Interplay between intra-pancreatic fat deposition, exchangeable apolipoproteins, and lipoprotein subclasses

Exchangeable apolipoproteins, including apolipoprotein C-II (apo C-II), apolipoprotein C-III (apo C-III), and apolipoprotein E (apo E), play central roles in the modulation of cardiovascular disease (CVD) risk by readily transferring between anti-atherogenic high-density lipoprotein (HDL) and pro-atherogenic triglyceride-rich lipoproteins (TRL). High intra-pancreatic fat deposition (IPFD) has also emerged as a novel risk factor for CVD. This study aimed to investigate the associations of apo C-II, apo C-III, and apo E with IPFD, as well as with TRL and HDL subclasses.

Abdominal magnetic resonance imaging at 3.0 T was used to quantify IPFD. Plasma levels of apo C-II, apo C-III, and apo E were measured. TRL and HDL subclasses were analysed, with TRL categorised into very-low-density lipoprotein (VLDL) and intermediate-density lipoprotein (IDL) subclasses (IDL-C, IDL-B, and IDL-A), and HDL into HDL-large, HDL-intermediate, and HDL-small subclasses. Univariate and multivariate linear regression analyses were performed to assess these associations. A total of 128 individuals were analysed. IPFD showed a significant inverse association with both apo C-II and apo C-III, consistent across all statistical models. In the most adjusted model, each unit increase in IPFD was associated with a 0.36-unit decrease in apo C-II (p = 0.001) and a 0.31-unit decrease in apo C-III (p = 0.004). Furthermore, apo C-II and apo C-III were significantly and inversely associated with all IDL subclasses (p < 0.02), but not with VLDL, across all models. No statistically significant association between apo E and IPFD or any IDL subclass was observed in the most adjusted model.

Apo C-II and apo C-III, but not apo E, contribute to the previously observed positive relationship between IPFD and IDL.