Superior mesenteric artery blood flow in systemic sclerosis patients.

OBJECTIVE: Intestinal involvement is frequently observed in systemic sclerosis (SSc) and is associated with malnutrition and a decreased survival rate. Vascular lesions are claimed to underlie and precede these changes. The aim of this study was to establish whether a reduced mesenteric blood flow was present in SSc patients with no signs or symptoms of small bowel involvement. METHODS: Superior mesenteric artery (SMA) blood flow in the fasting state was measured by colour Doppler ultrasonography in 27 SSc patients and in 25 controls. The effect of a balanced liquid meal on mesenteric blood flow was measured in six matched patients and controls. RESULTS: In fasting SSc patients, there were reductions in mean SMA diameter (P<0.001), blood flow (213+/-92 vs 398+/-125 ml/min in controls, P<0.0001) and pulsatility index (3.49+/-1.0 vs 4.13+/-0.97 in controls, P<0.07). In both groups, the meal increased basal flow values and the differences between controls and patients in the fasting state were not significant. CONCLUSIONS: In the absence of symptoms of small bowel involvement, reversible SMA vasoconstriction is demonstrable in the fasting state in SSc patients.

Apoptosis induced by serum withdrawal in human mesangial cells. Role of IGFBP-3.

Apoptosis has been reported to occur both during the course of kidney development and the progression of kidney injury to scarring. Insulin-like growth factor binding protein-3 (IGFBP-3), a component of the IGF system, has been shown to induce apoptosis in cancer cell lines. However, if IGFBP-3 has similar effects in human mesangial cells (HMC) remains unknown. The purpose of this study was to examine the expression of IGFBP-3 and its possible effect on the induction of apoptosis in HMC during serum deprivation. We have observed that IGFBP-3 accumulates progressively in HMC in which serum has been withdrawn. In these cells, an increase of IGFBP-3 is observed before the production of apoptosis suggesting a link between these phenomena. Furthermore, the addition of IGFBP-3 in physiological amounts (from 100 to 400 ng/ml) to culture medium devoid of growth factors accelerates and increases the apoptotic process with a dose-dependent effect. These findings suggest that IGFBP-3 is a mediator of cell death in human mesangial cells when the availability of growth factors is curtailed. These data also suggest that IGFBP-3 could contribute to apoptotic processes observed in human disease.

Effects of long-term cyclic iloprost therapy in systemic sclerosis with Raynaud's phenomenon. A randomized, controlled study.

OBJECTIVE: Iloprost is a stable prostacyclin analogue which has been shown to be effective in the short-term symptomatic treatment of Raynaud's phenomenon (RP) secondary to systemic sclerosis (SSc). The aim of this study was to evaluate the effects of long-term cyclic therapy with iloprost in comparison with nifedipine on the skin score, pulmonary function and Raynaud's severity score in patients with SSc and RP. METHODS: We conducted a 12-month prospective, randomised, parallel-group, blind-observer trial to compare the effects of intravenously infused iloprost (2 ng/kg/min on 5 consecutive days over a period of 8 hours/day and subsequently for 8 hours on one day every 6 weeks) with those of conventional vasodilating therapy with nifedipine (40 mg/day for os) in 46 patients with SSc and RP. RESULTS: At 12 months, iloprost but not nifedipine reduced the skin score (iloprost: from 13.26 +/- 2.05 to 9.26 +/- 1.32, p = 0.002; nifedipine: from 10.83 +/- 2.09 to 12.17 +/- 3.02, p = n.s.; iloprost vs nifedipine: p = 0.016) and the RP severity score (iloprost: from 2.17 +/- 0.2 to 1.22 +/- 0.13, p = 0.02 vs baseline; nifedipine: from 2.08 +/- 0.34 to 1.33 +/- 0.22, p = n.s.). Carbon monoxide diffusing capacity (DLCO), expressed as % of the predicted normal value, worsened significantly in the nifedipine group (from 69.6 +/- 7.4% to 61.5 +/- 6.5%, p = 0.044) and remained stable in patients treated with iloprost (from 53.2 +/- 4.8 to 56.0 +/- 4.6%, iloprost vs nifedipine: p = 0.026). CONCLUSION: In SSc patients, cyclic intravenous iloprost infusion is able to control vasospastic disease. Our results suggest that it might also act as a disease-modifying agent, as it seems to improve the course of the disease. Further studies principally focused on organ involvement and the natural history of the disease are needed to confirm our results.

