Undergraduate research- a tale of three African institutions.

Background: The inclusion of research in undergraduate medical curricula benefits students as well as the scientific community. Multiple studies report the presence of one or more barriers to research training in these curricula. Objectives: This paper presents and compares three studies done regarding the teaching of research in undergraduate medical curricula in South Africa, Sudan and Uganda. Methods: Two cross-sectional study designs (South Africa and Sudan) and one interventional study design (Uganda) were conducted. Both cross-sectional studies used mixed methods while the Ugandan study used a quantitative method. A total of 41 faculty members and 554 students participated. The studies used a combination of surveys, focus group discussions, key informant interviews and document analysis. Results: Participants from all three studies valued research and considered it useful and relevant to their studies. The findings from the South African and Sudanese studies align with the 'Four I's' framework that summarise the barriers to research training as lack of initiative, impulse, incentive and idols. The Ugandan study demonstrated improved self-reported knowledge and attitude (specifically anxiety) among participants after completion of a short course on research.

How to set up regional STEMI networks: a "Stent - Save a life!" initiative.

Clinical guidelines recommend the development of ST-elevation myocardial infarction (STEMI) networks at community, regional and/or national level to ideally offer primary coronary angioplasty, or at least the best available STEMI care to all patients. However, there is a discrepancy between this clinical recommendation and daily practice, with no coordinated care for STEMI patients in many regions of the world. While this can be a consequence of lack of resources, in reality it is more frequently a lack of organisational power. In this paper, the Stent - Save a Life! Initiative (www.stentsavealife.com) proposes a practical methodology to set up a STEMI network effectively in any region of the world with existing resources, and to develop the STEMI network continuously once it has been established.

Stent-Save a Life international survey on the practice of primary percutaneous coronary intervention during the COVID-19 pandemic.

Aim: To assess the impact of the COVID-19 pandemic on admissions of patients with acute coronary syndromes (ACS) and primary percutaneous coronary intervention (PPCI) in countries participating in the Stent-Save a Life (SSL) global initiative. Methods and Results: We conducted a multicenter observational survey to collect data on patient admissions for ACS, ST-elevation myocardial infarction (STEMI) and PPCI in participating SSL member countries through a period during the COVID-19 outbreak (March and April 2020) compared with the equivalent period in 2019. Of the 32 member countries of the SSL global initiative, 17 agreed to participate in the survey (three in Africa, five in Asia, six in Europe and three in Latin America). Overall reductions of 27.5% and 20.0% were observed in admissions for ACS and STEMI, respectively. The decrease in PPCI was 26.7%. This trend was observed in all except two countries. In these two, the pandemic peaked later than in the other countries. Conclusions: This survey shows that the COVID-19 outbreak was associated with a significant reduction in hospital admissions for ACS and STEMI as well as a reduction in PPCI, which can be explained by both patient- and system-related factors.

Objetivos: Avaliar o impacto da pandemia COVID-19 nas admissões de doentes com síndromes coronárias agudas (SCA) e angioplastia coronária primária (PPCI) em países que participam da iniciativa global Stent-Save a Life (SSL). Métodos e resultados: Realizámos estudo observacional multicêntrico para coletar dados sobre admissões de doentes por ACS, STEMI e PPCI nos países participantes no SSL durante um período do surto COVID-19 (março e abril de 2020) em comparação com o período homólogo de 2019. Dos 32 países membros da iniciativa global SSL, 17 aceitaram participar no estudo (3 de África, 5 da Ásia, 6 da Europa e 3 da América Latina (LATAM)). Observámos uma redução global de 27,5% e 20,0% nos internamentos com SCA e STEMI, respetivamente. A diminuição do PPCI foi de 26,7%. Essa tendência foi observada em todos os países, exceto dois. Nestes dois países, a pandemia atingiu o pico mais tarde do que nos restantes. Conclusões: Este estudo mostra que o surto de COVID-19 foi associado a uma redução significativa de admissões hospitalares por SCA e STEMI, bem como uma redução de PPCI, o que pode ser explicado por fatores relacionados com o doente e com o sistema.

Assessment of professionalism: recommendations from the Ottawa 2010 Conference.

Over the past 25 years, professionalism has emerged as a substantive and sustained theme, the operationalization and measurement of which has become a major concern for those involved in medical education. However, how to go about establishing the elements that constitute appropriate professionalism in order to assess them is difficult. Using a discourse analysis approach, the International Ottawa Conference Working Group on Professionalism studied some of the dominant notions of professionalism, and in particular the implications for its assessment. The results presented here reveal different ways of thinking about professionalism that can lead towards a multi-dimensional, multi-paradigmatic approach to assessing professionalism at different levels: individual, inter-personal, societal-institutional. Recommendations for research about professionalism assessment are also presented.

