[Efficacy and safety of intravenous levosimendan compared with dobutamine in decompensated heart failure].

OBJECTIVE: To compare the efficacy and safety of intravenous levosimendan and dobutamine in patients with decompensated heart failure refractory to conventional medications. METHODS: Patients were recruited into this multicentre, randomised, positive-controlled and parallel-group study to receive either levosimendan or dobutamine therapy. In the levosimendan group, an initial loading dose of levosimendan of 12 microg x kg was infused over 10 min, followed by a continuous infusion of 0.1 microg x kg(-1) x min(-1) for 1 h and then 0.2 microg x kg(-1) x min(-1) for 23 h. In the control group, dobutamine was infused for 1 h at an initial dose of 2 microg x kg(-1) x min(-1) without a loading dose, followed by a continuous infusion of 4 microg x kg(-1) x min(-1) for 23 h. Hemodynamic responses at 24 h were evaluated by echocardiography (in both groups) and Swan-Gans catheter (in the levosimendan group). Clinical assessment was performed to evaluate efficacy and safety of the medications. RESULTS: A total of 225 patients from 12 medical centers were evaluated; 119 assigned to levosimendan and 106 assigned to dobutamine group. The effectiveness rate was 31.9% (38 patients) in the levosimendan group and 17.9% (19 patients) in the dobutamine group (P < 0.01). At 24 h, left ventricular ejection fraction (LVEF) was improved by 6. 4% in the levosimendan group, compared with 4.6% in the dobutamine group (P > 0.05). Stroke volume (SV) was increased by 11.1 ml in the levosimendan group and 2.8 ml in the dobutamine group respectively (P < 0.05). Dyspnea and clinical manifestations improvements were more significant in levosimendan therapy group compared to dobutamine group. There were less adverse effects including hypokalemia, hypotension and ventricular premature beats in the levosimendan group than in the dobutamine group (P < 0.05). CONCLUSION: Levosimendan was well tolerated and superior to dobutamine for patients with decompensated heart failure refractory to conventional medications.

Nicotinamide overload may play a role in the development of type 2 diabetes.

AIM: To investigate whether nicotinamide overload plays a role in type 2 diabetes. METHODS: Nicotinamide metabolic patterns of 14 diabetic and 14 non-diabetic subjects were compared using HPLC. Cumulative effects of nicotinamide and N(1)-methylnicotinamide on glucose metabolism, plasma H(2)O(2) levels and tissue nicotinamide adenine dinucleotide (NAD) contents of adult Sprague-Dawley rats were observed. The role of human sweat glands and rat skin in nicotinamide metabolism was investigated using sauna and burn injury, respectively. RESULTS: Diabetic subjects had significantly higher plasma N(1)-methylnicotinamide levels 5 h after a 100-mg nicotinamide load than the non-diabetic subjects (0.89 +/- 0.13 micromol/L vs 0.6 +/- 0.13 micromol/L, P < 0.001). Cumulative doses of nicotinamide (2 g/kg) significantly increased rat plasma N(1)-methylnicotinamide concentrations associated with severe insulin resistance, which was mimicked by N(1)-methylnicotinamide. Moreover, cumulative exposure to N(1)-methylnicotinamide (2 g/kg) markedly reduced rat muscle and liver NAD contents and erythrocyte NAD/NADH ratio, and increased plasma H(2)O(2) levels. Decrease in NAD/NADH ratio and increase in H(2)O(2) generation were also observed in human erythrocytes after exposure to N(1)-methylnicotinamide in vitro. Sweating eliminated excessive nicotinamide (5.3-fold increase in sweat nicotinamide concentration 1 h after a 100-mg nicotinamide load). Skin damage or aldehyde oxidase inhibition with tamoxifen or olanzapine, both being notorious for impairing glucose tolerance, delayed N(1)-methylnicotinamide clearance. CONCLUSION: These findings suggest that nicotinamide overload, which induced an increase in plasma N(1)-methylnicotinamide, associated with oxidative stress and insulin resistance, plays a role in type 2 diabetes.