Effects of hiking at moderate and low altitude on cardiovascular parameters in male patients with metabolic syndrome: Austrian Moderate Altitude Study.

OBJECTIVE: Physical activity is a cornerstone in therapy for patients with metabolic syndrome. Walking and hiking in a mountain scenery represents an ideal approach to make them move. The Austrian Moderate Altitude Study (AMAS) 2000 main study is a randomized controlled trial to investigate the cardiovascular effects of hiking at moderate altitude on patients with metabolic syndrome compared with a control group at low altitude, to assess a potential altitude-specific effect. METHODS: Seventy-one male patients with metabolic syndrome were randomly assigned to a moderate altitude group (at 1700 m), with 36 participants, or to a low altitude group (at 200 m), with 35 participants. The 3-week vacation program included 12 hiking tours (4 per week, average duration 2.5 hours, intensity 55% to 65% of heart rate maximum). Physical parameters, performance capacity, 24-hour blood pressure, and heart rate profiles were obtained before, during, and after the stay. RESULTS: In both groups, we found a significant mean weight loss of -3.13 kg; changes in performance capacity were minor. Systolic, diastolic, and mean arterial pressures and circadian heart rate profiles were significantly reduced in both groups, with no differences between them. Consequently, the pressure-rate product was reduced as well. All study participants tolerated the vacation well without any adverse events. CONCLUSIONS: A 3-week hiking vacation at moderate or low altitude is safe for patients with metabolic syndrome and provides several improvements in their cardiovascular parameters. The cardiovascular benefits achieved are more likely to be the result of regular physical activity than the altitude-specific effect of a mountain environment.

Austrian Moderate Altitude Studies (AMAS): benefits of exposure to moderate altitudes (1,500-2,500 m).

OBJECTIVES: A considerable part of the millions of Alpine tourists suffer from pre-existing diseases (e.g., metabolic syndrome) and high daily stress levels. The main goal of the Austrian Moderate Altitude Study (AMAS) was to investigate (a) the consequences of an active vacation at moderate altitude on the key parameters of the metabolic syndrome (AMAS I) and (b) the effects of a short active vacation on adult progenitor cells, bio-psychological parameters, and heart rate variability (HRV). METHODS: During the AMAS I pilot study (n = 22; 1,700 m a.s.l.) and AMAS I main study (n = 71; 1,700 m a.s.l. and 200 m a.s.l.), the volunteers simulated 3-week coached hiking vacations. For AMAS II, healthy volunteers (n = 13) participated in a 1-week active holiday at 1,700 m. RESULTS: There were significant improvements of obesity, hypertension, dyslipidemia, and insulin resistance of AMAS I patients after the vacation. In AMAS II participants, we found an increase in circulating endothelial progenitor cells as well as improvements in bio-psychological and HRV parameters. CONCLUSIONS: Active vacations at moderate altitude are associated with a variety of positive health effects in persons with metabolic syndrome and in healthy subjects.

Increased levels of circulating progenitor cells after 1-week sojourn at moderate altitude (Austrian Moderate Altitude Study II, AMAS II).

We wanted to test if a sojourn at moderate altitude can activate circulation of adult progenitor cells in healthy individuals. Thus, we investigated 11 healthy volunteers, who spent 1-week at 1700 m (Oberlech, Austria,) simulating an active holiday. We measured circulating CD34(+) progenitor cell populations by flow cytometry and cytokines (using ELISA) in peripheral blood at baseline (500 m) and at the end of the sojourn. Extent of physical activity was documented via armband. CD34(+)CXCR-4(+) cells significantly increased in peripheral blood after the sojourn. CD34(+)CD31(+) and CD34(+)CD133(+) cells were upregulated in trend. Levels of SDF-1, G-CSF and VEGF decreased in trend whereas erythropoietin and SCF remained equal. Progenitor cells and degree of daily physical exercise did not correlate. We present the first study showing that exposure to moderate altitude with physical activity leads to increased levels of circulating progenitor cells. This effect may be due to hypoxia and/or physical activity.

Short Vacation Improves Stress-Level and Well-Being in German-Speaking Middle-Managers-A Randomized Controlled Trial.

Stress in the work place has a detrimental effect on people's health. Sufficient recovery is necessary to counteract severe chronic negative load reactions. Previous research has shown that vacationing for at least seven consecutive days provided an efficient recovery strategy. Yet, thus far, the effects of short vacations and the mode of vacation (whether at home or in a new environment) have rarely been studied. We investigated the immediate and long-term effects of a short vacation (four nights) on well-being and perceived stress and whether the mode of vacation impacted on these results. Data was obtained from 40 middle managers (67.5% men and 32.5% women). The intervention group (n = 20) spent a short vacation in a hotel outside their usual environment. The control group (n = 20) spent their vacation at home. Results indicated that one single short-term vacation, independent of the mode, has large, positive and immediate effects on perceived stress, recovery, strain, and well-being. Strain levels decreased to a greater extent in the intervention group compared to the control group. The effects can still be detected at 30 days (recovery) and 45 days (well-being and strain) post-vacation. Encouraging middle management employees to take short vacations seems to be an efficient health promotion strategy; environmental effects seem to play a minor role.

