1. Academic Wits Research Publications (Faculties submissions)
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Item The impact of diferences in plasma glucose between glucose oxidase and hexokinase methods on estimated gestational diabetes mellitus prevalence(Nature Research, 2019-05) Dickson, Lynnsay M.; Buchmann, Eckhart J.; Janse Van Rensburg, Charl; Norris, Shane A.We evaluated the extent of measurement discordance between glucose oxidase and hexokinase laboratory methods and the efect of this on estimated gestational diabetes mellitus (GDM) prevalence in a routine clinical setting. 592 consecutive urban African women were screened for GDM. Paired venous specimens were submitted to two independent calibrated laboratories that used either method to measure plasma glucose concentrations. World Health Organisation diagnostic criteria were applied. GDM prevalence determined by the glucose oxidase and hexokinase methods was 6.9% and 5.1% respectively. The overall GDM prevalence was 9%. Only 34% of GDM positive diagnoses were common to both laboratory methods. Bland Altman plots identifed a bias of 0.2mmol/l between laboratory methods. Plasma glucose concentrations measured by the glucose oxidase method were more platykurtic in distribution. Low diagnostic agreement between laboratory methods was further indicated by a Cohen’s kappa of 0.48 (p<0.001). Reports of GDM prevalence using either the glucose oxidase or hexokinase laboratory methods may not be truly interchangeable or directly comparable.Item The burden of cancers associated with HIV in the South African public health sector, 2004–2014: a record linkage study(2019-05) Dhokotera, Tafadzwa; Bohlius, Julia; Spoerr, Adrian; Egger, Matthias; Ncayiyana, Jabulani; Olago, Victor; Singh, Elvira; Sengayi, MazvitaIntroduction: The impact of South Africa’s high human immunodeficiency virus (HIV) burden on cancer risk is not fully understood, particularly in the context of antiretroviral treatment (ART) availability. We examined national cancer trends and excess cancer risk in people living with HIV (PLHIV) compared to those who are HIV-negative. Methods: We used probabilistic record linkage to match cancer records provided by the National Cancer Registry to HIV data provided by the National Health Laboratory Service (NHLS). We also used text search of specific HIV terms from the clinical section of pathology reports to determine HIV status of cancer patients. We used logistic and Joinpoint regression models to evaluate the risk and trends in cancers in PLHIV compared to HIV-negative patients from 2004 to 2014. In sensitivity analysis, we used inverse probability weighting (IPW) to correct for possible selection bias. Results: A total of 329,208 cancer cases from public sector laboratories were reported to the NCR from 2004 to 2014 with the HIV status known for 95,279 (28.9%) cancer cases. About 50% of all the female cancer cases (n = 30,486) with a known status were HIV-positive. PLHIV were at higher risk of AIDS-defining cancers (Kaposi sarcoma [adjusted OR:134, 95% CI:111–162], non-Hodgkin lymphoma [adjusted OR:2.73, 95% CI:2.56–2.91] and, cervix [adjusted OR:1.70, 95% CI:1.63–1.77], conjunctival cancer [adjusted OR:21.5, 95% CI:16.3–28.4] and human papilloma virus (HPV) related cancers (including; penis [adjusted OR:2.35, 95% CI:1.85–2.99], and vulva [adjusted OR:1.94, 95% CI:1.67–2.25]) compared to HIV-negative patients. Analysis using the IPW population yielded comparable results. Conclusion: There is need for improved awareness and screening of conjunctival cancer and HPV-associated cancers at HIV care centres. Further research and discussion is warranted on inclusive HPV vaccination in PLHIV.Item The prevalence of malnutrition and growth percentiles for urban South African children(BMC Public Health, 2019-05) Nyati, Lukhanyo H.; Pettifor, John M.; Norris, Shane A.Background: Low- and middle-income countries (LMIC) are experiencing a double-burden of malnutrition characterised by high prevalence of both under- and over-nutrition. We set out using data from the mixedlongitudinal Birth-to-Twenty Plus (Bt20+) birth cohort, to evaluate the patterns of malnutrition and growth in a large South African (SA) city by; (i) assessing the prevalence of undernutrition from birth to 5 years of age and overweight and obesity from ages 2 to 21 years in black and white, male and female children, and (ii) determining percentiles for height, weight, BMI, waist and hip circumferences and comparing the centiles to American and Dutch references. Methods: Height, weight, waist and hip circumferences were measured on urban black and white SA children from the Bt20+. A total of 3273 children born between April and June 1990 in the Greater Johannesburg Metropolitan area were included in the cohort. Z-scores were derived using the WHO 2006 child growth standards (0–5 years), for defining stunting, underweight and wasting. The International Obesity Task Force (IOTF) references