Accuracy of diabetes screening methods used for people with tuberculosis, Indonesia, Peru, Romania, South Africa

Impaired resolution of blood transcriptomes through tuberculosis treatment with diabetes comorbidity

BACKGROUND

People with diabetes are more likely to develop tuberculosis (TB) and to have poor TB-treatment outcomes than those without. We previously showed that blood transcriptomes in people with TB-diabetes (TB-DM) co-morbidity have excessive inflammatory and reduced interferon responses at diagnosis. It is unknown whether this persists through treatment and contributes to the adverse outcomes.

METHODS

Pulmonary TB patients recruited in South Africa, Indonesia and Romania were classified as having TB-DM, TB with prediabetes, TB-related hyperglycaemia or TB-only, based on glycated haemoglobin concentration at TB diagnosis and after 6 months of TB treatment. Gene expression in blood at diagnosis and intervals throughout treatment was measured by unbiased RNA-Seq and targeted Multiplex Ligation-dependent Probe Amplification. Transcriptomic data were analysed by longitudinal mixed-model regression to identify whether genes were differentially expressed between clinical groups through time. Predictive models of TB-treatment response across groups were developed and cross-tested.

RESULTS

Gene expression differed between TB and TB-DM patients at diagnosis and was modulated by TB treatment in all clinical groups but to different extents, such that differences remained in TB-DM relative to TB-only throughout. Expression of some genes increased through TB treatment, whereas others decreased: some were persistently more highly expressed in TB-DM and others in TB-only patients. Genes involved in innate immune responses, anti-microbial immunity and inflammation were significantly upregulated in people with TB-DM throughout treatment. The overall pattern of change was similar across clinical groups irrespective of diabetes status, permitting models predictive of TB treatment to be developed.

CONCLUSIONS

Exacerbated transcriptome changes in TB-DM take longer to resolve during TB treatment, meaning they remain different from those in uncomplicated TB after treatment completion. This may indicate a prolonged inflammatory response in TB-DM, requiring prolonged treatment or host-directed therapy for complete cure. Development of transcriptome-based biomarker signatures of TB-treatment response should include people with diabetes for use across populations.

Diagnostic accuracy of two confirmatory tests for diabetes mellitus in adult Ugandans with recently diagnosed tuberculosis

Objective

The optimal confirmatory tests for diabetes mellitus (DM) in patients with tuberculosis (TB) vary across populations. This study aimed to evaluate the performance of two confirmatory tests for DM against the oral glucose tolerance test (OGTT) as the reference test in adult Ugandans with recently diagnosed TB.

Methods

A total of 232 adult participants receiving TB treatment underwent initial screening for DM with random blood glucose (RBG) measurement. Participants with a RBG level ⩾6.1 mmol/l received additional screening with fasting blood glucose (FBG), laboratory-measured glycated haemoglobin (HbA1c) and an OGTT. Using the latter as the gold standard and reference test, we evaluated the diagnostic accuracy of laboratory-measured HbA1c and FBG.

Results

Of the 232 participants initially screened for DM using RBG measurement, 117 participants (50.4%) had RBG level ⩾6.1 mmol/l and were scheduled to return for additional blood glucose testing. Of these, 75 (64.1%) participants returned for FBG and HbA1c measurements. A diagnosis of DM was made in 32 participants, corresponding to a prevalence of 13.8% [95% CI 9.9-18.9].The areas under the curve (AUC) for FBG and laboratory-measured HbA1c were 0.69 [95% CI 0.47-0.90] and 0.65 [95% CI 0.43-0.87], respectively. The sensitivity and specificity of a FBG level of ⩾7 mmol/l were 57.1% [95% CI 18.4-90.1] and 74.6% [95% CI 62.5-84.5], respectively, whereas the sensitivity and specificity for laboratory-measured HbA1c of ⩾6.5 mmol/l (48 mmol/mol) were 14.3% [95% CI 0.40-57.9] and 95.3% (86.9-99.0%), respectively.

Conclusion

FBG may be better than laboratory-measured HbA1c in confirming DM in adult Ugandans with recently diagnosed TB. However, because of the small study sample size, larger studies evaluating the diagnostic utility of these diabetes screening tests in adult Ugandans with TB are needed to confirm these findings.

