Depressive Symptoms and 24-Hour Ambulatory Blood Pressure in Africans: The SABPA Study

Disturbances in circadian rhythm might play a central role in the neurobiology of depression. We examined the association between depressive symptoms and 24-hour ambulatory BP in a sample of 405 (197 black and 208 Caucasian) urbanized African teachers aged 25 to 60 yrs (mean 44.6 ± 9.6 yrs). Depressive symptoms were assessed using the self-administered 9-item Patient Health Questionnaire (PHQ-9). After adjusting for age, sex, and ethnicity, participants with severe depressive symptoms (PHQ-9 ≥ 15) had higher odds of hypertension defined from ambulatory BP and/or use of antihypertensive medication (odds ratio = 2.19, 95% CI, 1.00–4.90) in comparison to participants with no symptoms. Compared to Caucasians with no depressive symptoms, those with severe symptoms had blunted nocturnal systolic BP drop of 4.7 mmHg (95% CI, −0.5 to 10.0, P = 0.07). In summary, depressive symptoms were associated with the circadian BP profile in black and Caucasian Africans

Association between Nutritional Awareness and Diet Quality: Evidence from the Observation of Cardiovascular Risk Factors in Luxembourg (ORISCAV-LUX) Study

This study examined the association between nutritional awareness and diet quality, as indicated by energy density, dietary diversity and adequacy to achieve dietary recommendations, while considering the potentially important role of socioeconomic status (SES). Data were derived from 1351 subjects, aged 18–69 years and enrolled in the ORISCAV-LUX study. Energy density score (EDS), dietary diversity score (DDS) and Recommendation Compliance Index (RCI) were calculated based on data derived from a food frequency questionnaire. Nutritional awareness was defined as self-perception of the importance assigned to eating balanced meals, and classified as high, moderate, or of little importance. Initially, a General Linear Model was fit that adjusted for age, sex, country of birth, and body mass index (BMI). Furthermore, simultaneous contributions to diet quality of individual-level socioeconomic factors, education, and household income were examined across levels of nutritional awareness. Attributing high importance was associated inversely with energy density (p = 0.02), positively with both dietary diversity (p \u3c 0.0001), and adequacy to dietary recommendations (p \u3c 0.0001), independent of demographic factors, weight status and SES. Further adjustment for household income in the EDS-related multivariable model, reduced the β coefficient by 47% for the “moderate importance” category and 36% for the “high importance” category. Likewise, the β coefficient decreased by 13.6% and 10.7% in the DDS-related model, and by 12.5%, and 7.1% in the RCI-related model, respectively, across awareness categories. Nutritional awareness has a direct effect on diet quality, with a minor component of variance explained by improved income. The impact of nutritional awareness on diet quality seems to be a promising area for both health promotion and health policy research

Validation of the Teacher Stress Inventory (TSI) in a multicultural context: The SABPA study

The aim of this study was to validate the Teacher Stress Inventory (TSI) for use in a South African context. The process of scale validation also sheds significant light on this culturally diverse group of participants’ levels of psychological well-being and physical health, and its association with the level of stress that teachers reported. Using a cross-sectional survey design, Caucasian (n = 209) and African (n = 200) educators’ subsiding in the North-West Province of South Africa, completed the TSI, together with a number of self-report and physiological measures of stress and well-being. In contrast to the five factors of the TSI identified in US samples, statistical analysis yielded a two-factor model (i.e. General circumstance-related stress and Learner-related stress) with satisfactory reliability indices. Significant correlation with measures of psychological and physiological health also reflected positively on the criterion-related validity of the scale. The TSI proved to be a useful, brief self-report questionnaire for the assessment of teacher stress in this cohort of South African teachers.Keywords: psychological well-being; reliability; South African context; stress; Teacher Stress Inventory (TSI); validit

A Challenged Sympathetic System Is Associated with Retinal Vascular Calibre in a Black Male Cohort: The SABPA Study

Sympathetic system hyperactivity and depression are related to cardiac remodelling in Black men. We investigated whether sympathetic system hyperactivity and depressive symptoms are related to retinal vascular dysregulation. A total of 76 Black and 83 White men (23–68 years of age) from the SABPA study were included. Depressive symptoms, 24h pulse pressure (PP), fasting blood and 24-hour urinary catecholamine data were obtained. Retinal vascular calibre was quantified from digital photographs using standardized protocols. Black men demonstrated increased (p 50 mmHg), hypertension (78.9 % vs 48.4%) and depression (34.2% vs. 13.3%) prevalence compared to White men. Despite lower epinephrine levels, epinephrine was associated with arteriolar narrowing and venular widening in the Black men [Adj R2 −0.37 (95% CI: −0.66, −0.09), p=0.013; Adj R2 0.35 (95% CI: 0.13, 0.57), p=0.003]. This might suggest ß-adrenergic hyporesponsivity to epinephrine, which was accompanied by hyperpulsatile blood pressure in the Black group. In the White group, depressive symptoms and norepinephrine were associated with retinal arteriolar narrowing. A profile of ß-adrenergic hyporesponsivity, indicative of a chronically challenged sympathetic system, was associated with retinal vascular remodelling in Black men. ß-adrenergic hyporesponsivity as a result of chronic stress emphasized central control of the brain on the circulatory system irrespective of the vascular bed

Coping disability of Africans during urbanization: a risk marker in the development of lifestyle diseases?

