摘要:

BackgroundInsulin resistance is associated with hypertension. The relative influences of hyperinsulinaemia and high blood pressure on vascular hypertrophy and carotid distensibility is unclear in patients with longstanding hypertension.MethodsIn 88 unmedicated patients with stage II–III hypertension and left ventricular hypertrophy on electrocardiogram we measured blood pressure, minimal forearm vascular resistance (MFVR) using plethysmography, intima–media thickness (IMT) and the wall distensibility of the common carotid arteries using ultrasound, and insulin sensitivity using a 2-h isoglycaemic hyperinsulinaemic clamp.ResultsIMT was positively correlated to systolic blood pressure (r= 0.26,P< 0.05), whole body glucose uptake index (M/IG;r= 0.22,P< 0.05), age (r= 0.24,P< 0.05) and negatively correlated to body mass index (r= −0.24,P< 0.05); IMT did not correlate to fasting serum insulin (r= −0.14, NS). In men (n= 64) MFVR was positively correlated to systolic blood pressure (r= 0.30,P< 0.05), but was unrelated to M/G and serum insulin. The distensibility of the common carotid arteries was negatively correlated to systolic blood pressure (r= −0.40,P< 0.001) and in untreated patients (n = 22) positively correlated to M/IG (r= 0.47,P< 0.05).ConclusionsHigh systolic blood pressure was related to vascular hypertrophy, whereas hyperinsulinaemia and insulin resistance were not, suggesting that longstanding high blood pressure is a far more important determinant for structural vascular changes than insulin resistance at this stage of the hypertensive disease. However, hyperinsulinaemia and insulin resistance were associated with low distensibility of the common carotid arteries in the subgroup of never treated hypertensive patients.

ISSN:0263-6352    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

ObjectiveTo determine whether there is a longitudinal relationship between hypertension and hyperinsulinemia and to find the most useful parameter(s) for predicting the subsequent development of hypertension.Subjects and methodsThe oral glucose (75 g) tolerance test (OGTT) was performed in 313 patients, who were divided into three groups according to glucose tolerance based on the WHO criteria: normal, borderline and diabetes mellitus. The fasting insulin (IRI) levels, ΣIRI (the sum of the insulin levels 0, 30, 60 and 120 min after the OGTT), insulinogenic index and Homa's index, a candidate for the simple assessment of insulin sensitivity, of the normotensive and hypertensive subjects in each subgroup were compared. In addition, 145 normotensive subjects were followed up for over 3 years and observed for the development of hypertension.ResultsHypertensive diabetic subjects had not only higher fasting IRI levels and ΣIRI values, but they also had higher Homa's indices than normotensive diabetics. Normotensive subjects with normal glucose tolerance (n = 20) did not develop hypertension. However, 16 out of 94 patients with borderline glucose tolerance and five out of 31 diabetics became hypertensive. The incidence of hypertension in the group with fasting IRI ≥ 15, ΣIRI ≥ 150 or Homa's index ≥ 4 was between 5 and 9 times higher than that in the group with fasting IRI < 10, ΣIRI < 100 or Homa's index < 2. This difference was still significant when multivariate analysis, including various factors such as age, body mass index (BMI) and sex, was performed.ConclusionsThese results suggest that higher plasma IRI levels and/or insulin resistance are closely related to the pathogenesis of hypertension in patients with diabetes mellitus. Homa's index, fasting and ΣIRI may be useful predictors of the subsequent development of hypertension.

