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Biomedical subjects

J Redon

Publications and source records attributed to J Redon.

At least 19 recordsLinked to original sources
PubMed2006

Impact of the components of metabolic syndrome on oxidative stress and enzymatic antioxidant activity in essential hypertension.

The objective of the present study was to analyze the impact of metabolic syndrome (MS) and its individual components on oxidative stress (OX) and on the activity of antioxidant enzymes of patients with essential hypertension. One hundred and eighty-seven hypertensives, 127 (61.9%) of them having criteria for MS according to the International Diabetes Federation criteria and 30 healthy normotensive subjects were included. OX status was assessed by measuring glutathione oxidized/glutathione reduced and reactive oxygen species-induced byproducts of lipid peroxidation, malondialdehyde, and DNA damage, 8-oxo-dG genomic and mitochondrial. Antioxidant enzymatic activity of Cu/Zn extracellular-superoxide dismutase (SOD) and catalase (CAT) was measured in plasma and glutathione peroxidase 1 in hemolysed erythrocytes. In mononuclear cells, total-SOD activity, CAT and glutathione peroxidase 1, were assessed as well. The OX state in both blood and peripheral mononuclear cells observed in hypertensives were not enhanced by the addition of components of the so-called MS. Likewise, the reduction in the activity of antioxidant enzymes, both extracellular and cytoplasmic, was not affected by the presence of additional components of the MS. Neither the number of components nor the individual addition of each of them, low high-density lipoprotein, triglycerides, abdominal obesity or fasting glucose, further impact in the OX abnormalities observed in those with only hypertension in absence of other components. In conclusion, the present data indicates that contribution of MS components to the OX burden generated by high blood pressure is minimal.

Adult↗
PubMed2005

Renin-angiotensin system gene polymorphisms: relationship with blood pressure and microalbuminuria in telmisartan-treated hypertensive patients.

This study analyzed the relationship between four renin-angiotensin system (RAS) gene polymorphisms and the response to blood pressure lowering and development of microalbuminuria in 206 patients with essential hypertension treated once daily for 12 months with telmisartan 80 mg. Seated cuff blood pressure and urinary albumin excretion (UAE) were measured throughout the study. Patients were screened for the presence of the A-6G variant of the angiotensinogen gene, angiotensin-converting enzyme insertion/deletion polymorphism, and the A1166C and C573T polymorphisms of the angiotensin II type 1 receptor gene. No significant association was found between the presence of any gene polymorphism and the reduction of blood or UAE following telmisartan treatment. The results indicate that these RAS gene polymorphisms do not affect the antihypertensive activity and renoprotection in mild-to-moderate hypertensive patients treated with telmisartan.

Aged↗
PubMed2004

Polymorphisms of the angiotensinogen gene and the outcome of microalbuminuria in essential hypertension: a 3-year follow-up study.

BACKGROUND: The objective of this study was to analyse the relationship of polymorphisms of the angiotensinogen (AGT) gene with the changes in microalbuminuria during 3 years of antihypertensive treatment in a group of young adults with essential hypertension. METHODS: Essential hypertensives, less than 50 years old, never previously treated with antihypertensive drugs and in the absence of diabetes mellitus were included. After the initial evaluation, patients were treated using only nonpharmacological measures (n=23), only beta-blockers (n=26), only angiotensin-converting enzyme inhibitors (ACEi) (n=57) or a combination of treatments (n=25). The office blood pressure, biochemical profile and urinary albumin excretion (UAE) were measured at the beginning and then yearly. The polymorphism A-6G of the AGT gene located in the promoter region was analysed. RESULTS: In total, 131 patients, 35 (27%) microalbuminurics, were included. Although no significant differences in systolic blood pressure (SBP), diastolic blood pressure (DBP), fasting glucose and UAE were observed among genotypes at the initial examination, during the 3 years of antihypertensive treatment the slope values for the DBP, fasting glucose and UAE differed significantly despite no differences in the distribution of treatments being present. The subjects carrying the AA-6 genotype had the largest DBP decrease, but the lowest UAE reduction and the highest slope of glucose. Out of 35 initially microalbuminuric patients, 24 became normoalbuminuric and the lowest reduction rates were observed in subjects who carried the allele A-6. No interaction between the type of treatment and genotype was observed on the changes in UAE, BP or glucose values. In the subset of 57 patients treated with ACEi, the changes in UAE, BP and glucose had the same trend as was observed in the total population. CONCLUSIONS: Subjects carrying the AA genotype of the A-6G AGT gene polymorphism are resistant to a reduction of microalbuminuria. Whether this can be attributed to a predisposition to glucose metabolic disturbance or not needs to be confirmed in further studies.

