The impact of coexistent diabetes on the prevalence of coronary heart disease.

The increased risk of developing cardiovascular disease in diabetic population has been well documented, but the prevalent mechanism of this susceptibility is still only partly explained. We compared the impact of diabetes on ischemic heart disease in patients hospitalized in a public general hospital over a 10-year period. The prevalence of coronary heart disease (CHD) was consistently higher among diabetic population [namely, among non-insulin-dependent diabetes mellitus (NIDDM) patients] when compared with the nondiabetic population. The prevalence was similar in both genders, increasing with age, and was independent from body-mass index, history of smoking, metabolic control, or lipid pattern. Heart rate and blood pressure levels were significantly higher in NIDDM patients with CHD; similarly, there was a significant association between ischemic heart disease and atherosclerotic peripheral artery disease prevalence, and this trend was observed even in subjects with impaired glucose tolerance. These observations support the evidence that diabetes exerts a deleterious effect on general risk factors of atherosclerosis and increases susceptibility to cardiovascular disease by itself as an "independent" risk factor; on the other hand, the epidemiological evidence of an excessive occurrence of type II diabetes in individuals with pre-existing vascular disease suggests a genetically determined link between metabolic disturbances and cardiovascular disease.

[Cardiovascular "risk" and diabetes mellitus. Results of a retrospective study]. / "Rischio" cardiovascolare e diabete mellito. Risultati di uno studio retrospettivo.

BACKGROUND: To examine the relationship of non-insulin dependent diabetes mellitus (NIDDM) with the prevalence of coronary heart disease (CHD) in a hospitalized population. METHODS AND RESULTS: Diabetes was associated with a markedly increased risk of developing CHD, whose prevalence was of 48.3% in NIDDM subjects (528 males and 661 females). Between the two groups (with and without CHD) of diabetic patients, the mean age was higher in the CHD-group, but no differences were noted with regard to gender distribution, BMI, history of cigarette smoking, alcohol consumption, glycemic control, hypoglycemic treatment, lipid pattern (although a slight increase in mean level of serum total triglycerides was observed in NIDDM subjects with CHD). On the contrary, CHD was significantly associated with a higher prevalence of periferal vascular disease (49.3% vs 32.5%) and with hypertension and renal dysfunction. CONCLUSIONS: These observations support the evidence that diabetes exerts a deleterious effect on general risk factors of atherosclerosis and increases the susceptibility to cardiovascular disease, although the prevalent mechanism of this susceptibility is only partly explained. Because the adverse "independent" effect of diabetes on the risk of cardiovascular disease is amplified in the presence of other cardiovascular risk factors, these data underscore the importance of prevention of diabetes and, once diabetes is clinically established, the need for standard risk factors management (hypertension, obesity, elevated lipid levels) as well as the development of new therapeutic strategies, in order to reduce the progress of macrovascular disease and the hemostatic derangements which may predispose to thrombosis and endothelial cell injury.

Circulating endothelin-1 levels in type 2 diabetic patients with ischaemic heart disease.

To investigate whether circulating endothelin-1 (Et-1) may be related to the increased incidence and severity of ischaemic heart disease in type 2 diabetes mellitus, we compared the concentrations in type 2 diabetic patients and in non-diabetic patients with coronary artery disease (CAD) angiographically documented. Plasma levels of Et-1 were determined in 34 type 2 diabetic patients with CAD (16 with stable angina, 6 with unstable angina, 12 with previous myocardial infarction) and in 19 nondiabetic patients with CAD (4 with stable angina, 5 with unstable angina, 10 with previous myocardial infarction). Fifteen diabetic patients without CAD and 9 healthy volunteers served as control subjects. In the type 2 diabetic patients, the mean Et-1 levels were 3.19 +/- 1.61 pmol/l in those with stable angina, 3.58 +/- 1.92 pmol/l in those with unstable angina, 4.24 +/- 2.53 pmol/l in those with myocardial infarction. These values were not significantly different one another, nor from the values obtained from type 2 diabetic controls (3.64 +/- 2.13 pmol/l). In the non-diabetic patients, the mean Et-1 levels were 3.92 +/- 0.73 pmol/l in those with stable angina, 4.35 +/- 1.67 pmol/l in those with unstable angina, 4.33 +/- 1.66 pmol/l in those with myocardial infarction. These values were not significantly different one another, but significantly higher than those obtained from healthy controls (2.07 +/- 0.67 pmol/l; P < 0.001). No significant differences were found in Et-1 levels between diabetic and non-diabetic patients with stable, unstable angina and previous myocardial infarction. In contrast, a statistically significant difference was found in Et-1 levels between diabetic and non-diabetic control subjects (P < 0.05). In conclusion, similar raised concentrations of Et-1 in diabetic and non-diabetic patients with stable, unstable angina and previous myocardial infarction do not support the hypothesis that higher levels of Et-1 in diabetic patients are responsible for the increased incidence of CAD in diabetes mellitus. However, the raised Et-1 levels found in diabetic patients in the absence of CAD strongly suggest that a generalised endothelial dysfunction, documented in our study by increased levels of Et-1, most probably precedes subsequent cardiovascular diseases.

[Hypertension at the threshold of the year 2000: classification, treatment, prevention]. / La malattia ipertensiva alle soglie del 2000. Classificazione, trattamento, prevenzione.

