Vitamin D status in tuberculosis patients with diabetes, prediabetes and normal blood glucose in China: a cross-sectional study

Abstract

ObjectiveThe association between tuberculosis (TB), diabetes mellitus (DM) and vitamin D status is poorly characterised. We therefore: (1) determined vitamin D status in patients with TB in relation to whether they had normal fasting blood glucose (FBG), pre-DM or DM and (2) assessed whether baseline characteristics in patients with TB, including their DM status, were associated with vitamin D deficiency.MethodsIn patients with TB consecutively attending six clinics or hospitals in China, we measured 25-hydroxycholecalciferol (25-(OH)D3) at the time of registration using electrochemiluminescence in a COBASE 601 Roche analyser by chemiluminescence immunoassay. Data analysis was performed using the χ2 test, ORs and multivariate logistic regression.ResultsThere were 306 eligible patients with TB, including 96 with smear positive pulmonary TB, 187 with smear negative pulmonary TB and 23 with extrapulmonary TB. Of these, 95 (31%) had normal blood glucose, 83 (27%) had pre-DM and 128 (42%) had DM. Median serum vitamin D levels were 16.1 ng/mL in patients with TB with normal FBG, 12.6 ng/mL in patients with TB with pre-DM and 12.1 ng/mL in patients with TB with DM (p<0.001). The study highlighted certain baseline characteristics associated with vitamin D deficiency (25-(OH)D3<20 ng/mL). After adjusting for confounders, serum vitamin D deficiency was significantly more common in patients being registered in the cold season (November to April) (p=0.006) and in those with DM (p=0.003).ConclusionVitamin D levels are lower in patients with TB with pre-DM and DM and are also affected by certain baseline characteristics that include being registered in the cold season and having DM. TB programmes need to pay more attention to vitamin D status in their patients, especially if there is coexisting pre-DM or DM.

Vitamin D status of tuberculosis patients with diabetes mellitus in different economic areas and associated factors in China

“…Fourth, we did not find associations between vitamin D deficiency and baseline characteristics such as age, gender, residential community and number of daily cigarettes smoked, findings also in line with previous research [ 14 ]. Contrary to previous research [ 14 , 28 ], we found no strong association in this study with season, possibly because most of our patients lived in urban areas which may not have been so affected by reduced nutritional intake that occurs in the winter time. In the previous report, 32.5% of the study population resided in urban areas, but the figure was 50.0% in the current study.…”

“…Both DM and TB are associated with malnutrition and this association may be stronger with a longer duration of DM and multiple episodes of TB [ 32 ]. Amongst our study group, the proportion with older age and retreatment TB at nearly 30% was higher than found in a previous study of TB patients [ 14 ], a finding similar to that observed in Guangzhou [ 33 ].…”

“…First, there was a low median level of vitamin D in patients with dual disease, which was lower than levels found previously in non-DM patients with TB and in the general population [ 14 , 19 ]. This finding is also in line with previous research findings [ 10 , 12 , 13 ].…”

“…A small scale study in urban China, using liquid chromatography-tandem mass spectrometry, reported significant differences in vitamin D levels between patients with TB, patients with TB and pre-DM and patients with TB and DM [ 13 ]. A larger scale multi-center study in both urban and rural China, using the electrochemiluminescence (ECLIA) method, confirmed these findings and reported that DM was a strong independent risk factor for vitamin D deficiency [ 14 ]. However, there have been no large scale studies looking at associations between vitamin D levels and DM related risk factors in TB patients who have DM in routine programmatic settings.…”

Unfavourable treatment outcomes in tuberculosis patients with different vitamin D status and blood glucose levels in a programme setting in China

“…This was a prospective cohort study that recruited patients registered with TB at six clinics within the routine TB services in Jilin Province between November 2015 and July 2016 and followed them up until they all could have completed anti‐TB treatment. Details of the setting and sites, sample size, patient inclusion, blood sample collection and vitamin D measurements have been published elsewhere . Persons over the age of 18 years were consecutively recruited directly after the diagnosis of TB was recorded with no specific repeat in medical history or examination made.…”