Adrenergic beta-Antagonists↗
PubMed2004

The normal circadian pattern of blood pressure: implications for treatment.

Blood pressure fluctuates over 24 h following a circadian rhythm that reaches a peak in the morning shortly after awakening. The onset of many acute cardiovascular and cerebrovascular events shows a synchronous cyclical pattern, with the highest incidence of morbidity and mortality in the early morning hours. Strong, although circumstantial, evidence suggests that the early morning surge in blood pressure may contribute to the onset of acute cardiovascular episodes. Sustained blood pressure control that blunts the early morning blood pressure surge may help to reduce the incidence of these events. Antihypertensive agents are needed that provide smooth and sustained blood pressure control for the full 24 h, including the risky early morning hours. The angiotensin II receptor blocker telmisartan given once daily, because of its long half-life and mechanism of action, is likely to confer benefit in terms of 24-h blood pressure control and may reduce cardiovascular risk at the time of greatest patient vulnerability.

Antihypertensive Agents↗
PubMed2004

Polymorphisms of the renin-angiotensin system influence height in normotensive women in a Spanish population.

The objective of this study was to analyze the influence of the polymorphisms G-6A of the angiotensinogen gene, insertion/deletion (I/D) of the angiotensin-converting enzyme, and C573T of the angiotensin II AT1 receptor gene on a healthy, middle-age population. A total of 370 (194 women) healthy normotensive Caucasian subjects, aged 25-50 yr old, were selected from the general population. A significant association was found between height and the C573T polymorphism in women (P < 0.001). After adjustment for age, this association remained significant (P < 0.002). Thus, the lowest height values were from subjects carrying TT genotype (CC, 1.627 +/- 0.008 m; CT, 1.595 +/- 0.006 m; TT, 1.586 +/- 0.010 m; P = 0.002). Likewise, the I/D polymorphism was associated with height (P = 0.002) in women. It remained significant after adjustment for age and the lowest height for the DD genotype (II, 1.629 +/- 0.011 m; ID, 1.603 +/- 0.006 m; DD, 1.591 +/- 0.007 m; P = 0.016). For both C573T and I/D polymorphisms, there was an allele dosage effect. Moreover, an additive and independent effect of the C573T polymorphism (P = 0.006) and the I/D polymorphism (P = 0.045) on height was observed. In contrast, no association with height was observed for the G-6A polymorphism. In conclusion, additive effects between polymorphisms of the renin-angiotensin system genes and height were observed in healthy women. These results should be studied by other groups in other populations and ethnic groups. Whether or not these associations need to be considered in the epidemiological studies analyzing the relationship between polymorphisms of the renin-angiotensin system genes and such height-influenced parameters as blood pressure merits further study.

Adult↗
PubMed2002

Body weight changes and the A-6G polymorphism of the angiotensinogen gene.