Global, regional, and national prevalence of diabetes mellitus in patients with pulmonary tuberculosis: a systematic review and meta-analysis

BACKGROUND

Both pulmonary tuberculosis (PTB) and diabetes mellitus (DM) are major global public health problems. We estimated the global, regional, and national prevalence of diabetes mellitus in a population with PTB.

METHODS

We searched for observational studies of DM in people with PTB using the PubMed and Embase electronic bibliographic databases, focusing on articles published in the English language from database inception until March 31, 2021. We included original research that reported the prevalence of DM in PTB or those that had sufficient data to compute these estimates. Studies were excluded if they did not provide primary data or were case studies or reviews. Two authors independently extracted the articles and collected detailed information using a predefined questionnaire. A country-specific random-effects meta-analysis was used for countries with two or more available studies, and a fractional response regression model was employed to predict the prevalence of DM in PTB for countries with one or no study. The study was registered with the International Prospective Register of Systematic Reviews, using the registration number CRD42018101989.

RESULTS

We identified 22,658 studies, and 153, across 51 countries, were retained for data extraction. The global prevalence of DM among patients with PTB was estimated to be 13.73% (95% confidence interval [CI] 12.51-14.95). The prevalence rates were 19.32% (95% CI 13.18-25.46) in the region of the Americas, 17.31% (95% CI 12.48-22.14) in the European region, 14.62% (95% CI 12.05-17.18) in Southeast Asia, 13.59% (95% CI 7.24-19.95) in the western Pacific region, 9.61% (95% CI 4.55-14.68) in the eastern Mediterranean region, and 9.30% (95% CI 2.83-15.76) in the African region. The country with the highest estimated prevalence was the Marshall Islands (50.12%; 95% CI 4.28-95.76).

CONCLUSION

Comorbid PTB and DM remain prevalent worldwide.

Evaluation of point-of-care algorithms to detect diabetes during screening for latent TB infection

BACKGROUND: Individuals with both diabetes mellitus (DM) and TB infection are at higher risk of progressing to TB disease.OBJECTIVE: To determine DM prevalence in populations at high risk for latent TB infection (LTBI) and to identify the most accurate point-of-care (POC) method for DM screening.METHODS: Adults aged ≥25 years were recruited at health department clinics in Hawaii and Arizona, USA, and screened for LTBI and DM. Screening methods for DM included self-report, random blood glucose (RBG), and POC hemoglobin A1c (HbA1c). Using HbA1c ≥6.5% or self-reported history as the gold standard for DM, we compared test strategies to determine the most accurate method while keeping test costs low.RESULTS: Of 472 participants, 13% had DM and half were unaware of their diagnosis. Limiting HbA1c testing to ages ≥30 years with a RBG level of 120-180 mg/dL helped identify most participants with DM (sensitivity 85%, specificity 99%) at an average test cost of US$2.56 per person compared to US$9.56 per person using HbA1c for all patients.CONCLUSION: Self-report was insufficient to determine DM status because many participants were previously undiagnosed. Using a combination of POC RBG and HbA1c provided an inexpensive option to assess DM status in persons at high risk for LTBI.

The effect of a structured clinical algorithm on glycemic control in patients with combined tuberculosis and diabetes in Indonesia: A randomized trial

AIMS

Diabetes mellitus (DM) is associated with worse tuberculosis (TB) treatment outcomes, especially among those with poor glycemic control. We examined whether a structured clinical algorithm could improve glycemic control in TB patients with DM.

METHODS

In an open label randomized trial, TB-DM patients were randomized to scheduled counselling, glucose monitoring, and adjustment of medication using a structured clinical algorithm (intervention arm) or routine DM management (control arm), with glycated hemoglobin (HbA1c) at month 6 as the primary end point.

