Human Soluble Leptin Receptor Number in Healthy Normotensive Individuals With High Normal Blood Pressure

Abstract

High normal blood pressure (BP) seems to be related to increased cardiovascular risk in healthy normotensive subjects, whereas hyperleptinemia enhances both sympathetic tone and arterial BP. The aim of our study was to determine the human soluble leptin receptor number in healthy normotensive subjects with high normal BP and to compare these findings to those of healthy normotensive individuals with normal BP levels. We studied 36 healthy normotensive individuals with high normal BP (19 men and 17 women, mean age 42+/-8 years, body mass index [BMI] 23+/-1.5 kg/m2) and 40 healthy normotensive individuals with normal BP (23 men and 17 women, mean age 43+/-7 years, BMI 23.2+/-1.4 kg/m2). The two groups are matched for age, sex, and BMI. The human soluble leptin receptor number and immunoreactive leptin levels were determined in the study population by enzyme-linked immunoassay and radioimmunoassay, respectively. Mean plasma leptin levels were significantly higher, whereas mean human soluble leptin receptor numbers were lower in the group with high normal BP compared with the normotensive group (10+/-4.8 v 6+/-2.7 ng/mL, P<.001 and 18+/-7 v 27+/-9 IU/mL, P<.001, respectively). Our findings indicate that normotensive individuals with high normal BP have statistically significantly higher plasma leptin levels and lower numbers of human soluble leptin receptors. This observation may play a important role in the pathogenesis of cardiovascular events in this special group of patients and needs further investigation.