Undiagnosed dysglycaemia and inflammation in cardiovascular disease.

BACKGROUND: Cardiovascular (CV) disease is associated with increased levels of glucose, but the prevalence of dysglycaemia in CV diseases is not fully known. The study examined the prevalence of unknown dysglycaemia and its association with inflammation in Caucasian patients with ischaemic vascular complications, i.e. coronary artery disease (CAD), cerebrovascular disease (CVD) and peripheral artery disease (PAD). MATERIALS AND METHODS: This case-controlled study involved 149 patients (mean age 68 years) hospitalized for CAD, PAD or CVD and 59 control-subjects (CTR) free from CV-disease. The prevalence of dysglycaemia according to WHO/ADA criteria (impaired fasting glycaemia, impaired glucose tolerance or diabetes mellitus) was assessed by a 75-g oral glucose tolerance test. Inflammatory parameters were analyzed in fasting samples. RESULTS: Dysglycaemia was found in 49%, 55% and 57% of patients with CAD, CVD and PAD, respectively; all were significantly higher than among the controls (29%). The odds ratio (95% CI) for being dysglycaemic were 1.7 (1.04-2.77), 1.9 (1.19-3.06) and 2.0 (1.25-3.19) for CAD, CVD and PAD, respectively. Inflammatory markers (the total leucocyte count, soluble tumour necrosis factor-receptor type I, C-reactive protein) were elevated in patient groups and tended to increase with increasing blood glucose levels in all groups. The levels of the anti-inflammatory cytokine transforming growth factor-beta1 and insulin-like growth factor binding protein 3 were lowered in patients with CAD and, in patients with PAD, the former was inversely related to the levels of the blood glucose. CONCLUSIONS: Undiagnosed dysglycaemia was common in patients with ischaemic CV manifestations regardless of vascular bed involved. Inflammation was associated in a dosage-related manner to glucose levels.

Lung function, smoking and mortality in a 26-year follow-up of healthy middle-aged males.

Lung function has been associated with mortality after adjusting for other risk factors; however, few studies have adjusted for physical fitness and reported separate analyses according to smoking status. In 1972-1975, spirometry, clinical and physiological parameters were recorded in 1,623 apparently healthy males aged 40-59 yrs. After 26 yrs of follow-up, the current authors investigated the association between baseline lung function and mortality, adjusting for smoking, physical fitness and other potential factors. By 2000, 615 individuals (38%) had died, with 308 (50%) of these deaths from cardiovascular (CV) causes. Forced expiratory volume in one second was a predictor of all-cause mortality (risk ratio (RR) 1.10 per reduction of 10%) after adjusting for smoking, physical fitness, age, systolic blood pressure, body mass index and serum cholesterol. The corresponding multivariate RR was 1.07 for CV causes and 1.34 for respiratory death. In conclusion, in stratified analyses among current and former smokers, forced expiratory volume in one second % predicted was a strong independent predictor of all-cause mortality and respiratory death among current smokers. Forced expiratory volume in one second % predicted was not associated with mortality among never-smokers.

Interaction between chemokines and oxidative stress: possible pathogenic role in acute coronary syndromes.

OBJECTIVES: We sought to study the relationships between chemokines and oxidative stress in acute coronary syndrome. BACKGROUND: In view of existing knowledge on the participation of leukocytes and oxidative stress in the pathogenesis of acute coronary syndrome, we hypothesized that chemokines may play a role in recruiting and activating leukocytes in this disorder. METHODS: The levels of chemokines and oxidative stress were studied in 38 patients with stable and 38 with unstable angina and in 20 controls. In separate in vitro experiments the effect of chemokines on reactive oxygen species in monocytes and the effect of antioxidants on chemokine levels in these cells were also studied. RESULTS: 1) Angina patients had raised serum levels of chemokines in both cross-sectional and longitudinal testing, with particularly high levels of interleukin (IL)-8, monocyte chemoattractant protein (MCP)-1 and macrophage inflammatory peptide (MIP)-1-alpha in unstable disease. 2) T cells, and particularly monocytes, seem to contribute to the raised IL-8, MCP-1 and MIP-1-alpha levels in unstable angina. 3) Concomitantly, and significantly correlated with MCP-1 and IL-8 levels, stable and particularly unstable angina patients had decreased plasma levels of antioxidants and increased lipid peroxidation, suggesting enhanced oxidative stress. 4) Monocyte chemoattractant protein-1 enhanced the generation of O2- in monocytes from unstable angina patients, and the antioxidant glutathione-monoethyl ester suppressed the production of IL-8 and MCP-1 in these cells. CONCLUSIONS: Our findings suggest an interaction between chemokines and oxidative stress in unstable angina. This interaction may represent a vicious circle involved in the pathogenesis of acute coronary syndromes.

