Endothelial nitric oxide synthase gene polymorphism and elite endurance athlete status: the Genathlete study.

In the Genathlete study, we examined the contribution of three polymorphisms in the endothelial nitric oxide synthase (NOS3) gene to discriminate elite endurance athletes (EEA) from sedentary controls (SC). The EEA group included a total of 316 Caucasian males with a VO2max >75 mL/kg. The SC group comprised 299 unrelated sedentary Caucasian males who had VO2max values below 50 mL/kg. The polymerase chain reaction technique was used to amplify a microsatellite (CA)(n) repeat in intron 13, a 27 bp repeat in intron 4 and a third fragment in exon 7 containing the Glu298Asp SNP. No difference was found between the EEA and SC groups for the 27 bp repeat and the Glu298Asp polymorphism. Chi-square analysis of the overall allelic distribution of the (CA)(n) repeat revealed no significant difference between the two groups (P=0.135). However, comparing carriers and non-carriers for the most common (CA)(n) repeat alleles, we found significant differences between SC and EEA, with more EEA subjects carrying the 164 bp allele (P=0.007). In summary, we found suggestive evidence that the 164 bp allele of the (CA)(n) repeat in intron 13 is associated with EEA status and may account for some of the differences between EEA and SC.

Prevention of atrial fibrillation after coronary artery bypass graft surgery using a potassium-magnesium-aspartate solution (Inzolen).

BACKGROUND: Atrial fibrillation (AFIB) following cardiac surgery is a frequent complication. The purpose of this study was to evaluate the efficacy of a potassium-magnesium-aspartate solution (Inzolen) for the prevention of AFIB. METHODS: In a randomised, prospective, double-blinded study, we studied 88 patients undergoing elective coronary artery bypass graft surgery (CABG). After surgery, patients were allocated randomly to one of two groups. Group A (n = 43) received a potassium-magnesium-aspartate solution (Inzolen), group B (n = 45) received potassium chloride; both solutions were administered continuously for 48 hours to keep the potassium serum levels between 4.5 and 5.5 mmol/l. Patients were observed for 5 days postoperatively and the incidence of atrial fibrillation was noted. At the end of surgery (T0), 4 h (T1), 24 h (T2), 48 h (T3), and 120 h (T4) postoperatively, magnesium and potassium serum levels were measured. RESULTS: The two groups did not differ significantly with regard to demographics and perioperative data. No significant difference in the incidence of postoperative atrial fibrillation was seen (group A: 41.9 % vs. group B 31.1 %; P = 0.53). In group A, the magnesium serum levels were significantly higher at T1 (1.15 +/- 0.18 vs. 0.87 +/- 0.11 mmol/l), T2 (1.24 +/- 0.22 vs. 0.82 +/- 0.10 mmol/l) and T3 (1.15 +/- 0.18 vs. 0.81 +/- 0.20 mmol/l) compared to group B, whereas potassium levels were similar in the two groups throughout the study period. CONCLUSIONS: The use of a potassium-magnesium-aspartate solution (Inzolen) showed no significant difference in potassium chloride for the prophylaxis of postoperative atrial fibrillation secondary to CABG.