Interval exercise increases angiogenic cell function in postmenopausal women

Introduction: Exercise can help to negate the increased cardiovascular disease risk observed in women after the menopausal transition. This study sought to determine whether interval or continuous exercise have differential effects on endothelial function and circulating angiogenic cell (CAC) number and function in postmenopausal women. Methods: Fifteen healthy postmenopausal women completed a 30 min acute moderate-intensity continuous (CON) and interval exercise (MOD-INT) session on a cycle ergometer on separate days. Nine participants completed a further single 30 min acute heavy-intensity interval (HEAVY-INT) exercise session. Brachial artery flow-mediated dilation (FMD) was assessed pre and 15 min post exercise session. CAC number and colony forming capacity in vitro were assessed post exercise and compared to resting levels. Results: FMD and CAC number did not change post exercise regardless of exercise type (p > 0.05). However, the number (mean ± SD) of colony forming units (CFUs) increased from visit one (12 ± 10 CFUs/well) to post MOD-INT (32 ± 30 CFUs/well) and post HEAVY-INT (38 ± 23 CFUs/well) but not post CON (13 ± 14 CFUs/well). Conclusion: A single session of interval exercise is more effective than a continuous exercise session for increasing the intercellular communication of CACs, regardless of exercise intensity. The enhanced ability of CACs to form colonies may reflect an increased number and/or function of angiogenic T-cells. The repeated exertions to higher work-rates during interval exercise may explain this response. Repeated exercise sessions might be required to improve FMD in postmenopausal women

Is the somatotropic axis related to sympathetic nerve activity in healthy ageing men?

OBJECTIVE: The mechanisms underlying the age-related increase in blood pressure and sympathetic nerve activity remain largely unknown. The decline in growth hormone (GH) secretion and insulin-like growth factor-I (IGF-I) with age has been related to several cardiovascular risk factors. Low serum IGF-I levels in severe adult GH deficiency is associated with markedly increased sympathetic nerve activity. This study evaluates whether a relationship between serum IGF-I and sympathetic nerve traffic exists in healthy aging men. DESIGN AND METHODS: Sympathetic nerve activity to the muscle vascular bed (MSA) was recorded in 56 healthy normotensive males, and related to age (range 21-71 years), body mass index (BMI, range 18.4-32.2), serum IGF-I and plasma nitrate levels. Blood pressure, BMI and MSA increased with age, whereas IGF-I and plasma nitrate decreased. In a forward stepwise multiple regression analysis, age explained 40% of the variability in MSA and excluded other variables. Omitting age, IGF-I became the strongest independent predictor, explaining 23% of the variability in MSA. MSA was an independent predictor of diastolic blood pressure, but its influence (10%) was less than that of BMI (28%). BMI was not related to MSA or IGF-I. CONCLUSIONS: Decreased serum IGF-I levels are coupled to increased MSA during ageing, an effect independent from the impact of increased body weight. Although MSA is a weak predictor of rising blood pressure with age, it constitutes one possible pathway for the somatotropic axis to affect cardiovascular function in ageing