Diabetes in a TB and HIV-endemic South African population: Analysis of a virtual cohort using routine health data

Implementation of a genotyped African population cohort, with virtual follow-up: A feasibility study in the Western Cape Province, South Africa

Background

There is limited knowledge regarding African genetic drivers of disease due to prohibitive costs of large-scale genomic research in Africa.

Methods

We piloted a scalable virtual genotyped cohort in South Africa that was affordable in this resource-limited context, cost-effective, scalable virtual genotyped cohort in South Africa, with participant recruitment using a tiered informed consent model and DNA collection by buccal swab. Genotype data was generated using the H3Africa Illumina micro-array, and phenotype data was derived from routine health data of participants. We demonstrated feasibility of nested case control genome wide association studies using these data for phenotypes type 2 diabetes mellitus (T2DM) and severe COVID-19.

Results

2267346 variants were analysed in 459 participant samples, of which 229 (66.8%) are female. 78.6% of SNPs and 74% of samples passed quality control (QC). Principal component analysis showed extensive ancestry admixture in study participants. Of the 343 samples that passed QC, 93 participants had T2DM and 63 had severe COVID-19. For 1780 previously published COVID-19-associated variants, 3 SNPs in the pre-imputation data and 23 SNPS in the imputed data were significantly associated with severe COVID-19 cases compared to controls (p<0.05). For 2755 published T2DM associated variants, 69 SNPs in the pre-imputation data and 419 SNPs in the imputed data were significantly associated with T2DM cases when compared to controls (p<0.05).

Conclusions

The results shown here are illustrative of what will be possible as the cohort expands in the future. Here we demonstrate the feasibility of this approach, recognising that the findings presented here are preliminary and require further validation once we have a sufficient sample size to improve statistical significance of findings.We implemented a genotyped population cohort with virtual follow up data in a resource-constrained African environment, demonstrating feasibility for scale up and novel health discoveries through nested case-control studies.

Digital continuous glucose monitoring systems for patients with HIV-diabetes comorbidity in Ethiopia: a situational analysis

In patients with HIV-diabetes mellitus (DM) comorbidity, invasive blood glucose testing can increase the risk of HIV-related blood contamination and discourage regular glucose monitoring. Digital continuous glucose monitoring (CGM) systems may allow real-time glucose monitoring without the need for blood specimens. However, in high-burden HIV-DM countries, current glucose monitoring practices and their challenges are insufficiently explored to guide digital CGM research and developments. This study sought to explore the lived experiences of patients with HIV-DM comorbidity and their healthcare providers regarding glucose monitoring practices, and their openness to CGM and other digital technologies, to provide formative insights for a planned implementation trial of digital CGM in Ethiopia. A phenomenological qualitative study was conducted among patients with HIV-DM and their providers at the two largest public hospitals in Ethiopia. Both groups were interviewed face-to-face about DM clinic workflows, blood glucose monitoring and self-testing practices, and potential benefits and limitations of digital CGM systems. Interviews were audio-recorded, transcribed verbatim, and analyzed thematically. A total of 37 participants were interviewed, consisting of 18 patients with HIV-DM comorbidity and 19 healthcare providers. Patients had an average (min-max) duration of living with HIV and DM of 14 (8-31) and 6.6 (1-16) years, respectively, with 61% taking insulin-33% alone and 28% alongside oral hypoglycemic agents-and 79% having comorbid hypertension. The thematic analysis identified five main themes: "Diabetes routine clinical care and follow-up", "Blood glucose monitoring practices", "Perceptions about digital CGMs", "Technology adoption", and "Financial coverage". Home self-testing was deemed beneficial, but the need for regular follow-ups, result cross-referencing, and glucometer reliability were emphasized. Patients performed fingerstick themselves or with family members, expressing concerns about waste disposal and the risk of HIV transmission. They rely mainly on health insurance for DM care. Patients and providers are happy with the quality of DM services but note a lack of integrated HIV-DM care. Very few providers and patients possessed background information about digital CGMs, and all have not yet utilized them in practice, but expressed keen interest in trying them, representing an important step for upcoming CGM clinical trials in these settings. Given the crucial role of regular glucose testing in managing HIV-DM comorbidity, it is essential to explore testing options that align with patient preferences and minimize the risk of HIV transmission.

