Blood Pressure In Diabetic Patients Research Articles

Diabetes and haemodynamic reactions to acute coronary occlusion

Background: The risk of early sudden death before hospital admission is higher in diabetic than non-diabetic men with acute myocardial infarction and autonomic nervous activity may modify the clinical outcome of abrupt coronary occlusion. Since diabetes mellitus may interfere with autonomic and myocardial function, we decided to study whether diabetes alters autonomic and haemodynamic responses to acute coronary occlusion. Methods: We analyzed the changes in heart rate, heart rate variability and blood pressure, and the occurrence of ventricular ectopy during a 2-min coronary occlusion in 238 non-diabetic and 32 diabetic patients referred for single vessel coronary angioplasty. The ranges of non-specific responses were determined by analyzing a control group of 19 patients with no ischaemia during a 2-min balloon inflation in a totally occluded coronary artery. Results: Diabetic patients were more often ( p<0.05) female, but there were no significant differences in the occluded vessel or incidence of ST changes or chest pain during coronary occlusion between the groups. Incidence of significant heart rate reactions and ventricular arrhythmias was comparable in both groups. Systolic blood pressure decreased ( p=0.01) in the diabetic patients during coronary occlusion, but did not change significantly in the non-diabetic group. Coronary occlusion caused more often (34% vs. 14%, p<0.01) a significant decrease in blood pressure in diabetic patients . Logistic regression models developed to analyze the significance of diabetes while controlling for baseline variables and signs of ischaemia identified diabetes to be an independent predictor of hypotensive reactions (odds ratio [OR] 2.9, 95% confidence intervals 1.1–7.8, p<0.05), while female gender and high short-term heart rate variability were other independent predictors of hypotensive reactions. Conclusions: Diabetic patients often develop significant hypotension during the early phase of acute coronary occlusion. This abnormality may be related to diabetic cardiomyopathy and impairment of baroreflex-mediated regulation of circulation. Predisposition to hypotension may contribute to the observed differences in the clinical presentation and outcome of acute coronary events.

Calcium antagonists in patients with type 2 diabetes and hypertension.

Hypertension is twice as common in patients with diabetes compared to those without diabetes. It accounts for up to 75% of cardiovascular disease risk leading to the substantial increase in morbidity and mortality. Control of blood pressure in people with diabetes has been shown in randomized controlled trials to decrease cardiovascular risk and improve outcome especially in preventing stroke. A target blood pressure goal of <130/80 mm Hg is currently recommended for patients with diabetes. However, less than 1/3 of these patients achieve such a goal. This is in part due to the inherent difficulty in controlling blood pressure in these patients where hypertension is usually associated with increased salt sensitivity, volume expansion and isolated systolic hypertension. Therefore, patients with diabetes usually require multiple medications for optimal blood pressure control. Calcium channel antagonists have been shown in large clinical trials to be both safe and effective in controlling blood pressure in diabetic patients and will continue to play a major role in the management of hypertension in this population, particularly in the combination therapy that these patients usually require.

Total plasma homocysteine is associated with hypertension in Type I diabetic patients

Although hyperhomocysteinaemia and methylenetetrahydrofolate reductase gene polymorphism are accepted risk factors for cardiovascular disease, their association with micro angiopathy or blood pressure in diabetic patients is still being debated. This study explores the relation between plasma homocysteine concentrations, methylenetetrahydrofolate reductase gene polymorphism, hypertension, diabetic microvascular and macrovascular complications associated with kidney function. Vascular complications, hypertension, methylenetetrahydrofolate reductase genotype (RFLP with Hinf I digestion), and total plasma homocysteine (HPLC) were investigated in 389 well-characterized Type I (insulin-dependent) diabetic patients with normal (GFR> or=75 ml x min(-1) x (1.73 m(2))(-1); n=273), or impaired renal function (GFR <75 ml x min(-1) x (1.73 m(2))(-1); n=116). Patients with microvascular and macrovascular complications showed higher total plasma homocysteine concentrations than those without complications. However, after the data for GFR (main determinant for plasma homocysteine) was adjusted we observed that plasma homocysteine concentrations greater than 8.6 micro mol/l in patients with normal GFR are not related to vascular complications, but to hypertension (8.6-11.3 micro mol/l: OR 1.9; >11.3 micro mol/l: OR 3.7). The risk for coronary heart disease (CHD) was also enhanced by a plasma homocysteine concentration greater than 11.3 micro mol/l (OR 5.9). Although the T allele was an independent determinant of plasma homocysteine, the methylenetetrahydrofolate reductase gene polymorphism was neither associated with diabetic vascular complications nor with hypertension. Increased plasma homocysteine concentrations but not the T allele per se, enhance the risk of hypertension and of CHD in Danish Type I diabetic patients with normal renal function.

