Does the plasma endothelin-1 concentration reflect atherosclerosis in the elderly?

Recently, attention has been focused on endothelin-1 (ET-1) as an indicator of atherosclerosis. However, normal levels of ET-1 are frequently found in elderly patients. We investigated the relationships between echocardiographic findings and ET-1 in 117 inpatients for rehabilitation.

The patients were 34 men and 83 women, 83.4 +/- 0.8 years old (mean +/- SE), with the following diseases: cerebrovascular diseases (n = 83), cardiovascular diseases of New York Heart Association Class I or II (n = 57), diabetes mellitus (n = 11) and hyperlipidemia (n = 12). Ejection fraction (EF) and left ventricular mass index (LVMI) were calculated by echocardiographic studies.

The average ET-1 was within the normal range, but a significant positive correlation was observed between age and ET-1 (ET-1 = 1.8 +/- 0.1 pg/ml, r = 0. 248, p < 0.01). Moreover, plasma ET-1 was positively correlated to total cholesterol and to low density lipoprotein cholesterol in patients with a history of hypertension (n = 41, r = 0.318 and r = 0. 314, both p < 0.05). Gender was not a significant factor. There was no significant difference in ET-1 between patients with mild renal dysfunction (n = 54) and patients with normal renal function (n = 63) (blood urea nitrogen = 30.9 +/- 2.4 vs. 15.1 +/- 0.5 mg/dl, serum creatinine = 1.03 +/- 0.06 vs. 0.59 +/-0.02 mg/dl, ET-1 = 1.7 +/- 0.1 vs. 1.8 +/- 0.1 pg/ml), or between patients with (n = 50) and without (n = 67) left ventricular hypertrophy (LVMI = 146 +/- 6 vs. 83 +/- 2 g/m(2), ET-1 = 1.8 +/- 0.1 vs. 1.8 +/- 0.1 pg/ml). There was no difference in ET-1 between patients with EF <50% (n = 27) and EF >/=50% (n = 90) (ET-1 = 1.8 +/- 0.2 vs. 1.7 +/- 0.1 pg/ml).

There were no significant relationships between echocardiographic findings and ET-1 in elderly subjects without overt heart failure. However, in patients with a history of hypertension, measuring ET-1 may be useful for estimating the extent of atherosclerosis.