Routine health data describe adherence and persistence patterns for oral diabetes medication for a virtual cohort in the Khayelitsha sub-district of Cape Town, South Africa

Type 2 diabetes mellitus (T2DM) is managed with combined lifestyle modifications and antidiabetic drugs, but people on treatment often fail to reach glycaemic control. Adherence is important for achieving optimal glycaemic control, and management of diabetes with drugs is a lifelong process, so understanding adherence through analysis of longitudinal medications data is important. Using retrospective routine health data and metformin dispensing records as a proxy for medication use, we describe longitudinal persistence and adherence to oral diabetes medication in a virtual cohort of 10541 people with diabetes (PLWD) in Khayelitsha subdistrict, Cape Town. Adherence was measured in 120-day sliding windows over two years and used to estimate metformin adherence trajectories. Multinomial logistic regression identified factors influencing these trajectories. Analysis of pharmacy dispensing records showed varying medication refill patterns: while some PLWD refilled prescriptions consistently, others had treatment gaps with periods of non-persistence and multiple treatment episodes-from one to five per individual across two years. There was a general trend of decreasing adherence over time across all sliding windows in the two-year period, with only 25% of the study population achieved medication adherence (> = 80% adherence) after two years. Four adherence trajectories; 'low adherence gradual decline (A), 'high adherence rapid decline' (B), 'low adherence gradual increase (C) and 'adherent' (D) were identified. Only trajectory D represented participants who were adherent at treatment start and remained adherent after two years. Taking HIV antiretroviral treatment before or concurrently with diabetes treatment and taking metformin in combination with sulphonylurea and/or insulin were associated with the long-term adherence (trajectory D). Routine data shows real life medication implementation patterns which might not be seen under controlled study conditions. This study illustrates the utility of these data in describing longitudinal adherence patterns at both an individual and population level.

Association between prior tuberculosis disease and dysglycemia within an HIV-endemic, rural South African population

OBJECTIVE

Tuberculosis (TB) may predispose individuals to the development of diabetes. Such a relationship could have an outsized impact in high-prevalence TB settings. However, few studies have explored this relationship in populations heavily burdened by diabetes and TB.

METHODS

We analyzed data from a community-based population cohort that enrolled adults in rural South Africa. Individuals were considered to have prior TB if they self-reported a history of TB treatment. We fitted sex-specific logistic regression models, adjusted for potential clinical and demographic confounders, to estimate relationships between dysglycemia (HBA1c ≥6.5%) and prior TB. Propensity score-matched cohorts accounted for the differential age distributions between comparator groups. We examined the interactions between sex, prior TB, and HIV status.

RESULTS

In the analytic cohort (n = 17,593), the prevalence of prior TB was 13.8% among men and 10.7% among women. Dysglycemia was found in 9.1% of the population, and HIV prevalence was 34.0%. We found no difference in dysglycemia prevalence by prior TB (men OR 0.96, 95% CI 0.60-1.56: women OR 1.05, 95% CI 0.79-1.39). However, there was a qualitative interaction by HIV serostatus, such that among men without HIV, those with a history of TB had a greater prevalence of dysglycemia than those without prior TB (10.1% vs. 4.6%, p = 0.0077). An inverse relationship was observed among men living with HIV (prior TB 3.3% vs. no TB 7.3%, p = 0.0073).

CONCLUSIONS

Treated TB disease was not associated with dysglycemia in an HIV-endemic, rural South African population. However, we found a significant interaction between prior TB and HIV status among men, suggesting distinct pathophysiological mechanisms between the two infections that may impact glucose metabolism. Longitudinal studies are needed to better establish a causal effect and underlying mechanisms related to resolved TB, HIV, and diabetes.

Multimorbidity research in Sub-Saharan Africa: Proceedings of an interdisciplinary workshop

As life expectancies rise globally, the number of people living with multiple chronic health conditions – commonly referred to as ‘multimorbidity’ – is rising. Multimorbidity has been recognised as especially challenging to respond to in countries whose health systems are under-funded, fragmented, and designed primarily for acute care, including in sub-Saharan Africa. A growing body of research in sub-Saharan Africa has sought to better understand the particular challenges multimorbidity poses in the region and to develop context-sensitive responses. However, with multimorbidity still crystallising as a subject of enquiry, there remains considerable heterogeneity in conceptualising multimorbidity across disciplines and fields, hindering coordinated action. In June 2022, 60 researchers, practitioners, and stakeholders with regional expertise from nine sub-Saharan African countries gathered in Blantyre, Malawi to discuss ongoing multimorbidity research across the region. Drawing on insights from disciplines including epidemiology, public health, clinical medicine, anthropology, history, and sociology, participants critically considered the meaning, singular potential, and limitations of the concept of multimorbidity in sub-Saharan Africa. The workshop emphasised  the need to move beyond a disease-centred concept of multimorbidity to one foregrounding patients’ values, needs, and social context; the importance of foregrounding structures and systems rather than behaviour and lifestyles; the value of a flexible (rather than standard) definition of multimorbidity; and the need to leverage local knowledge, expertise, resources, and infrastructure. The workshop further served as a platform for exploring opportunities for training, writing, and ongoing collaboration.