Increasing the discrimination power of forensic STR testing by employing high-performance mass spectrometry, as illustrated in indigenous South African and Central Asian populations.

Short tandem repeat (STR) typing has become the standard technique in forensic methodology for the identification of unknown samples. National DNA databases have been established that contain STR genotypes for intelligence purposes. Due to their success, national DNA databases have been growing so fast that the number of advantageous matches may become a logistic problem for the analysts. This is especially true for partial STR profiles as they display reduced discrimination power. To overcome this drawback, modified versions (so-called mini-STRs) of existing loci were introduced as well as new loci to improve the information content of (partial) STR profiles. We pursue an alternative approach that makes use of nucleotide variation within the amplified STR fragments, which can be discerned by mass spectrometry. We have developed an assay that determines molecular masses from crude STR amplicons which were purified and separated by a liquid chromatographic system directly hyphenated to an electrospray ionization mass spectrometer. We present here new population data of forensically relevant STRs in Khoisan and Yakut populations. These autochthonous groups were selected as they may harbor additional STR alleles that are rare or unobserved in modern humans from cosmopolitan areas, especially for the Khoisan, which are known to represent a very ancient human population. The analysis of the molecular mass of STRs offered a widened spectrum of allele variability escorted by enhanced forensic use. Thus, established STR data derived from fragment size analysis can still be used in casework or in the context of intelligence databasing.

Alterations in male reproductive hormones in relation to environmental DDT exposure.

DDT [1, 1, 1-trichloro-2,2-bis (p-chlorophenyl)-ethane] compounds are used for indoor residual spraying (IRS) to control malaria mosquitoes. DDT is an endocrine disruptor chemical in experimental conditions, but little is known of adverse effects related to living conditions with continual uptake across a time span by all possible means of exposure. Based on estrogenic and/or anti-androgenic effects found in animal studies, we hypothesized that chronic DDT/DDE exposures in men may be associated with changes in male reproductive hormones. We tested this hypothesis by compared the magnitude and direction of associations between DDT and DDE (1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene) concentrations and male reproductive hormones in samples collected from IRS and non-IRS areas. We sampled a cross-section of 535 men (aged 18-40 years). Men living in IRS villages had significantly higher DDT and DDE concentrations compared with men from non-IRS villages. Men with DDT or DDE uptake (as reflected in detectable plasma concentrations) had significantly higher total-, free and bio-available testosterone (T), and lower follicle stimulating hormone (FSH) concentrations; lower luteinizing hormone (LH) concentrations were only evident with DDT uptake. To establish a dose-dependent effect, four sub-categories were defined. Men with the highest DDT (74-519 µg/g) and DDE (173-997 µg/g) concentrations had significantly higher total-, free and bio-available T, and lower FSH concentrations compared with subjects with non-detectable isomer concentrations. Estradiol concentrations were significantly higher in men with DDT and DDE concentrations in both the third (DDE: 27-172 µg/g; DDT: 5-73 µg/g) and fourth (DDE: 173-997 µg/g; DDT: 74-519 µg/g) categories. Men from IRS villages were significantly more likely to have higher total and bioavailable T as well as higher estradiol concentrations OR = 2.5 (95% CI 1.2, 3.2); OR 2.5 (95% CI 1.6, 4.0) and OR = 2.3 (95% CI 1.3, 4.1) compared to men from non-IRS villages, after controlling for age, BMI, personal use of pesticides, and smoking. Men living in IRS villages with life-long exposure (17.6 (±6) years) at the current residence with multiple exposure modalities incurred the highest degree of physiological imbalance over and above circulating isomer concentrations. Further studies are needed to elucidate the health implications of these findings.

Troponin T release is associated with silent myocardial ischaemia in black men: The SABPA Study.

