Qiuzhen Wang1, Aiguo Ma2, Xiuxia Han1, Huizhen Zhang3, Shanliang Zhao4, Hui Liang1, Jing Cai1, Frans J Kok5, Evert G Schouten5. 1. Institute of Human Nutrition, Medical College of Qingdao University, Qingdao, China. 2. Institute of Human Nutrition, Medical College of Qingdao University, Qingdao, China. Email: ma91503@126.com. 3. Qingdao Institute For Food and Drug Control, Qingdao, China. 4. Linyi Chest Hospital, East Fenghuang Avenue, Linyi, China. 5. Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands.
Abstract
BACKGROUND AND OBJECTIVES: Although vitamin D is implicated in the generation of anti-microbial peptide cathelicidin, which plays a key role against pulmonary tuberculosis (PTB), and may have an inverse association with the risk of type 2 diabetes (DM), its role in the co-existence of these two diseases (PTB-DM) is still uncertain. This study explored the association of vitamin D status with prevalent PTB, PTB-DM and DM. METHODS AND STUDY DESIGN: We randomly selected 130 PTB patients, 90 PTB-DM, 91 DM and 134 controls. Serum 25(OH)D levels were determined. A structured questionnaire and anthropometric measurements were administered. RESULTS: Serum 25(OH)D levels in PTB and PTB-DM were 12.2±2.2 ng/mL and 12.9±2.5 ng/mL, respectively, which were lower than those in DM and control groups. Odds ratios of PTB and PTB-DM comparing extreme quartiles of 25(OH)D (lower than 8.6 ng/mL versus >=26.6 ng/mL) were 3.26 and 2.27, respectively. These associations remained after adjustment for possible risk factors [OR (95% CI)=4.73 (2.04-10.9) and 2.50 (1.04- 6.02), respectively]. A synergistic interaction was observed between low 25(OH)D and underweight in respect to prevalent PTB-DM [OR=24.6 vs 2.50 for lowest quartile of 25(OH) D and 4.59 for underweight]. CONCLUSIONS: Odds ratios of low serum 25(OH)D levels for PTB and PTB-DM were greater than 1.0, and were even much greater when combined with underweight. However, since the association of serum 25(OH)D levels with PTB was stronger than with PTB-DM, we could not draw the conclusion that vitamin D is a link between PTB and DM.
BACKGROUND AND OBJECTIVES: Although vitamin D is implicated in the generation of anti-microbial peptide cathelicidin, which plays a key role against pulmonary tuberculosis (PTB), and may have an inverse association with the risk of type 2 diabetes (DM), its role in the co-existence of these two diseases (PTB-DM) is still uncertain. This study explored the association of vitamin D status with prevalent PTB, PTB-DM and DM. METHODS AND STUDY DESIGN: We randomly selected 130 PTB patients, 90 PTB-DM, 91 DM and 134 controls. Serum 25(OH)D levels were determined. A structured questionnaire and anthropometric measurements were administered. RESULTS: Serum 25(OH)D levels in PTB and PTB-DM were 12.2±2.2 ng/mL and 12.9±2.5 ng/mL, respectively, which were lower than those in DM and control groups. Odds ratios of PTB and PTB-DM comparing extreme quartiles of 25(OH)D (lower than 8.6 ng/mL versus >=26.6 ng/mL) were 3.26 and 2.27, respectively. These associations remained after adjustment for possible risk factors [OR (95% CI)=4.73 (2.04-10.9) and 2.50 (1.04- 6.02), respectively]. A synergistic interaction was observed between low 25(OH)D and underweight in respect to prevalent PTB-DM [OR=24.6 vs 2.50 for lowest quartile of 25(OH) D and 4.59 for underweight]. CONCLUSIONS: Odds ratios of low serum 25(OH)D levels for PTB and PTB-DM were greater than 1.0, and were even much greater when combined with underweight. However, since the association of serum 25(OH)D levels with PTB was stronger than with PTB-DM, we could not draw the conclusion that vitamin D is a link between PTB and DM.