Maria Philipina Wissing

An epidemiological study of hypertension and its determinants in a population in transition: the THUSA study

Background: Many black persons in South Africa have been subjected to urbanisation and urbanisation has led to a significant increase in diseases of lifestyle. The determinants of hypertension in a population in transition have not been well-defined and there is a pressing need for observational epidemiological studies as well as randomised-controlled trials in populations from Africa. The aim of this study was to investigate the association between blood pressure and factors known to contribute to hypertension.Methods: The study sample consisted mainly of Setswana speaking people, divided into different levels (strata) of urbanisation, namely stratum 1 (rural) to stratum 5 (urbanised). A total of 1821 black subjects, which included 1040 woman, were recruited and randomly selected from 37 sites from the four geographical quarters of the North West Province of South Africa. The following questionnaires were used: demographic, anthropometric, quantitative food frequency, physical activity and scales to measure psychosocial variables. Biochemical analysis (standardised methods) were done on the serum and plasma of the subjects and the blood pressure was measured with a sphygmo- manometer.Results: Of the total sample, 22.8% of the subjects had systolic and 20.7% diastolic blood pressures above 140/90 mm Hg. Males and females from stratum 3 showed the highest rate of hypertension (32.9% systolic and 25.1% diastolic) and stratum 5 the lowest. Blood pressure correlated positively with age, level of urbanisation, WHR (waist:hip ratio) and smoking. In the woman the diastolic blood pressure correlated the best with body mass index (BMI), serum triglycerides, total serum cholesterol, low-density lipoprotein (LDL) cholesterol and s-GGT. Coping strategies, experience of social support, cultural aspects and affect balance are related to blood pressure, especially in the case of women.Conclusions: It seems that factors associated with urbanisation are related to the manifestation of hypertension in black people of the North West Province, given the highest mean blood pressure in people living in informal settlements, where most newcomers to the urban areas live.

Coping with urbanization: A cardiometabolic risk? The THUSA study

An assessment of specific coping styles in rural-urban Africans is done to evaluate its contribution as cardiometabolic risk factor. In total, 608 apparently healthy Africans were included in a cross-sectional comparative study from the North-West Province in South Africa. The adapted and translated COPE Questionnaire classified participants according to their responses into active (AC) or passive (PC) copers. Fasting resting metabolic syndrome (MS) indicators using the WHO definition (glucose, high density lipoproteins, waist/hip ratio, hypertension prevalence, and triglyceride) and associated MS values, i.e. fibrinogen were obtained. The Finapres recorded resting blood pressure continuously. Co-variates for all statistical analyses included age, body mass index (BMI) and lifestyle factors (alcohol consumption, smoking habits and physical activity). The only MS values prevalent in urbanized participants were higher hypertension prevalence rates and fibrinogen (women only) compared to their rural counterparts. Adding coping styles, it was mainly the urbanized AC participants that indicated higher MS values (hypertension prevalence, glucose and fibrinogen) when compared to their rural and PC counterparts. In conclusion, urbanization is associated with enhanced blood pressure and fibrinogen (women) values only. Coping as cardiometabolic risk is accentuated in the urbanized AC group, especially the men. The urbanized AC group with their higher blood pressure values and more MS indicators appears to have behaviorally an AC style but physiologically a dissociated AC style.

Specific coping strategies of Africans during urbanization: Comparing cardiovascular responses and perception of health data

Specific coping mechanisms of Africans during urbanization were compared to and correlated with cardiovascular responses and perception of health data. Subjects included men (N=286) and women (N=360). The COPE questionnaire classified subjects as active (AC) or passive (PC) copers and the General Health Questionnaire measured subjective perception of health. The Finapres recorded blood pressure continuously before and during application of a handgrip test. Analyses adjusting for age, body mass index and resting cardiovascular data revealed that AC rural subjects showed predominantly cardiac responses and PC rural subjects predominantly vascular responses. All urbanized African men and women showed higher resting blood pressure, vascular responsiveness and hypertension prevalences than their rural counterparts. All rural AC subjects, especially women, and all urban PC subjects, especially men, reported a poorer perception of health. In conclusion, subjects with a PC style showed a predominantly vascular response in rural and urban areas whereas subjects with an AC style seem to shift from a predominant cardiac output response to a predominant vascular resistance response when moving from a rural to an urban area.

Exploring the Validity of the Values-In-Action Inventory of Strengths (VIA-IS) in an African Context

This study explored the validity of the Values-In-Action Inventory of Strengths (VIA-IS) in an African context. A convenience sample of 256 African students completed the VIA-IS in English. The majority of strengths subscales had good reliability coefficients and mean scores comparable to those reported in a Western context. Satisfactory criterion-related validity was established through correlations with other well-being indices. First and second order confirmatory factor analyses only partly supported construct validity. All strengths subscales consisted of more than one factor. The hypothesised six-virtue cluster pattern was partially supported. Exploratory factor analysis suggested the possibility of an emic factor pattern of strengths consisting of 3 components: Within the first factor, Intrapersonal and Relationship Strengths, two clusters are distinguished, namely, Intrapersonal Strengths, and Horizontal and Vertical Relationship Strengths. The second factor was Integrity in Group Context. Thus, the VIA-IS has merit, but is not completely valid in its original form.