BACKGROUND: The objective of the study was to analyze the relationship of polymorphisms of the angiotensinogen gene with changes in body weight during 3 y of antihypertensive treatment, in a group of young adults with essential hypertension. METHODS: Essential hypertensives, less than 50 y old, never previously treated with antihypertensive drugs and in the absence of diabetes mellitus were included. After the initial evaluation, patients were treated using only non-pharmacological measures (n=29), beta-blockers (n=40) or angiotensin-converting enzyme inhibitors (n=66). Resting blood pressure, biochemical profile and body weight at the beginning and yearly were measured. The polymorphism A-6G of the angiotensinogen gene located in the promoter region was analyzed. RESULTS: One-hundred and thirty-five patients were included. Genotypes of the A-6G polymorphism of the AGT gene were in Hardy-Weinberg equilibrium (AA 34, AG 63, GG 38). No significant differences were observed among genotypes in terms of age, body mass index, body weight, systolic or diastolic blood pressure. No significant differences in the genotype distribution or in the allele frequencies were observed, although the A allele was most frequent among the obese subjects. During the 3 y of antihypertensive treatment, there was a trend to increase weight despite the dietary recommendations. The slopes of body weight over time, adjusted by age and baseline BMI, differed significantly among the homozygote genotypes (P=0.006). The highest were for those with the AA genotype and the lowest for the GG genotype (1.180+/-0.25 and -0.128+/-0.24 kg/y; P=0.0001). The influence of the genotype in the changes on body weight remained significant after considering its interaction with the kind of antihypertensive treatment, although among subjects carrying the AA genotype those treated with ACEi showed the least body weight change. Furthermore, A-6G genotypes had the largest influence on weight changes, accounting for 19% of the variance, when age, sex and initial body mass index were included in the model. CONCLUSIONS: In a group of young adult hypertensive subjects, there was a trend to increase weight despite dietary recommendations. Subjects with the AA genotype were those with the largest weight gain, but this effect was modified by the antihypertensive treatment.

Adrenergic beta-Antagonists↗
PubMed2001

Angiotensin II AT1 receptor gene polymorphism and microalbuminuria in essential hypertension.

The objective of this study was to analyze the relationship of polymorphisms of the angiotensin II AT1 receptor gene with microalbuminuria in a group of young adults with essential hypertension. Essential hypertensives, less than 50 years old, never previously treated with antihypertensive drugs, and in absence of diabetes mellitus were included. Office blood pressure (BP), 24-h ambulatory BP monitoring, urinary albumin excretion (UAE) measurements, and DNA analysis were performed. Polymorphisms of the angiotensin II AT1-receptor gene (A1166C and C573T) were studied by polymerase chain reaction and single-strand conformation polymorphism techniques. One hundred eighty-three patients, 49 (27%) microalbuminurics, were included. Office and ambulatory BP values were significantly higher in the microalbuminuria group. No differences in the presence of microalbuminuria were observed among the genotypes of either A1166C or C573T polymorphisms of the angiotensin II receptor AT1 gene, or in the allele frequency of the A1166C or the C573T polymorphism. LogUAE was significantly different among genotypes of the C573T polymorphism [CC 1.30(1.15-1.45), CT 1.14(1.00-1.28), and TT 0.94(0.68-1.20), P < .05]. Both office and ambulatory blood pressure and the TT/C573T genotype were independently related to logUAE, and, at the same BP values, UAE was lower in subjects with this genotype. We have found that the C573T polymorphism is on linkage disequilibrium with A1166C, as the 573T allele is closely linked to the presence of the 1166A allele, but not vice versa. Haplotype analysis among subjects with the AA genotype for the A1166C polymorphism confirms the influence of the TT genotype of the C573T polymorphism on the UAE in hypertensives. The C573T polymorphism of the angiotensin II receptor AT1 gene seems to be a genetic protective factor for UAE in a population of essential hypertensives.

Adult↗
PubMed2001

Effect of two antihypertensive combinations on metabolic control in type-2 diabetic hypertensive patients with albuminuria: a randomised, double-blind study.

