BDNF, IGF-I, Glucose and Insulin during Continuous and Interval Exercise in Type 1 Diabetes.

Type 1 diabetes (T1D) can have a significant impact on brain function, mostly ascribed to episodes of hypoglycemia and chronic hyperglycemia. Exercise has positive effects on acute and chronic glycemic control in T1D, and has beneficial effects on cognitive function by increasing neurotrophins such as BDNF and IGF-I in non-diabetic humans. The present study examines the effects of different types of exercise intensities on neurotrophins in T1D. 10 participants with type 1 diabetes were evaluated in 3 sessions: high-intensity exercise (10×[60 s 90%Wmax, 60 s 50 W]), continuous exercise (22 min, 70% VO2 max) and a control session. Blood glucose, serum free insulin, serum BDNF and IGF-I were assessed pre/post all the trials and after recovery. Blood glucose significantly decreased after both exercise intensities and BDNF levels increased, with a dose-response effect for exercise intensity on BDNF. IGF-I changed over time, but without a difference between the different exercise protocols. Both exercise intensities change neurotrophins in T1D, but also exhibit a dose response effect for BDNF. The intensity-dependent findings may aid in designing exercise prescriptions for maintaining or improving neurological health in T1D, but both types of exercise can be implemented.

Diagnosing overtraining in athletes using the two-bout exercise protocol.

OBJECTIVE: In this work, whether a two-bout exercise protocol can be used to make an objective, immediately available distinction between non-functional over reaching (NFO) and overtraining syndrome (OTS) was studied. DESIGN: Underperforming athletes who were diagnosed with the suspicion of NFO or OTS were included in the study. Recovery of the athletes was monitored by a sports physician to retrospectively distinguish NFO from OTS. SETTING: Sports medicine laboratory PARTICIPANTS: The protocol was started and completed by 10 underperforming athletes. NFO was retrospectively diagnosed in five athletes, and OTS was diagnosed in five athletes. INTERVENTIONS: A two-bout maximal exercise protocol was used to measure physical performance and stressinduced hormonal reactions. MAIN OUTCOME MEASUREMENTS: Exercise duration, heart rate and blood lactate concentration were measured at the end of both exercise tests. Venous concentrations cortisol, adrenocorticotrophic hormone (ACTH), prolactin and growth hormone were measured both before and after both exercise tests. RESULTS: Maximal blood lactate concentration was lower in OTS compared with NFO, while resting concentrations of cortisol, ACTH and prolactin concentrations were higher. However, sensitivity of these measures was low. The ACTH and prolactin reactions to the second exercise bout were much higher in NFO athletes compared with OTS and showed the highest sensitivity for making the distinction. CONCLUSIONS: NFO might be distinguished from OTS based on ACTH and prolactin reactions to a two-bout exercise protocol. This protocol could be a useful tool for diagnosing NFO and OTS; however, more data should be collected before this test can be used as the gold standard.

Hormonal responses during prolonged exercise are influenced by a selective DA/NA reuptake inhibitor.

OBJECTIVE: A decrease in dopamine activity is thought to lead to a reduction in motivation and arousal and therefore to the "central" component of fatigue. The purpose of the present study was to investigate the effects of a dopamine (DA) noradrenaline (NA) reuptake inhibitor, bupropion (Zyban), on exercise performance and on the hormonal response to exercise. METHODS: Eight healthy well trained male cyclists (Watt(max) 397+/-15 W) participated in the study. Subjects completed one maximal exercise test (to determine maximal power output Watt(max)), and two endurance performance tests (time trials) in a double blind randomised cross-over design. Subjects took either placebo capsules (lactose) or 2 x 300 mg bupropion (BUP). Blood samples were collected for adrenocorticotropin (ACTH), prolactin, cortisol, growth hormone, beta-endorphins, and catecholamines. RESULTS: Performance was not influenced by BUP (placebo: 89+/-1 min; BUP 2 x 300 mg: 89+/-0.7 min). All hormones increased during exercise in all trials. Cortisol plasma concentrations were significantly higher in the BUP trial at rest, at min 60, and at the end of exercise, while beta-endorphins were higher in the BUP trial at the end of exercise and during recovery, and ACTH at the end of exercise. CONCLUSION: From the present results, we can conclude that bupropion had a more marked central noradrenergic effect (compared to dopaminergic) on the hormonal response to exercise, but no effect on the outcome of performance.

