequent interdialytic period. Mobil-O-Graph is an oscillometric device that records brachial BP and pulse waves and estimates, via generalized transfer function, aortic BP, augmentation index (AIx) as a measure of wave reflections, and pulse wave velocity (PWV) as an index of arterial stiffness. RESULTS: AIx was lower during dialysis than in the interdialytic period of dialysis-on day (Day 1) (mean±SD, 24.7%±9.7% versus 26.8%±9.4%; P<0.001). In contrast, PWV remained unchanged between these intervals (9.31±2.2 versus 9.29±2.3 m/sec; P=0.60). Both AIx and PWV increased during dialysis-off day (Day 2) versus the out-of-dialysis period of Day 1 (28.8%±9.8% versus 26.8%±9.4% [P<0.001] and 9.39±2.3 versus 9.29±2.3 m/sec [P<0.001]). Older age (odds ratio [OR], 1.09; 95% confidence interval [95% CI], 1.02 to 1.15), female sex (OR, 7.56; 95% CI, 1.64 to 34.81), diabetic status (OR, 8.84; 95% CI, 1.76 to 17.48), and higher mean BP (OR, 1.17; 95% CI, 1.09 to 1.27) were associated with higher odds of high AIx; higher heart rate was associated with lower odds (OR, 0.71; 95% CI, 0.63 to 0.80) of high AIx. Older age (OR, 2.04; 95% CI, 1.61 to 2.58) and higher mean BP (OR, 1.15; 95% CI, 1.05 to 1.27) were independent correlates of high PWV. CONCLUSIONS: This study showed a gradual interdialytic increase in AIx, whereas PWV was only slightly elevated during Day 2. Future studies are needed to elucidate the value of these ambulatory measures for cardiovascular risk prediction in ESRD.

Ambulatory blood pressure reduction after rosiglitazone treatment in patients with type 2 diabetes and hypertension correlates with insulin sensitivity increase.

BACKGROUND: Within the metabolic syndrome, insulin resistance and compensatory hyperinsulinemia are associated with blood pressure (BP) elevation through various potential mechanisms. Thiazolidinediones are antihyperglycemic agents that decrease insulin resistance. OBJECTIVE: To determine the effect of the thiazolidinedione rosiglitazone on BP and insulin resistance in patients with type 2 diabetes and hypertension. METHODS: In 20 subjects (nine men and 11 women) with type 2 diabetes but with a poor glycemic control, and with poorly controlled or newly diagnosed hypertension, rosiglitazone 4 mg daily was added-on therapy for 26 weeks. At baseline and at the end of the treatment period patients underwent ambulatory blood pressure monitoring, a hyperinsulinemic euglycemic clamp, and blood tests for glucose, insulin, HbA1c, lipids, and routine laboratory parameters. RESULTS: Insulin sensitivity estimated with the clamp significantly increased (Mbw/I index changed from 33.9 +/- 2.6 to 41.9 +/- 3.2 micromol/min per kg per nmol/l, P < 0.001) and the HOMA-IR index significantly decreased (6.34 +/- 0.39 versus 4.40 +/- 0.33, P < 0.001) during rosiglitazone treatment. Ambulatory BP presented small but significant reductions for the total 24-h period (135.3 +/- 1.8 versus 129.9 +/- 1.7 mmHg, P < 0.001 for systolic BP and 76.0 +/- 1.6 versus 71.9 +/- 1.6 mmHg, P < 0.001 for diastolic BP), daytime and night-time. The changes in systolic and diastolic BP correlated with the change in insulin sensitivity (r = -0.78, P < 0.01 and r = -0.68, P < 0.01, respectively). There were also significant reductions in fasting plasma glucose (9.39 +/- 0.41 versus 7.55 +/- 0.31 mmol/l, P < 0.001), insulin (94.0 +/- 0.41 versus 79.5 +/- 5.6 pmol/l, P < 0.01) and HbA1c (8.15 +/- 0.24 versus 7.24 +/- 0.19%, P < 0.001). CONCLUSIONS: Treatment of type 2 diabetic hypertensive patients with rosiglitazone significantly increased insulin sensitivity and lowered ambulatory BP. These changes were strongly correlated. Thiazolidinediones may thus possess a BP-lowering effect beyond their antihyperglycemic properties.