Urbanization with accompanying insecurities and disruption in African social relationships is consistent with an increase in the prevalence of lifestyle diseases such as hypertension and the metabolic syndrome. The individual with less positive social relationships like those experienced during urbanization will perceive this interaction as being particularly stressful. If lifestyle factors (smoking habits, alcohol consumption, physical inactivity) additionally are added to their inherently higher levels of salt sensitivity, lower levels of plasma renin activity and vascular hyperreactivity, the prevalence of hypertension in Africans is more understandable. How Africans cope with urbanization though has not been well described and it is not certain how a particular coping style may be associated with factors that maintain and aggravate psychosomatic diseases in Africans. Certain coping behaviors over time can induce stress-activation of the sympathetic nervous system (SNS) and the hypothalamus-pituitary-adrenal cortex (HPA) axis leading to changes in stress hormone levels and cardiovascular adjustments that may increase hypertension risks. Recent research indicated that a dissociation of physiological but not behavioral coping styles of Africans during urbanization occurs. An even more disturbed cardiovascular, endocrine and psychological profile was associated with a specific coping style which inevitably poses two questions: Firstly, is only urbanization responsible for these changes and secondly,does a specific coping style (behaviorally and physiologically) during urbanization still have the same outcome when compared to that seen in a rural setting? It, therefore, accentuates the need to explore the dynamics of coping styles of Africans on health indicators during psychosocial stress/urbanization. By addressing these issues valuable contributions can be made by inducing the acquisition of certain coping strategies in formative years