Background High sensitivity cardiac troponin T (hs-cTnT) is a validated marker of myocardial damage and may reflect the degree of silent myocardial ischaemia (SMI) and ventricular strain. Our aim was to compare hs-cTnT levels in black and white South Africans taking SMI into consideration. We further explored the capability of hs-cTnT to predict the presence of compensatory systolic hypertension in this South African cohort. Methods A bi-ethnic sex cohort ( n = 404) with similar socioeconomic status (198 black participants and 206 white participants, aged 20-65 years) participated in this target population study where 24 h ambulatory blood pressure, electrocardiogram and overnight fasting cardiometabolic variables were measured. Results Hypertension, higher glycated haemoglobin levels and more frequent and longer SMI events were observed more often in the black participants. Multivariate linear regression analysis showed positive associations between SMI events [Adj. R2 = 0.19; ß 0.35 (0.08-0.62); p < 0.01], SMI event maximum duration [Adj. R2 = 0.17, ß 0.43 (0.16-0.70), p < 0.01], SMI total duration [Adj. R2 = 0.12; ß 0.37 (0.10; 0.65), p = 0.05] and hs-cTnT in black males only.] A lower hs-cTnT cut-point ≥4.2 pg/ml for 24 h systolic hypertension was predicted in the black participants compared with ≥5.6 pg/ml in the white participants (area under the curve 0.66-67 (95% CI: 0.57-0.75), p < 0.001) with a respective sensitivity/specificity of 64/68% and 61/71%. Conclusions hs-cTnT may be a potential marker of SMI in the prediction of systolic blood pressure increases, as well as clusters of risk factors for cardiovascular disease. Ethnic- and possibly sex-specific references values for hs-cTnT should be considered for risk stratification.

Chronic defensiveness and neuroendocrine dysfunction reflect a novel cardiac troponin T cut point: The SABPA study.

BACKGROUND: Sympatho-adrenal responses are activated as an innate defense coping (DefS) mechanism during emotional stress. Whether these sympatho-adrenal responses drive cardiac troponin T (cTnT) increases are unknown. Therefore, associations between cTnT and sympatho-adrenal responses were assessed. METHODS: A prospective bi-ethnic cohort, excluding atrial fibrillation, myocardial infarction and stroke cases, was followed for 3 years (N=342; 45.6±9.0years). We obtained serum high-sensitive cTnT and exposure measures [Coping-Strategy-Indicator, depression/Patient-Health-Questionnarie-9, 24h BP, 24h heart-rate-variability (HRV) and 24h urinary catecholamines]. RESULTS: Blacks showed moderate depression (45% vs. 16%) and 24h hypertension (67% vs. 42%) prevalence compared to Whites. A receiver-operating-characteristics cTnT cut-point 4.2ng/L predicting hypertension in Blacks was used as binary outcome measure in relation to exposure measures [AUC 0.68 (95% CI 0.60-0.76); sensitivity/specificity 63/70%; P≤0.001]. Bi-ethnic cTnT-incidence was similar (Blacks=27%, Whites=25%) with cTnT-recovery better in Blacks (9%) compared to Whites (5%), P=0.001. In cross-sectional analyses, elevated cTnT was related to DefS [OR 1.08 (95% CI 0.99-1.16); P=0.06]; 24h BP [OR 1.03-1.04 (95% CI 1.01-1.08); P≤0.02] and depressed HRV [OR 2.19 (95% CI 1.09-4.41); P=0.03] in Blacks, but not in Whites. At 3year follow-up, elevated cTnT was related to attenuated urine norepinephrine:creatinine ratio in Blacks [OR 1.46 (95% CI 1.01-2.10); P=0.04]. In Whites, a cut point of 5.6ng/L cTnT predicting hypertension was not associated with exposure measures. CONCLUSION: Central neural control systems exemplified a brain-heart stress pathway. Desensitization of sympatho-adrenal responses occurred with initial neural- (HRV) followed by neuroendocrine dysfunction (norepinephrine:creatinine) in relation to elevated cTnT. Chronic defensiveness may thus drive the desensitization or physiological depression, reflecting ischemic heart disease risk at a novel 4.2ng/L cTnT cut-point in Blacks.

Effect of rapamycin on hepatic osteodystrophy in rats with portasystemic shunting.