ISSN:0263-6352    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

ObjectiveSeveral experimental and clinical studies indicate that the renin system may play a pivotal role in progressing renal disease. The combination of an angiotensin-converting enzyme inhibitor and an angiotensin receptor blocker could provide a higher degree of blockade of the renin-angiotensin system than either agent alone. Such enhanced suppression might be of benefit for patients exhibiting a progressive decline in renal function because of chronic renal disease.MethodsA pilot multinational, multicentre, randomized, active-controlled, parallel group open-label study has been conducted in a group of patients with progressive chronic renal failure (creatinine clearance 20–45 ml/min) either with or without proteinuria and hypertension. The primary aim of the study was to investigate the safety and tolerability of the combination of valsartan and benazepril. Patients were randomly assigned to one of three groups: group 1 received valsartan 160 mg once daily (n = 22); group 2 received valsartan 80 mg once daily plus benazepril 5 or 10 mg once daily (n = 42); group 3 received valsartan 160 mg once daily plus benazepril 5 or 10 mg once daily (n = 44). The study lasted for 5 weeks, and in groups 2 and 3 benazepril was added on top of valsartan after the first week of therapy with the angiotensin receptor blocker.ResultsSerum creatinine increased in all three groups (mean change within a group: 11 μmol/l in group 1,P= 0.045; 9 μmol/l in group 2,P= 0.030; 15 μmol/l in group 3,P= 0.0006). Serum potassium also increased in all three groups of patients (mean change within a group:0.28 mmol/l in group 1,P= 0.28; 0.48 mmol/l in group 2,P= 0.0008; 0.36 mmol/l in group 3,P= 0.02). After 5 weeks of treatment, the largest decrease in blood pressure was observed in group 3 (the mean change from baseline in seated diastolic blood pressure (SDBP) and seated systolic blood pressure (SSBP), respectively, were: −2.0 and −11.5 mmHg in group 1; −7.6 and −15.4 mmHg in group 2; −12.6 and −21.6 mmHg in group 3). In addition, both combination treatments resulted in the reduction of proteinuria. The total number of patients with adverse experiences were 10 (45.5%), 14 (33.3%) and 11 (25%) in groups 1, 2 and 3, respectively. In six patients (5.6%) therapy was discontinued as a result of adverse experiences. Only one patient in each of the combined therapy groups withdrew from the study because of hyperkalaemia and no patients were forced to withdraw because of an increase in serum creatinine, acute renal failure or hospitalization.ConclusionsThese results indicate that short-term combination of an angiotensin-converting enzyme inhibitor and an angiotensin receptor blocker is safe and well tolerated in patients with moderate chronic renal failure.

ISSN:0263-6352    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

BackgroundThere has been speculation whether serum uric acid levels are an independent prognostic factor in patients with hypertension.ObjectiveTo investigate the clinical associations and prognostic value of serum urate in patients with malignant phase hypertension (MHT), by comparing clinical features in patients with serum urate levels above and below the median levels for this population, and secondly, by performing a survival analysis in these patients.Patients and methodsReview of the data on 153 patients (98 males; mean age 50.3 years, SD 13.5) with MHT on the west Birmingham MHT register. Median uric acid levels in this population was 0.41 mmol/l (6.9 mg/dl), with an interquartile range of 0.34–0.50 mmol/l (5.7–8.4 mg/dl). Clinical characteristics of patients with a serum urate < 0.41mmol/l (group 1) were compared to those with levels above the median (0.41 mmol/l, group 2).ResultsMean duration of follow-up was similar in both groups. The mean diastolic blood pressure at presentation and both mean systolic and diastolic blood pressures at follow-up were significantly higher in group 2 (that is, those with high serum urate levels) (unpaired t test,P= 0.039). There was also more renal dysfunction in group 2 patients with MHT, with higher mean serum urea and creatinine levels, both at presentation and at follow-up (unpaired t test,P< 0.01). The commonest causes of death were myocardial infarction (n= 7), heart failure(n= 4), stroke (n= 10) and renal failure (n= 5). There was no difference in mean survival duration between groups 1 and 2 (Kaplan–Meier, 64.6 versus 66.8 months; log-rank test,P= 0.519). Serum urate levels also did not predict the rise in serum creatinine levels (log-rank test,P= 0.84) or urea (P= 0.4033) amongst these patients. Using a multivariate Cox proportional hazards analysis, the only independent predictors of outcomes (death or the need for dialysis) were age (P= 0.007) and serum creatinine levels at presentation (P= 0.0046).ConclusionOur analysis of a large series of patients with MHT shows that those with high urate levels had higher diastolic blood pressures and greater renal impairment at baseline. At follow-up, patients with median serum urate > 0.41mmol/l showed a greater deterioration in renal function and higher blood pressures, but no significant difference in survival. Serum urate levels also do not appear to be predictive of the deterioration in renal function or overall survival in patients with MHT.