Integrated nutrition science: from theory to practice in South Africa.

OBJECTIVE To describe an integrated, holistic conceptual framework and research paradigm for a better understanding of the nutrition transition in middle- and low-income countries. MOTIVATION Current inability effectively to prevent the increasing burden related to changes in food consumption patterns and other health behaviours of populations in transition motivates a new approach for nutrition research and practice. In this proposed approach, broader and integrated dimensions of science and practice may be applied for a better understanding of this complex phenomenon. RESULT Examples from our own studies are given and quoted to illustrate how results from transdisciplinary studies were used to design an integrated, holistic programme to improve quality of life of people infected with HIV. CONCLUSION Based on these experiences it is argued that the more holistic and integrated approach should and could lead to more effective and sustainable interventions to prevent the adverse health consequences of the nutrition transition. At the same time such an approach will contribute to efforts to conserve the environment and also human, living and natural resources.

Psychosocial Well-being in a Group of South African Adolescents

The aim of this study was to explore the psychosocial well-being of a group of South African adolescents. Participants (N=665, ages 15–17 years; males = 214, females = 451) from three high schools completed questionnaires on psychosocial well-being. Structured interviews were also conducted with 24 participants selected from various levels of functioning as established quantitatively. Quantitative findings indicate that 60% of the adolescents had lower psychological well-being as measured on the Mental Health Continuum-Short Form (Keyes, 2005). Adolescents experienced psychological well-being as characterised by purposeful living and meaning; positive relationships; being a role-model; self-regard; constructive coping; positive emotions and gratitude. Lower mental health was experienced as characterized by meaninglessness, impaired relationships, identification with dysfunctional outsiders, self-incompetence, dysfunctional behaviours, negative emotions and helplessness. The youth distinguished between experiences of well-being and the absence thereof. Interventions are indicated to enhance psycho-social well-being in the adolescents.

Psychometric Properties of Various Scales Measuring Psychological Well-Being in a South African Context: The FORT 1 Project

The aim of this study was to do a first phase screening of psychometric properties of various scales measuring facets of psychological well-being so as to address further questions in the FORT 1 project (FORT 1 = Clarifying the nature of psychological strengths). All scales (except one) were developed in a Western context, and measure facets of cognitive, affective, conative, social, and spiritual psychological well-being. As it could not be assumed that scales are valid in South African contexts, a broad screening of their psychometric properties was necessary before specific questions could be adressed. A convenience sample (N=514) including white (n=384) and black (n=130) students and adults from the North West Province and Gauteng areas completed all questionnaires. Psychometric properties of scales varied from acceptable to unacceptable for use in a specific subgroup.

The role of personality factors in the dynamics of context and psychological well-being

The purpose of this study was to determine personality factors that mediate between context and psychological well-being. A convenience sample of 514 mutlicultural participants from Potchefstroom (n=384) and Mafikeng (n=130) comprising mainly of black and white students was drawn. The participants completed measures on extraversion and agreeableness and psychological well-being in a cross-sectional survey. Context was defined in terms of differentials pertaining to race, socioeconomic differentials and infrastructural resources. Regression analyses indicated the viability of relationships among context, personality and psychological well-being. Structural equation models showed that both extraversion and agreeableness mediate the relationship between context and psychological well-being. Future research using longitudinal designs may study the importance of social context, personality factors and psychological well-being within and between groups.

Coping self-efficacy as mediator in the dynamics of psychological well-being in various contexts

The aim of this study was to explore whether coping self-efficacy mediates between various distress related variables on the one hand (symptoms of stress and depression), and the degree of psycho-social well-being as measured on the upper end of the mental health continuum on the other hand. Participants were two multi-cultural student groups (n1 = 568; n2=1480) as well as two community samples of Setswana speaking adults (n3=477; n4=1275). Students completed the English versions of measures, and the community samples of adults the Setswana versions. Mediation was evaluated through the testing of structural equation models. Coping self-efficacy mediated significantly between distress and wellbeing, although stressors also influenced the level of psychosocial well-being directly.

Well-being in the Batswana cultural context: constructs and measures

The study investigated wellbeing in a Setswana-speaking sample. Participants (n=459, males =141 females =318; 22% = aged between 30 and 40 years) completed the General Psychological Well-being Scale (GPWS: Khumalo, Temane & Wissing, 2010) and the Mental Health Continuum Short-Form (MHC-SF: Keyes, 2005b). Data were analyzed applying classical test theory (CTT), structural equation modelling (SEM; measurement model) and item response theory (IRT; Rasch model). Both GPWS and MHC-SF measures yielded a multidimensional wellbeing factor structures indicative of a hedonic-eudaimonic wellbeing overlap. Further qualitative research could explore the cultural contextual meanings of wellbeing in Setswana culture.