were used to define overweight and obesity. Percentiles were developed using the lambda mu sigma (LMS) method and compared to American and Dutch references. Results: Black children were consistently shorter and black males lighter than white children and American references. The prevalence of stunting peaked at 2 years and was significantly higher in males than females and in black than white children. Black females had a greater prevalence of overweight and obesity than black males from 10 to 17 years. The percentiles for black females for weight and BMI were similar to those of South African white and American references but both black and white South African females had lower waist circumferences than American references. Conclusion: The growth percentiles show that young South African urban black females are experiencing general but not central obesity due to a secular change which is faster in weight than height. High levels of undernutrition persist alongside high levels of over-nutrition with adolescence being a critical period for the upsurge in obesity in females. Early intervention is needed to combat the rise in obesity.Item Religiosity and sexual abstinence among Nigerian youths: does parent religion matter?(BioMed Central, 2019-04) Somefun, Oluwaseyi DolapoBackground: Religion plays an important role in youth behaviours, making it a significant factor in the discourse on youth sexuality in sub-Saharan Africa. Several studies have found that religion and religiosity play an important role in the sexual behaviours of young people. However, little research in Nigeria has examined the mechanisms through which religiosity influences youth sexual behaviour and if parents’ religion moderates this relationship. Guided by the social control theory, this paper contributes to the existing literature by examining the relationship between religiosity and youth sexual behaviour. Methods: Data for the study came from 2399 male and female youth aged 16–24 years in four states purposively selected from four regions in Nigeria. Abstinence was the sexual behaviour of interest. Logistic regression was used to examine this relationship. Results: Results showed that 68% of the youth had never had sex. Religiosity was a protective factor for youth sexual behaviour and this positive association was still evident even after controlling for other covariates. Youth who were highly religious (OR – 1.81, CI- 1.13-2.88) had significantly higher odds of abstaining compared to their counterparts who were not religious. Conclusion: Religiosity is a protective factor for sexual abstinence among youth in Nigeria. Policy makers can work around using religious institutions for behavioural change among youth in Nigeria.Item Prevention care for secondary health conditions among people living with spinal cord injuries: research protocol(Springer Nature, 2019-03) Pilusa, S.; Myezwa, Hellen; Potterton, JoanneObjective: People living with spinal cord injuries are at a high risk to experience preventable secondary health conditions in their lifetime, which can lead to rehospitalisation and death. Given the fact that spinal cord injury is a long term disability requiring on-going care, there is need to strengthen prevention of secondary health conditions. This study aims to establish factors influencing prevention care for secondary health conditions among people living with spinal cord injuries in a metropolitan area in order to develop a prevention model of care. Results: A record review of patients living with spinal cord injuries will be conducted to identify the prevalence of secondary health conditions and associated factors. Semi-structured interviews will be conducted on patients living with spinal cord injuries, their caregivers and therapists to explore the contextual factors (personal and environmental factors) influencing the prevention of secondary health conditions. Thematic analysis will be used to identify the themes. Nominal group technique will be used to develop the prevention model of care for secondary health conditions. This study will be conducted at a tertiary and specialised rehabilitation hospital in South Africa.Item Fat redistribution and accumulation of visceral adipose tissue predicts type 2 diabetes risk in middle-aged black South African women: a 13-year longitudinal study(Springer Nature, 2019-03) Mtintsilana, Asanda; Micklesfield, Lisa K.; Chorell, Elin; Olsson, Tommy; Goedecke, Julia H.Background: Cross-sectional studies in South Africa (SA) have shown that black SA women, despite being more insulin resistant, have less visceral adipose tissue (VAT) and more subcutaneous adipose tissue (SAT) than white women. This study aimed to investigate whether baseline and/or change in body fat and its distribution predict type 2 diabetes (T2D) risk in middle-aged black SA women, 13 years later. Methods: We studied 142 black SA women who are the caregivers of the Birth-to-Twenty plus cohort, and who