BMC Endocrine Disorders 2014, 14:57
 

Different associations between obesity and impaired fasting glucose depending on serum gamma-glutamyltransferase levels within normal range: a cross-sectional study

Nam Soo Hong1, Jeong-Gook Kim2, Yu-Mi Lee1, Hyun-Woo Kim3, Sin Kam1, Keon-Yeop Kim1, Ki-Su Kim1
and Duk-Hee Lee1,4*
 

Abstract

Background: Despite the consistent relationship between serum γ-glutamyltransferase (GGT) and type 2 diabetes
(T2D), one unsolved issue is the role of serum GGT in the well-known association between obesity and T2D. This
study was performed to investigate whether the association between body mass index (BMI) and impaired fasting
glucose (IFG) differed depending on serum GGT levels within the normal range.

Methods: Study subjects were 2,424 men and 3,652 women aged ≥ 40, participating in the Fifth Korean National
Health and Nutrition Examination Survey. Serum GGT levels within the normal range were classified into
gender-specific tertiles.

Results: Among men and women belonging to the lowest tertile of serum GGT, BMI showed statistically
non-significant weak associations with the risk of IFG. However, among persons in the highest tertile of serum
GGT, the risk of IFG was 3 − 4 times higher among persons with BMI ≥ 25 kg/m2 than those with BMI < 23 kg/m2
(Pinteraction = 0.032 in men and 0.059 in women).

Conclusions: The well-known strong association between BMI and IFG was observed mainly among persons with
elevation of serum GGT to certain physiological levels, suggesting a critical role of serum GGT in the pathogenesis
of IFG. This finding has an important clinical implication because serum GGT can be used to detect high-risk
obese persons.

Keywords: γ-Glutamyltransferase (GGT), Impaired fasting glucose, Obesity, Type 2 diabetes