A double burden of tuberculosis and diabetes mellitus and the possible role of vitamin D deficiency

Association Between Promoter Methylation of Vitamin D Metabolic Pathway Genes and Tuberculosis and Diabetes Comorbidity in a Chinese Han Population: A Case-Control Study

Background

Deficiency vitamin D and hyperglycemia could be related to weakened innate immune response and aggravate the progression of tuberculosis (TB). This study hypothesized that DNA promoter methylation of the pivotal genes in the vitamin D metabolic pathway might be related to diabetes and tuberculosis co-morbidity (TB-DM) susceptibility.

Methods

A total of 50 TB-DM and 50 healthy subjects (HS) were included in the present study. Targeted bisulfite sequencing was applied to detect the methylation of the promoter regions of candidate genes in the vitamin D metabolic pathway (CYP24A1, CYP27B1, CYP2R1, DHCR7, and VDR) in whole blood.

Results

The overall methylation level of candidate genes in this study was lower in patients with TB-DM than HS, except for CYP2R1. The results of the ROC demonstrated the potential of CYP24A1, CYP27B1, DHCR7, and VDR promoter methylation as a biomarker for diagnosing TB-DM, with all the AUC above 0.7. In subgroup analysis, we found that lower circulating vitamin D is related to a low level of CYP24A1, CYP27B1, and DHCR7 promoter methylation in patients with TB-DM. With decreasing methylation level, risk of TB-DM was significantly increased (odds ratio, 95% CI 0.343, 0.144-0.821 for CYP24A1; 0.461, 0.275-0.773 for CYP27B1; 0.09, 0.015-0.530 for DHCR7; 0.006, 0.0003-0.115 for VDR). Besides, our results revealed that there was a significant correlation between DNA promoter methylation of selected genes in the vitamin D metabolic pathway and platelet indices in TB-DM. However, there was no correlation between DNA methylation of the four genes and fasting glucose and HbA1c.

Conclusion

Our results could suggest that the selected genes in the vitamin D metabolic pathway may be involved in the pathological process of TB-DM, but independent of the process of hyperglycemia to impaired immune responses to Mtb.

Analysis on the Risk Factors of Malnutrition in Type 2 Diabetes Mellitus Patients with Pulmonary Tuberculosis

Objective

To explore the risk factors of malnutrition in type 2 diabetes mellitus combined with pulmonary tuberculosis (PTB-T2DM) patients and further to provide a clinical research basis for the identification and prevention of malnutrition.

Methods

From January 2020 to February 2022, 307 adult patients diagnosed with PTB-T2DM were enrolled in this retrospective study. According to whether malnutrition occurred after 6 months of treatment, patients were divided into malnutrition group (n = 123) and non-malnutrition group (n = 184). The nutritional status of patients was evaluated according to the Micro-Nutrition Assessment Scale (MNA). Evaluation of indicators was performed, including general information, disease characteristics of PTB-T2DM and laboratory indicators.

Results

Univariate logistic regression analysis showed that drinking, divorced, BMI <18.5kg/m2, weight <45kg, waist circumference <79cm, hip circumference <88cm, waist-to-hip ratio <69.99, calf circumference <26kg, grip strength <28kg, NRS score ≥3, Hb <106g/L, Alb <29.00g/L, PA <48.00μmol/L, GHB <3.40%, serum transferrin <1.37 mmol/L, serum potassium <3.18mmol/L, serum sodium <142.95 mmol/L, FEV1 ≥67.90% and RV <2.89% were risk factors for malnutrition in PTB-T2DM patients (all P < 0.05). The results of multivariate logistic regression analysis showed that drinking, divorced, weight <45kg, BMI <18.5kg/m2, NRS score ≥3, Hb <106g/L, Alb <29.00g/L, PA <48.00μmol/L, serum transferrin <1.37mmol/L, FEV1 ≥67.90% and RV <2.89% were independent risk factors for malnutrition in PTB-T2DM patients (all P < 0.05).

