Elisabetta Campana

The relationship between glycated hemoglobin and polymorphonuclear leukocyte leukotriene B4 release in people with diabetes mellitus

In order to evaluate polymorphonuclear leukocyte (PMN) activity in diabetes mellitus, leukotriene B4 (LTB4) levels were measured in sixty patients, 31 affected with Type 1 diabetes mellitus and 29 affected with Type 2 diabetes mellitus. The LTB4 levels (12.1+/-0.2 pg/100 microl) in diabetic patients were higher compared to those of the control group (7.9+/-0.1 pg/100 microl) (P < 0.001), and remained significantly higher (P < 0.001) (12.8+/-0.2 pg/100 microl) than in the control group (11.0+/-0.2 pg/100 microl) after stimulation with calcium ionophore. A significant and positive correlation between glycated hemoglobin and LTB4 was demonstrated (P < 0.001, r = 0.80). This study demonstrates that in diabetic patients there is a PMN activation and that this activation is correlated to glycated hemoglobin level.

ET-1 Plasma Levels During Cold Stress Test in Sclerodermic Patients

Endothelial cell injury in blood vessels of small arteries and capillaries is considered the primary event in the pathogenesis of systemic sclerosis (SSc). Because endothelin-1 (ET-1) is mainly released in the site of endothelial cell damage, thereby inducing a potent vasoconstriction, it was our intention to study ET-1 release in a group of SSc patients during a cold pressor test (CPT). Twelve SSc patients and a control group of 10 healthy subjects underwent CPT. Blood samples for ET-1 assay were collected at 90 and 180 seconds of exposure to cold stress. Heart rate and blood pressure were recorded at the same intervals. A capillaroscopic examination was performed in both groups before and after CPT. We observed significantly higher levels of plasma ET-1 in SSc patients compared with those of the control group at baseline (P=0.007) and at 90 (P=0.006) and 180 seconds (P=0.03) of CPT. During the test, the capillaroscopic examination showed a dramatic worsening of the vascular picture that was parallel to the increase in ET-1 plasma levels. This suggests that higher ET-1 plasma levels can have a part in the acute vascular reac tivity of SSc patients undergoing CPT.

PLASMA ATRIAL NATRIURETIC HORMONE IN HYPERTHYROIDISM

In 22 hyperthyroid patients, atrial natriuretic hormone (ANH) levels (71.91 +/- 21.03 pg/ml), measured during a 3-h-Holter, were found to be significantly higher (p < 0.001) than those in 20 age-matched normal subjects (37.22 +/- 8.73 pg/ml). We have demonstrated that the presence of tachiarrhythmias does not influence ANH release. The positive and significant correlation of FT3 with both ANH and heart rate confirms the hypothesis of a direct action of thyroid hormones on ANH release.

Increased plasma concentration of atrial natriuretic hormone in myotonic dystrophy.

Atrial natriuretic hormone (ANH) concentrations were measured in 16 patients affected with myotonic dystrophy (MyD) undergoing 24-hour Holter ECG and in 15 age-matched normal subjects. Although the MyD patients did not show overt left ventricular function impairment, their plasma ANH levels were found to be higher (183.76 ± 113.25 pg/ml) compared to those of the control subjects (39.73 ± 9.95 pg/ml, p < 0.001). Nine patients with arrhythmias and some echocardiographic alterations formed subgroup A. Seven patients without cardiac alterations formed subgroup B. No significant difference in ANH emerged between the two subgroups. This evidence suggests that high plasma ANH levels in MyD cannot always be related to overt or latent heart failure and to arrhythmias.