5,10-Methylenetetrahydrofolate reductase polymorphism and early organ damage in primary hypertension.

Hyperhomocyst(e)inemia is a known risk factor for the development of atherosclerotic vascular damage. Plasma homocyst(e)ine levels are influenced by nutritional and hereditary factors. A point mutation (cytosine to thymidine substitution; C677T) in the gene encoding 5,10-methylenetetrahydrofolate reductase (MTHFR) makes the enzyme thermolabile and has been associated with elevated homocyst(e)ine levels in homozygous carriers (TT genotypes). We evaluated the relationship between the T allele encoding for the thermolabile variant of MTHFR and several biochemical risk factors and early signs of hypertensive and atherosclerotic organ damage in 206 untreated patients with primary hypertension. The MTHFR genotype was evaluated by polymerase chain reaction. Albuminuria was measured as albumin-to-creatinine ratio in three nonconsecutive first morning urine samples (negative urine culture). Persistent Mi (Alb+) was defined as an average albumin-to-creatinine ratio between 2.38 and 19 (men) and 2.96 and 20 (women). Left ventricular (LV) mass index (LVMI) was assessed by M-B mode echocardiography (LV hypertrophy, LVH = LVMI > or = 125 g/m2), carotid geometry by high-resolution ultrasound scan, and retinal vascular changes by direct ophthalmoscopy (Keith-Wagener classification). The prevalence of Mi, LVH, and retinopathy was 14%, 45%, and 42%, respectively. The prevalence of carotid plaque was 25%. Allele frequencies for C (wild-type allele) and T allele (mutant allele) were 56% and 44%, respectively. Genotype frequencies were CC 29%, CT 54%, TT 17% according to Hardy Weinberg equilibrium. There were no differences as for age, sex, body mass index, blood pressure levels, lipid profile, smoking habits, and alcohol intake, and LVMI and urinary albumin excretion on the basis of MTHFR genotype. Patients with TT polymorphism showed a higher prevalence of retinal vascular changes (TT, 61% v CT + CC, 38%; P < .02) and carotid plaque (TT, 42% v CT + CC, 21%; P < .05) compared to patients with CC and CT polymorphism. Moreover, patients with T allele showed increased carotid artery size as demonstrated by intima plus media thickness (IT, 0.79 +/- 0.05 mm v CT + CC, 0.67 +/- 0.02 mm; P < .02), relative wall thickness (TT, 0.23 +/- 0.01 mm v CT + CC, 0.20 +/- 0.005 mm; P < .02), and surface area (TT, 19 +/- 1.9 mm2 v CT + CC, 15 +/- 0.55 mm2; P < .05). Multiple linear regression analysis demonstrated that MTHFR genotype and systolic blood pressure independently influence intima-media thickness and together account for about 11% of its variations (r2 = 0.11, F = 9.7, dF = 1-205, P < .0001). Homozygosity for the T allele of the MTHFR gene is an independent risk factor for the development of early atherosclerotic organ damage in hypertensive patients.

Long term effect of nifedipine GITS and lisinopril on subclinical organ damage in patients with essential hypertension.

