Latent tuberculosis in patients with diabetes mellitus: prevalence, progression and public health implications.

BACKGROUND: Diabetes mellitus (DM) confers a higher risk for tuberculosis (TB). Yet, TB screening and chemoprophylaxis for latent TB infection (LTBI) in DM remains controversial. We conducted a cross-sectional study to elucidate LTBI prevalence and longitudinal follow-up to ascertain LTBI to active TB progression rate in DM. METHODS: 220 DM patients without previous TB from the outpatient diabetes clinic of the hospital were enrolled. T-Spot TB, tuberculin-skin-test (TST) and chest radiography (CXR) were performed. LTBI was defined by negative CXR with reactive T-Spot TB. Progression to active TB was confirmed by cross-checking against the TB registry. RESULTS: The prevalence of LTBI was 28.2% (62/220) by reactive T-Spot. None progressed to active TB from 2007-2013. Multivariate analysis revealed that any co-morbidity (p=0.016) was positively associated while metformin (p=0.008) was negatively associated with LTBI. CONCLUSIONS: Over a quarter of DM patients harbor LTBI. While the lack of demonstrable progression to active TB within the follow-up time frame up to this point does not unequivocally support a routine TB screening policy or anti-TB chemoprophylaxis for LTBI in a diabetic population for now, this preliminary evidence needs re-evaluation with longer follow-up of this enrolled cohort over the next decade.

Clinical utility of selective intra-arterial calcium-stimulated hepatic venous sampling in regionalisation of insulinomas--the Singapore experience.

INTRODUCTION: To evaluate the efficacy and safety of selective intra-arterial calcium-stimulated hepatic venous sampling (ASVS) as a preoperative regionalisation modality for insulinomas. DESIGN AND METHODS: Four patients with biochemically-proven endogenous hyperinsulinism and negative spiral computed tomographic (CT) pancreas were subjected to ASVS between October 1999 to May 2001. Results obtained from ASVS were compared with localisation studies using either magnetic resonance imaging (MRI) or endoscopic ultrasonography (EUS); and these were confirmed surgically whenever possible. RESULTS: ASVS led to a definitive regionalisation in all 4 patients evaluated; the predicted location of the insulinoma matched the findings intraoperatively in all 3 patients who were operated upon. These were all proven to be insulinoma histologically. However, 1 patient showed a positive ASVS result in samples obtained from the left hepatic vein only. In the patient who was unable to undergo surgical resection due to other co-morbid factors, his ASVS findings were corroborated by localisation obtained from the MRI study. Conversely, EUS was found to give an incorrect localisation of insulinoma in 1 patient. Adverse effects were encountered in 3 patients (2 with mild hypotension and 1 with transient atrial fibrillation); however, premature termination of the procedure was not necessary in any of the patients. CONCLUSION: ASVS is accurate and reliable for regionalisation of insulinoma, especially in patients who do not have an obvious, unequivocal tumour using high quality current-generation MRI scans.