The objective of this study was to compare, at equal blood pressure (BP) reduction, the effect of two different combinations on metabolic control and albuminuria in type 2 diabetic hypertensive patients with albuminuria. This was a prospective, randomised, double-blind, parallel, controlled trial carried out in 11 Spanish hospitals. A total of 103 type 2 diabetic patients with stable albuminuria and BP not controlled on monotherapy were randomised of which 93 finished the study. After a 4-week single-blind placebo period, patients were randomised to verapamil SR/trandolapril 180/2 mg (VT) or to enalapril/hydroclorothiazide 20/12.5 mg (EH). Treatment duration was 6 months. The main outcome measures were changes in BP, 24-h albuminuria, blood glucose and glycated haemoglobin. Overall BP was significantly reduced from 157.3 +/- 12.0/98.3 +/- 6.4 mm Hg to 140.5 +/- 14.5/86.1 +/- 8.2 mm Hg (P < 0.001) and albuminuria significantly decreased from 508.6 +/- 693.8 mg/24 h to 253.4 +/- 517.2 mg/24 h (P < 0.001), both without significant differences between treatments. Glycated haemoglobin was not modified on VT: baseline, 5.91 +/- 1.43%; end of treatment, 5.94 +/- 1.62%, but increased on EH: baseline, 5.96 +/- 1.25%; final, 6.41 +/- 1.51%, (ANOVA interaction P = 0.040). At the end of the study, a blood glucose <126 mg/dL was attained in 72.7% of the VT group-improving in 29.5% and worsening in 6.8% of patients (P = 0.021)-and in 50% of the EH group, 13.6% of patients improved and 11.4% worsened (P = 1.000). There were no changes in body weight, serum creatinine, uric acid, potassium, cholesterol, tryglicerides and serum albumin. In hypertensive type 2 diabetic patients not controlled on monotherapy, both treatments similarly reduced albuminuria. The combination verapamil/ trandolapril seems to allow a better metabolic control than enalapril/hydroclorothiazide.

Aged↗
PubMed2001

Losartan reduces microalbuminuria in hypertensive microalbuminuric type 2 diabetics.

BACKGROUND: The aim of the present study was to assess the antialbuminuric effect of losartan in a large number of hypertensive type 2 diabetics. METHODS: This was a 6-month, open-label, prospective and multicentre study. A total of 422 patients with type 2 diabetes who were hypertensive [sitting systolic blood pressure (SBP) > or = 140 mmHg and/or diastolic blood pressure (DBP) > or = 90 mmHg] and microalbuminuric [urinary albumin excretion (UAE) 30-300 mg/day] were eligible for the study. After a 2-week run-in period, patients were placed on losartan 50 mg once a day. If the BP did not reach the desired goal (< 140/90 mmHg) after a 4-week period, the losartan dose was doubled. In the absence of control of BP, losartan 50 mg/day+hydroclorothiazide 12.5 mg/day was administrated. Initially and at 12 and 24 weeks of active treatment, BP, UAE, HbA(1c) and other renal function parameters were evaluated. RESULTS: A significant decrease in SBP and DBP was observed, as well as in parameters reflecting metabolic control, fasting glucose and HbA(1c). UAE also decreased significantly, but the percentage of the variance of change in UAE explained by the changes in SBP and HbA(1c) was, however, negligible, i.e. 4%. Moreover, small but significant reductions in uric acid, total cholesterol and triglycerides, and an increase in HDL-cholesterol levels were also observed. CONCLUSION: Antihypertensive treatment with losartan exerts a beneficial effect on UAE, a benchmark for measuring the efficacy of therapeutic interventions in diabetic nephropathy, by reducing BP and allowing better diabetes control. The role of other mechanisms influencing the favourable outcome, beyond these measured effects, needs to be assessed in further studies.

Albuminuria↗
PubMed2001

The spectrum of circadian blood pressure changes in type I diabetic patients.

