Genetic factors influencing bone mineral content in a black South African population

Abstract Background: While elevations in fasting plasma glucose (FPG) and glycosylated hemoglobin (HbA1c) are both recognized by the American Diabetes Association (ADA) as diagnostic of hyperglycemia, previous comparisons of these tests have demonstrated discordant individual classifications and population estimates. This may be due to additional postprandial glycemia reflected by HbA1c and, in African-descent populations, to non-glycemic factors that contribute to higher HbA1c at any given level of glycemia. We hypothesized that glycemic classifications based on FPG or HbA1c would differ in a Black South African population and investigated factors associated with discordance. Methods: 889 Black adults with previously undiagnosed diabetes, aged 40-79 years, from the population-based Health and Ageing in Africa: a Longitudinal Study of an INDEPTH Community in South Africa (HAALSI) cohort were included. Concordance between ADA FPG (normoglycemia [NG] <100 mg/dl, prediabetes [pre-DM] 100-125 mg/dl, diabetes [DM] ≥ 126 mg/dl) and HbA1c (NG <5.7%, pre-DM 5.7-6.4%, DM ≥ 6.5%) classifications was assessed using Cohen’s kappa statistic and logistic regression models were used to identify predictors of discordance. Results: Median age was 55 years (IQR 49-62) and 49.3% of the sample was male. Median glucose was 86.4 mg/dl and median HbA1c was 5.4%. Pre-DM, as defined by HbA1c, was present in 204 participants (22.9%), while FPG-defined pre-DM was present in 122 (13.7%). DM defined by HbA1c was present in 146 (16.4%), while FPG-defined DM was present in 36 (4.0%). Concordance between the two tests was poor (kappa statistic 0.18; 95%CI 0.13-0.24). Self-reported history of tuberculosis (OR 1.90, p=0.026) and higher HbA1c (OR 4.70, p<0.001) were associated with increased likelihood of discordance, whereas higher fasting glucose was associated with decreased likelihood of discordance (OR 0.58, p<0.001). There was no association between discordance and hemoglobin, HIV status, BMI, waist circumference or hip circumference. Conclusion: FPG and HbA1c exhibit poor concordance in classifying hyperglycemia in this Black South African population, with HbA1c-based definitions identifying higher prevalences of pre-DM and DM. Further work is needed to confirm whether these discrepancies are due solely to elevations in postprandial glucose. In the interim, clinicians should consider confirming elevated HbA1c concentrations with oral glucose tolerance testing, particularly in those with a history of tuberculosis, prior to making a diagnosis of DM in this population.

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A comparison of the visual status of dyslexic and non-dyslexic schoolchildren in Durban, South Africa

African Vision and Eye Health ◽

10.4102/aveh.v70i1.92 ◽

2011 ◽

Vol 70 (1) ◽

Author(s):

S. O. Wajuihian ◽

K. S. Naidoo

Keyword(s):

South African ◽

Educational Achievement ◽

Economic Status ◽

African Population ◽

South African Population ◽

Research Perspective ◽

Black South African ◽

Visual Status ◽

Lag Of Accommodation ◽

Vision Defects

Background: Reading difficulties constitute an impediment to the learning process and in the educational achievement of a child. Consequently, several studies examined the visual status of dyslexic children in the Caucasian populations. Such studies are lacking in the African populations.Aim: To determine the prevalence of vision defects and investigate if there is an association between dyslexia and vision in a South African population of dyslexic school children. Methods: This comparative study assessed the visual function of 62 children (31 dyslexic and 31 normally-reading children), mean age 13 ± 1.42 years and 11.90 ± 0.93 years respectively. The participants were matched for gender, race and socio-economic status. The visual functions evaluated and the techniques used were: visual acuity (LogMAR acuity chart), refraction (static retinos-copy), ocular alignment (cover test) near point of convergence (RAF rule), accommodation facility (± 2 D flipper lenses), amplitude of accommodation (push-up method) relative accommodation(trial lenses) accommodation posture (monocular estimation technique) and vergence reserves (prism bars). Results: In the following, results are provided for the dyslexic versus control: Refractive errors: (hyperopia 6.5% vs 3%,) (myopia 6.5% vs 6.5%), (astigmatism 10% vs 13%), (anisometropia 6.5% vs 6.5%) (amblyopia 6.5% vs 0%), (remote NPC 33% vs 48%) (esophoria at near 3% vs 0%) (exophoria at near 9.5% vs 0%), (accommodative infacility at near 54% vs 33%), lag of accommodation 39.28% vs 41,93%, (poor positive fusional amplitude at near, 25% vs 16%). Only the binocular accommodative facility at near was significantly associated with dyslexia (p=0.027). Conclusion: The prevalence of vision defects was similar between the dyslexic and non-dyslexic participants, which suggest that an association between dyslexia and vision variables investigated, cannot be inferred. This study provides a research perspective on the prevalence of vision defects in a Black South African population of dyslexic children and has clinical relevance and implications for the assessment, detection and management of vision anomalies in dyslexic schoolchildren. (S Afr Optom 2011 70(1) 29-43)

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Genetic variants inCYP(-1A2,-2C9,-2C19,-3A4and-3A5),VKORC1andABCB1genes in a black South African population: a window into diversity

Pharmacogenomics ◽

10.2217/pgs.11.106 ◽

2011 ◽

Vol 12 (12) ◽

pp. 1663-1670 ◽

Cited By ~ 39

Author(s):

Collet Dandara ◽

Zané Lombard ◽

Ingrid Du Plooy ◽

Tracy McLellan ◽

Shane A Norris ◽

...