had normal glucose tolerance (NGT) at baseline. At baseline and follow-up, fasting blood samples, basic anthropometry and dual-energy X-ray absorptiometry-derived body composition were measured. At follow-up, an oral glucose tolerance test was completed. The WHO diabetes diagnostic criteria were used to define NGT, impaired fasting glucose (IFG)/impaired glucose tolerance (IGT), impaired glucose metabolism (IGM) and T2D. Results: At follow-up, 64% of participants remained NGT, whereas 25% developed IGM, and 11% developed T2D. The IGM and the T2D groups were combined for statistical analyses. At baseline, trunk fat mass (FM), VAT but not SAT (measures of central FM) were higher in the IGM/T2D group than the NGT group (p < 0.0001). In contrast, the IGM/T2D group had lower leg %FM at baseline than the NGT group (p < 0.0001). Baseline trunk FM (Odds ratio per 1 kg increase (95% confidence interval, 1.95 (1.43–2.67))), and VAT (OR per 10 cm2 increase, 1.25 (1.10–1.42)), and the change in VAT (1.12 (1.03–1.23)) were associated with greater odds of developing IGM/T2D, whereas baseline leg FM (OR per 1 kg increase, 0.55 (0.41–0.73)) were associated with reduced IGM/T2D risk at follow-up (p < 0.05). Conclusions: Relative fat redistribution, with VAT accumulation, predicted the development of IGM/T2D 13 years before its onset. Prevention of central obesity is a key factor to reduce the risk of developing T2D among middle-aged urban black SA women.Item Hypertension in a rural community in South Africa: what they know, what they think they know and what they recommend(BioMed Central, 2019-03) Klipstein-Grobusch, Kerstin; Jongen, Vita W.; Lalla-Edward, Samanta T.; Vos, Alinda G.; Godijk, Noortje G.; Tempelman, Hugo; Grobbee, Diederick E.; Devillé, WalterBackground: Hypertension is one of the most important risk factors for cardiovascular disease and has a high prevalence in South Africa and other low- and middle-income countries. However, awareness of hypertension has been reported to be low. Health programmes can increase awareness of hypertension and its causes, but hinge on the knowledge and perception of the targeted community. Therefore, this study investigated knowledge on and perceptions about hypertension of community members in a rural area in Limpopo, South Africa with the aim to increase awareness of hypertension and cardiovascular disease in the local population. Methods: Using a mixed methods study approach, 451 participants of the Ndlovu Cohort Study, attending a follow-up visit between August 2017 and January 2018, completed a questionnaire on cardiovascular risk perception. A knowledge score was calculated for all participants. Sixty participants were invited to participate in six focus group discussions, of which 56 participated. Audio recordings were transcribed verbatim, transcripts coded, and thematic analysis of the data undertaken to obtain an understanding of knowledge and perception of hypertension in the community. Results: Most members of the community seemed to have intermediate (74.3%) or good (14.0%) knowledge of hypertension based on the knowledge score, and only 11.8% of the population had poor knowledge. The risk factors of hypertension seemed to be well known in the community. Poverty was identified as a major vulnerability in this community limiting choices for healthy lifestyles such as nutritious foods, recreational physical activity and accessing health care timely. Participants proposed community-based activities as an effective way to reach out to community members for prevention and management of hypertension. Conclusion: This study highlights the need for improved health promotion efforts to increase knowledge of hypertension in rural communities, and to address poverty as a major obstacle to healthy life-style choices.Item Increases in statin eligibility to reduce cardiovascular risk according to the 2013 ACC/AHA cholesterol guidelines in the Africa Middle East region: a sub-analysis of the Africa Middle East Cardiovascular Epidemiological (ACE) study(BioMed Central, 2019-03) Raal, Frederick J.; Hamoui, Omar; Omar, Mohamed I.; Rashed, Wafa; Kane, Abdoul; Alami, Mohamed; Abreu, Paula; Mashhoud, Walid; Alsheikh-Ali, Alawi A.Background: With development of cholesterol management guidelines by the American College of Cardiology/ American Heart Association (ACC/AHA), more individuals at risk of cardiovascular disease may be eligible for statin therapy. It is not known how this affects statin eligibility in the Africa and Middle East Region. Methods: Data were used from the Africa Middle East Cardiovascular Epidemiological (ACE) study. The percentage of subjects eligible for statins per the ACC/AHA 2013 cholesterol guidelines and the 2002 National Cholesterol Education Program-Adult Treatment Panel (NCEP-ATP III) recommendations were compared. Analyses were carried out according to age, gender, community (urban/rural), and country income categories based on World Bank