BACKGROUND: Preventing subclinical organ damage is currently a major issue in the management of patients with essential hypertension. Antihypertensive drugs which act through different pathophysiological mechanisms might confer specific target organ protection beyond what is already provided by their blood pressure lowering effect. METHODS: Thirty-one patients with essential hypertension were randomized to receive long-term treatment with either a calcium channel blocker (nifedipine GITS, 90 mg/day) or an ACE-inhibitor (lisinopril, 20 mg/day). Blood pressure, left ventricular mass, carotid wall thickness and timed urinary albumin excretion were measured at baseline and over the course of 24 months of treatment. RESULTS: Both regimens significantly lowered mean blood pressure over the 24 months (from 124+/-2 to 103+/-2 mmHg in the lisinopril group and from 122+/-2 to 104+/-1 in the nifedipine group). Overall, end-organ damage improved with persistent blood pressure control. However, the two treatments had different specific effects. Lisinopril induced a more pronounced reduction of the left ventricular mass index (from 56+/-3 to 52+/-2 g/m2.7, P< 0.05) and urinary albumin excretion (from 34+/-15 to 9+/-2 microg/min, P< 0.01), while nifedipine achieved a greater reduction of carotid intima plus media thickness (from 0.8+/-0.06 to 0.6+/-0.06 mm, P< 0.01). CONCLUSIONS: Blood pressure control does help reduce the severity of organ damage in patients with essential hypertension. Different antihypertensive treatments may confer additional specific cardiorenal and vascular protection regardless of blood pressure control. These data could be useful when devising individualized therapeutic strategies in high-risk hypertensive patients.

Genetic polymorphism of the renin-angiotensin system and organ damage in essential hypertension.

BACKGROUND: The renin-angiotensin-aldosterone system (RAAS) plays a significant role in the development of hypertensive cardiac and vascular remodeling. Recently, several genetic variants of its key components, which may be clinically relevant and thus prove to be useful in the evaluation of cardiovascular risk, have been described. We therefore investigated the association between ACE I/D, AGT M235T, and AT1 A1266C gene polymorphisms and early signs of target organ damage in 215 untreated patients with essential hypertension (EH). METHODS: Genotyping was based on the polymerase chain reaction technique, with further restriction analysis when required. Albuminuria was measured as the albumin-to-creatinine ratio (ACR). The left ventricular mass index (LVMI) was assessed by echocardiography (LVH = LVMI > or = 125 g/m2), carotid wall thickness (IMT) by an ultrasonographic (US) scan, and retinal vascular changes by direct ophthalmoscopy (Keith-Wagener classification). RESULTS: The prevalence of microalbuminuria (Mi), LVH, and retinal vascular changes was 14, 46, and 74%, respectively. ACE, AGT, and AT1 genotype distribution was in agreement with the Hardy-Weinberg equilibrium. There was no difference in age, duration of disease, body mass index (BMI), blood pressure, and lipid profile when data were analyzed on the basis of genotype. Serum levels of angiotensin-converting enzyme (ACE) were related to the ACE genotype (10.2 +/- 0.5, DD; 8.2 +/- 0.3, ID; 6.5 +/- 0.4 IU/mL, II; P < 0. 0001 by analysis of variance). The ACE genotype independently influences serum ACE levels and accounts for approximately 14% of its variations (F = 26.7, r2 = 0.1393, df 1 to 214, P < 0.0001). Patients with DD and ID genotypes showed higher levels of ACR (1.59 +/- 0.2, DD + ID; 0.8 +/- 0.2 mg/mmol, II; P < 0.006 by ANOVA) and bigger LVMI (124.1 +/- 2.3, DD + ID vs. 117.8 +/- 3.6 g/m2, II; P < 0.01 by ANOVA). No differences in the prevalence and degree of target organ damage (TOD) were found when data were analyzed on the basis of the AGT and AT1 genotypes, respectively. Potentially unfavorable combinations of genotypes were also investigated by K-means cluster analysis. Two subgroups of patients were identified (cluster 1, N = 70; cluster 2, N = 57), and each differed significantly with regards to the presence and degree of TOD and patterns of RAAS gene polymorphisms (F, 15.97 for ACR; F, 7.19 for IMT; F, 217.03 for LVMI; F, 3.91 for ACE; F, 4.06 for AGT; and F, 5. 22 for AT1; df 1 to 214, P < 0.02, for each one of the variables examined). CONCLUSION: The D allele of the ACE gene may be an independent risk factor for the development of target organ damage, and evaluating it could be useful for assessing cardiovascular risk in EH. Unfavorable patterns of RAAS genotypes seem to predispose patients to subclinical cardiovascular disease in EH.

Left ventricular geometry and function in patients with essential hypertension and microalbuminuria.

