Type 2 diabetes and tuberculosis in a dynamic bi-national border population

Mycobacterial clearance from sputum is delayed during the first phase of treatment in patients with diabetes

Although type 2 diabetes (DM) is a recognized risk factor for development of tuberculosis (TB), the impact on treatment is unclear. Among the few published reports, some suggest that mycobacterial clearance during treatment is delayed in TB patients with DM. Using survival analysis on data from 469 culture-positive TB patients retrospectively identified in south Texas, we found DM to be an independent risk factor for a 5-day delay in mycobacterial clearance within the first 60 days of treatment.

Impact of type 2 diabetes on manifestations and treatment outcome of pulmonary tuberculosis

Diabetes mellitus (DM) is a known risk factor for pulmonary tuberculosis (PTB). This study aimed to determine if type 2 DM alters manifestations and treatment outcome of PTB. Records of 217 consecutive culture-proven PTB patients were analysed retrospectively. The manifestations and treatment outcomes of 74 patients with type 2 DM (PTB-DM group) were compared to 143 patients without DM (PTB group). PTB-DM patients showed higher frequencies of fever, haemoptysis, positive acid-fast bacilli sputum smears, and consolidation, cavity, and lower lung field lesions on chest radiographs, and higher mortality rate. Furthermore, type 2 DM, age 65 years, and extensive radiographic disease were factors independently associated with an unfavorable outcome. This study confirmed that clinical manifestations and chest radiographs of PTB patients associated with type 2 DM significantly depart from the typical presentation. Type 2 DM seems to have a negative effect on treatment outcome of PTB.

Type 2 diabetes and multidrug-resistant tuberculosis

The association between tuberculosis (TB) and diabetes is re-emerging with the epidemic of type 2 diabetes (T2DM). We analyzed retrospective data from 2878 TB patients across the Texas/Mexico border. Overall, 161/2878 (5.6%) patients had MDR TB (resistance to rifampin and isoniazid): Texas 49/1442 (3.4%) and Mexico 112/1436 (7.8%). In Texas, MDR TB was significantly associated with T2DM (OR 2.1, 95% CI 1.1-4.2) when adjusted for age, gender, drug and alcohol abuse, HIV infection and history of previous episode of TB; and in Mexico (OR 1.80, 95% CI 1.1-2.9) when adjusted for age and gender. Patients with T2DM in both countries were more likely to be compliant with DOTS therapy (Texas: OR 2.4, 95% CI 1.1-5.4) than patients without T2DM. In Texas, all but 3 of the T2DM patients with MDR TB were resistant at their first culture at the time of diagnosis. It is possible that impaired immunity in T2DM increases susceptibility to infection with resistant strains.

Diabetes and the risk of tuberculosis: a neglected threat to public health?

OBJECTIVES

Tuberculosis (TB) remains a major global public health problem. In the past, a relationship between TB and diabetes mellitus (DM) was recognized, and its importance was acknowledged through joint treatment clinics. However, this is rarely highlighted in current research or control priorities. This paper aims to evaluate the evidence for an association between these two diseases.

METHODS

A Medline literature search was undertaken, supplemented by checking references and contacting experts. We critically appraised studies that quantified the association between TB and DM, and were published after 1995. We assessed study quality according to criteria such as sample size, method of selection of cases and controls, losses to follow-up, quality and method of control of confounding, and summarized the results narratively and in tabular form.

RESULTS

All studies identified statistically significant and clinically important associations, with the increase in risk or odds of TB varying between 1.5- and 7.8-fold for those with DM. Risk was highest at younger ages. Most studies had not measured and controlled adequately for potential major confounders.

DISCUSSION

There is strong evidence for an association between TB and DM, which has potential public health implications. Further well-designed studies are needed to assess the magnitude precisely.

The effect of type 2 diabetes mellitus on the presentation and treatment response of pulmonary tuberculosis

BACKGROUND

Diabetes mellitus (DM) is a known risk factor for tuberculosis (TB), and with the increasing prevalence of type 2 DM in less developed regions, many patients with TB will have concomitant DM. Presently, little is known about the effect of DM on the clinical presentation and treatment outcome of TB.

METHODS

In an urban setting in Indonesia, 737 patients with pulmonary TB were screened for DM and were followed up prospectively during TB treatment. Clinical characteristics and outcome were compared between patients with TB who had DM and patients with TB who did not have DM.

RESULTS

DM was diagnosed in 14.8% of patients with TB and was associated with older age and a greater body weight. On presentation, diabetic patients with TB had more symptoms but had no evidence of more-severe TB. After 2 months, results of sputum microscopic examination was more often positive in diabetic patients (18.1% vs. 10.0%). After 6 months, 22.2% of cultured sputum specimens from diabetic patients were positive for Mycobacterium tuberculosis (adjusted odds ratio, 7.65; P=.004).

CONCLUSION

DM seems to have a negative effect on the outcome of TB treatment. The underlying mechanisms for the different response to treatment in diabetic patients with TB must be explored. Screening for DM and subsequent glycemic control may improve the outcome of TB treatment.

Degradation of myxovirus virion RNA by periodate

Extensively degraded RNA was isolated from virions of influenza virus which had been oxidized with sodium m-periodate. Similarly, although to a lesser extent, RNA isolated from periodate-treated ribonucleoprotein of influenza virus was also degraded. In contrast, influenza virus RNA, if first freed from other virion components, was not degraded by periodate oxidation.