Treatment of hypertension in type 2 diabetes mellitus--2002 update

Arterial hypertension and diabetes are potent independent risk factors for cardiovascular, cerebral, renal and peripheral (atherosclerotic) vascular disease. The prevalence of hypertension in diabetic individuals is approximately twice that in the non-diabetic population. Diabetic individuals with hypertension have a greater risk of macrovascular and microvascular disease than normotensive diabetic individuals. Hypertension is a major contributor to morbidity and mortality in diabetes, and should be recognized and treated early. Type 2 diabetes and hypertension share certain risk factors such as overweight, visceral obesity, and possibly insulin resistance. Life-style modifications (weight reduction, exercise, limitation of daily alcohol intake, stop smoking) are the foundation of hypertension and diabetes management as the definitive treatment or adjunctive to pharmacological therapy. Additional pharmacological therapy should be initiated when life-style modifications are unsuccessful or hypertension is too severe at the time of diagnosis. All classes of antihypertensive drugs are effective in controlling blood pressure in diabetic patients. For single-agent therapy, ACE-inhibitors, angiotensin receptor blocker, beta-blockers, and diuretics can be recommended. Because of concerns about the lower effectiveness of calcium channel blockers in decreasing coronary events and heart failure and in reducing progression of renal disease in diabetes, it is recommended to use these agents as second-line drugs for patients who cannot tolerate the other preferred classes or who require additional agents to achieve the target blood pressure. The choice depends on the patients specific treatment indications since each of these drugs have potential advantages and disadvantages. In patients with microalbuminuria or clinical nephropathy, both ACE-inhibitors and angiotensin receptor blockers are considered first line therapy for the prevention of and progression of nephropathy. Since treatment is usually life-long, cost effectiveness should be included in treatment evaluation.

Review: interventions that lower cholesterol concentrations or blood pressure in diabetic patients prevent cardiovascular disease

(2001) Am J Med 111, 633; Huang ES, Meigs JB, Singer DE. . The effect of interventions to prevent cardiovascular disease in patients with type 2 diabetes mellitus. . Dec...

Review: Interventions that lower cholesterol levels or blood pressure in diabetic patients prevent cardiovascular disease

Review: Interventions that lower cholesterol levels or blood pressure in diabetic patients prevent cardiovascular disease

Predictive value of ambulatory blood pressure in diabetic patients

Predictive value of ambulatory blood pressure in diabetic patients

The Role of Angiotensin II Receptor Antagonists in the Management of Diabetes

Diabetic nephropathy, which develops in about 30% of patients with diabetes, is a progressive condition. It is characterized by increased blood pressure, declining glomerular filtration rate and albuminuria. Lowering of blood pressure in diabetic patients is associated with reduced cardiovascular risk and renal protection. Inhibitors of angiotensin-converting enzyme (ACE) are the current gold standard treatment for hypertension in patients with type I diabetes because, in addition to their blood pressure lowering ability, they are thought to oppose the increased intraglomerular pressure that is mediated in part by angiotensin II. The angiotensin II receptor antagonists, a more recently developed class of antihypertensive agents, appear to be as effective as ACE inhibitors in delaying the progression of renal injury in animal models of diabetes. They act by selectively blocking the binding of angiotensin II to the AT 1 receptor and may, therefore, offer a more complete blockade of the renin-angiotensin system than ACE inhibitors. The renal and antihypertensive effects of this class of drug in patients with diabetes are now being investigated in long-term clinical trials. The multicentre Diabetics Exposed to Telmisartan And EnalaprIL (DETAIL) study is a randomized, double-blind, parallel-group comparison of the renal and antihypertensive effects of the angiotensin II receptor antagonist telmisartan and the ACE inhibitor enalapril in 272 patients with type II diabetes. The primary outcome is change in glomerular filtration rate over the 5 years of the study.