BACKGROUND: Microalbuminuria has recently emerged as a strong, independent predictor of cardiovascular mortality in patients with essential hypertension, yet the pathophysiological mechanisms underlying this association remain to be elucidated. OBJECTIVE: To study the relationship between microalbuminuria and left ventricular geometry and function and extra-cardiac vascular changes in a group of 211 untreated hypertensive patients. METHODS: Albuminuria was evaluated as albumin-to-creatinine ratio in three non-consecutive first morning urine samples. Left ventricular mass index and function were assessed by M-B mode echocardiography and carotid wall thickness by high-resolution ultrasound scan. RESULTS: The prevalences of microalbuminuria and left ventricular hypertrophy were 14 and 47% respectively. Patients in the top quartile of albuminuria showed a higher left ventricular mass index (57 +/- 1.8, 55 +/- 2, 47 +/- 1.4 and 48 +/- 1.6 g/m2.7, respectively; P< 0.0001) as well as a higher prevalence of left ventricular hypertrophy (72, 65, 26 and 25%, respectively; P< 0.001) and especially concentric hypertrophy (56, 47, 17 and 21%, respectively; P< 0.0001) in the four quartiles of albuminuria. Microalbuminuric patients showed depressed left ventricular performance as indicated by a reduced midwall fractional shortening (15.7 +/- 0.3, 15.9 +/- 0.3, 16.7 +/- 0.4 and 16.8 +/- 0.3%, respectively; P< 0.02). Furthermore patients in the top quartile of albuminuria showed increased carotid wall thickness as compared to normoalbuminuric patients (0.78 +/- 0.03, 0.7 +/- 0.04, 0.65 +/- 0.03 and 0.6 +/- 0.03 mm, respectively; P < 0.001). CONCLUSIONS: Hypertensive patients with microalbuminuria show a higher prevalence of unfavourable left ventricular geometric patterns, depressed left ventricular function and early signs of extra-cardiac vascular damage. These findings strengthen the role of microalbuminuria as an indicator of subclinical cardiovascular disease and may account for the worse outcome that is usually associated with increased urinary albumin excretion in essential hypertension.

Increased renal resistive index in patients with essential hypertension: a marker of target organ damage.

BACKGROUND: Increased renal resistance detected by ultrasound (US) Doppler has been reported in severe essential hypertension (EH) and recently was shown to correlate with the degree of renal impairment in hypertensive patients with chronic renal failure. However, the pathophysiological significance of this finding is still controversial. METHODS: In a group of 211 untreated patients with EH, we evaluated renal resistive index (RI) by US Doppler of interlobar arteries and early signs of target organ damage (TOD). Albuminuria was measured as the albumin to creatinine ratio (ACR) in three non-consecutive first morning urine samples. Left ventricular mass was evaluated by M-B mode echocardiography, and carotid wall thickness (IMT) by high resolution US scan. RESULTS: RI was positively correlated with age (r=0.25, P=0.003) and systolic blood pressure (SBP) (r=0.2, P=0.02) and with signs of early TOD, namely ACR (r=0.22, P=0.01) and IMT (r=0.17, P<0.05), and inversely correlated with renal volume (r=-0.22, P=0.01) and diastolic blood pressure (r=-0.23, P=0.006). Multiple linear regression analysis demonstrated that age, gender, ACR and SBP independently influence RI and together account for approximately 20% of its variations (F=8.153, P<0.0001). When clinical data were analysed according to the degree of RI, the patients in the top quartile were found to be older (P<0.05) and with higher SBP (P<0.05) as well as early signs of TOD, namely increased ACR (P<0.002) and IMT (P<0.005 by ANOVA), despite similar body mass index, uric acid, fasting blood glucose, lipid profile and duration of hypertension. Furthermore, patients with higher RI showed a significantly higher prevalence of microalbuminuria (13 vs 12 vs 3 vs 33% chi2=11.72, P=0.008) and left ventricular hypertrophy (40 vs 43 vs 32 vs 60%, chi2=9.25, P<0.05). CONCLUSIONS: Increased RI is associated with early signs of TOD in EH and could be a marker of intrarenal atherosclerosis.

Microalbuminuria is an early marker of target organ damage in essential hypertension.