Keyword(s):

South African ◽

Genetic Variants ◽

African Population ◽

South African Population ◽

Black South African

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Clinical spectrum and complications of Bell's palsy in a black South African population at the Dr George Mukhari Academic Hospital

Journal of the Neurological Sciences ◽

10.1016/j.jns.2015.08.250 ◽

2015 ◽

Vol 357 ◽

pp. e67-e68

Author(s):

D. Magazi ◽

B. Longo-Mbenza ◽

S. Mda

Keyword(s):

South African ◽

Bell’S Palsy ◽

African Population ◽

Clinical Spectrum ◽

Academic Hospital ◽

Bell's Palsy ◽

South African Population ◽

Black South African

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Multimorbidity and mortality in an older, rural black South African population cohort with high prevalence of HIV findings from the HAALSI Study

BMJ Open ◽

10.1136/bmjopen-2020-047777 ◽

2021 ◽

Vol 11 (9) ◽

pp. e047777

Author(s):

Alisha N Wade ◽

Collin F Payne ◽

Lisa Berkman ◽

Angela Chang ◽

F Xavier Gómez-Olivé ◽

...

Keyword(s):

South African ◽

Mortality Risk ◽

Outcome Measure ◽

African Population ◽

Secondary Outcome ◽

South African Population ◽

Black South African ◽

Risk Of Death ◽

Population Cohort ◽

The Relationship

ObjectivesMultimorbidity is associated with mortality in high-income countries. Our objective was to investigate the relationship between multimorbidity (≥2 of the following chronic medical conditions: hypertension, diabetes, dyslipidaemia, anaemia, HIV, angina, depression, post-traumatic stress disorder, alcohol dependence) and all-cause mortality in an older, rural black South African population. We further investigated the relationship between HIV multimorbidity (HIV as part of the multimorbidity cluster) and mortality, while testing for the effect of frailty in all models.DesignPopulation cohort study.SettingAgincourt subdistrict of Mpumalanga province, South Africa.Participants4455 individuals (54.7% female), aged ≥40 years (median age 61 years, IQR 52–71) and resident in the study area.Primary and secondary outcome measuresThe primary outcome measure was time to death and the secondary outcome measure was likelihood of death within 2 years of the initial study visit. Mortality was determined during annual population surveillance updates.Results3157 individuals (70.9%) had multimorbidity; 29% of these had HIV. In models adjusted for age and sociodemographic factors, multimorbidity was associated with greater risk of death (women: HR 1.72; 95% CI: 1.18 to 2.50; men: HR 1.46; 95% CI: 1.09 to 1.95) and greater odds of dying within 2 years (women: OR 2.34; 95% CI: 1.32 to 4.16; men: OR 1.51; 95% CI: 1.02 to 2.24). HIV multimorbidity was associated with increased risk of death compared with non-HIV multimorbidity in men (HR 1.93; 95% CI: 1.05 to 3.54), but was not statistically significant in women (HR 1.85; 95% CI: 0.85 to 4.04); when detectable, HIV viral loads were higher in men (p=0.021). Further adjustment for frailty slightly attenuated the associations between multimorbidity and mortality risk (women: HR 1.55; 95% CI: 1.06 to 2.26; men: HR 1.36; 95% CI: 1.01 to 1.82), but slightly increased associations between HIV multimorbidity and mortality risk.ConclusionsMultimorbidity is associated with mortality in this older black South African population. Health systems which currently focus on HIV should be reorganised to optimise identification and management of other prevalent chronic diseases.

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Updated lower limb stature estimation equations for a South African population group

South African Journal of Science ◽

10.17159/sajs.2020/6871 ◽

2020 ◽

Vol 116 (5/6) ◽

Author(s):

Mubarak A. Bidmos ◽

Desiré Brits

Keyword(s):

South African ◽

Standard Error ◽

Lower Limb ◽

Population Group ◽

African Population ◽

Regression Equations ◽

South African Population ◽

Stature Estimation ◽

Limb Bones ◽

Black South African

One of the main steps in the identification of an unknown person, from their skeletal remains, is the estimation of stature. Measurements of intact long bones of the upper and lower extremities are widely used for this purpose because of the high correlation that exists between these bones and stature. In 1987, Lundy and Feldesman presented regression equations for stature estimation for the black South African population group based on measurements of bones from the Raymond A. Dart Collection of Human Skeletons. Local anthropologists have questioned the validity of these equations. Living stature measurement and magnetic resonance imaging scanograms of 58 adult volunteers (28 males and 30 females) representing the modern black South African population group were obtained. Physiological length of the femur (FEPL) and physiological length of the tibia (TPL) were measured on each scanogram and substituted into appropriate equations of Lundy and Feldesman (S Afr J Sci. 1987;83:54–55) to obtain total skeletal height (TSHL&F). Measured total skeletal height (TSHMeas) for each subject from scanograms was compared with TSHL&F. Both FEPL and TPL presented with significantly high positive correlations with TSHMeas. A comparison between TSHL&F and TSHMeas using a paired t-test, showed a statistically significant difference – an indication of non-validity of Lundy and Feldesman’s equations. New regression equations for estimation of living stature were formulated separately for male and female subjects. The standard error of estimate was low, which compared well with those reported for other studies that used long limb bones. Significance: • Statistically significant differences were observed between measured and estimated skeletal height, thus confirming non-validity of Lundy and Fieldsman’s (1987) equations for lower limb bones. • New regression equations for living stature estimation were formulated for femur and tibia lengths, and the low standard error of estimates of equations compared well to results from other studies.

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