BACKGROUND: The objective of the present study was to characterize the spectrum of circadian blood pressure changes in type I diabetes at different stages of nephropathy by using two monitorings in each patient in order to avoid intra-individual variability. PATIENTS AND METHODS: A total of 80 type I diabetic subjects and the same number of age, sex and awake mean blood pressure (BP)-matched controls were included. According to urinary albumin excretion, there were 57 normoalbuminurics, 15 persistent microalbuminurics and eight proteinurics. Two 24 h ambulatory blood pressure monitorings were performed at the same urinary albumin excretion stage in absence of antihypertensive treatment for each diabetic subject and for their respective control. Blood pressure and heart rate averages during 24 h, awake, sleep, and day: night ratio were calculated. RESULTS: Seven of the eight proteinuric subjects were hypertensives, whereas hypertension was absent in the normoalbuminuric and microalbuminuric groups. The intraindividual reproducibility in diabetics showed repeatability coefficients for the 24 h systolic and diastolic pressure of 33 and 42%, respectively. This reproducibility for the day: night ratio was generally worse, 57% for systolic and 59% for diastolic. A progressive increment in the mean ambulatory BP was observed across the three groups of diabetics and the differences in BP observed were most evident during the night-time period. Though no differences in the 24 h circadian pattern were present between the normoalbuminurics and their controls, nocturnal differences were observed, not only in microalbuminurics for systolic BP (P < 0.05), but also in proteinurics for both systolic BP (P < 0.01) as well as diastolic BP (P < 0.05). No differences were observed in heart rate among the diabetic groups. The non-dipping pattern in the two monitorings was observed in 80, 58, 18 and 10% of the proteinurics, microalbuminurics, normoalbuminurics and control groups, respectively. CONCLUSIONS: Persistent abnormal circadian variability seems to be an early and frequent characteristic of type I diabetics with an increased urinary albumin excretion. Although present in some normalbuminuric subjects, the frequency of this abnormality increases as the incipient nephropathy progresses. By the time proteinuria is established, nearly all subjects present the abnormal pattern.

Adolescent↗
PubMed2001

Polymorphism insertion/deletion of the ACE gene and ambulatory blood pressure circadian variability in essential hypertension.

OBJECTIVE: The objective of the present study was to analyze the influence of the insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme on ambulatory blood pressure values and circadian variability in untreated patients with hypertension. MATERIAL AND METHODS: Ninety-nine essential hypertensive patients, less than 50 years old (mean age 39.5+/-7.0 years), previously untreated with antihypertensive drugs were included. Twenty-four hour ambulatory blood pressure monitoring (ABPM) was performed with a Spacelabs (90202 and 90207) monitor, during a regular working day in unrestricted ambulatory conditions. The I/D polymorphism of the ACE was determined by PCR. RESULTS: The distributions of genotypes were in Hardy-Weinberg equilibrium: I=17 (17%), ID=41 (41.5%), DD=41 (41.5%). No significant differences were present among the groups in terms of age, sex, and biochemical and lipid profiles. The average of 24-h ambulatory blood pressure was slightly higher in patients with the DD genotype as compared with patients with the II and ID genotypes. This was the result of higher nighttime blood pressure values, because no differences in blood pressure were observed during daytime. The systolic blood pressure (SBP) day:night ratio, as an estimate of circadian variability, was significantly lower in subjects homozygous for the D allele than it was in patients carrying the I allele (1.13+/-0.09 vs. 1.17+/-0.08, P=0.014). The subjects in the lowest tertile of the SBP day:night ratio, exhibited a higher frequency of the D allele when compared with those in the middle tertile (0.74 vs. 0.59, P<0.05) or with those in the highest tertile (0.74 vs. 0.54, P<0.01). By using two-way ANOVA with repeated measures, significant differences in SBP variation over time were observed when comparing homozygous for the D allele with subjects carrying the I allele (F=2.11, P=0.002). CONCLUSIONS: Among the genotypes of the I/D polymorphism, subjects carrying DD genotype showed a blunted decline of the physiological nocturnal fall of blood pressure that was significant for SBP.

Adult↗
PubMed2001

Overview of ambulatory blood pressure monitoring in childhood and pregnancy.

Despite the fact that the study and applicability of ambulatory blood pressure in children and pregnant women share characteristics which limit the potential development of knowledge for their use, advances produced in the last few years provided the present knowledge regarding the significance and the potential use of ambulatory blood pressure in children and in the pregnant women. In children ambulatory blood pressure monitoring is useful for the diagnosis of mild hypertensives, assessment of refractory hypertension, therapeutic trials with antihypertensive drugs, and clinical investigation when BP is one of the parameters to be taken into account and/or when subtle BP abnormalities are the objective of the study. In pregnant women, the main applicability is to assess the maternal and fetal risk in the hypertensive disorders of pregnancy.