Transient impairment of flow-mediated vasodilation in patients with metabolic syndrome at moderate altitude (1,700 m).

BACKGROUND: The influence of moderate altitude on the cardiovascular system in patients with metabolic syndrome has not been investigated sufficiently, yet. The aim of this study was to assess the effect of acute and mid-term exposure to moderate altitude (1,700 m) on endothelial function in patients with metabolic syndrome. METHODS: Flow-mediated (FMD) and nitroglycerin-mediated vasodilation (NMD) were assessed in 18 patients with coronary risk factors on 5 occasions: (1) at location A (576 m), (2) on the first day at moderate altitude (location B, 1,700 m), (3) after 3 weeks at moderate altitude, (4) and (5) again at location A (6 and 16 weeks after the stay at moderate altitude, respectively). In addition, markers of lipid metabolism, serum erythropoietin and endothelin were measured. RESULTS: FMD on the first day at moderate altitude was similar compared to baseline FMD at location A (7.0 +/- 3.3 vs. 7.4 +/- 4.6%; NS). A 3-week stay at moderate altitude was associated with a significant reduction in FMD (7.4 +/- 4.6 vs. 3.8 +/- 2.5%; p < 0.05) despite a decrease in baseline diameter (4.5 +/- 0.3 vs. 4.3 +/- 0.4 mm; p < 0.05). Six weeks after returning to location A, FMD was still reduced compared to baseline (4.3 +/- 2.8%; p < 0.05) and after further 16 weeks, FMD returned to baseline values (5.5 +/- 3.5%). However, metabolic parameters improved significantly. In contrast, NMD and endothelin levels remained unchanged. CONCLUSION: In patients with metabolic syndrome, a sojourn of 3 weeks at moderate altitude leads to a prolonged, but reversible impairment of FMD. The discrepancy to improvement of other cardiovascular and metabolic parameters requires further investigation.

Austrian Moderate Altitude Study (AMAS 2000): erythropoietic activity and Hb-O(2) affinity during a 3-week hiking holiday at moderate altitude in persons with metabolic syndrome.

Moderate altitude hypoxia (1500 to 2500 m) is known to stimulate erythropoiesis and to improve oxygen transport to tissue by a reduction of Hb-O(2) affinity. Whether this adaptation also occurs in tourists with metabolic syndrome has not yet been investigated sufficiently. Thus, we performed a prospective field study to measure erythropoietic parameters and oxygen transport properties in 24 male volunteers with metabolic syndrome during a 3- week holiday program at 1700 m consisting of four guided, individually adapted hiking tours per week. The following examinations were performed: baseline investigations at 500 m (T1); examinations at moderate altitude on day 1 (T2), day 4 (T3), day 9 (T4), and day 19 (T5); and postaltitude tests (T6) 7 to 10 days after return. On day 1 and day 19, a walk on a standardized hiking test route with oxygen saturation (SpO(2)) measure points was performed. Hemoglobin, packed cell volume, and red cell count showed changes over time, with higher values at T5 as compared to baseline. Reticulocyte count and erythropoietin (EPO) were increased at T2 and increased further until T5. EPO declined toward prealtitude values. P50-value (blood PO(2) at 50% hemoglobin oxygen saturation at actual pH) increased during the altitude sojourn (maximum increase at T5 by +0.40 kPa). At T5 all volunteers had a higher SpO(2) before, during, and at the end of the test route compared to T1. During adaptation to moderate altitude, persons with metabolic syndrome exhibit an increase in EPO and a rightward shift of the oxygen dissociation curve that is similar to healthy subjects.

Vacation at moderate and low altitude improves perceived health in individuals with metabolic syndrome.

BACKGROUND: Recent data suggest that vacation may improve cardiovascular health, an effect possibly moderated by altitude. The aim of the present study was to study the effect of a 3-week vacation at moderate and low altitude on perceived health in individuals with increased cardiovascular risk. METHODS: Seventy-two overweight males, both occupationally active and retired (mean age=56.6 +/- 7.2 years), with signs of metabolic syndrome were randomly assigned to identical sojourns at either moderate (1,700 m) or low (300 m) altitude and engaged in four 3- to 4-h heart-rate-controlled hiking tours per week. Perceived health was measured 2 weeks before vacation, at the beginning and end of vacation, and 7 weeks after vacation. RESULTS: Fitness, recreational ability, positive and negative mood and social activities improved during vacation, independent of altitude and occupational status, although the day-to-day improvement in quality of sleep was delayed at moderate altitude. During the follow-up examinations, improvements in all reported aspects of health except for social activities were maintained. In comparison to retired individuals, active individuals showed a greater long-term improvement in social activities. CONCLUSION: Vacation positively affects perceived health independent of altitude or occupational status in generally inactive overweight males.

