Reactive hyperemia (RH) in forearm muscle or skin microcirculation has been considered as a surrogate endpoint in clinical studies of cardiovascular disea e. We evaluated two potential confounders that might limit such use of RH, namely laterality of measurement and intake of non-steroidal anti-inflammatory drugs (NSAIDS). Twenty-three young non-smoking healthy adults were enrolled. In Experiment 1 (n=16), the RH elicited by 3 min of ischemia was recorded in the muscle (strain gauge plethysmography, hand excluded) and skin (laser Doppler imaging) of both forearms. In Experiment 2 (n=7), RH was determined in the dominant forearm only, one hour following oral acetylsalicylic acid (1 g) or placebo. In Experiment 1, peak RH was identical in both forearms, and so were the corresponding durations of responses. RH lasted significantly less in muscle than in skin (p=0.003), a hitherto unrecognized fact. In the skin, acetylsalicylate reduced duration (43 vs. 57.4 s for placebo, p=0.03), without affecting the peak response. In muscle, duration tended to decrease with acetylsalicylate (21.4 vs. 26.0 s with placebo, p=0.06) and the peak increase in blood flow was blunted (27.2 vs. 32.4 ml/min/100 ml tissue with placebo, p=0.003). We conclude that, when using RH as a surrogate endpoint in studies of cardiovascular disease, a confounding by laterality of measurement need not be feared, but NSAIDS may have an influence, although perhaps not on the peak response in the skin., G. Addor, A. Delachaux, B. Dischl, D. Hayoz, L. Liaudet, B. Waeber, F. Feihl., and Obsahuje bibliografii a bibliografické odkazy
Whole-body vibration (WBV) is a new exercise method, with good acceptance among sedentary subjects. The metabolic response to WBV has not been well documented. Three groups of male subjects, inactive (SED), endurance (END) and strength trained (SPRINT) underwent a session of side-alternating WBV composed of three 3-min exercises (isometric half-squat, dynamic squat, dynamic squat with added load), and repeated at three frequencies (20, 26 and 32 Hz). VO2, heart rate and Borg scale were monitored. Twenty-seven healthy young subjects (10 SED, 8 SPRINT and 9 END) were included. When expressed in % of their maximal value recorded in a treadmill test, both the peak oxygen consumption (VO2) and heart rate (HR) attained during WBV were greatest in the SED, compared to the other two groups (VO2: 59.3 % in SED vs 50.8 % in SPRINT and 48.0 % in END, p<0.01; HR 82.7 % in SED vs 80.4 % in SPRINT and 72.4 % in END, p<0.05). In conclusions, the heart rate and metabolic response to WBV differs according to fitness level and type, exercise type and vibration frequency. In SED, WBV can elicit sufficient cardiovascular response to benefit overall fitness and thus be a potentially useful modality for the reduction of cardiovascular risk., B. Gojanovic, F. Feihl, G. Gremion, B. Waeber., and Obsahuje bibliografii