Hormonal responses in athletes: the use of a two bout exercise protocol to detect subtle differences in (over)training status.

In overtrained athletes, several signs and symptoms have been associated with the imbalance between training and recovery. However, reliable diagnostic markers for distinguishing between well-trained, overreached (OR) and overtrained (OT) athletes are lacking. A hallmark feature of overtraining syndrome (OTS) is the inability to sustain intense exercise and recover for the next training or competition session. We therefore devised a test protocol utilizing two bouts of maximal work. With this test protocol we tried to establish a difference in hormonal responses between the training status of T and OR athletes. Seven well-trained cyclists participated in this study and were tested before and after a training camp. We also present the data of one OT motocross athlete who was clinically diagnosed as overtrained. All athletes performed two maximal exercise tests separated by 4 h. Blood was analyzed for cortisol, adrenocorticotrophic hormone (ACTH), growth hormone and prolactin (PRL). Performance decreased by 6% between the first and the second exercise test in the OR group and by 11% in the OT subject. Moreover, during the second exercise test there were more marked differences between the T and OR athletes; in particular, the OT subject did not show an increase in some of the hormonal responses. PRL increased only by 14% in the OT subject's second test and there was a 7% decrease in ACTH. The two exercise approach enables us to detect subtle performance decrements that will not be identified by one exercise trigger. The hormonal responses to the second exercise test were different between the T and OR athletes (the increase in the T group was higher than in the OR that was higher than in the OT). The results of the case presentation of an overtrained athlete provide evidence of an altered and dysfunctional hypothalamic-pituitary axis response to two bouts of maximal exercise. These findings can be used to develop markers for diagnosis of OTS and to begin to address the pathologic mechanism operative in the syndrome, as well as providing an outcome measure to evaluate possible therapeutic regimes.

Influence of intravenous clonidine pretreatment on anesthetic requirements during bispectral EEG-guided sevoflurane anesthesia.

STUDY OBJECTIVE: To assess the anesthetic effects of clonidine during sevoflurane anesthesia guided by the bispectral index (BIS), which is a processed EEG variable correlated with anesthetic-hypnotic depth. DESIGN: Placebo-controlled, double-blind clinical trial. SETTINGS: Elective laparoscopic surgery. PATIENTS: 60 ASA physical status I patients scheduled for laparoscopic surgery. INTERVENTIONS: Patients received either clonidine (3 micrograms/kg, 15 min before induction) or placebo premedication for a sevoflurane-induced and sevoflurane-maintained anesthesia. Sevoflurane was titrated against a BIS held between 40 and 50. Analgesia was provided by local infiltration with bupivacaine. Need for postoperative analgesia was recorded. RESULTS AND CONCLUSION: Mean sevoflurane requirements were not lower with clonidine pretreatment. There was statistically better perioperative hemodynamic stability (i.e., fewer episodes of hypertension and tachycardia) without clinical relevance. A decreased need for postoperative analgesia was observed.

Rocuronium with alfentanil and propofol allows intubation within 45 seconds.

Following induction with alfentanil (20 micrograms kg-1) and propofol (2.0-2.5 mg kg-1), four groups of patients were given rocuronium to determine conditions for rapid sequence intubation. Two groups received 0.9 mg kg-1 and two groups received 0.6 mg kg-1. In one of each dose groups, intubation was attempted after 45 s and in the other after 60 s. Intubating conditions were scored on a four point scale but all were rated as excellent or good. Almost all intubating conditions were excellent in the 0.9 mg kg-1 groups.

Collodion baby dehydration: the danger of high transepidermal water loss.

We describe transepidermal water loss (TEWL) measurements in a collodion baby suffering from severe hypernatraemic dehydration and hypothermia, who required intravenous fluid therapy in a special incubator. The TEWL values 4 days after birth were abnormally high compared with normal infants of the same age. The TEWL measurements returned towards normal within the first month, in parallel with the improvement of both the skin signs and the electrolyte and fluid balance.