Undiagnosed diabetes tied to greater TB risk among adults in China
Among residents of China, adults with diabetes are substantially more likely to develop tuberculosis vs. those without diabetes, particularly those who are unaware that they have diabetes, according to findings published in Diabetes/Metabolism Research and Reviews.
“Undiagnosed, but not diagnosed, diabetics had elevated rates of tuberculosis infection and modified the relationship between tuberculosis infection and diabetes,” Wei Lu, of the department of chronic communicable disease at the Center for Disease Control and Prevention of Jiangsu province in Nanjing, China, and colleagues wrote. “These results may explain heterogeneity between prior studies and suggest improving diabetic control through rapidly identifying undiagnosed diabetes patients may have indirect benefits to tuberculosis control.”
Lu and colleagues assessed the diabetes status of 5,405 adults (median age, 50 years; 53.2% women) from Danyang in the Jiangsu province of China via fasting blood glucose levels in blood samples taken in July 2013 and then followed participants until April 2018. If participants reported or medical records indicated they had diabetes, they were considered to have diagnosed diabetes. If participants had “no evidence of prior diabetes diagnosis” but had 7 mmol/L of fasting glucose in their blood sample, they were considered to have undiagnosed diabetes.
The researchers also assessed TB status at baseline with QuantiFERON-TB (QFT) and tuberculin skin tests (TST), with 0.35 IU/mL in QFT and 10 mm or more in TST confirming positivity. During the follow-up period, cases of TB were recorded.
According to the researchers, diabetes was identified in 5.6% of the cohort while positive QFT results were identified in 20.4% and positive TST results were identified in 37.8%. There were 131.1 cases per 100,000 persons of TB during follow-up for those with diabetes and 39.2 cases per 100,000 persons for those without diabetes.
A larger proportion of participants with undiagnosed diabetes (32.5%) had positive QFT results vs. those with diagnosed diabetes (23.2%) and those without diabetes (20%; P = .001). In contrast, the researchers noted that there was no significant difference among the groups in terms of TST results.
Based on QFT results, the adjusted odds of TB infection were 58% greater for those with undiagnosed diabetes vs. those without diabetes (adjusted OR = 1.58; 95% CI, 1.07-2.35), whereas the adjusted odds for TB infection based on TST results were 36% greater for those with diabetes of any kind (aOR = 1.36; 95% CI, 1.06-1.74) and 53% greater for those with undiagnosed diabetes (aOR = 1.53; 95% CI, 1.05-2.23). The researchers further noted that “QFT positivity was strongly predictive of tuberculosis progression” while the same was not true for TST.
“Our results showing that undiagnosed diabetics have elevated levels of tuberculosis infection suggest improving diabetic control through rapidly identifying undiagnosed diabetes patients may have subsidiary benefits to tuberculosis control,” the researchers wrote. “Integration of tuberculosis and diabetic control through patient-centered care is clearly needed to manage this emerging dual epidemic.”
Liu Q, et al. Diabetes Metab Res Rev. 2019;doi:10.1002/dmrr.3227.
Source: Healio