3-week hiking holidays at moderate altitude do not impair cardiac function in individuals with metabolic syndrome.

We studied the influence of a 3-week hiking vacation at moderate altitude on cardiac pump and endocrine function. 18 males (mean age: 55 years, range 36-60) with metabolic syndrome participated in a 3-week structured guided hiking vacation program (4 times per week at 55-65% of maximal heart rate, total exercise time 29 h). Echocardiography, B-type natriuretic peptide (BNP), NT-proBNP, and endothelin-1 measurements were performed at baseline in Innsbruck (576 m a.s.l., Austria), on the first day at moderate altitude (Obertauern, 1700 m a.s.l., Austria), after 3 weeks in Obertauern, and at follow-up in Innsbruck. We found no adverse cardiovascular effects and no significant changes in echocardiographic measures of systolic or diastolic function, estimated systolic pulmonary artery pressure, exercise capacities, BNP and NT-proBNP, or endothelin-1 concentrations. The blood pressure at rest significantly decreased from baseline to follow-up.

Austrian Moderate Altitude Study (AMAS 2000) - fluid shifts, erythropoiesis, and angiogenesis in patients with metabolic syndrome at moderate altitude (congruent with 1700 m).

It was hypothesized that subjects with metabolic syndrome (hypertension, obesity, hyperlipidemia, diabetes mellitus): (1) develop measurable peripheral edema at moderate altitude and (2) might show differences on erythropoiesis, iron status and vascular endothelial growth factor (VEGF) in comparison to healthy subjects during and after a long-term stay (3-week exposure) at moderate altitude (congruent with 1700 m). Twenty-two male subjects with metabolic syndrome were selected. Baseline investigations (t1) were performed in Innsbruck (500 m). All participants were transferred by bus to 1700 m (Alps) and remained there for 3 weeks with examinations on day 1 (after the first night at altitude, t2), day 4 (t3), day 9 (t4) and day 19 (t5). After returning to Innsbruck, post-altitude examinations were conducted after 7-10 days (t6) and 6-7 weeks (t7), respectively. Body mass was decreased from t1 to t7 (P<0.01). Total body water was decreased at t2 (P<0.01), returned to control level (t3, t4), and was found elevated at t7 (P<0.01). Lean body mass did not change, but body fat decreased during the study (P<0.01). Tissue thickness at the forehead decreased during and after altitude exposure (P<0.01), whereas tissue thickness at the tibia did not alter. Erythropoietin (EPO) was elevated as early as t2 and remained increased until t5. Reticulocyte count was increased at t3 and remained above pre-altitude values. VEGF levels were unchanged. After a 3-week exposure to moderate altitude, patients with metabolic syndrome had reduced their body mass, mainly because of a reduction in body fat. The moderate altitude was found to stimulate erythropoiesis in these patients but this was not sufficient to increase serum VEGF concentration.

Austrian Moderate Altitude Study 2000 (AMAS 2000). The effects of moderate altitude (1,700 m) on cardiovascular and metabolic variables in patients with metabolic syndrome.

We investigated the changes in the cardiovascular system [resting blood pressure (BP) and heart rate (HR), measured by means of a 24-h ambulatory BP and a holter-electrocardiogram (ECG)], glycemic parameters, and lipid metabolism of subjects suffering from metabolic syndrome during a 3-week sojourn at 1,700 m in the Austrian Alps. A total of 22 male subjects with metabolic syndrome were selected. Baseline investigations were performed at Innsbruck (500 m above sea level). During the 3-week altitude stay the participants simulated a holiday with moderate sports activities. Examinations were performed on days 1, 4, 9, and 19. After returning to Innsbruck, post-altitude examinations were conducted after 7-10 days and 6-7 weeks, respectively. The 24-h ambulatory BP and holter ECG revealed a decrease in average HR, BP, and rate pressure product (RPP: systolic blood pressure x HR) after 3 weeks of altitude exposure. In some patients, an increase in premature ventricular beats was observed at the end compared to the beginning of the exposure to moderate altitude. The ECG revealed no ischemic ST-segment changes. Maximal physical capacity as measured by symptom-limited maximal cycle ergometry tests remained unchanged during the study. Six weeks after the altitude exposure the blood pressure increased again and returned to pretest levels. The Homeostasis Model Assessment index, which is a measure of insulin resistance, decreased significantly and glucose concentrations obtained after an oral glucose tolerance test were significantly lower after the stay at altitude compared to the basal values. We conclude that after a 3-week exposure to moderate altitude, patients with metabolic syndrome (1) tolerated their sojourn without any physical problems, (2) exhibited short-term favorable effects on the cardiovascular system, and (3) had significant improvements in glycemic parameters that were paralleled by a significant increase in high-density-lipoprotein-cholesterol.