Conclusion

Drinking, divorced, weight <45kg, BMI <18.5kg/m2, NRS score ≥3, Hb <106g/L, Alb <29.00g/L, PA <48.00μmol/L, serum transferrin <1.37mmol/L, FEV1 ≥67.90% and RV <2.89% may be independent risk factors for malnutrition in PTB-T2DM patients, and timely identification of high-risk groups could improve the prognosis of PTB-T2DM patients.

Effect of Vitamin D Supplementation in Type 2 Diabetes Patients with Tuberculosis: A Systematic Review

BACKGROUND

Diabetes mellitus (DM) and tuberculosis (TB) have been recognized as reemerging epidemics, especially in developing countries. Among all the risk factors, diabetes causes immunosuppression, increasing the risk of active TB three times. Vitamin D has been found as a link between DM-TB co-morbidity.

OBJECTIVE

Vitamin D affects the immune response, suppresses Mycobacterium tuberculosis (Mtb) growth, and affects insulin secretion. The present systematic review determines the effect of vitamin D supplementation on clinical and therapeutic outcomes of DM-TB patients.

METHOD

A comprehensive literature search was carried out in PubMed, Cochrane, Web of Science, and Scopus database to determine eligible studies from inception to January 2021. Out of the 639 articles retrieved, three randomized controlled trials (RCTs) were included in the systematic review.

RESULT

The effect of vitamin D3 or oral cholecalciferol supplementation was assessed on outcomes, such as duration to sputum smear conversion, TB scores improvement, change in glycemic parameters, including HbA1c, FBS, and PLBS, and laboratory parameters, such as Hb, ESR, and CRP. Duration of sputum smear conversion was decreased by two weeks in the vitamin D3 supplemented group in two studies. TB score improvement and changes in glycemic parameters were inclined towards supplemented group; however, they were not significant.

CONCLUSION

The overall effect of vitamin D3 supplementation on TB patients with DM was not significant. Further studies are required in the future examining the effect of supplementation on outcomes in this population.

Vitamin D deficiency in pregnant women: Influenced by multiple risk factors and increase the risks of spontaneous abortion and small-for-gestational age

OBJECTIVE

To analyze the level of vitamin D and its influencing factors in pregnant women, and to explore the influence of vitamin D deficiency on common adverse pregnancy outcomes in pregnant women, providing evidence for prevention and intervention of vitamin D deficiency in pregnant women.

METHODS

The basic data and blood samples of pregnant women in our hospital from January 2019 to June 2020 were collected, and the 25-(OH) D levels of the serum samples were detected. Then the vitamin D levels and its influencing factors were analyzed, and the relationships between vitamin D levels and common adverse pregnancy outcomes in the pregnant women as well as the incidence of small-for-gestational-age newborns were analyzed.

RESULTS

The vitamin D deficiency rate, insufficiency rate and sufficiency rate of pregnant women were 83.28%, 15.36%, and 1.36% respectively, with vast majority of the pregnant women in a state of vitamin D deficiency. Analysis of the influencing factors on the vitamin D level of pregnant women showed "28 weeks ≤ gestational age ≤32 weeks, summer and autumn, high school education and above, weekly time outdoors ≥10 hours, supplement of vitamin D and trace elements during pregnancy" were protective factors for vitamin D sufficiency in pregnant women. Linear correlation analysis showed the vitamin D level of pregnant women was highly positively correlated with temperature, the higher the temperature, the higher the vitamin D level (r = 0.907, t = 6.818, P < .001). The level of vitamin D in pregnant women was related to the occurrence of spontaneous abortion and small-for-gestational age (SGA), with the incidence of spontaneous abortion and SGA in the "vitamin D deficiency group" higher than those of other groups (P = .018, P = .016).

CONCLUSIONS

The vitamin D level of pregnant women in this area is relatively low, which is affected by multiple factors such as gestational age, season, education level of pregnant women, weekly time outdoors, vitamin D and trace element supplement during pregnancy. Low vitamin D levels can increase the risk of spontaneous abortion and SGA in pregnant women, so relevant measures should be adopted to improve the vitamin D status of pregnant women.