LAS VEGAS — Vitamin D levels are inversely associated with nonalcoholic fatty liver disease severity, per data presented in a liver plenary session at ACG 2016.
“It is still controversial whether vitamin D level defers by severity of NAFLD,” Hyun-seok Kim, MD, MPH, resident at Rutgers New Jersey Medical School, said during his presentation. “Furthermore. … vitamin D level as a prognostic factor in the NAFLD patient is unknown. Our objective was to investigate the association between vitamin D level severity of NAFLD and its relationship to mortality using nationally representative data.”
Kim and colleagues conducted a population-based study by evaluating data of 14,797 adults extracted from the Third National Health and Nutrition Examination Survey. Of these, 10,960 had available data, such as liver ultrasound and vitamin D levels, between 1988 and 1994 and subsequent follow-up mortality data through December 2011. These patients were included in the final analysis where researchers used NAFLD fibrosis score to determine severity of hepatic fibrosis in those with NAFLD; Diasorin 25-OH-D assay to measure vitamin D levels; and the ANOVA (F-test) to evaluate association between vitamin D level and degree of NAFLD.
Overall, 35% of patients had NAFLD; liver ultrasound found 1,491 of these had mild, 1,707 people had moderate and 817 had severe steatosis. There were 2,354 patients who had low NAFLD fibrosis score, implying no significant fibrosis, per Kim, 1,379 presented with intermediate NAFLD fibrosis score and 282 had high NAFLD fibrosis score.
Per Kim’s presentation, vitamin D levels classified as normal were 25.1 ± 0.3 ng/mL, mild were 24.6 ± 0.4 ng/mL, moderate were 23.7 ± 0.3 ng/mL and severe were 23.5 ± 0.6 ng/mL (P < .001). In addition, vitamin D levels for low NAFLD fibrosis score was 24.7 ± 0.4 ng/mL, intermediate was 23.4 ± 0.4 ng/mL and high was 21.8 ± 0.5 ng/mL (P < .001).
“Vitamin D level was inversely related to the degree of steatosis and liver fibrosis among NAFLD patients based on the liver ultrasound findings,” Kim said.
After a median follow-up of 19 years, vitamin D deficiency less than 20 ng/mL was significantly associated with diabetes-related mortality (HR = 3; 95% CI, 1.5-6) and Alzheimer’s disease-related mortality (HR = 4.8; 95% CI, 1.5-15.5). However, this vitamin D level was not associated with all-cause mortality in people with NAFLD, after adjustment for age, sex, race, BMI, and evidence of diabetes.
Kim concluded: “Prospective or clinical trials are needed to confirm our findings and investigate whether treating vitamin D deficiency would be helpful in preventing or slowing the progression of NAFLD.” – by Melinda Stevens
Kim H-s, et al. Abstract #47. Presented at: American College of Gastroenterology Annual Scientific Meeting; Oct. 14-19, 2016; Las Vegas, NV.
Disclosure: The researchers report no relevant financial disclosures.