AIM: To study if T-cell activation related to portasystemic shunting causes osteoclast-mediated bone loss through RANKL-dependent pathways. We also investigated if T-cell inhibition using rapamycin would protect against bone loss in rats. METHODS: Portasystemic shunting was performed in male Sprague-Dawley rats and rapamycin 0.1 mg/kg was administered for 15 wk by gavage. Rats received powderized chow and supplemental feeds to prevent the effects of malnutrition on bone composition. Weight gain and growth was restored after surgery in shunted animals. At termination, biochemical parameters of bone turnover and quantitative bone histology were assessed. Markers of T-cell activation, inflammatory cytokine production, and RANKL-dependent pathways were measured. In addition, the roles of IGF-1 and hypogonadism were investigated. RESULTS: Portasystemic shunting caused low turnover osteoporosis that was RANKL independent. Bone resorbing cytokine levels, including IL-1, IL-6 and TNFalpha, were not increased in serum and TNFalpha and RANKL expression were not upregulated in PBMC. Portasystemic shunting increased the circulating CD8+ T-cell population. Rapamycin decreased the circulating CD8+ T-cell population, increased CD8+ CD25+ T-regulatory cell population and improved all parameters of bone turnover. CONCLUSION: Osteoporosis caused by portasystemic shunting may be partially ameliorated by rapamycin in the rat model of hepatic osteodystrophy.

Lack of association of rs3798220 with small apolipoprotein(a) isoforms and high lipoprotein(a) levels in East and Southeast Asians.

OBJECTIVE: The variant allele of rs3798220 in the apolipoprotein(a) gene (LPA) is used to assess the risk for coronary artery disease (CAD) in Europeans, where it is associated with short alleles of the Kringle IV-2 (KIV-2) copy number variation (CNV) and high lipoprotein(a) (Lp(a)) concentrations. No association of rs3798220 with CAD was detected in a GWAS of East Asians. Our study investigated the association of rs3798220 with Lp(a) concentrations and KIV-2 CNV size in non-European populations to explain the missing association of the variant with CAD in Asians. METHODS: We screened three populations from Africa and seven from Asia by TaqMan Assay for rs3798220 and determined KIV-2 CNV sizes of LPA alleles by pulsed-field gel electrophoresis (PFGE). Additionally, CAD cases from India were analysed. To investigate the phylogenetic origin of rs3798220, 40 LPA alleles from Chinese individuals were separated by PFGE and haplotyped for further SNPs. RESULTS: The variant was not found in Africans. Allele frequencies in East and Southeast Asians ranged from 2.9% to 11.6%, and were very low (0.15%) in CAD cases and controls from India. The variant was neither associated with short KIV-2 CNV alleles nor elevated Lp(a) concentrations in Asians. CONCLUSION: Our study shows that rs3798220 is no marker for short KIV-2 CNV alleles and high Lp(a) in East and Southeast Asians, although the haplotype background is shared with Europeans. It appears unlikely that this SNP confers atherogenic potential on its own. Furthermore, this SNP does not explain Lp(a) attributed risk for CAD in Asian Indians.

Variability of post-methionine load plasma homocysteine assays.

BACKGROUND: Numerous variations of the methionine load test are frequently used as dynamic function tests to assess homocysteine metabolism. Lack of standardization impedes inter-laboratory comparisons. Criteria based on biological variation are suggested to standardize the methionine load test. METHODS: Weekly methionine load tests (n=5) with blood sampling at 0, 4, 6 and 8 h were performed on 15 young men. For both basal and post-methionine load homocysteine measurements, total variance (sigma(S)(2)), within-subject variance (sigma(I)(2)), between-subject variance (sigma(G)(2)) and analytical variance (sigma(A)(2)) were calculated from an appropriate analysis of variance (ANOVA). RESULTS: Plasma homocysteine concentrations measured 6 h after methionine loading had analytical, within-subject and between-subject coefficients of variation of 5.2%, 17.5% and 9.7%, respectively. Measurements at 4 h had a higher within-subject coefficient of variation. Adjustment of post-methionine load homocysteine concentrations for basal levels resulted in considerable increases of all the measures of variation. CONCLUSIONS: Adjustment of post-methionine load plasma homocysteine concentrations for basal levels does not improve the interpretation of changes in serial results due to the higher analytical and biological variance of adjusted concentrations. It is suggested that the methionine load test is standardized to a single, unadjusted homocysteine measurement at 6 h.

Biological variation in sweat sodium chloride conductivity.

