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Implementing the general adaptation syndrome 10 to interpret the dissociation between behavioural and physiological AC cardio-neuro-metabolic responses in urban black Africans. HT = hypertension; AC = active coping; IFG = impaired fasting glucose.
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Psychosocial stress is a contributing factor to cardiovascular disease. An important way of investigating the mechanisms underlying this association is acute psycho-physiological stress testing, involving measurement of physiological responses to laboratory-induced stress. Psycho-physiological stress testing allows individual differences in respons...
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In this Editorial we provide a review of the issues and manuscripts included in the special issue “ICT for Global Competitiveness and Economic Growth in Emerging Economies”. First, we outline the concepts and indicators of ICT, human capital, innovations, economic growth, competitiveness, and human development. Next, we use these indicators to clas...
Citations
... BP is a major risk factor in people of African descent generally, regardless of country of residence. [21][22][23][24][25] However, recent findings in a Zulu-speaking rural community in South Africa demonstrated that the optimal WC cut-point to predict the presence of at least two other components of the metabolic syndrome was 86 cm for males and 92 cm for females. 26 More research is needed to clarify the matter on WC cut-points in different ethnic groups in South Africa. ...
Background: Current waist circumference (WC) cut-points of the Joint Statement Consensus (JSC) (male ≥ 94 cm, female ≥ 80 cm) were compared with a recently proposed WC cut-point (RPWC) (male ≥ 90 cm, female ≥ 98 cm). In this study, we aimed to compare the two cut-points to assess the association between central obesity and perception of own health.Method: We determined blood pressure and fasting bloods [glucose, high-density lipoprotein (HDL) and triglycerides] as metabolic syndrome markers for 171 urban teachers. Perception of own health was determined via the General Health Questionnaire-28 (GHQ-28) to indicate probable psychological distress or a psychiatric disorder or caseness (≥ 4).Results: The RPWC was an improved discrimination between the WC groups on perception of own health as reflected in the GHQ-28 subscales. In the male group, higher scores were found in the RPWC high WC group (≥ 90 cm) with regard to somatic symptoms, social dysfunction and GHQ-28 caseness, compared to those of the low WC groups (< 90 cm). Compared to the RPWC high WC females (≥ 98 cm), the low WC (< 98 cm) reflected significantly higher anxiety and sleeplessness subscale scores.Conclusion: Our results suggest that the RPWC (men 90 cm, women 98 cm), (determined in this African cohort when adding GHQ-28 caseness as a discriminatory variable between WC cut-point), distinguished better between WC groups based on their perception of own health than the JSC cut-point.
... Psychosocial stress has previously been associated with pathology [1,2]. The impact of stress on physiological functioning is, however, partly dependent on the utilised coping responses when dealing with stress, as well as genetics, lifestyle, and previous experiences [3]. ...
... Chong et al. concur that ethnic variations in coping responses play an important role in their correspondingly diverse pathologies [4]. And so, preceding studies agree that the defensive active coping response, rather than the emotional avoidance response, is more associated with cardiovascular disease (CVD) in Africans than in Caucasians, and especially in African men [1,2,5]. Additionally, Malan et al. discovered dissociation in the behavioural and physiological defensive coping responses in Africans, with resultant increased CVD risk [2,5]. ...
... And so, preceding studies agree that the defensive active coping response, rather than the emotional avoidance response, is more associated with cardiovascular disease (CVD) in Africans than in Caucasians, and especially in African men [1,2,5]. Additionally, Malan et al. discovered dissociation in the behavioural and physiological defensive coping responses in Africans, with resultant increased CVD risk [2,5]. Defensive active coping can be summarised as a direct approach to actively solve problems and manage stress, with a sense of being in control and an intense focus until the stress is eliminated [6]. ...
Objective:
The defensive active coping response is a recognised cardiovascular risk factor in Africans, especially in men. It is uncertain whether autonomic dysfunction might be the underlying cause. We therefore investigated associations between salivary MHPG (3-methoxy-4-hydroxyphenolglycol), as a marker of sympathetic activity, and subclinical vascular disease risk in defensive coping Africans and Caucasians.
Methods:
The Coping Strategy Indicator questionnaire identified participants who preferably utilise defensive coping. Ambulatory blood pressure was monitored for 24 h and carotid intima-media thickness (CIMT) was determined from ultrasound images, as an indicator of subclinical vascular disease risk. Salivary MHPG was analysed with high performance liquid chromatography.
Results:
Defensive active coping Africans (n = 143) showed overall poorer health than Caucasians (n = 148), with higher self-reported stress, alcohol abuse, hypertension, abdominal obesity, and risk of diabetes (p ≤ 0.05). African women demonstrated lower levels of MHPG compared with Caucasian women, although no differences in men were found. Furthermore, Africans revealed a trend of increased low grade inflammation and glycated haemoglobin which was associated with increased CIMT. There was an inverse association between MHPG and CIMT [β = -0.22 (-0.40, -0.03)], in African men with a high risk of subclinical vascular disease (n = 30).
Conclusions:
Novel findings revealed that defensive active coping Africans are more at risk of subclinical vascular disease, possibly resultant of autonomic exhaustion (decreased MHPG). When defensive coping fails, sympathetic hyperactivity may be followed by autonomic exhaustion and sympatho-adrenal-medullary system desensitisation, resulting in pathology.
... Descriptors: Heart rate, Blood pressure, Cognition, Ethnicity Hypertension is more prevalent and severe, and its onset occurs earlier in life in individuals of African descent than in the White population (Kurian & Cardarelli, 2007;Malan et al., 2010). A complex interaction of genetic factors, personality traits, and physiological susceptibility has been proposed to contribute to interethnic differences in the occurrence of hypertension. ...
Underlying mechanisms of increased pressor responses to stress in Blacks are poorly understood. Cardiovascular regulation of normotensive Black (n=43) and Caucasian (n=90) Africans was studied during a cold pressor and color-word conflict test. Autonomic evaluation was performed by spectral analysis. Higher diastolic pressor and heart rate responses to the cold pressor test were observed in Black compared to Caucasian Africans. Autonomic efferent outflow to stress was comparable between groups. Transient downregulation of baroreflex during stress was evident in Blacks but not in Caucasians. Greater diastolic pressor responses were related to a higher cardiac reactivity, a baroreflex desensitization, and higher stress perception in Black Africans. Thus, increased stress perception may facilitate cardiac and diastolic hyperreactivity, indirectly affecting baroreflex function in Black Africans.