Treatment of elevated blood pressure in diabetic patients

rterial hypertension is a major contributor to A the secondary complications of diabetes. Moreover, prevention or treatment of hypertension reduces the incidence and progression of diabetic complications. In May 1993 the American Diabetes Association sponsored a Consensus Development Conference to emphasize the importance of detection and managment of hypertension in diabetes.’ The panel attempted to reach a consensus on an answer to the question: “What are the treatments for hypertension in diabetes, and what can be accomplished by treatment?” Consensus was reached concerning lifestyle modifications as the foundation of diabetic and hypertension management (Table 1).

Albuminuria in diabetes mellitus: Relation to ambulatory versus office blood pressure and effects of cilazapril

This study aimed to investigate the relationship between microalbuminuria and office blood pressure (BP) as compared with ambulatory BP in patients with diabetes mellitus under everyday practice conditions. It was also undertaken to assess the effect of the angiotensin converting enzyme inhibitor cilazapril on diabetes-associated albuminuria. Ambulatory BP was recorded during daytime in 54 patients with type II diabetes mellitus at the end of a 4-week period during which they received no vasoactive drug. The difference between office and ambulatory BP was unpredictable in the individual patient. There was no significant correlation between either ambulatory or office BP and urinary albumin/p5eatinine ratio. Fifty-one patients underwent a 40-week treatment with 5 mg/day of cilazapril. There was, in the absence of satisfactory BP control, the possibility of adding the calcium antagonist amlodipine (5 mg/day) from the 10th week onward and 12.5 mg/day of hydrochlorothiazide from the 20th week onward. Office mean BP was significantly reduced after 30 to 40 weeks of therapy in patients with normoalbuminuria (n = 19, -14%, P < .001), in those with microalbuminuria (n = 22, -6.6%, P < .01), as well as in those with clinical proteinuria (n = 9, -11.4%, P < .01). During the same time, the urinary albumin/creatinine ratio was not modified in normoalbuminuric patients (n = 19, +24.6%, P = .72) as well as in those with clinical proteinuria (n = 9, -29.4%, P = .09). On the other hand this value was significantly reduced for the group with microalbuminuria (n = 23, -24.3%, P < .05). In the overall population, as well as in hyperalbuminuric patients (patients with microalbuminuria + patients with clinical proteinuria), the reduction of the albumin/ creatinine ratio was also significant (n = 51, -7%, P < .01 and n = 32, -25,7%, P < .01, respectively). In conclusion, the findings of this study performed by practicing physicians show that ambulatory BP may differ greatly from office BP in diabetic patients. They also indicate that urinary albumin excretion is poorly correlated with office and ambulatory BP in type II diabetics. Finally, they demonstrate the antiproteinuric action of prolonged treatment with the angiotensin converting enzyme inhibitor cilazapril, whether given alone or combined with amlodipine.

Relationship between diastolic hypertension and myocardial morphology and function in elderly males with diabetes mellitus.

The existence of a distinct diabetic cardiomyopathy, characterized by a raised left ventricular mass, has previously been suggested. However, as diabetes mellitus is associated with both left ventricular hypertrophy and hypertension a confounding effect of raised blood pressure in diabetic patients has to be considered. In the present cross-sectional study an echocardiographical examination was performed as part of a health screening survey in 582 males, aged 70 years. After the exclusion of subjects with coronary heart disease or those on regular antihypertensive treatment, 30 normotensive subjects with diabetes were compared with 10 subjects with non-insulin-dependent diabetes (NIDDM) and a diastolic blood pressure 90 mm Hg or more and 203 normotensive control subjects with normal glucose tolerance. Both groups with NIDDM showed a significantly increased left atrial diameter (4.4 +/- 0.7 vs 4.0 +/- 0.5 cm, p < 0.05) and an increased atrial component in diastole (A-wave, p < 0.01) compared to the control subjects. Left ventricular mass was, however, only marginally and not significantly elevated in the diabetic subjects when compared to the healthy control subjects (133 +/- 19 and 133 +/- 28 vs 128 +/- 25 g/m2). Only in the subjects with concomitant diabetes and a raised blood pressure was the intraventricular septum significantly enlarged (p < 0.05). Thus, in the present sample no distinct diabetic cardiomyopathy with an increased left ventricular mass, independent of the influence of hypertension could be detected. The myocardial alterations in these diabetic males were restricted to an increased left atrial size and an impaired diastolic function.