BACKGROUND: Sweat conductivity, which is equivalent to sweat NaCl concentration, is used as a screening test to identify possible cystic fibrosis (CF) patients. No data exist on the biological variation of this variable and the influence it may have on the interpretation of sweat testing. The aim of this study was to determine the components of biological variation for sweat sodium chloride conductivity and to apply biological variation parameters in the interpretation of sweat conductivity. METHODS: Sweat conductivity was determined once a week for 5 consecutive weeks on 15 healthy volunteers, 20 healthy infants and 20 known CF patients. RESULTS: The analytical coefficient of variation (CV(A)) was 1.15% for the high-level control material, with a value of 123 mmol/L, and 1.32% for the normal-level control material with a value of 40 mmoL/L. The within-subject (CV) and between-subject (CV(G)) biological variations were 12.0% and 30.0%, respectively, for healthy controls; 18% and 20% for healthy infants; and 7.3% and 6.5% for CF patients, respectively. Using the CV(A), CV(G) and CV(I), the 95% reference ranges were determined for the above-mentioned three groups. The calculated 95% ranges for the healthy babies and CF patients were 18-60 mmoL/L and 96-144 mmoL/L. CONCLUSIONS: Our data support a decision level of > 60 mmoL/L for confirmatory CF testing. A lower decision level will result in an unacceptable high rate of unnecessary confirmation testing.

Stent for Life Initiative: leading example in building STEMI systems of care in emerging countries.

This paper describes the opportunities and challenges in building ST-elevation acute myocardial infarction (STEMI) systems of care in Stent for Life affiliated and collaborating so-called emerging countries, namely India, China, South Africa and Mexico, where CAD mortality is increasing and becoming a significant healthcare problem. The Stent for Life model supports the implementation of ESC STEMI Guidelines in Europe and endeavours to impact on morbidity and mortality by improving services and developing regional STEMI systems of care, whereby STEMI patients' timely access to a primary percutaneous coronary intervention (PPCI) is assured. In India, the STEMI India model incorporates a dual approach of combining PPCI with a pharmacoinvasive strategy of reperfusion. The architecture of the system is based on a hub and spoke model with each unit called a STEMI cluster. The project is driven by a private non-profit organisation. In China, the STEMI PCI programme is led by the Chinese College of Cardiovascular Physicians and supported by the national government. Although primary PCI is performed nationwide, a thrombolytic treatment strategy is still the first option in many rural areas because of logistic considerations. Establishing local STEMI transfer networks and then implementing a pharmacoinvasive strategy of reperfusion are being considered and promoted currently. In South Africa, the pharmacoinvasive approach currently dominates as STEMI treatment option in many areas. A pilot study shows that low symptom awareness leads to long patient delays. The education of all role players, from patients to healthcare professionals and including institutions and governmental structures, is needed to achieve prompt diagnosis and treatment. In Mexico, improving the treatment of STEMI requires considering myocardial infarction to be an emergency that must be treated by an entire system and not just by a particular service. Patients need to receive quick treatment from clinical and interventional cardiologists, and the emergency medical system (EMS) must understand the importance of early reperfusion therapy when appropriate. Mexican health authorities have used registries as their main strategy for improving the use of health resources for ACS patients. In general, building regional STEMI systems of care and an EMS system infrastructure are critical success factors in the stepwise development of STEMI systems of care at a national level in emerging countries as they are in Europe. An in-depth understanding of healthcare system-level barriers to timely and appropriate reperfusion therapy facilitates the development of more effective strategies for improving the quality of STEMI care in each region and country.

WITHDRAWN: Erratum to "Evaluation of next generation mtGenome sequencing using the Ion Torrent Personal Genome Machine (PGM)" [Forensic Sci. Int.: Genet. 7 (2013) 543-549].

The Publisher regrets that this article is an accidental duplication of an article that has already been published, http://dx.doi.org/10.1016/j.fsigen.2013.09.007. The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.

Reprint of: Evaluation of next generation mtGenome sequencing using the Ion Torrent Personal Genome Machine (PGM).

Insights into the human mitochondrial phylogeny have been primarily achieved by sequencing full mitochondrial genomes (mtGenomes). In forensic genetics (partial) mtGenome information can be used to assign haplotypes to their phylogenetic backgrounds, which may, in turn, have characteristic geographic distributions that would offer useful information in a forensic case. In addition and perhaps even more relevant in the forensic context, haplogroup-specific patterns of mutations form the basis for quality control of mtDNA sequences. The current method for establishing (partial) mtDNA haplotypes is Sanger-type sequencing (STS), which is laborious, time-consuming, and expensive. With the emergence of Next Generation Sequencing (NGS) technologies, the body of available mtDNA data can potentially be extended much more quickly and cost-efficiently. Customized chemistries, laboratory workflows and data analysis packages could support the community and increase the utility of mtDNA analysis in forensics. We have evaluated the performance of mtGenome sequencing using the Personal Genome Machine (PGM) and compared the resulting haplotypes directly with conventional Sanger-type sequencing. A total of 64mtGenomes (>1 million bases) were established that yielded high concordance with the corresponding STS haplotypes (<0.02% differences). About two-thirds of the differences were observed in or around homopolymeric sequence stretches. In addition, the sequence alignment algorithm employed to align NGS reads played a significant role in the analysis of the data and the resulting mtDNA haplotypes. Further development of alignment software would be desirable to facilitate the application of NGS in mtDNA forensic genetics.