Cardiovascular dysfunction and specific coping mechanisms in Africans

Thesis (Ph.D. (Physiology))--North-West University, Potchefstroom Campus, 2005.Motivation: Cardiovascular dysfunction and hypertension are some of the leading causes of morbidity and mortality in the African population. According to the World Health Organisation the increases in these diseases are escalating in developing countries. Apart from the contributory role of genetics towards the incidence of hypertension, evidence regarding lifestyle as a determinant or marker of cardiovascular diseases in this group is not well known. The interaction of psychological and physiological mechanisms can contribute towards a broader scope of behavioural physiology in the higher prevalence of hypertension in Africans. Objectives: The main objective of the research in this thesis was to compare specific coping mechanisms of Africans with regard to cardiovascular dysfunction. Methodology: Manuscripts presented in Chapters 3, 4, and 5 made use of the cross-sectional comparative epidemiological "Transition and Health during Urbanisation in South Africa" (THUSA) project. The subjects included apparently healthy African men and women, which were recruited as a convenience sample from the North West Province, South Africa. Anthropometric measurements were taken and demographic questionnaires completed. An adapted Setswana COPE questionnaire was used to classify men and women as predominantly active (AC) or passive (PC) in coping style. Subjects were further subdivided into rural and urban groups (Manuscript Two), as well as younger (≤ 40) and older (≥ 45) age groups (Manuscript Three). The General Health Questionnaire (GHQ) was used to measure subjective perception of health in all three manuscripts. Blood pressure was recorded continuously before and during application of the handgrip test using the Finapres apparatus. Subjects were classified as normotensive and hypertensive after blood pressure measurement by the Finapres and the Riva-Rocci/Korotkoff method. The emphasis in this study was on the cardiovascular reactivity values. Fasting, resting serum renin activity, cortisol, prolactin, testosterone, high density lipoprotein, triglycerides, glucose and plasma fibrinogen values were correlated with cardiovascular and psychological variables. Significant differences between variables were determined by means of variance analyses (Manuscript One and Two adjusted for age; Manuscripts One, Two and Three adjusted for resting cardiovascular data). A logistic regression analysis was performed to determine the most significant determinants of urbanisation. All THUSA subjects and parents of under-aged adolescents gave informed consent and the study - was approved by the Ethics Committee of the Potchefstroom University for Christian Higher Education. The reader is referred to the abstracts at the beginning of each separate manuscript in Chapters 3 - 5 for a description of the subjects, study design and analytical methods used in each paper. Results and conclusions of the individual manuscripts: Results from the THUSA study showed that PC men and women reported more symptoms typical of an abnormal psychological and physiological profile than AC men and women. The PC men, compared to AC men, exhibited a larger vascular reactivity response as well as larger plasma renin activity. In contrast, the AC women showed a larger non-significant vascular reactivity response than PC women. All subjects though reacted with increased vascular reactivity on the stressor. Men with a PC strategy showed enhanced vascular reactivity, a perception of poorer health and larger stressor plasma renin activity. PC women reported more depressive symptoms and younger PC women indicated a higher prevalence of hypertension than younger AC women. As a follow-up on the first manuscript, the aim was focused mainly on including the environmental effect, namely urbanisation, as possible explanatory factor for the atypical physiological AC women’s' coping style. The rural AC subjects indicated more typical active coping central cardiac responses than rural PC subjects whereas urbanised AC and PC subjects indicated greater peripheral responses and hypertension prevalence rates. In addition, the urbanised AC men and women and PC women as opposed to their rural counterparts indicated symptoms more of a distress situation with increased values of prolactin and decreased values of testosterone. This was also accompanied by a perception of poorer health in women. Results of the AC style suggests that the typical physiological AC stimulation pattern of urbanised subjects and especially the women is dissociated from the "normal" physiological AC reaction and is now exhibited as a typical PC physiological stimulation pattern. The greater vascular reactivity, hypertension prevalence, perception of poorer health and endocrine distressed profile are associated with a PC and dissociated physiological AC style in an urban context in African men and women. No differences with regard to resting blood pressure or endocrine values were obtained when the AC and PC urbanised groups were compared. Africans develop cardiovascular dysfunction/hypertension during chronic stress or urbanisation. This implies a dissociation/habituation of physiological systems of African men and women despite having an active coping strategy. Active coping is, therefore, not necessarily "successful". Results of the first two manuscripts direct further investigation concerning the effects of ageing and urbanisation on the development of cardiovascular dysfunction and metabolic syndrome indicators in gender groups. The second manuscript showed that all rural AC subjects exhibit a more typical active coping central cardiac response and that rural PC and all urbanised subjects (AC and PC) exhibit enhanced peripheral vascular responses on the - handgrip test. Where peripheral vascular responses were more expected from older individuals in Manuscript Three, the occurrence of this pattern is strengthened in the younger subjects. The greater fibrinogen values in all younger urbanised women (AC and PC) compared to rural women further strengthen the risk for the development of cardiovascular disease. Increased vascular reactivity, abdominal obesity and increased levels of triglycerides as well as perception of poorer health were apparent in the urbanised AC women, PC men and women in comparison to their rural counterparts. The typical physiological AC stimulation pattern of urbanised women is dissociated from the "normal" physiological AC responses and is now exhibited as a typical PC physiological stimulation pattern. A typical PC style in older urbanised subjects is implicated in the greater hypertension prevalence. To conclude, it seems as if young urbanised Africans, and especially women, exhibit an AC style behaviourally with a dissociated physiological AC reaction pattern. Physiologically these women resemble a typical PC physiological cardiovascular and endocrine profile. This typical PC cardiovascular stimulation pattern is strengthened by a distressed endocrine profile, significant metabolic syndrome indicators and a 'perception of poorer health. Older PC style subjects also presented a greater hypertension prevalence. In this study it seems that cardiovascular changes that appear at a younger age might be influenced by other factors including urbanisation as a lifestyle factor as well as specific coping styles. Finally, a careful suggestion is made that specific coping mechanisms could be seen as a possible risk marker in the development of the metabolic syndrome.Doctora

Emotional stress as a risk for hypertension in sub-Saharan Africans: Are we ignoring the odds?

"Globally most interventions focus on improving lifestyle habits and treatment regimens to combat hypertension as a non-communicable disease (NCD). However, despite these interventions and improved medical treatments, blood pressure (BP) values are still on the rise and poorly controlled in sub-Saharan Africa (SSA). Other factors contributing to hypertension prevalence, such as chronic emotional stress, might provide some insight for future health policy approaches. Currently, Hypertension Society guidelines do not mention emotional stress as a probable cause for hypertension. Recently the 2014 World Global Health reports, suggested that African governments should consider using World Health Organization hypertension data as a proxy indicator for social well-being. However, the possibility that a stressful life and taxing environmental factors might disturb central neural control of BP regulation has largely been ignored in SSA. Linking emotional stress to vascular dysregulation is therefore one way to investigate increased cardiometabolic challenges, neurotransmitter depletion and disturbed hemodynamics. Disruption of stress response pathways and subsequent changes in lifestyle habits as ways of coping with a stressful life, and as probable cause for hypertension prevalence in SSA, may be included in future preventive measures. We will provide an overview on emotional stress and central neural control of BP and will include also implications thereof for clinical practice in SSA cohorts.