||Central obesity is associated with insulin
resistance and elevated levels of FFAs. As illustrated in slide 23, FFAs can
reduce insulin-mediated glucose disposal under experimental conditions.
However, it remains to be determined whether increased FFAs cause insulin
resistance or vice versa in obese subjects. In either case, insulin
resistance and elevated FFAs stimulate hepatic apolipoprotein B secretion
and increase hepatic lipase activity. This enzyme catalyzes the removal of
lipids from LDL and HDL, which makes them smaller and more dense. In turn,
these effects lead to hypertriglyceridemia, production of small, dense LDL
particles, and reduced HDL2-cholesterol levels. This dyslipidemic pattern,
which has been termed the atherogenic lipoprotein phenotype, is also
characteristic of that found in type 2 diabetes.
Brunzell JD, et al. Diabetes Care. 1999;22(suppl 3):C10-C13.