Evaluation of next generation mtGenome sequencing using the Ion Torrent Personal Genome Machine (PGM).

Insights into the human mitochondrial phylogeny have been primarily achieved by sequencing full mitochondrial genomes (mtGenomes). In forensic genetics (partial) mtGenome information can be used to assign haplotypes to their phylogenetic backgrounds, which may, in turn, have characteristic geographic distributions that would offer useful information in a forensic case. In addition and perhaps even more relevant in the forensic context, haplogroup-specific patterns of mutations form the basis for quality control of mtDNA sequences. The current method for establishing (partial) mtDNA haplotypes is Sanger-type sequencing (STS), which is laborious, time-consuming, and expensive. With the emergence of Next Generation Sequencing (NGS) technologies, the body of available mtDNA data can potentially be extended much more quickly and cost-efficiently. Customized chemistries, laboratory workflows and data analysis packages could support the community and increase the utility of mtDNA analysis in forensics. We have evaluated the performance of mtGenome sequencing using the Personal Genome Machine (PGM) and compared the resulting haplotypes directly with conventional Sanger-type sequencing. A total of 64mtGenomes (>1 million bases) were established that yielded high concordance with the corresponding STS haplotypes (<0.02% differences). About two-thirds of the differences were observed in or around homopolymeric sequence stretches. In addition, the sequence alignment algorithm employed to align NGS reads played a significant role in the analysis of the data and the resulting mtDNA haplotypes. Further development of alignment software would be desirable to facilitate the application of NGS in mtDNA forensic genetics.

Mitochondrial DNA control region data from indigenous Angolan Khoe-San lineages.

Here we provide 129 complete mitochondrial control region sequences of indigenous Khoe-San individuals from Angola to contribute to the still underrepresented pool of data from Africa. The dataset consists of exclusively African lineages with a majority of Sub-Saharan haplogroups. The probability of a random match was calculated as 0.09. The data set comprises 21 haplotypes occurring more than once and 17 unique haplotypes. Upon publication, haplotypes were incorporated in the EMPOP database (www.empop.org; EMP00069) [1].

Changes in retinol-binding protein concentrations and thyroid homeostasis with nonoccupational exposure to DDT.

BACKGROUND: The insecticide dichlorodiphenyltrichloroethane (DDT) has been used for malaria vector control in the northern and eastern parts of the Vhembe District of Limpopo Province, South Africa, since 1945. Bioaccumulation of DDT raises concern because it reportedly affects thyroid function. OBJECTIVE: Our objective was to investigate the association between DDT uptake (as reflected in plasma concentrations) and thyroid homeostasis while considering related factors. METHODS: We compared dietary intake, serum retinol-binding protein (RBP), transthyretin (TTR) and albumin concentrations, and liver and thyroid function between cases with evidence of a body burden of DDT in the circulation (concentration of any DDT isomer ≥ 0.02 µg/g lipid; n = 278) and controls (concentration of all DDT isomers < 0.02 µg/g lipid; n = 40) in a cross-sectional study. Further analyses were performed to assess the relevance of changes in RBP status associated with DDT uptake. RESULTS: RBP concentrations below the reference range were more prevalent in cases (54% vs. 10% in controls; χ² = 27.4; p < 0.001), which could not be explained by nutrient intake. We observed significantly lower thyroid hormone concentrations among cases (p ≤ 0.01). We also observed a significant linear trend for serum concentrations of free thyroxine and free triiodothyronine (p < 0.001) and a significant quadratic trend for serum thyroid-stimulating hormone (p = 0.025) and TTR (p < 0.001) across the control group and case groups with normal and relatively low RBP concentrations. Relatively low RBP concentrations were associated with significantly higher DDT and 1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene (DDE) isomer concentrations and with a higher DDE/DDT ratio (p ≤ 0.01), which signifies long-term exposure. Inadequate intake of vitamin A and zinc were observed in 84% and 58%, respectively, of the total study population. CONCLUSION: RBP concentrations appear to decrease in the presence of long-term DDT uptake, which may have deleterious effects on thyroid function and vitamin A nutritional status. This is of major concern in a population with poor vitamin A and zinc intake.