Sf. Obrien et al., LOW-DENSITY-LIPOPROTEIN SIZE, HIGH-DENSITY-LIPOPROTEIN CONCENTRATION,AND ENDOTHELIAL DYSFUNCTION IN NON-INSULIN-DEPENDENT DIABETES, Diabetic medicine, 14(11), 1997, pp. 974-978
We examined endothelial function (nitric-oxide mediated) in 29 men wit
h diet-treated non-insulin-dependent (Type 2) diabetes mellitus (NIDDM
) and 18 male age-matched controls. Forearm blood flow was measured by
venous occlusive plethysmography during intra-arterial administration
of acetylcholine (ACh, 7.5 and 15 mu g min(-1)) and sodium nitropruss
ide (SNP, 3 and 10 mu g min(-1)). LDL particle size was estimated by n
on-denaturing gel electrophoresis. Serum lipids, blood pressure, and g
lycated haemoglobin were also measured. LDL particle size was smaller
(p = 0.048) in the diabetic patients than controls. In the diabetic pa
tients, LDL particle size was a significant positive predictor (p = 0.
01) of the area under the dose-response curve for ACh, after adjusting
for age, HbA(1c), systolic BP, and cholesterol (R-2 0.20). In stepwis
e regression including serum lipid and lipoprotein concentrations and
LDL particle size, decreased HDL cholesterol was the best predictor of
an impaired vasodilatory response to ACh. Vasodilatory responses to s
odium nitroprusside were not significantly correlated with LDL particl
e size or serum lipid and lipoprotein concentrations. We conclude that
in men with NIDDM, small, dense LDL particle size is associated with
abnormal endogenous release of nitric oxide. The contribution of small
, dense LDL particles to the development of endothelial dysfunction an
d early diabetic vasculopathy may not, however, be as great as decreas
ed HDL cholesterol. (C) 1997 by John Wiley & Sons, Ltd.