Influence of ethanol consumption and food intake on serum concentrations of endogenous steroids.

Steroid biosynthesis and biotransformation are based on a cascade of enzymatic processes being highly sensitive to various external influences. Amongst those, ethanol was shown to affect testosterone metabolism. For doping analyses, athlete steroid profiles comprise seven urinary steroid metabolites, of which relevant ratios are significantly increased following ethanol consumption. This effect is presumably based on the lack of hepatic NAD+-coenzyme as a consequence of ethanol oxidation. Only recently, testosterone (T) and androstenedione (A4) blood profiles have been introduced as additional approach for doping control. However, a potential influence of ethanol intake on testosterone biosynthesis and thus on blood steroid profiles has not been investigated so far. Therefore, steroid concentrations from 10 males and 10 females receiving an ethanol infusion up to a breath alcohol concentration of 0.5 mg/L which was hold as a plateau for two hours were conducted. Blood samples were drawn every 15 min for steroid quantification. An ethanol-dependent T/A4 increase up to 385% resulting from A4 suppression was observed in 14 volunteers. In addition, we observed sporadic A4 increases coinciding with cortisol and ACTH pulses pointing to a meal-induced adrenal stimulation. While testosterone levels in males showed diurnal variation solely, testosterone levels in some females were found to be susceptible to ethanol- and ACTH-dependent perturbations, which is thought to be due to its predominant adrenal synthesis in females. In conclusion, the results of the present study emphasize the importance of blood sampling at a sufficient time interval from food and ethanol intake. This is of interest if T and A4 are used for diagnostics in doping control.

Holiday trip to Norway - a stable isotope project on hair strands of individuals of a travel group from Bavaria.

Hair strands were taken from individuals of a travel group from Bavaria that stayed on the Lofoten Islands/Norway for 3 weeks. By means of serial stable isotope analyses of carbon, nitrogen, sulphur and hydrogen along the hair strands, food-specific changes during travel could be detected. The higher consumption of marine fish led to significant changes of the stable isotope values of nitrogen, sulphur and hydrogen. The highest differences for the values were found in the most proximal part of hair strands which were taken shortly after the trip. The basic values for the isotope distribution of the elements in the hair also indicate specific diets of some individuals that could be confirmed upon request.

Impact of acute ethanol intake on cardiac autonomic regulation.

Acute alcohol consumption may facilitate cardiac arrhythmias underlying the 'Holiday Heart Syndrome'. Autonomic imbalance is promoting atrial arrhythmias. We analyzed the effects of alcohol on measures of the cardiac autonomic nervous system and their relation to arrhythmias. In 15 healthy individuals, alcohol was administered parenterally until a breath alcohol concentration of 0.50 mg/l. High-resolution digital 30-min ECGs were recorded at baseline, at the time of maximum alcohol concentration, and after alcohol concentration returned to near baseline. Using customized software, we assessed periodic repolarization dynamics (PRD), deceleration capacity (DC), standard measures of heart rate variability (SDNN; RMSSD; LF; HF), and standard ECG parameters (mean heart rate; PQ; QRS; QTc interval). At the maximum alcohol concentration, PRD levels were significantly increased compared to baseline [1.92 (IQR 1.14-3.33) deg2 vs. 0.85 (0.69-1.48) deg2; p = 0.001]. PRD levels remained slightly increased when alcohol concentrations returned to baseline. DC levels were significantly decreased at the maximum alcohol concentration compared to baseline [7.79 (5.89-9.62) ms vs. 9.97 (8.20-10.99) ms; p = 0.030], and returned to baseline levels upon reaching baseline levels of alcohol. Standard HRV measures were reduced at maximum alcohol concentration. The mean heart rate increased significantly during alcohol administration. QRS and QTc duration were significantly prolonged, whereas PQ interval showed no change. Our findings revealed an increase of sympathetic activity and a reduction of parasympathetic activity under the influence of alcohol administration, resulting in autonomic imbalance. This imbalance might ultimately trigger arrhythmias underlying the 'Holiday Heart Syndrome'.