Serum vitamin D is associated with non-alcoholic fatty liver disease in Chinese males with normal weight and liver enzymes
Abstract
Ya-ping HAO1, #, Xiao-jing MA1, #, Yu-qi LUO1, Jie NI1, Jian-xin DOU1, Ya-qin HU1, Jia-an ZHU2, Yu-qian BAO1, *, Wei-ping JIA1
1Department of Endocrinology and Metabolism, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital; Shanghai Clinical Center for Diabetes; Shanghai Key Clinical Center for Metabolic Disease; Shanghai Diabetes Institute; Shanghai Key Laboratory of Diabetes Mellitus, Shanghai 200233, China; 2Department of Ultrasound, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital; Shanghai Institute of Ultrasound in Medicine, Shanghai 200233, China
Aim: Considering the characterization of vitamin D deficiency as a risk factor of ectopic fat deposition, the association of serum 25-hydroxy vitamin D3 [25(OH)D3] levels with non-alcoholic fatty liver disease (NAFLD) was evaluated in Chinese men with normal body mass index (BMI) and enzyme markers of liver function.
Methods: A total of 514 participants (22 to 79 years old) with normal BMI and liver enzymes were identified for analysis. Abdominal ultrasound was performed to diagnose NAFLD, and the fatty liver index (FLI) was calculated to quantify liver steatosis. Serum 25(OH)D3 levels were determined by an electrochemiluminescence immunoassay.
Results: Among the entire study population, the mean levels of serum 25(OH)D3 were 15.32±5.77 ng/mL. However, when serum 25(OH)D3 levels were compared between non-NAFLD subjects (n=438) and NAFLD subjects (n=76), the latter showed significantly lower levels (15.65±5.89 ng/mL vs 13.46±4.65 ng/mL, P=0.002). In addition, serum 25(OH)D3 levels were found to be significantly correlated with FLI after adjustment for age and BMI (r=-0.108, P=0.014). Logistic regression showed that serum 25(OH)D3 levels were independently correlated with NAFLD (OR: 0.937, 95% CI: 0.884–0.993, P=0.028). Furthermore, stepwise regression analysis revealed that serum 25(OH)D3 levels were inversely associated with FLI (β=-0.055, P=0.040).
Conclusion: The present study demonstrated that serum 25(OH)D3 levels were inversely associated with NAFLD, even in subjects with normal total body fat, suggesting a potential role of lower levels of vitamin D in the occurrence and development of NAFLD.
Keywords: 25-hydroxy vitamin D3; non-alcoholic fatty liver disease; fatty liver index
This work was funded by the 973 Program of China (2013CB530606), National Natural Science Foundation of China (81100563), National Key Technology R&D Program of China (2012BAI02B03), Key Project of Science and Technology of Shanghai (13XD1403000) and a grant from Shanghai Health and Family Planning Commission (2013ZYJB1001).
# These authors contributed equally to this work.
* To whom correspondence should be addressed.
E-mail byq522@163.com
Received 2014-03-23 Accepted 2014-05-04
Keywords:
1Department of Endocrinology and Metabolism, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital; Shanghai Clinical Center for Diabetes; Shanghai Key Clinical Center for Metabolic Disease; Shanghai Diabetes Institute; Shanghai Key Laboratory of Diabetes Mellitus, Shanghai 200233, China; 2Department of Ultrasound, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital; Shanghai Institute of Ultrasound in Medicine, Shanghai 200233, China
Aim: Considering the characterization of vitamin D deficiency as a risk factor of ectopic fat deposition, the association of serum 25-hydroxy vitamin D3 [25(OH)D3] levels with non-alcoholic fatty liver disease (NAFLD) was evaluated in Chinese men with normal body mass index (BMI) and enzyme markers of liver function.
Methods: A total of 514 participants (22 to 79 years old) with normal BMI and liver enzymes were identified for analysis. Abdominal ultrasound was performed to diagnose NAFLD, and the fatty liver index (FLI) was calculated to quantify liver steatosis. Serum 25(OH)D3 levels were determined by an electrochemiluminescence immunoassay.
Results: Among the entire study population, the mean levels of serum 25(OH)D3 were 15.32±5.77 ng/mL. However, when serum 25(OH)D3 levels were compared between non-NAFLD subjects (n=438) and NAFLD subjects (n=76), the latter showed significantly lower levels (15.65±5.89 ng/mL vs 13.46±4.65 ng/mL, P=0.002). In addition, serum 25(OH)D3 levels were found to be significantly correlated with FLI after adjustment for age and BMI (r=-0.108, P=0.014). Logistic regression showed that serum 25(OH)D3 levels were independently correlated with NAFLD (OR: 0.937, 95% CI: 0.884–0.993, P=0.028). Furthermore, stepwise regression analysis revealed that serum 25(OH)D3 levels were inversely associated with FLI (β=-0.055, P=0.040).
Conclusion: The present study demonstrated that serum 25(OH)D3 levels were inversely associated with NAFLD, even in subjects with normal total body fat, suggesting a potential role of lower levels of vitamin D in the occurrence and development of NAFLD.
Keywords: 25-hydroxy vitamin D3; non-alcoholic fatty liver disease; fatty liver index
This work was funded by the 973 Program of China (2013CB530606), National Natural Science Foundation of China (81100563), National Key Technology R&D Program of China (2012BAI02B03), Key Project of Science and Technology of Shanghai (13XD1403000) and a grant from Shanghai Health and Family Planning Commission (2013ZYJB1001).
# These authors contributed equally to this work.
* To whom correspondence should be addressed.
E-mail byq522@163.com
Received 2014-03-23 Accepted 2014-05-04