RESULTS

We randomized 150 pulmonary TB-DM patients (92% culture positive, 51.3% male, mean age 53 years). Baseline mean HbA1c was 11.0% in the intervention arm (n = 76) and 11.6% in the control arm (n = 74). At 6 months, HbA1c had decreased more in the intervention arm compared with the control arm (a difference of 1.82% HbA1c, 95% CI 0.82-2.83, p < 0.001). Five patients were hospitalized in the intervention arm and seven in the control arm. There was more hypoglycemia (35.0% vs 11.8%; p = 0.002) in the intervention arm. Two deaths occurred in the intervention arm, one due to cardiorespiratory failure and one because of suspected septic shock and multiorgan failure.

CONCLUSION

Regular monitoring and algorithmic adjustment of DM treatment led to improved glycemic control.

The Interaction of Diabetes and Tuberculosis: Translating Research to Policy and Practice

Diabetes Mellitus increases the risk of developing Tuberculosis (TB) disease by about three times; it also doubles the risk of death during TB treatment and other poor TB treatment outcomes. Diabetes may increase the risk of latent infection with Mycobacterium tuberculosis (LTBI), but the magnitude of this effect is less clear. Whilst this syndemic has received considerable attention, most of the published research has focussed on screening for undiagnosed diabetes in TB patients or observational follow-up of TB treatment outcomes by diabetes status. There are thus substantial research and policy gaps, particularly with regard to prevention of TB disease in people with diabetes and management of patients with TB-diabetes, both during TB treatment and after successful completion of TB treatment, when they likely remain at high risk of TB recurrence, mortality from TB and cardiovascular disease. Potential strategies to prevent development of TB disease might include targeted vaccination programmes, screening for LTBI and preventive therapy among diabetes patients or, perhaps ideally, improved diabetes management and prevention. The cost-effectiveness of each of these, and in particular how each strategy might compare with targeted TB prevention among other population groups at higher risk of developing TB disease, is also unknown. Despite research gaps, clinicians urgently need practical management advice and more research evidence on the choice and dose of different anti-diabetes medication and effective medical therapies to reduce cardiovascular risks (statins, anti-hypertensives and aspirin). Substantial health system strengthening and integration may be needed to prevent these at risk patients being lost to care at the end of TB treatment.

Diabetes Mellitus Among Pulmonary Tuberculosis Patients From 4 Tuberculosis-endemic Countries: The TANDEM Study

BACKGROUND

Diabetes mellitus (DM) increases active tuberculosis (TB) risk and worsens TB outcomes, jeopardizing TB control especially in TB-endemic countries with rising DM prevalence rates. We assessed DM status and clinical correlates in TB patients across settings in Indonesia, Peru, Romania, and South Africa.

METHODS

Age-adjusted DM prevalence was estimated using laboratory glycated hemoglobin (HbA1c) or fasting plasma glucose in TB patients. Detailed and standardized sociodemographic, anthropometric, and clinical measurements were made. Characteristics of TB patients with or without DM were compared using multilevel mixed-effect regression models with robust standard errors.

RESULTS

Of 2185 TB patients (median age 36.6 years, 61.2% male, 3.8% human immunodeficiency virus-infected), 12.5% (267/2128) had DM, one third of whom were newly diagnosed. Age-standardized DM prevalence ranged from 10.9% (South Africa) to 19.7% (Indonesia). Median HbA1c in TB-DM patients ranged from 7.4% (Romania) to 11.3% (Indonesia). Compared to those without DM, TB-DM patients were older and had a higher body mass index (BMI) (P value < .05). Compared to those with newly diagnosed DM, TB patients with diagnosed DM had higher BMI and HbA1c, less severe TB, and more frequent comorbidities, DM complications, and hypertension (P value < .05).

CONCLUSIONS

We show that DM prevalence and clinical characteristics of TB-DM vary across settings. Diabetes is primarily known but untreated, hyperglycemia is often severe, and many patients with TB-DM have significant cardiovascular disease risk and severe TB. This underlines the need to improve strategies for better clinical management of combined TB and DM.

