Circulating acyl-CoA-binding protein/diazepam-binding inhibitor in gestational diabetes mellitus

BACKGROUND

Acyl-CoA-binding protein (ACBP)/diazepam-binding inhibitor has recently been characterized as an endocrine factor affecting energy balance and lipid metabolism. However, regulation of ACBP in women with gestational diabetes mellitus (GDM) during pregnancy, as well as postpartum, has not been investigated, so far.

METHODS

ACBP was quantified in 74 women with GDM and 74 healthy, gestational age-matched, pregnant controls using an enzyme-linked immunosorbent assay. Furthermore, ACBP was quantified post-partum in 82 women (i.e. 41 women with previous GDM vs. 41 previous control women). ACBP was related to measures of obesity, hypertension, glucose and lipid metabolism, renal function, and inflammation during pregnancy and postpartum.

RESULTS

During pregnancy, median [interquartile range] ACBP levels were not significantly different in women with GDM (40.9 [40.0] µg/l) compared to healthy, pregnant controls (29.1 [32.3] µg/l) (p = 0.215). ACBP serum concentrations increased from 30.3 [40.5] µg/l during pregnancy to 59.7 [33.2] µg/l after pregnancy in the entire cohort (p < 0.001). This observed elevation was consistent across both subgroups of women, those with prior GDM and those without. Multivariate analysis revealed that homeostasis model assessment of beta cell function (HOMA2-B) and creatinine positively and independently correlated with serum ACBP after pregnancy, while multivariate analysis during pregnancy showed no significant correlations.

CONCLUSIONS

Circulating ACBP is not a marker of GDM status, but ACBP is decreased during pregnancy, irrespective of GDM status. Furthermore, ACBP is related to beta cell function and renal markers in women after pregnancy.

Renal function is a major predictor of circulating acyl-CoA-binding protein/diazepam-binding inhibitor

Objective

Acyl-CoA-binding protein (ACBP)/diazepam-binding inhibitor has lately been described as an endocrine factor affecting food intake and lipid metabolism. ACBP is dysregulated in catabolic/malnutrition states like sepsis or systemic inflammation. However, regulation of ACBP has not been investigated in conditions with impaired kidney function, so far.

Design/methods

Serum ACBP concentrations were investigated by enzyme-linked immunosorbent assay i) in a cohort of 60 individuals with kidney failure (KF) on chronic haemodialysis and compared to 60 individuals with a preserved kidney function; and ii) in a human model of acute kidney dysfunction (AKD). In addition, mACBP mRNA expression was assessed in two CKD mouse models and in two distinct groups of non-CKD mice. Further, mRNA expression of mACBP was measured in vitro in isolated, differentiated mouse adipocytes - brown and white - after exposure to the uremic agent indoxyl sulfate.

Results

Median [interquartile range] serum ACBP was almost 20-fold increased in KF (514.0 [339.3] µg/l) compared to subjects without KF (26.1 [39.1] µg/l) (p<0.001). eGFR was the most important, inverse predictor of circulating ACBP in multivariate analysis (standardized β=-0.839; p<0.001). Furthermore, AKD increased ACBP concentrations almost 3-fold (p<0.001). Increased ACBP levels were not caused by augmented mACBP mRNA expression in different tissues of CKD mice in vivo or in indoxyl sulfate-treated adipocytes in vitro.

Conclusions

Circulating ACBP inversely associates with renal function, most likely through renal retention of the cytokine. Future studies need to investigate ACBP physiology in malnutrition-related disease states, such as CKD, and to adjust for markers of renal function.