The Potential of Moringa oleifera to Ameliorate HAART-Induced Pathophysiological Complications

Highly active antiretroviral therapy (HAART) comprises a combination of two or three antiretroviral (ARV) drugs that are administered together in a single tablet. These drugs target different steps within the human immunodeficiency virus (HIV) life cycle, providing either a synergistic or additive antiviral effect; this enhances the efficiency in which viral replication is suppressed. HIV cannot be completely eliminated, making HAART a lifetime treatment. With long-term HAART usage, an increasing number of patients experience a broadening array of complications, and this significantly affects their quality of life, despite cautious use. The mechanism through which ARV drugs induce toxicity is associated with metabolic complications such as mitochondrial dysfunction, oxidative stress, and inflammation. To address this, it is necessary to improve ARV drug formulation without compromising its efficacy; alternatively, safe supplementary medicine may be a suitable solution. The medicinal plant Moringa oleifera (MO) is considered one of the most important sources of novel nutritionally and pharmacologically active compounds that have been shown to prevent and treat various diseases. MO leaves are rich in polyphenols, vitamins, minerals, and tannins; studies have confirmed the therapeutic properties of MO. MO leaves provide powerful antioxidants, scavenge free radicals, promote carbohydrate metabolism, and repair DNA. MO also induces anti-inflammatory, hepatoprotective, anti-proliferative, and anti-mutagenic effects. Therefore, MO can be a source of affordable and safe supplement therapy for HAART-induced toxicity. This review highlights the potential of MO leaves to protect against HAART-induced toxicity in HIV patients.

Tuberculosis risk among people with diabetes mellitus in Sub-Saharan Africa: a systematic review

Objectives

People with diabetes mellitus (DM) have a higher tuberculosis (TB) risk, but the evidence from sub‐Saharan Africa (SSA) was scarce until recently and not included in earlier global summaries. Therefore, this systematic review aims to determine the risk of active TB disease among people with DM in SSA and whether HIV alters this association.

Methods

Medline, Embase, CINAHL, Web of Science, Global Health and African Index Medicus were searched between January 1980 and February 2021. Cohort, case‐control and cross‐sectional studies from SSA, which assessed the association between DM and active TB, were included if adjusted for age. Two researchers independently assessed titles, abstracts, full texts, extracted data and assessed the risk of bias. Estimates for the association between DM and TB were summarised using a random effects meta‐analysis. PROSPERO: CRD42021241743.

Results

Nine eligible studies were identified, which reported on 110,905 people from 5 countries. Individual study odds ratios (OR) of the TB–DM association ranged from 0.88 (95% CI 0.17–4.58) to 10.7 (95% CI 4.5–26). The pooled OR was 2.77 (95% CI 1.90–4.05). High heterogeneity was reduced in sensitivity analysis (from I² = 57% to I² = 6.9%), by excluding one study which ascertained DM by HbA1c. Risk of bias varied widely between studies, especially concerning the way in which DM status was determined.

Conclusions

There is a strong positive association between DM and active TB in SSA. More research is needed to determine whether HIV, a key risk factor for TB in SSA, modifies this relationship.

Analysis of CD4 and CD8 expression in multidrug-resistant tuberculosis infection with diabetes mellitus: An experimental study in mice

BACKGROUND

Tuberculosis (TB) remains a major global health problem, in the top 10 causes of death. As a regulator of the immune response, T-helper (Th) cells activate other lymphocytes from the immune system, such as B cells, to destroy the TB pathogen by releasing CD4 and CD8 Th cells. Diabetes mellitus (DM) is a known cause of developing active pulmonary TB. Few studies have examined the biomolecular expression affecting Mycobacterium tuberculosis (MTB) and multidrug-resistant (MDR) MTB, which are associated with low immunity represented by TB in diabetes and CD4 and CD8 levels.

MATERIALS AND METHODS

This animal study used a post-test control group design. We performed an experimental study using 30 BALB/c mice, each weighing 25 g. It included six experimental animal groups, of which three had a diabetes condition induced using intraperitoneal streptozotocin, and all were infected with MTB or MDR TB. We evaluated the CD4 and CD8 levels in each group and analyzed the differences.

RESULTS

We found a significant difference in CD4 and CD8 levels in MTB and MDR TB conditions.

CONCLUSION

This study shows that acute infection in experimental mice with MTB and MDR TB with or without diabetes had the highest levels of both CD4 and CD8 cells, which can be a sign of increased cellular immunity in a mice model.