Patterns of non-communicable comorbidities at start of tuberculosis treatment in three regions of the Philippines: The St-ATT cohort

Diabetes and undernutrition are common risk factors for tuberculosis (TB), associated with poor treatment outcomes and exacerbated by TB. Limited data exist describing patterns and risk factors of multiple comorbidities in persons with TB. Nine-hundred participants (69.6% male) were enrolled in the Starting Anti-TB Treatment (St-ATT) cohort, including 133 (14.8%) initiating treatment for multi-drug resistant TB (MDR-TB). Comorbidities were defined as: diabetes, HbA1c ≥6.5% and/or on medication; hypertension, systolic blood pressure ≥140 mmHg or diastolic blood pressure ≥90 mmHg and/or on medication; anaemia (moderate/severe), haemoglobin <11g/dL; and, undernutrition (moderate/severe) body-mass-index <17 kg/m2. The most common comorbidities were undernutrition 23.4% (210/899), diabetes 22.5% (199/881), hypertension 19.0% (164/864) and anaemia 13.5% (121/899). Fifty-eight percent had ≥1 comorbid condition (496/847), with 17.1% having ≥2; most frequently diabetes and hypertension (N = 57, 6.7%). Just over half of diabetes (54.8%) and hypertension (54.9%) was previously undiagnosed. Poor glycemic control in those on medication (HbA1c≥8.0%) was common (N = 50/73, 68.5%). MDR-TB treatment was associated with increased odds of diabetes (Adjusted odds ratio (AOR) = 2.48, 95% CI: 1.55-3.95); but decreased odds of hypertension (AOR = 0.55, 95% CI: 0.39-0.78). HIV infection was only associated with anaemia (AOR = 4.51, 95% CI: 1.01-20.1). Previous TB treatment was associated with moderate/severe undernutrition (AOR = 1.98, 95% CI: 1.40-2.80), as was duration of TB-symptoms before starting treatment and household food insecurity. No associations for sex, alcohol or tobacco use were observed. MDR-TB treatment was marginally associated with having ≥2 comorbidities (OR = 1.52, 95% CI: 0.97-2.39). TB treatment programmes should plan for large proportions of persons requiring diagnosis and management of comorbidities with the potential to adversely affect TB treatment outcomes and quality of life. Dietary advice and nutritional management are components of comprehensive care for the above conditions as well as TB and should be included in planning of patient-centred services.

Tuberculosis, Human Immunodeficiency Virus, and the Association With Transient Hyperglycemia in Periurban South Africa

BACKGROUND

Diabetes mellitus (DM) increases tuberculosis (TB) risk. We assessed the prevalence of hyperglycemia (DM and impaired glucose regulation [IGR]) in persons with TB and the association between hyperglycemia and TB at enrollment and 3 months after TB treatment in the context of human immunodeficiency virus (HIV) infection.

METHODS

Adults presenting at a Cape Town TB clinic were enrolled. TB cases were defined by South African guidelines, while non-TB participants were those who presented with respiratory symptoms, negative TB tests, and resolution of symptoms 3 months later without TB treatment. HIV status was ascertained through medical records or HIV testing. All participants were screened for DM using glycated hemoglobin and fasting plasma glucose at TB treatment and after 3 months. The association between TB and DM was assessed.

RESULTS

Overall DM prevalence was 11.9% (95% confidence interval [CI], 9.1%-15.4%) at enrollment and 9.3% (95% CI, 6.4%-13%) at follow-up; IGR prevalence was 46.9% (95% CI, 42.2%-51.8%) and 21.5% (95% CI, 16.9%-26.3%) at enrollment and follow-up. TB/DM association was significant at enrollment (odds ratio [OR], 2.41 [95% CI, 1.3-4.3]) and follow-up (OR, 3.3 [95% CI, 1.5-7.3]), whereas TB/IGR association was only positive at enrollment (OR, 2.3 [95% CI, 1.6-3.3]). The TB/DM association was significant at enrollment in both new and preexisting DM, but only persisted at follow-up in preexisting DM in patients with HIV-1 infection.

CONCLUSIONS

Our study demonstrated high prevalence of transient hyperglycemia and a significant TB/DM and TB/IGR association at enrollment in newly diagnosed DM, but persistent hyperglycemia and TB/DM association in patients with HIV-1 infection and preexisting DM, despite TB therapy.

Exposure to cholinesterase inhibiting insecticides and blood glucose level in a population of Ugandan smallholder farmers

Objectives

The risk of diabetes mellitus may be elevated among persons exposed to some pesticides, including cholinesterase-inhibiting insecticides (organophosphates and carbamates). The objective of this study was to investigate how acetylcholinesterase activity was associated with mean blood glucose levels among smallholder farmers in Uganda.

