4.1. Influence of the study design
Several features of the study design may help to explain the
results. Although changes in some of the markers of adipocyte
function and inflammation we measured were detected among
dietary groups during the course of the study (for example, serum
PAI-1 was different at week 4, and serum leptin and MCP-1 were
different at week 8), most groups were not different from each
other by the end of the 12-week study. This finding suggests that
the animals were able to adapt to the dietary treatments over
time, and demonstrates that long-term high-fat feeding may yield
fewer phenotypic physiological changes than previously thought.
In addition, although the PUFA/SFA ratios and the n6/n3 ratios
in the adipose tissue phospholipids and triglycerides closely
reflected the differences in fatty acid composition among diets,
they appeared to have little effect on adipokine production and
adipocyte function in this model.