Adult↗
PubMed2001

Hypertension in obesity.

AIM: To review various topics regarding the relationship between obesity and hypertension. DATA SUMMARY: Obesity is a widespread and increasingly prevalent condition associated with a large number of comorbid diseases, one of the most important of which is obesity-induced hypertension (HTN). The association between obesity and HTN has been well documented in most racial, ethnic and socio-economic groups, although the relationship between body mass index (BMI) and blood pressure values depends on age, gender, type of obesity and race differences. Obesity-induced HTN has some unique characteristics that differ from those observed in lean hypertensive patients. The hemodynamic profile of obese subjects is characterised by high cardiac output, high plasma and total blood volume, and inappropriately normal to total peripheral resistance. Clinically, hypertensive obese subjects are more likely to develop left ventricular hypertrophy and kidney damage than their lean counterparts. Various common factors are involved in establishing sodium retention and vascular resistance and may be critically influenced by the neurobiological/genetic mechanisms leading to obesity, in which insulin, leptin and the adrenergic system play major roles. Obesity is one of the main causes of therapeutic failure, and a number of studies have demonstrated that obese subjects need more antihypertensive drugs than sex and age-matched lean hypertensives. Long-term dietary treatment, consisting of a moderate restriction of energy and salt intake, is the most effective and safe treatment for obesity-associated HTN. The use of treatments other than calorie restriction should be considered with caution. Drugs that increase energy expenditure or reduce appetite may variably increase blood pressure (BP) and are unsuitable for hypertensive subjects. There do not seem to be any clear differences in the efficacy of the various antihypertensive drug classes. The clustering of cardiovascular risk factors other than HTN needs to be taken into account when choosing antihypertensive treatment for obese subjects. CONCLUSIONS: Obesity is a highly prevalent condition that causes or exacerbates many health problems including HTN. Combined interventions at different levels can help in losing weight and therefore reduce the cardiovascular risk, morbidity and mortality associated with obesity.

Age Factors↗
PubMed2000

[Factors associated with changes in microalbuminuria during antihypertensive treatment].

BACKGROUND: The objective of the present study was to analyze the factors related with changes of microalbuminuria during antihypertensive treatment in patients with essential hypertension. METHODS: One hundred and six patients (57 men, mean age 40.8 [SD 6.6] years) never treated with antihypertensive treatment were included. At the beginning and after one year, blood pressure biochemical profile and urinary albumin excretion (UAE) were measured. After the initial evaluation, 53 patients received angiotensin converting enzyme inhibitors (ACEi) and 53 beta-blockers (BB). Hydrochlorothiazide was added to achieve the blood pressure target < 140/90 mmHg. RESULTS: The average of UAE was 32.1 (43.1) mg/24 h, and 41 (39%) patients had microalbuminuretics. After 12 months of treatment, a significative fall of systolic BP (-20.6 [8.03] mmHg, p < 0.001), and diastolic BP (-14.18 [10.34] mmHg, p < 0.001) were observed, whereas baseline glucose increases (3.08 [11.07] mg/dl, p = 0.006). The changes of UAE were only related with the baseline UAE values. Neither, age, sex, baseline diastolic BP and changes in diastolic BP were significantly related with the changes in UAE. In spite of similar mean BP reduction (medial BP 17.4 [10.9] vs 14.8 [10.4] mmHg), UAE only was reduced in patients treated with ACEi (LogUAE: 0.203 [0.872] mg/24 h; p < 0.04). In addition, in patients treated with BB a significative increase in baseline glucose (4.4 [12.3] mg/dl; p = 0.013) and uric acid (1.18 [4.18]; p = 0.031) were observed. CONCLUSIONS: In patients with essential hypertension, changes in microalbuminuria depends of the initial UAE values and the kind of antihypertensive treatment. ACEi produced higher UAE reduction and lower derangement of the glucose metabolism than BB.

Adrenergic beta-Antagonists↗