Methods

We conducted a short-term follow-up study among 364 smallholder farmers in Uganda. Participants were examined three times from September 2018 to February 2019. At each visit, we measured glycosylated haemoglobin A (HbA_1c) as a measure of long-term average blood glucose levels. Exposure to organophosphate and carbamate insecticides was quantified using erythrocyte acetylcholinesterase normalised by haemoglobin (AChE/Hb). For a subgroup of participants, fasting plasma glucose (FPG) was also available. We analysed HbA_1c and FPG versus AChE/Hb in linear mixed and fixed effect models adjusting for age, sex, physical activity level, and consumption of fruits and vegetables, alcohol and tobacco.

Results

Contrary to our hypothesis, our mixed effect models showed significant correlation between low AChE/Hb and low HbA_1c. Adjusted mean HbA_1c was 0.74 (95% CI 0.17 to 1.31) mmol/mol lower for subjects with AChE/Hb=24.3 U/g (35th percentile) compared with subjects with AChE/Hb=25.8 U/g (50th percentile). Similar results were demonstrated for FPG. Fixed effect models showed less clear correlations for between-phase changes in AChE/Hb and HbA_1c.

Conclusions

Our results do not clearly support a causal link between exposure to cholinesterase-inhibiting insecticides and elevated blood glucose levels (expressed as HbA_1c and FPG), but results should be interpreted with caution due to the risk of reverse causality.

Patterns and predictors of co-morbidities in Tuberculosis: A cross-sectional study in the Philippines

Diabetes and undernutrition are common risk factors for TB, associated with poor treatment outcomes and exacerbated by TB. We aimed to assess non-communicable multimorbidity (co-occurrence of two or more medical conditions) in Filipino TB outpatients, focusing on malnutrition and diabetes. In a cross-sectional study, 637 adults (70% male) from clinics in urban Metro Manila (N = 338) and rural Negros Occidental (N = 299) were enrolled. Diabetes was defined as HbA1c of ≥6.5% and/or current diabetes medication. Study-specific HIV screening was conducted. The prevalence of diabetes was 9.2% (54/589, 95%CI: 7.0-11.8%) with 52% newly diagnosed. Moderate/severe undernutrition (body mass index (BMI) <17 kg/2) was 20.5% (130/634, 95%CI: 17.4-23.9%). Forty percent of participants had at least one co-morbidity (diabetes, moderate/severe undernutrition or moderate/severe anaemia (haemoglobin <11 g/dL)). HIV infection (24.4%, 74/303) was not associated with other co-morbidities (but high refusal in rural clinics). Central obesity assessed by waist-to-hip ratio was more strongly associated with diabetes (Adjusted Odds Ratio (AOR) = 6.16, 95%CI: 3.15-12.0) than BMI. Undernutrition was less common in men (AOR = 0.44, 95%CI: 0.28-0.70), and associated with previous history of TB (AOR = 1.97, 95%CI: 1.28-3.04) and recent reduced food intake. The prevalence of multimorbidity was high demonstrating a significant unmet need. HIV was not a risk factor for increased non-communicable multimorbidity.

High prevalence and heterogeneity of Dysglycemia in patients with tuberculosis from Peru: a prospective cohort study

BACKGROUND

The accuracy of different laboratory tests for diagnosis of diabetes mellitus (DM) and prediabetes (preDM) in populations exposed to tuberculosis (TB) remains poorly understood. Here, we examined the prevalence of DM and preDM in TB affected people in Lima, Peru.

METHODS

A prospective cohort study of patients affected TB and their household contacts (HHC), was conducted between February and November 2017 in Lima, Peru. Fasting plasma glucose (FPG), HbA1c and oral glucose tolerance test (OGTT) were used to detect DM and preDM in a prospective cohort of TB patients (n = 136) and household contacts (n = 138). Diagnostic performance of the laboratory tests was analyzed. Potential effects of sociodemographic and clinical factors on detection of dysglycemia were analyzed.

