Free fatty acids/triglycerides increase ocular and subcutaneous blood flow

Elevated plasma free fatty acids (FFA) induce skeletal muscle insulin resis tance and impair endothelial function. The aim of this study was to charact erize the acute hemodynamic effects of FFA in the eye and skin. A triglycer ide (Intralipid 20%, 1.5 ml/min)/heparin (bolus: 200 IU; constant infusion rate: 0.2 IU.kg(-1).min(-1)) emulsion or placebo was administered to 10 hea lthy subjects. Measurements of pulsatile choroidal blood flow with laser in terferometry, retinal blood flow with the blue field entoptic technique, pe ak systolic and end diastolic blood velocity (PSV, EDV) in the ophthalmic a rtery with Doppler sonography, and subcutaneous blood flow with laser Doppl er flowmetry were performed during an euglycemic somatostatin-insulin clamp over 405 min. Plasma FFA/triglyceride elevation induced a rise in pulsatil e choroidal blood flow by 25 +/- 3% (P< 0.001) and in retinal blood flow by 60 +/- 23% (P = 0.0125). PSV increased by 27 +/- 8% (P = 0.001), whereas E DV was not affected. Skin blood flow increased by 149 +/- 38% (P = 0.001). Mean blood pressure and pulse rate remained unchanged, whereas pulse pressu re amplitude increased by 17 +/- 5% (P = 0.019). Infusion of heparin alone had no hemodynamic effect in the eye or skin. In conclusion, FFA/triglyceri de elevation increases subcutaneous and ocular blood flow with a more prono unced effect in the retina than in the choroid, which may play a role for e arly changes of ocular perfusion in the insulin resistance syndrome.