Olaniyan Toyib, Olatunji Lawrence A
Cardiovascular and Membrane Physiology Unit, Department of Physiology, University of Ilorin , Nigeria.
J Public Health Afr. 2015 Aug 17;6(2):420. doi: 10.4081/jphia.2015.420.
Exaggerated sympathetic-mediated cardiovascular responses to stressful stimuli (such as cold exposure) has been linked to the development of hypertension and cardiovascular disease, which in turn has been demonstrated to predict the development of future hypertension. The aim of the present study was to test the hypothesis that enhanced change in myocardial oxygen consumption (MVO) to cutaneous cold stress may be one potential mechanism that predisposes overweight/obese individuals in Africa to developing hypertension. The Rate-Pressure-Product (a non-invasive determinant of MVO) was measured in normotensive young individuals aged between 18 and 25 years at baseline and during sympathetic activation elicited by cutaneous cold stimulation (CCS). Following CCS, there was a significant enhanced rate pressure product (RPP) change in overweight individuals (P = 0.019). Furthermore, multivariate regression analysis showed that body mass index, but not body weight had a significant influence on RPP variation following CCS. Thus, it can be concluded that normotensive overweight or obese individuals have an exaggerated RPP response to the CCS. However, exposure to cold may augment sympathetic reactivity in overweight/obese individuals, which may contribute to increased risk of developing myocardial dysfunction, even in young normotensive individuals.
对压力刺激（如冷暴露）的交感神经介导的心血管反应过度，已与高血压和心血管疾病的发生相关联，而这反过来又被证明可预测未来高血压的发生。本研究的目的是检验以下假设：心肌氧耗（MVO）对皮肤冷应激的变化增强，可能是非洲超重/肥胖个体易患高血压的一种潜在机制。在18至25岁的血压正常的年轻个体中，于基线时以及皮肤冷刺激（CCS）引发交感神经激活期间，测量了速率 - 压力乘积（MVO的一种非侵入性决定因素）。CCS后，超重个体的速率压力乘积（RPP）变化显著增强（P = 0.019）。此外，多变量回归分析表明，体重指数而非体重对CCS后的RPP变化有显著影响。因此，可以得出结论，血压正常的超重或肥胖个体对CCS有过度的RPP反应。然而，即使在年轻血压正常的个体中，冷暴露也可能增强超重/肥胖个体的交感反应性，这可能导致发生心肌功能障碍的风险增加。