Pain intensity and blood pressure reactions during a cold pressor test in IDDM patients.

To determine the contribution of altered pain perception to the impaired blood pressure reactions during a cold pressor test in diabetic patients. Reduced blood pressure increases have been observed in diabetic patients during a cold pressor test and have been attributed to an impaired efferent sympathetic function. We investigated pain intensities and blood pressure reactions simultaneously during a cold pressor test in 30 IDDM patients (diabetes duration 12 +/- 6 years, HbA1c 7.5 +/- 1.4%) and in 30 normal control subjects with comparable sex distribution, age, height, BMI, physical fitness, and smoking habits. Initial pain intensities and respective time courses did not differ between the two groups. The initial blood pressure response was significantly smaller in diabetic patients (P < 0.002). Correlations of diastolic blood pressure increases in diabetic patients with initial pain intensity, standard cardiovascular reflex tests, age, clock time, smoking habits, disease duration, and actual blood glucose concentrations did not reach statistical significance. Pain intensity and diastolic blood pressure increases, however, were correlated to HbA1c concentrations in diabetic patients. Impaired pain perception is not the cause of the impaired reactions of blood pressure in diabetic patients during the cold pressor test, leaving very early deterioration of either cerebral processing of pain stimuli, cardiac function, efferent sympathetic nerves, or decreased vascular reactivity as possible explanations.

Diurnal blood pressure variations in normoalbuminuric type 1 diabetic patients

To test the hypothesis that normoalbuminuric type 1 diabetic patients segregate into groups with normal and elevated ambulatory blood pressure. To evaluate diurnal variation of blood pressure assessed by individual or fixed night-time periods. Cross-sectional study. Tertiary referral centre. Inclusion criteria for type 1 diabetic patients (n = 33): normal urinary albumin excretion (UAE age < 45 < 20 micrograms min-1), diabetes duration < or = 20 years, age 45 years. Healthy controls (n = 33) were matched for sex and age. Twenty-four hour, day-time, night-time and night/day ratio of ambulatory blood pressure. Twenty-four-hour blood pressure in diabetic patients did not differ significantly from a normal distribution. The 24-h systolic blood pressure was higher in diabetic patients than in healthy controls (difference: 6 mmHg, 95% confidence interval (CI) from 1 to 10 mmHg, P < 0.05), while no significant differences were found for diastolic values. The 24-h systolic blood pressure in diabetic patients with UAE above the median value (5.8 micrograms min-1) was higher than for those with lower UAE (difference: 7 mmHg, 95% CI from 0.5 to 13 mmHg, P < 0.05). The night/day ratio of diastolic blood pressure based on individual informations of the night period was (mean +/- SD) 80 +/- 6% in diabetic patients and 78 +/- 8% in controls (difference: 2%, 95% CI from -1 to 5%, not significant [NS]). This ratio increase significantly (P < 0.00001) to 90 +/- 5% in diabetes and to 84 +/- 7% in controls if a fixed night period from 22.30 hours to 06.30 hours was assumed. It was not possible to identify a well-separated group of normoalbuminuric type 1 diabetic patients with elevated ambulatory blood pressure. Values of UAE above the median in diabetic patients are associated with higher ambulatory blood pressure. Assessment of the night/day variation from fixed time-points should be abandoned because this leads to a serious underestimation of the nocturnal reduction in blood pressure.

