Acute hyperhomocysteinemia impairs endothelium function in subjects with type 2 diabetes mellitus.

The objective of the present study was to examine the effect of acute, methionine-induced hyperhomocysteinemia (HHCY) on endothelial function and indices of arterial stiffness in subjects with type 2 diabetes mellitus (T2DM). A total of 30 subjects with T2DM, free of macrovascular disease were examined in a crossover study. L-methionine (M) (0.1 g/kg) and water (W) load were given in random order with an interval of about 1 week in between. Endothelial function was assessed by flow-mediated vasodilation (FMD). Arterial stiffness was assessed by determination of augmentation index (AI). Measurements were performed in the fasting state, 1, 2 and 3 h after the M or the W load. Total plasma homocysteine (HCY) levels did not change after W administration, while M administration resulted in a significant increase in HCY concentrations at 3 h. FMD throughout the experiment expressed as area under the curve (AUC) was significantly lower after the M than after the W load. Consistent with impairment in endothelial function, the AUC of AI was significantly higher after the M than after the W administration. Acute HHCY impairs endothelial function and increases arterial stiffness in patients with T2DM. This effect is probably mediated by a reduction of nitric oxide bioavailability in endothelium.

Hypercalcaemia in Greek patients with tuberculosis before the initiation of anti-tuberculosis treatment.

Hypercalcaemia has been known to occur in association with granulomatous diseases. The aim of this study was to ascertain the incidence of hypercalcaemia and determine the prevalence of symptoms associated with it in Greek patients with newly-diagnosed tuberculosis (TB), before the initiation of anti-tuberculosis treatment. We prospectively evaluated all patients with newly-diagnosed TB presenting, either as inpatients or as outpatients, to our hospital, during a 3-year period. We evaluated 88 patients with TB (50 males and 38 females), aged between 23 and 89 years (mean age+/-SD: 46.4+/-19 years), and 65 age- and sex-matched controls with chronic obstructive pulmonary disease (36 males and 29 females), aged between 28 and 88 years (mean age+/-SD: 47.2+/-18 years). Among TB patients, 56 had pulmonary TB, 20 had pleural TB without evidence of pulmonary parenchyma involvement, eight had pulmonary and pleural TB, and four had disseminated disease. The mean (+/-SD) albumin-adjusted serum calcium concentration and the mean ionized calcium concentration were significantly higher in the TB group (2.49+/-0.21 mmol l(-1) and 1.27+/-0.02 mmol l(-1) respectively) than in the control group (2.36+/-0.11 mmol l(-1) and 1.19+/-0.02 mmol l(-1), P<0.05). In the TB group no correlation between type of disease and albumin-adjusted or ionized calcium concentration was seen. Hypercalcaemia was detected in 22 patients with TB (25%) but only three showed symptoms associated with it. We conclude that, although hypercalcaemia is a common laboratory finding among Greek patients with TB before anti-TB chemotherapy, it is usually asymtomatic.