Despite the clear benefits of treating established hypertension, this approach alone will not prevent all of the blood pressure-related cardiovascular-renal disease in the community. Primary prevention of hypertension is a natural extension of hypertension treatment which provides opportunity to reduce costly cycle of managing hypertension and its complications. The purpose of this report is to guide practician physicians and health professionals in their care of hypertensive patients. In order to provide specific guidelines, a new classification schema of high blood pressure that includes systolic as well diastolic levels is proposed (source, Joint National Committee on Detection, Evaluation and Treatment of High Blood Pressure 1993). Furthermore, recommendations for follow-up based on initial set of blood pressure measurements, life-style modifications and pharmacologic therapy are proposed, suggesting a new treatment algorithm in which diuretics and beta-blockers are preferred as first-choice agents because their confirmed reduction in morbidity and mortality (unless they are contraindicated or unacceptable), but including an expanded list of agents that are suitable for initial monotherapy and guidelines for selecting and individualizing the antihypertensive drug regimen.

Plasma levels of atrial natriuretic peptide and hemodynamic function in cardiac disease.

Plasma concentrations of atrial natriuretic peptide were measured in eight patients with cardiac disease but normal resting right atrial pressure, during cardiac catheterization. No patient had clinical evidence of overt heart failure. An increase in peptide concentrations was observed between the aorta or the peripheral vein and the pulmonary artery. A linear relation was found between peripheral vein and pulmonary artery peptide concentration. Mean pulmonary artery and capillary wedge pressure also correlated with the peptide levels. No correlation was observed between mean right atrial pressure and peptide concentration. These findings demonstrate that atrial natriuretic peptide release, even in the absence of cardiac failure, seems at least partly regulated by left atrial pressure. Finally, peripheral levels reflect the central concentrations of atrial natriuretic peptide.

Effects of moderate low sodium/high potassium diet on essential hypertension: results of a comparative study.

It is generally accepted that a significant restriction in sodium intake can lower blood pressure in hypertensive patients and more recently it has also been suggested that a high potassium intake can exert an antihypertensive effect. We have therefore, conducted a double-blind, randomized, cross-over study to evaluate the antihypertensive efficacy of the combination of a modest dietary sodium restriction and a high potassium intake in hypertensive patients of mild and moderate degrees. During the modest sodium (100 mmol/day)/high potassium (130 mmol/day) diet the blood pressure was significantly reduced (-17/-6 mmHg) when compared to the normal diet (160 mmol Na/day and 80 mmol K/day). The blood pressure reduction did not interfere with hemodynamic and humoral responses to dynamic exercise. The modest reduction in sodium intake and increase in potassium content in the diet was well tolerated by the patients.

Effects of dynamic exercise and metabolic control on left ventricular performance in insulin-dependent diabetes mellitus.

In subclinical diabetic cardiomyopathy, previous reports did not positively correlate the altered cardiac performance with metabolic parameters. Fifteen insulin-dependent diabetic subjects, without any clinical or instrumental evidence of heart diseases, were studied. Signs of diabetic microangiopathy were absent. Systolic time intervals, metabolic and hormonal parameters (blood glucose, free fatty acids, blood lactate and plasma norepinephrine) were evaluated at rest and after dynamic exercise during poor (MAGE 6.36 +/- 0.72 mmol/l) and good (MAGE 3.46 +/- 0.66 mmol/l) metabolic control, obtained by means of insulin therapy. Rest values of systolic time intervals were normal during poor and good metabolic control. After exercise, pre-ejection period/left ventricular ejection time ratio increased mainly during poor control as a result of an increased pre-ejection period: conversely, a smaller increase in pre-ejection period/left ventricular ejection time ratio occurred during good metabolic control. The exercise induced free fatty acids utilization did not occur during poor control as it occurred during good control. The percentage of increments in blood lactate was virtually identical in ketotic and non-ketotic patients and in normal subjects. High norepinephrine plasma levels were observed both at rest and during dynamic exercise in poorly controlled diabetic patients. Conclusively, testing of systolic time intervals after exercise might be useful in the detection of preclinical diabetic cardiomyopathy. The decreased cardiac functional reserve observed during poor control might be related to an altered energetic fuel utilization.

The relationship between potassium balance and circulating catecholamines in essential hypertension.

A study of neuroendocrine trend and electrolytes balance was carried out in 29 patients with essential hypertension and 20 normotensive controls. Based on plasma norepinephrine (NE) resting values to subgroups of hypertensives were defined, one in the "normal" range (NE less than 268 pg/ml) and one in the "high" range (NE greater than 268 pg/ml). In response to graded exercise the "high" NE hypertensive patients showed a mean NE increase significantly higher than both normal controls and "normal" NE hypertensives (p less than 0.05). No significant differences in the electrolytes excretion rates were found between the two subsets, but only in the hyper-noradrenergic hypertensives a negative correlation between potassium excretion and circulating NE levels was observed (r = -0.68; p less than 0.005). These findings suggest that in the hypertensive population there is a not negligible proportion of patients with elevated NE levels under basal conditions which are, moreover, hyper-responsive to stressful situations. This abnormal sympathetic function could be probably related to the state of potassium balance.

[The neuroendocrine response to Alfatesine or Ethrane anesthesia in humans]. / La réponse neuro-endocrinienne chez l'homme à l'anesthésie par alfatésine ou éthrane.

The description of neuro-endocrine effects due to surgical stress and certain anaesthetic products led the authors to look for the action of alfadione and enflurane on the hypothalamic-hypophyseal-thyroidian-adrenal axis. Taking 20 subjects who were divided into three groups of 10, the authors measured the plasma levels of T3, T4, TSH, cortisol and ACTH during anaesthesia with alfadione (without surgery). This was group I. Group II were patients during surgery under alfadione. Group III was during surgery under enflurane. The results show the absence of significant changes in the plasma levels of the hormones measured. The authors conclude that alfadione changes the levels of T3, T4, TSH and cortisol even less than does enflurane, whether the anaesthesia is isolated or in a patient undergoing surgery.