ISSN:0263-6352    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

ObjectiveStudies of experimental animals show glomerular hypertension to be important in the progression of glomerular disease. We evaluated this connection clinically by examining the relationship between glomerular hemodynamics and histological changes in patients with immunoglobulin (Ig)A nephropathy.MethodsThe subjects were 23 patients with IgA nephropathy. All patients underwent renal biopsies. Glomerular hemodynamics, in terms of glomerular capillary hydraulic pressure (PGC) and the whole-kidney ultrafiltration coefficient, were calculated from the renal clearance, plasma total protein concentration, and pressure–natriuresis relationship. The severity of glomerulosclerosis, tubulointerstitial damage and mesangial matrix expansion was evaluated semiquantitatively.ResultsPGC ranged from 33–69 mm Hg, and the mean arterial pressure (MAP) from 79–112 mm Hg. Their correlation was not significant (r= 0.29,P= 0.18). PGC was significantly correlated with the glomerulosclerosis score, and also with the score for tubulointerstitial damage (r= 0.65,P< 0.001 andrs= 0.59,P= 0.007, respectively), but not with the score for mesangial matrix expansion(r= 0.08,P= 0.72). MAP was significantly correlated only with the score for tubulointerstitial damage (rs= 0.63,P= 0.004). In multiple linear regression analysis of the histological changes and hemodynamics, the glomerulosclerosis score and the score for tubulointerstitial damage were correlated with PGC, but not with MAP.ConclusionThese clinical results support the speculation that glomerular hypertension is involved in the glomerulosclerosis and tubulointerstitial damage that occurs in IgA nephropathy.

ISSN:0263-6352    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

ObjectiveThere are two phenotypes of heart failure, systolic failure and isolated diastolic heart failure with preserved left ventricular systolic function. Although isolated diastolic heart failure frequently occurs, there are only models for diastolic dysfunction unassociated with heart failure and models with overt diastolic heart failure have not been established. We attempted to develop two different models, i.e. diastolic and systolic failure models, based on hypertension.Materials and methodsDahl salt-sensitive rats were placed on 8% NaCl diet from 7 weeks old (7-week starting group) or 8 weeks old (8-week starting group). As an age-matched control, Dahl salt-sensitive rats were consistently placed on normal chow. In these rats, echocardiogram was serially recorded, followed by hemodynamic and histological studies.ResultsThe 7-week starting rats showed a steep elevation in blood pressure and progressive left ventricular hypertrophy, and fell into overt heart failure at approximately 19 weeks. The development of heart failure was not associated with a decrease in left ventricular midwall fractional shortening or an increase in left ventricular end-diastolic dimension as compared with the age-matched control, which mimics the characteristics of clinically observed isolated diastolic heart failure. The 8-week starting rats showed a gradual rise in blood pressure and less progressive left ventricular hypertrophy, and fell into heart failure at approximately 26 weeks with a decrease in mid-wall fractional shortening and an increase in left ventricular end-diastolic dimension. Hemodynamic and histological studies at failing stage revealed comparable elevation of left ventricular end-diastolic pressure and comparable left ventricular fibrosis in both groups.ConclusionThese two different models of overt heart failure may be useful as models of isolated diastolic heart failure and systolic heart failure based on the same hypertensive heart disease, respectively, and may contribute to discrimination of the mechanisms of the development of the two different phenotypes of heart failure.

ISSN:0263-6352    

出版商:OVID    

年代:2000

数据来源: OVID

ISSN:0263-6352    

出版商:OVID    

年代:2000

数据来源: OVID