Effect of vitamin D and B12 levels on hepatosteatosis in overweight and obese children

Abstract

Background. The childhood non-alcoholic hepatosteatosis leads to significant morbidity and mortality in adulthood. In recent years, vitamin D and B12 deficiency has been controversially associated with non-alcoholic fatty liver disease. Therefore, we aimed to evaluate the relationship of vitamin levels and insulin resistance (IR) with non-alcoholic hepatosteatosis in obese and overweight children. Material and methods. A total of 167 overweight and obese children aged 5–18 years were enrolled in this prospective study. The anthropometric measurements including body weight, height, body mass index (BMI) (weight/height2, kg/m2) were recorded. Children and adolescents with ≥ 95th percentile of BMI for their age and gender were diagnosed with obesity, and BMI between the 85th and 94th percentiles was classified as overweight. Children and adolescents classified into two groups according to the presence of hepatosteatosis: normal liver and hepatosteatosis group. Additionally, hepatosteatosis grading was performed by ultrasonographic evaluation. Participants’ demographic characteristics, physical examination, imaging and laboratory findings including serum levels of vitamin B12, 25(OH)D analysis and insulin resistance index were documented and compared between groups. Results. One hundred and sixty-seven patients included in this study were: 103 (61.7 %) males, 64 (38.3 %) females, and the mean age of total participants was 11.48 ± 2.99 years. According to BMI-Z score, 26.3 % of individuals were defined as overweight and 73.7 % were obese. Hepatosteatosis was determined in 70.7 % (n = 118) of our cases and it was significantly higher in male patients (79.6 %) than in females (p = 0.001). Mean IR was statistically higher in non-alcoholic fatty liver disease group (11.15 ± 13.39) than in normal liver group (6.95 ± 6.20) (p = 0.029). Moreover, there were statistically significant differences found in IR levels according to severity of hepatosteatosis (p = 0.013). In addition, vitamin D and B12 deficiencies were not significantly associated with hepatosteatosis or severity of hepatosteatosis (p > 0.05). Also, no statistically significant differences were found in mean levels of vitamin D, vitamin B12 and IR between obese and overweight children. Conclusions. Our findings support the published data that vitamin D and B12 deficiencies do not contribute to the pathology of hepatosteatosis. In addition, insulin resistance has been demonstrated to be a risk factor for non-alcoholic fatty liver and hepatosteatosis severity.

Keywords

• hepatosteatosis
• non-alcoholic fatty liver disease
• childhood obesity
• vitamin b12 deficiency
• vitamin d deficiency, insulin resistance