Development of Non-alcoholic Fatty Liver Disease (NAFLD) in Young Obese Tribal Subjects of Tripura: Link between Low 25 (OH) Vitamin-D Levels and Immune Modulators.

BACKGROUND: There have been many studies conducted so far on Non Alcoholic Fatty Liver Disease (NAFLD) with its many aspects including its association with 25 hydroxy Vitamin D levels and its rather complex interplay with pro-inflammatory cytokines such as Interleukin-1a (IL-1a), Interleukin-6 (IL-6) and Tumour Necrosis Factor-Alpha (TNF-α), Interleukin-17a (IL-17a) and anti-inflammatory cytokines such as Interleukin-4 (IL-4) and Interleukin-10 (IL-10). This study was designed to show the development of NAFLD in the young tribal population of Tripura and the link between 25(OH) Vitamin D and pro-inflammatory cytokines (IL-1a, IL-6, IL-17a and TNF-ɑ) and -inflammatory cytokines such as IL - 4 and IL - 10 and the development of NAFLD while at the same time throws light on the prevalence of 25(OH) Vitamin D deficiencies and the levels of pro-inflammatory cytokines in the study group.
METHODS: The study is an analytical cross-sectional study with final population of 94 cases between 18 to 40 years of age fulfilling inclusion and exclusion criteria and an equal number of subjects from same tribal community age and sex matched taken as control population.
RESULTS: There was a significant relationship between level of 25(OH) Vitamin D and fatty liver (OR: 9.46, 95% CI: 4.82 - 18.59; p < 0.001). The mean serum 25(OH) Vitamin D level in the cases was significantly higher than the controls (17.21 ng/ ml + 6.34 ng/ml vs 26.56 ng/ml + 10.63 ng/ml; p < 0.001). There was a significant difference between the mean serum levels of IL-1a (11.50 Pg/ml ± 2.75 Pg/ml vs 8.28 Pg/ml ± 2.08 Pg/ml; p < 0.001), IL-4 (0.69 Pg/ml ± 0.43 Pg/ml vs 0.84 Pg/ml ± 0.36 Pg/ml; p = 0.009), IL-6 (2.99 ± 1.11 Pg/ml vs 2.22 ± 1.08 Pg/ml; p < 0.001), IL-10 (6.50 ± 2.76 Pg/ml vs 5.23 Pg/ml ± 2.67 Pg/ml; p = 0.002), IL-17a (5.33 Pg/ml ± 2.22 Pg/ml vs 3.64 Pg/ml ± 1.99 Pg/ml; p < 0.001) and TNF-α (6.99 ± 2.81 Pg/ml vs 5.40 ± 3.08 Pg/ml; p < 0.001) of the cases and the controls Low serum 25(OH) D [OR: 0.87 (95% CI: 0.83 - 0.92), p = 0.0001], and high IL-1a [OR: 1.52 (95% CI: 1.26 - 1.84), p < 0.0001] were independently associated with the risk of NAFLD.
CONCLUSION: 25(OH) Vitamin D concentration are lower while that of IL-1a, IL-4, IL-6, IL-10, IL-17a and TNF-α are higher in subjects with fatty liver in comparison to those without. 25(OH) Vitamin D deficiency and high levels of serum IL-1a were independently associated with the risk of development of NAFLD. © Journal of the Association of Physicians of India 2011.