Enhanced levels of soluble and membrane-bound CD40 ligand in patients with unstable angina. Possible reflection of T lymphocyte and platelet involvement in the pathogenesis of acute coronary syndromes.

BACKGROUND: The CD40 ligand (CD40L) on activated T cells and platelets may be activating matrix metalloproteinases, inducing procoagulant activity, and be involved in the pathogenesis of acute coronary syndromes by promoting plaque rupture in atheroma. METHODS AND RESULTS: To study the role of CD40L-CD40 interaction in coronary disease, we analyzed levels of soluble (s) and membrane-bound CD40L in the peripheral blood from 29 patients with stable angina, 26 with unstable angina, and 19 controls. Our main findings follow. (1) Patients with unstable angina had significantly raised serum levels of sCD40L when compared with patients with stable angina and controls. (2) Platelets could release large amounts of sCD40L when stimulated ex vivo with the thrombin receptor-agonist peptide SFLLRN in both patients and controls. (3) Platelets in patients with unstable angina were characterized ex vivo by decreased intracellular levels and decreased SFLLRN-stimulated release of sCD40L, which may possibly represent a higher percentage of degranulated platelets in these patients. (4) T cells in patients with unstable angina had enhanced surface expression of CD40L and increased release of sCD40L on anti-CD3/anti-CD28 stimulation in vitro when compared with patients with stable angina and controls. (5) Recombinant CD40L and serum from patients with unstable angina who had high sCD40L levels induced enhanced release of monocyte chemoattractant peptide-1 from mononuclear cells, a CC-chemokine involved in the pathogenesis of atherosclerosis. CONCLUSIONS: This first demonstration of enhanced levels of soluble and membrane-bound forms of CD40L in angina patients, with particularly high levels in patients with unstable angina, suggests that CD40L-CD40 interaction may play a pathogenic role in both the long-term atherosclerotic process and in the triggering and propagation of acute coronary syndromes.

Fasting blood glucose: an underestimated risk factor for cardiovascular death. Results from a 22-year follow-up of healthy nondiabetic men.

OBJECTIVE: Because of the available conflicting epidemiological data, we investigated the possible impact of fasting blood glucose as a risk factor for cardiovascular death in nondiabetic men. This study reports the results from a 22-year prospective study on fasting blood glucose as a predictor of cardiovascular death. RESEARCH DESIGN AND METHODS: Of the 1,998 apparently healthy nondiabetic men (aged 40-59 years), a total of 1,973 with fasting blood glucose < 110 mg/dl were included in the study in which also a number of conventional risk factors were measured at baseline. RESULTS: After 22 years of follow-up, 483 men had died, 53% from cardiovascular diseases. After dividing men into quartiles of fasting blood glucose level, it was found that men in the highest glucose quartile (fasting blood glucose > 85 mg/dl) had a significantly higher mortality rate from cardiovascular diseases compared with those in the three lowest quartiles. Even after adjusting for age, smoking habits, serum lipids, blood pressure, forced expiratory volume in 1 s, and physical fitness (Cox model), the relative risk of cardiovascular death for men with fasting blood glucose > 85 mg/dl remained 1.4 (95% CI 1.04-1.8). Noncardiovascular deaths were unrelated to fasting blood glucose level. CONCLUSIONS: Fasting blood glucose values in the upper normal range appears to be an important independent predictor of cardiovascular death in nondiabetic apparently healthy middle-aged men.

Effect of bolus injection versus continuous infusion of furosemide on diuresis and neurohormonal activation in patients with severe congestive heart failure.

Previous studies have demonstrated that continuous infusion of furosemide results in increased diuresis and natriuresis compared with bolus administration of the drug in patients with severe heart failure. We reasoned that continuous infusion of furosemide caused less activation of neurohumoral mechanisms, since other studies have shown that bolus administration of furosemide may activate this system. We therefore tested the hypothesis that continuous administration of furosemide would increase water and sodium excretion due to less activation of neurohormones. Eight patients with severe heart failure were studied during continuous infusion over 24 h and bolus injections of furosemide twice daily in a randomized cross-over study. Bolus administration of furosemide increased diuresis and natriuresis significantly in the first 4 h after administration compared with continuous administration, but this was later reversed, resulting in similar 24 h total output. The neurohormones measured at baseline were all markedly elevated. Neither regimens of furosemide caused any further significant changes in neurohumoral response except that pro-ANF decreased more during the first 8 h after bolus administration compared to continuous infusion. This study has demonstrated that bolus administration of furosemide in conventional doses is equally effective as continuous intravenous infusion in patients with severe heart failure. This may be due to maximal neurohormonal activation in severe heart failure (NYHA III-IV) which could not be further activated by bolus administration.