Current TB infection influences hyperglycemia diagnosis
Recent data suggested African patients with tuberculosis infection often test positive for hyperglycemia, but may return to normal blood glucose levels once tuberculosis treatment is completed.
As a result, diabetes testing should be conducted upon admission for tuberculosis infection and then reconfirmed during follow-up, according to researchers.
“As an infectious disease, TB increases insulin resistance and stress-induced hyperglycemia, which may lead to over-diagnosis of [diabetes] during the acute phase of TB,” they wrote. “Few small studies have examined the longitudinal course of glycemia during TB treatment, but none was conducted on the African continent or compared the performance of different [diabetes] screening tests over time within the same study population.”
To explore associations between TB infection and hyperglycemia, researchers recruited adult patients presenting to Tanzanian hospitals with new active TB and matched controls without TB between June 2012 and December 2013. Diagnosis was confirmed through sputum smear microscopy, chest X-ray, clinical evidence and clinician decision, and patients received at least 6 months of therapy until treatment success or adverse outcome. All participants provided demographic information and underwent clinical examination for hyperglycemia at enrollment, with TB patients repeating examination upon completion of treatment. Blood glucose was determined through fasting capillary glucose (FCG), 2-hour capillary glucose (2-hCG) and glycated hemoglobin (HbA1c) screening.
There were 530 TB patients and 491 age- and sex-matched controls included in the final analysis. Patients with TB were more likely to have HIV, anemia and low weight, according to the researchers. Prevalence of both diabetes and pre-diabetes upon enrollment was greater among TB patients, and each was independently associated with TB infection. Mean values of FCG, 2-hCG and HbA1c were higher within this group as well.
Results suggested these associations dispersed after TB patients completed their treatment regimens. Mean values of the three screening tests decreased over the course of the study, and the majority of TB patients who demonstrated glucose levels consistent with diabetes at enrollment were no longer diabetic at follow-up. Hyperglycemic FCG values at enrollment were the only screening result significantly associated with treatment failure or death (adjusted OR = 3.32; 95% CI, 1.2-9.14).
In light of these findings, the researchers recommended African patients with diabetes and TB be retested following treatment, and that patients recently admitted with TB should also receive FCG testing to determine the risk of adverse outcomes.
“Testing for the presence of transient hyperglycemia with FCG detects TB patients at higher risk of adverse TB outcomes and gives the opportunity to manage hyperglycemia, but the impact of such intervention on TB outcome needs to be confirmed,” the researchers wrote.
Source: Healio
