The relationship between 25-hydroxyvitamin D concentration and liver enzymes in overweight or obese adults: Cross-sectional and interventional outcomes. Issue 177 (March 2018)

• Record Type: Journal Article
• Authors: Naderpoor, Negar; Mousa, Aya; de Courten, Maximilian; Scragg, Robert; de Courten, Barbora
• Is Part Of: Journal of steroid biochemistry and molecular biology. Issue 177(2017)
• Page Start: 193
• Page End: 199
• Publication Date: 2018-03
• Subjects: γ-Glutamyl transferase (GGT) -- Alanine aminotransferase (ALT) -- Alkaline phosphatase (ALP) -- 25-Hydroxyvitamin D (25(OH)D) -- Obesity -- Insulin resistance; Steroid hormones -- Periodicals; Biochemistry -- Periodicals; Hormones -- Periodicals; Molecular Biology -- Periodicals; Hormones stéroïdes -- Périodiques; Steroid hormones; Periodicals; 572.579
• DOI: 10.1016/j.jsbmb.2017.09.009
• Languages: English
• ISSNs: 0960-0760

Abstract

Highlights: Serum 25(OH)D concentrations were not related to GGT, ALT and ALP in drug-naïve individuals with no history of liver disease. Vitamin D supplementation had no effect on the liver enzymes in a vitamin D-deficient overweight or obese otherwise healthy cohort. The three liver enzymes were directly related to abdominal obesity (waist to hip ratio), cholesterol and triglycerides, and inversely to insulin sensitivity. Abstract: Vitamin D deficiency is prevalent in individuals with non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis. However, there is limited and inconsistent data on the effect of vitamin D supplementation on liver function. Hepatic enzymes have been used as surrogate markers for NAFLD and have been associated with metabolic syndrome. We examined the relationships between 25-hydroxyvitamin D (25(OH)D) and γ-glutamyl transferase (GGT), alanine aminotransferase (ALT), alkaline phosphatase (ALP) in 120 drug-naïve individuals with no history of liver disease. In addition, the effect of vitamin D supplementation (100, 000 loading dose of cholecalciferol followed by 4000IU daily for 16 weeks) on hepatic enzymes was investigated in a subgroup of 54 vitamin D-deficient overweight or obese individuals (28 randomised to cholecalciferol and 26 to placebo). Hepatic enzymes, anthropometric parameters, lipid profile, insulin sensitivity (hyperinsulinaemic-euglycaemic clamp, M value) and high sensitivity C-reactive protein (hs-CRP) were measured before and after the intervention. In the cross-sectional study, levels of GGT and ALT were higher in men compared to women (both p = 0.001). There were no significant differences in GGT, ALT and ALP between vitamin D categories (25(OH)D< 25 nmol/L, 25–50 nmol/L, and >50 nmol/L) and no relationships were found between the three enzymes and 25(OH)D before and after adjustment for age, sex, BMI, WHR, and insulin sensitivity (all p >0.5). In the randomised trial, 25(OH)D concentrations increased in the vitamin D group (mean change 57.0 ± 21.3 nmol/L) compared to the placebo group (mean change 1.9 ± 15.1 nmol/L). Mean changes in GGT, ALT and ALP were not significantly different between vitamin D and placebo groups (all p >0.2). Change in 25(OH)D concentration was not correlated with changes in GGT, ALT and ALP before and after adjustments for age and sex (all p >0.1). In summary, 25(OH)D concentrations were not related to hepatic enzymes in drug-naive adults with no history of liver disease, and vitamin D supplementation had no effect on the serum levels of hepatic enzymes in vitamin D-deficient and overweight or obese, otherwise healthy individuals. Hence, vitamin D supplementation is unlikely to prevent incident NAFLD.