ACE inhibitors and diabetic nephropathy: clinical and experimental findings

Apart from near normal metabolic control, early treatment of an increase in blood pressure in diabetic patients with nephropathy, is one of the most important therapeutic methods to prevent further progression of this complication. Long-term studies, recently published, suggest that ACE inhibitors have a beneficial effect on albuminuria and progression of nephropathy, irrespective of their hemodynamic effects. However, the mechanism by which ACE inhibitors exert these positive effects on glomerular pathology is still unclear. Several non-hemodynamic factors have been identified as being involved in the pathogenesis of diabetic nephropathy: (a) changes in the composition of glomerular basement membrane due to a changed metabolism of the proteins which make up this structure; consequences are an impairment of the filtration properties, onset of proteinuria as well as thickening of basement membrane; (b) Mesangial expansion due to an overproduction of mesangial matrix and deposition of proteins as well as (c) impairment of mesangial clearance function; consequences are development of glomerulosclerosis and reduction of filtration surface. It is known that the renin-angiotensin-system is stimulated in diabetic patients with nephropathy and that angiotensin II influences the synthesis of glomerular and mesangial proteins as well as the function of mesangial cells. Hypothetically, these points could explain the beneficial effects of ACE-inhibitors on the progression of diabetic nephropathy.

Angiotensin converting enzyme inhibitors versus calcium antagonists in the treatment of diabetic hypertensive patients.

Angiotensin converting enzyme inhibitors and calcium antagonists are effective agents for controlling high blood pressure in diabetic patients. We selected 30 type II diabetic patients with proteinuria and evaluated the effect of these drugs on renal function and proteinuria. In a double-blind trial, patients received either 40 mg/day enalapril or 40 mg/day nifedipine during 12 months. They also received a hypoproteic diet with 0.8 g/kg wt/day of protein. In the enalapril group (10 men and eight women), mean arterial blood pressure was 112.0 +/- 12 mm Hg, creatinine clearance was 58.6 +/- 12.4 ml/min, and 24-hour proteinuria was 4.36 +/- 3.23 g/24 hr before treatment. After treatment, mean arterial blood pressure was 82.0 +/- 8.30 mm Hg (p less than 0.001), creatinine clearance was 66.6 +/- 13.8 ml/min (NS), and 24-hour proteinuria was 0.56 +/- 0.78 g/24 hr (p less than 0.001). In the nifedipine group (six men and six women), mean arterial blood pressure was 114.0 +/- 8.0 mm Hg, creatinine clearance was 67.8 +/- 19.6 ml/min, and 24-hour proteinuria was 2.84 +/- 1.31 g/24 hr before treatment. After treatment, mean arterial blood pressure was 86.0 +/- 7.0 mm Hg (p less than 0.001), creatinine clearance was 51.4 +/- 7.9 ml/min (p less than 0.001), and 24-hour proteinuria was 2.66 +/- 0.89 g/24 hr (NS). These results show a similar hypotensive action and different renal effects between these two drugs after 12 months of treatment.

Loss of nocturnal decline in blood pressure in diabetic patients with autonomic neuropathy.

We investigated loss of the nocturnal decline in blood pressure (BP) and its mechanism in diabetes mellitus with autonomic neuropathy (ANP). BP was measured every 30 min using ambulatory BP recorders in 52 diabetic patients and 11 nondiabetic controls. As an index of autonomic nervous dysfunction, CVRR (the coefficient of variation of the R-R interval on ECGs) and diastolic blood pressure response on standing were measured. Plasma volume (PV) was measured with RISA. The difference between daytime mean BP (09:00 to 13:00) and nighttime mean BP (01:00 to 05:00) was analyzed. The normal control group showed a significant reduction in mean BP during the nighttime (-12.8 +/- 7.5 mmHg) as compared with the DM group (-3.3 +/- 8.6 mmHg, p < 0.001). The diabetic patients with loss of the nocturnal decline in blood pressure showed autonomic nervous dysfunction and increased PV. In conclusion, the nocturnal elevation of blood pressure might result from an imbalance between reduced tone of sympathetic and parasympathetic functions in addition to the postural effect and increased plasma volume present in diabetic patients.