RESULTS

In TB patients, prevalence of DM and preDM was 13.97 and 30.88% respectively. Lower prevalence of both DM (6.52%) and preDM (28.99%) were observed in contacts. FPG, HbA1c and OGTT had poor agreement in detection of preDM in either TB cases or contacts. TB-DM patients had substantially lower hemoglobin levels, which resulted in low accuracy of HbA1c-based diagnosis. Classic sociodemographic and clinical characteristics were not different between TB patients with or without dysglycemia.

CONCLUSION

High prevalence of DM and preDM was found in both TB patients and contacts in Lima. Anemia was strongly associated with TB-DM, which directly affected the diagnostic performance of HbA1c in such population.

Random glucose sampling as screening tool for diabetes among disadvantaged tuberculosis patients residing in urban slums in India

Noncommunicable diseases like diabetes are increasingly recognised as important risk factors for tuberculosis (TB) and poor treatment outcomes [1]. While the link between TB and diabetes was described many decades ago, several recent epidemiological studies and systematic reviews have confirmed the association of diabetes with a three-fold increased risk of developing TB [2]. Since 2011, the World Health Organization has recommended bidirectional screening of all TB patients for diabetes [3]. However, it is currently unclear at which point in treatment one should screen and which diagnostic tools should be used. Following the American Diabetes Association, diabetes is diagnosed by a fasting plasma glucose ≥7 mmol·L⁻¹, a 2-h plasma glucose value ≥11.1 mmol·L⁻¹ during the oral glucose tolerance test, glycated haemoglobin (HbA1C) ≥48 mmol·mol⁻¹ or a random plasma glucose value ≥11.1 mmol·L⁻¹ in patients with classic symptoms of hyperglycaemia [4]. The Concurrent Tuberculosis and Diabetes Mellitus (TANDEM) consortium recently suggested a simplified two-step diagnostic algorithm where all patients with random plasma glucose levels >6.1 mmol·L⁻¹ receive point-of-care HbA1C testing [4]. With laboratory-based HbA1C as the gold standard, this two-step combination resulted in a sensitivity and specificity of >90% to detect diabetes. Here, we evaluate the feasibility of diabetes screening by random glucose sampling among disadvantaged TB patients residing in urban slums in New Delhi, India.

Recently, a two-step diagnostic algorithm to diagnose diabetes among TB patients was proposed comprising random glucose and point-of-care HbA1c. This study evaluates the first part of this algorithm among disadvantaged TB patients.http://ow.ly/UI7d30nK1UN

Tuberculosis and diabetes: bidirectional association in a UK primary care data set

BACKGROUND

Many studies have found an increased risk of pulmonary tuberculosis (PTB) among those with diabetes mellitus (DM). However, evidence on whether the association is bidirectional remains sparse. This study investigates DM rates among those with and without prior tuberculosis (TB) disease as well as the reverse.

METHODS

Data on a UK general practice population, between 2003 and 2009, were obtained from The Health Improvement Network database. A series of retrospective cohort studies were completed. Individuals were successively classified as 'exposed' or 'unexposed' to TB, PTB, extrapulmonary TB (EPTB) or DM. Multivariate negative binomial regression was used to calculate incidence rate ratios (IRR) among each exposure group for outcomes of interest (TB, PTB, EPTB or DM in turn) adjusting for plausible confounding variables (age, sex, region, Townsend quintile and smoking status). Potential confounding due to ethnicity was adjusted for using McNamee's external method.

RESULTS

DM risk was substantially raised among individuals with a history of TB disease (IRR 5.65 (95% CI 5.19 to 6.16)), PTB (IRR 5.74 (95% CI 5.08 to 6.50)) and EPTB (IRR 4.66 (95% CI 3.94 to 5.51)) compared with those without; results were attenuated after external adjustment for ethnicity (IRR 2.33 (95% CI 2.14 to 2.53)). TB risk was raised modestly among individuals with DM (IRR 1.50 (95% CI 1.27 to 1.76)) and was attenuated slightly after adjustment for ethnicity (IRR 1.26 (95% CI 1.07 to 1.48)).

CONCLUSION

DM risk was raised among those with previous TB disease; this finding has implications for follow-up and screening of patients with TB, who may be at high risk of developing DM or related complications.