Visceral fat area is a strong predictor of leukocyte cell-derived chemotaxin 2, a potential biomarker of dyslipidemia

Abstract

Background: Leukocyte cell-derived chemotaxin 2 (LECT2) is a hepatokine linking obesity to skeletal muscle insulin resistance. Although previous studies reported that obesity was associated with high levels of circulating LECT2 in human, the associations of detailed body fat distribution with LECT2 levels have not been examined. Furthermore, although animal study suggested that exercise decreased circulating LECT2 levels, it remains unknown whether physical fitness is associated with LECT2 levels in human. We therefore examined the relationship of plasma LECT2 levels with various adiposity indices and cardiorespiratory fitness (CRF) in middle-aged and elderly Japanese men. Furthermore, we examined the relationship of LECT2 levels with the presence of metabolic syndrome, hypertension, insulin resistance and dyslipidemia to determine the clinical significance of measuring circulating LECT2.

Materials and methods: This was a cross-sectional study of 143 Japanese men (age: 30-79 years). Participants' plasma LECT2 levels were measured by an enzyme-linked immunosorbent assay. To assess their abdominal fat distributions, visceral fat area (VFA) and subcutaneous fat area (SFA) were measured using magnetic resonance imaging. CRF was assessed by measuring peak oxygen uptake ([Formula: see text]).

Results: All adiposity indices measured in this study were positively correlated with plasma LECT2 levels, while [Formula: see text] was negatively correlated with LECT2 levels after adjustment for age. The correlations, except for VFA were no longer significant with further adjustment for VFA. Stepwise multiple linear regression analysis revealed that VFA was the strongest predictor of plasma LECT2 levels. Plasma LECT2 levels differed based on the presence of metabolic syndrome and dyslipidemia, but not hypertension and insulin resistance. Logistic regression analyses revealed that plasma LECT2 levels were significantly associated with dyslipidemia independently of VFA; VFA was not significantly associated with dyslipidemia after adjustment for LECT2.

Conclusion: VFA was the strongest predictor of plasma LECT2 that is a potential biomarker linking visceral obesity to dyslipidemia.

Fig 1. Differences in Plasma LECT2 levels Based on the Presence of (A) Metabolic Syndrome, (B) Dyslipidemia, (C) Hypertension, and (D) Insulin resistance.

Box-plots show the median value and interquartile range of plasma LECT2 levels; open circles indicate outliers from 1.5- to 3.0-fold interquartile range.

Fig 2. Correlations Between Plasma LECT2 Levels and BMI (A), Body Fat (B), WC (C), VFA (D), SFA (E), and V˙O2peak (F).

LECT2 and SFA were log-transformed for analysis.

Fig 3. Differences in Plasma LECT2 Levels Between the Participants with High and Low VFA Stratified by High and Low WC (A) or SFA (B) Categories.

Data are expressed as geometric mean and geometric standard deviation. Values in the bar graph represent the number of participants in each category. *P < 0.001 vs. low VFA.