Reduced glomerular filtration rate and cardiovascular damage in diabetes: a key role for abnormal albuminuria

There is general agreement that a fall rate in glomerular filtration rate (GFR) is the principal endpoint in diabetics with renal disease, and that abnormal albuminuria (including microalbuminuria) is an important intermediate end-point. The relative roles of blood pressure (BP) elevation and abnormal albuminuria in the prediction and genesis of renal disease are a matter of debate, and are further analysed in this paper. New studies show that neither genetic predisposition to hypertension (parental BP) nor parental abnormal albuminuria can be used to predict renal disease in patients with type 1 (insulin-dependent) diabetes. However, parental predisposition to proteinuria seems to be important to certain types of patients with type 2 (non-insulin-dependent) diabetes. Cross-sectional as well as follow-up studies document that GFR is generally well preserved in microalbuminuria (in both type 1 and type 2 patients), while the transition to clinical proteinuria is associated with a decline in GFR. Thus, prevention of overt proteinuria is important in clinical trials in microalbuminuric patients. In type 1 diabetes clear ultrastructural changes have been documented with microalbuminuria and a good correlation between abnormal albuminuria and structural damage is seen. Structural damage in normo- and microalbuminuric patients correlates poorly with BP. New studies in type 1 diabetes document that microalbuminuria (but not elevated BP) predicts not only clinical diabetic nephropathy but also end-stage renal failure and mortality. In type 2 diabetes microalbuminuria is the strongest predictor of mortality, whereas BP elevation is not a predictor. Several studies now document that antihypertensive treatment, especially with inhibitors of angiotensin converting enzyme, is able to reverse or reduce abnormal albuminuria, even in non-hypertensive type 1 patients, and possibly preserve GFR. Therefore, microalbuminuria may be the main indicator for starting antihypertensive treatment in these patients. With respect to organ damage in the retina, abnormal albuminuria is an important indicator of the risk of severe diabetic retinopathy. BP elevation seems not to be an initiating factor, but rather aggravates established retinopathy. Left ventricular hypertrophy has a stronger correlation with BP elevation than normoalbuminuria, suggesting that left ventricular hypertrophy is at least partially a phenomenon secondary to elevated BP in diabetic patients with abnormal albuminuria. Generally, abnormal albuminuria is a strong indicator of cardiovascular renal damage in diabetic patients and in most organs is a stronger factor than elevated BP.

Circadian Pattern of Blood Pressure in Diabetic Patients with Hypertension; Relationship to Diabetic Complications

Circadian Pattern of Blood Pressure in Diabetic Patients with Hypertension; Relationship to Diabetic Complications

Management of hypertension in the patient with diabetes mellitus. Focus on the use of angiotensin-converting enzyme inhibitors.

Hypertension in patients with diabetes mellitus increases the risk of both macrovascular and microvascular complications. Such microvascular complications as diabetic nephropathy and retinopathy are accelerated in the presence of arterial hypertension. Evidence suggests that the complications of diabetes mellitus begin early in the course of the disorder as manifested by microalbuminuria and increased vascular reactivity. These findings are accompanied by changes in the renin-angiotensin-aldosterone system including reductions in plasma renin activity. These changes could be secondary to volume expansion that may be a direct consequence of elevated blood glucose, suggesting that the metabolic disorder in diabetes contributes to the etiology of hypertension in these patients. Adequate treatment of hypertension is crucial to the prevention of complications; however, many antihypertensive agents have limited usefulness in diabetes mainly because of their unfavorable side effects. Diuretics lower blood pressure in hypertensive diabetics, but their metabolic effects are especially undesirable in this population. beta-Blockers alter glucose and lipid metabolism in diabetic patients and reduce regional blood flow. Central acting agents and alpha-blockers are often associated with orthostatic hypotension, sexual dysfunction, and central nervous system side effects. Angiotensin-converting enzyme inhibitors (ACEIs) such as captopril effectively lower blood pressure in diabetic patients and have few unwanted effects. They may improve metabolic control and have favorable effects on glucose metabolism. The ACEIs also produce improved regional hemodynamics which may lead to the improvement in or prevention of the progression of diabetic nephropathy.

The favorable influence of adequate (higher) carbohydrate diets on the blood pressure of diabetic patients: Sansum, W. D.: South. Med. J. 29: 414, 1936

The favorable influence of adequate (higher) carbohydrate diets on the blood pressure of diabetic patients: Sansum, W. D.: South. Med. J. 29: 414, 1936