Factors underlying the association of body mass index with serum ALT in Chinese hypertensive adults without known hepatic diseases

Folate Deficiency Was Associated with Increased Alanine Aminotransferase and Glutamyl Transpeptidase Concentrations in a Chinese Hypertensive Population: A Cross-Sectional Study

Alanine aminotransferase (ALT), aspartate transaminase (AST), and glutamyl transpeptidase (GGT) were three key enzymes in the hepatic metabolism. This study aimed to investigate the effect of homocysteine (Hcy) metabolism gene polymorphisms and serum Hcy and folate level on the hepatic functions in a Chinese hypertensive population. A representative sample with 480 subjects aged 28-75 was enrolled in 2005.9-2005.12 from six hospitals in different Chinese regions. Serum ALT, AST and GGT were measured by using an automatic biochemistry analyzer. Serum Hcy was measured by high-performance liquid chromatography, and serum folate was measured by chemiluminescent immunoassay. Known genotypes were detected by PCR-RFLP methods. The results showed that the MTHFR C677T mutation was related a decreased serum AST level (r=-0.11, p=0.026), whereas the MTHFR A1298C mutation elevated serum AST level (r=0.11, p=0.032). Furthermore, multiple regression analysis showed that folate deficiency was associated with higher serum ALT (β (SE): 0.13 (0.06), p=0.031) and GGT level (β (SE): 0.18 (0.07), p=0.011). However, serum Hcy level may not affect the hepatic functions. Our data suggested that hepatic functions were affected by MTHFR gene polymorphisms and serum folate level. Further studies are needed to confirm these correlations in a larger population.

Obesity is associated with increased red blood cell folate despite lower dietary intakes and serum concentrations

BACKGROUND

Folates are essential cofactors in metabolic pathways that facilitate biological methylation and nucleotide synthesis, and therefore have widespread effects on health and diseases. Although obesity is prevalent worldwide, few studies have investigated how obesity interacts with folate status.

OBJECTIVE

Based on data from the NHANES, this study aims to examine the association between body mass index (BMI) and obesity-related metabolic factors with blood folate status.

METHODS

A nationally representative sample of 3767 adults from the NHANES (2003-2006) was used as the study population. Regression analyses, with and without adjustment for demographic factors and dietary intakes, were performed to examine associations between BMI and metabolic factors with serum and RBC folate.

RESULTS

The results indicate serum folate concentrations were lower in obese groups compared to the desirable BMI and overweight categories, paralleling lower intakes in this group. In contrast, RBC folate increased incrementally with BMI. Regression analyses demonstrated an inverse relation between BMI and serum folate but a positive relation for RBC folate (P < 0.01). Waist circumference, serum triglycerides, and fasting plasma glucose each displayed significant positive relations with RBC folate (P < 0.01), although relations with serum folate were not significant and consistent.

CONCLUSIONS

In summary, obesity is associated with decreased serum folate, which parallels decreased folate intakes. In contrast, obesity is positively associated with RBC folate. Therefore, RBC folate, in addition to serum folate, should also be considered as a critical biomarker for folate status, especially in the obese population. Future research is needed to understand how obesity differentially alters serum and RBC folate status because they are associated with a variety of medical complications.