A call for attention: Is it time to revise the exercise guidelines for hypertension in African and Asian populations?

Hypertension (HT) is an important global health challenge, mainly because of its high prevalence resulting in cardiovascular disease and mortality.1 Globally, 31.1% of the adult population had HT in 2010 and this prevalence is higher in low- and middle-income (31.5%) than in high-income countries (28.5%).2 HT awareness, treatment, and control are much lower in low- and middle-income than in high-income countries.2 In addition, from 2000–2010, the HT prevalence in low- and middle-income countries increased by 7.7% and there were only modest improvements in awareness, treatment, and control.2 Among these countries, HT prevalence has been shown to be largest in low- and middle-income countries in South Asia and Sub-Saharan Africa.3 Global disparity of HT prevalence might involve ethnic differences in the control of blood pressure (BP). For instance, in the USA the HT prevalence is higher in African than in Hispanic Americans, Whites, and Native Americans.4 An ethnic-based difference in hypertension prevalence was also found in the Netherlands, where a cohort encompassing different ethnic groups revealed a higher prevalence of HT in African- and Asian-descendent men and women compared to the population of Dutch origin.5 Many factors may contribute to ethnic differences in HT, such as socioeconomic status, obesity, and higher smoking rates.5 In addition, higher vascular resistance and higher salt-sensitivity has been reported as an important physiological mechanism contributing to BP differences in African descent population compared to Western European descent population.6,7 Based on the recognized differences in BP control between different ethnic groups and on the reported higher rates of hypertension in individuals with African- and Asian- origin, effective strategies for cardiovascular prevention targeting BP control are paramount for reducing the global burden of blood pressure-related diseases in these populations. International HT guidelines broadly recommend that proper BP control may be achieved by a combination of appropriate lifestyle management and pharmacological therapy. Interestingly, although this overall recommendation for HT treatment is universally accepted, data from recent studies suggest that ethnic group differences may also apply with regard to the optimal type, doses, and even timing of both pharmacological and lifestyle interventions.8 As highlighted by Besaoiu et al.,9 although national and international guidelines strongly recommend regular physical activity as part of the first-line therapy of primary or secondary prevention of HT treatment, most of the supporting evidence involve studies with predominantly Caucasian populations. In order to overcome such a limitation, in this current edition of the European Journal of Preventive Cardiology, Besaoiu et al.9 have summarized the studies investigating the effects of exercise in the non-Caucasian population, including Asians and African descendants. In brief, the authors found favorable effects of aerobic exercise training on BP in African and Asian population. On the other hand, the lack of data on resistance or combined exercise training precluded any conclusions about their effect on BP in the non-Caucasian population. Although the present review results shed light on important information regarding the effects of exercise training on BP in two demographically representative but understudied populations, as reported by the authors of this review it is important to note the several limitations in the studies included in the meta-analysis which need to be better addressed by the next studies. Amongst these which should be highlighted are: the high heterogeneity explained by the presence of different exercise types, intensities, durations, and frequencies; the absence of trials investigating the effectiveness of resistance training and combined training in Africans; and the dearth of information on the mechanisms underlying the effects of aerobic and resistance exercise in BP control in these populations. In addition, the limited data on exercise therapy in non-Caucasian groups does not allow analysis for potential cofounders, such as sociodemographic characteristics, body mass index, waist-to-hip ratio, and lifestyle. The study by Bersaoiu et al.9 has established the “bottom line” for future studies investigating ethnic influence on BP response to exercise training. These studies should investigate the effects of different types, frequencies, intensities, and durations of exercise, and also eventual side effects. The information from these studies may pave the way for future guidelines on physical activity in non-Caucasian BP control, which may also extend to pharmacological and/or other non-pharmacological interventions. In due course, we recommend a conservative approach in the prescription of exercise to these populations, supplemented by adequate pre-exercise screening, attention to co-existing risk factors, and careful monitoring of BP responses during and after exercise training. We would like to praise Bersaoiu et al.9 for moving us forward with the effect of exercise therapy on BP in non-Caucasian population. This information goes in line with the recent American guidelines that recommend special attention to pharmacological therapy in the BP control of specific patient subgroups with different racial and ethnic backgrounds,10 and with the 2016 European guidelines on cardiovascular risk prevention that states that ethnicity should be weighted in cardiovascular risk assessment.11 We encourage the scientific community to persevere in this field as new evidence might ameliorate the still suboptimal BP control in these understudied populations, representing more than half of the global population. The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article. The author(s) received no financial support for the research, authorship, and/or publication of this article.