Microalbuminuria has been associated with a cluster of metabolic and nonmetabolic risk factors, suggesting that it might indicate the presence of generalized microvascular damage in patients with essential hypertension. To explore whether microalbuminuria is associated with early target organ damage, two groups of essential hypertensive patients, with (n = 17) (HtAlb+) and without (n = 16) (HtAlb-) microalbuminuria, and a control group (C) of healthy normotensive subjects (n = 20) were studied. The study groups, selected among participants of a large epidemiologic trial, were carefully matched for several potentially confounding variables such as gender, age, duration of hypertension, and body mass index. Albumin excretion rate was evaluated by radioimmunoassay in three nonconsecutive timed overnight collections after 3 weeks of pharmacologic wash-out. Left ventricular mass was assessed by M-B-mode echocardiography, carotid wall thickness by a high resolution ultrasound scan, and renal vascular impedance by Doppler scan. Office as well as 24-h ambulatory pressure monitoring (Takeda TM-2420) were also evaluated. There was no difference between the two hypertensive groups for office and 24-h blood pressure levels except for a lower daytime/nighttime systolic blood pressure ratio in the group with microalbuminuria. Microalbuminuric patients showed signs of early organ damage as compared to normoalbuminuric patients and normal subjects, namely greater left ventricular mass indices (LVMI 167+/-7 g/m2 in HtAlb+; 139+/-9 g/m2 in HtAlb-; 118+/-5 g/m2 in C, P < .001) and increased wall thickness of common carotid arteries (intima plus media thickness 12.5+/-0.2 mm in HtAlb+; 11.7+/-0.3 mm in HtAlb-; 11.2+/-0.2 mm in C, P < .001) as well as higher intrarenal vascular resistance (mean resistive index 0.62+/-0.01 in HtAlb+; 0.59+/-0.01 in HtAlb-; 0.59+/-0.01 in C, P < .05). In conclusion, microalbuminuria is an early marker of diffuse target organ damage in essential hypertension and therefore can be useful to identify patients for whom more aggressive preventive strategies or additional treatment measures are advisable.

Effect of iloprost infusion on the resistance index of renal vessels of patients with systemic sclerosis.

OBJECTIVE: To investigate the effect of iloprost, a stable prostacycline analog, on kidney blood flow in patients with systemic sclerosis (SSc), using color flow Doppler sonography. METHODS: The acute effect of the drug was studied in 10 patients with SSc with elevated resistance index (RI) levels (all RI values reported are multiplied by 100). Iloprost was administered intravenously (2 ng/kg/min for a period of 8 h). To study the effects of chronic drug administration, 16 patients with SSc were randomly assigned to 2 groups of 8 cases each. The first group was treated with 9 infusions of iloprost in 6 mo. The second group was treated with slow release nifedipine (40 mg/day) for 6 mo. RESULTS: Interlobar artery RI (median 67 vs 61; p = 0.02) and cortical vessel RI (median 65 vs 54; p = 0.001) were reduced after acute treatment. In chronic drug administration, RI values were not modified by nifedipine, while iloprost reduced the RI of the interlobar (median 69 vs 61; p < 0.03) and cortical arteries (median 66 vs 58: p < 0.01). CONCLUSION: Our findings suggest iloprost might be useful for treatment of scleroderma renal vasospasm.

Renal vascular damage in systemic sclerosis patients without clinical evidence of nephropathy.

OBJECTIVE: To evaluate the use of color-flow Doppler ultrasonography, a direct, noninvasive technique, for measurement of kidney blood flow in patients with systemic sclerosis (SSc). METHODS: Twenty-five normal volunteers and 25 SSc patients (median disease duration 8 years, range 2-21 years) were studied. All were free of clinical symptoms of renal damage. The resistance index (RI) was determined on main, interlobar, and cortical vessels. RESULTS: In SSc patients, the RI was significantly increased at every sampling site examined (P < 0.001). RI values were strongly correlated with disease duration (main artery r = 0.56, P < 0.04; interlobar artery r = 0.63, P < 0.02; cortical artery r = 0.75, P < 0.002). Regression analysis showed no relationship between RI and creatinine clearance values. CONCLUSION: Color-flow Doppler ultrasonography is a sensitive and noninvasive technique for evaluating vascular damage of the kidney in patients with SSc.