[Intima-media thickness in healthy probands without risk factors for arteriosclerosis]

Ultrasound examination of the intima-media thickness (IMT) is a well accepted, highly reproducible method for the evaluation of early atherosclerosis. However, for the exact interpretation of these measurements reference values for IMT should be determined. The present work provides for the first time normal values for IMT of the common carotid artery and the arteries of the lower limbs (common femoral, superficial and popliteal arteries) in a German population of healthy subjects without risk factors.

A total of 112 subjects (50 men, 62 women), aged 40 to 70, were examined, according to the following inclusion criteria: no diabetes or marked elevation of postprandial plasma glucose; non-smokers; no hypertension, obesity, dys/hyperlipidaemia or albuminuria; no history of coronary heart disease, stroke and peripheral arterial occlusion. IMT was measured and standardized by the method of Pignoli. Total cholesterol, triglycerides, HDL-cholesterol, HbA1c, plasma glucose (fasting and postprandial) and albuminuria were examined by routine methods.

The mean values of double measurements bilaterally in the distal part of the common carotid artery in men were 0.79 (0.73 ... 0.84) mm (40-54 years) and 0.87 (0.81 ... 0.93) mm (55-70 years). In women the values were: -0.70 (0.67 ... 0.75) mm and 0.82 (0.75 ... 0.90) mm, resp. In the group aged 40-54 years the men showed significantly higher IMT of all examined vessels in comparison to the women. In the group aged 55-70 years somewhat higher IMT of the common carotid artery and significantly higher IMT of the arteries of the lower extremity were observed in men. In multivariate analysis age was found to be a significant determinant of IMT of all examined vessels.

Intima-media thickening of the common carotid artery in men aged 40-70 years is to be accepted if a single measurement of IMT exceeds > or = 1 mm. For women, aged 40-54 years, IMT is defined as pathological if one IMT is above 0.85 mm, and for those aged 55-70 years if IMT exceeds 1 mm.