definitions. Results: According to the ACC/AHA recommendations, 1695 out of 4378 subjects (39%; 95% confidence interval [CI], 37–40%) satisfied statin eligibility criteria vs. 1043/4378 (24%; 95% CI, 23–25%) per NCEP-ATP recommendations, representing a 63% increase in statin eligibility. Consistent increases in eligibility for statin therapy were seen according to the ACC/AHA vs. NCEP-ATP guidelines across sub-groups of age, gender, community, and country income. Notable increases for statin eligibility according to ACC/AHA vs. NCEP-ATP were seen, respectively, in subjects aged ≥65 years (86% vs. 39%), in males (46% vs. 25%), in low-income countries (28% vs. 14%), and rural communities (37% vs. 19%). Conclusion: An increase in statin eligibility was seen applying ACC/AHA cholesterol guidelines compared with previous NCEP-ATP recommendations in the Africa Middle East region. The economic consequences of these guideline recommendations will need further research.Item The physical sequelae of perinatally acquired HIV in adolescents: a research proposal(2019-01) Comley‑White, Nicolette; Potterton, Joanne; Ntsiea, VeronicaObjectives: As the global access of antiretrovirals for HIV-infected infants improves, so the body of perinatally HIV-infected adolescents (PHIVA) grows. The neurological and physical complications of HIV, both in children and in adults, are well established, however there is a paucity of data pertaining to PHIVA, a group of people who have had a lifetime exposure to the virus and to antiretrovirals. There has been a resounding call for further research in this area, as well as for the development of policies and programmes for this population. The aim of this study is to determine the physical sequelae in PHIVA and to propose a model of care for this population. Methods: Through interviews with PHIVA, the perceived physical challenges will be established. Thereafter a cohort study with age-matched participants will determine if PHIVA have any limitations in fatigue, endurance, motor func‑ tion and muscle strength, body mass index, peripheral neuropathy, level of disability and quality of life. Using these results, a model of care will be proposed through the nominal group technique with both PHIVA and clinicians work‑ ing in HIV and adolescence.Item Ad libitum water consumption prevents exercise-associated hyponatremia and protects against dehydration in soldiers performing a 40-km route-march(BioMed Central, 2019-01) Nolte, Heinrich W.; Nolte, Kim; Hew-Butler, TamaraBackground: It remains unclear if ad libitum water drinking, as a hydration strategy, prevents exercise-associated hyponatremia (EAH) during prolonged exercise. The aim of this study was to determine the incidence of EAH within the broader context of fluid regulation among soldiers performing a 40-km route-march ingesting water ad libitum. Methods: Twenty-eight healthy male soldiers participated in this observational trial. Pre- and post-exercise body mass, blood and urine samples were collected. Blood samples were assessed for serum sodium ([Na+]), glucose, creatinine, urea nitrogen (BUN), plasma osmolality, creatine kinase (CK), and plasma arginine vasopressin (AVP) concentrations. Plasma volume (PV) was calculated using hematocrit and hemoglobin. Urine samples were analyzed for osmolality and [Na+]. Water intake was assessed by weighing bottles before, during and after the march. The mean relative humidity was 55.7% (21.9–94.3%) and the mean dry bulb temperature was 27.1 °C (19.5 °C - 37.0 °C) during the exercise. Results: Twenty-five soldiers (72 ± 10 kg) (Mean ± SD) completed the march in 09:11 ± 00:43 (hr:min). Participants consumed 736 ± 259 ml/h of water and lost 2.8 ± 0.9 kg (4.0% ± 1.4%, P < 0.05) of body mass. Significant (pre-march vs. post-march; P < 0.05) decreases in serum [Na+] (141 mmol/L vs. 136 mmol/L), plasma osmolality (303 mOsmol/kg H2O vs. 298 mOsmol/kg H2O), and serum creatinine (111 μmol/L vs. 101 μmol/L) and urine [Na+] (168 mmol/L vs. 142 mmol/L), as well as significant increases in plasma AVP (2 pg/ml vs. 11 pg/ml), plasma CK (1423 U/L vs. 3894 U/L) and urine osmolality (1035 mOsmol/kg H2O vs. 1097 mOsmol/kg H2O) were found. The soldier (72 kg) with the lowest postexercise sodium level completed the march in 08:38. He drank 800 ml/h, lost 2% body mass, and demonstrated (prepost) increases in plasma osmolality (294–314 mOsmol/kg H2O), BUN (20–30 mg/dl), AVP (2–16 pg/ml) and PV (41%). His urine osmolality decreased from 1114 mOsmol/kg H2O to 1110 mOsmol/kg H2O. No participants finished the route-march with a serum [Na+] indicating hypernatremia (range, 134–143 mmol/L). Conclusions: Ad libitum drinking resulted in 4% body mass loss with a 2 mmol/L serum [Na+] reduction in conjunction with high urine osmolality (> 1000 mOsmol/kg H2O) and plasma AVP. No single hydration strategy likely prevents EAH, but hypernatremia (cellular dehydration) was not seen despite > 2% body mass losses and high urine osmolality.