BACKGROUND: On the basis of evidence of plasma leptin (LE) effects on cardiovascular system, we assessed possible association of LE and Doppler-derived left ventricular (LV) diastolic function in arterial hypertension. METHODS: Doppler echocardiography, blood sample for fasting plasma LE levels, and euglycemic hyperinsulinemic glucose clamp were performed on 15 healthy insulin-sensitive men and 40 newly diagnosed hypertensive men, who were divided into two groups according to insulin sensitivity degree: 15 insulin sensitive (IS) and 25 insulin resistant (IR) individuals (whole body glucose disposal >33.3 and <33.3 micromol/kg, respectively). RESULTS: The IR hypertensives had significantly higher body mass index (BMI), waist/hip ratio, LE and LV mass index than the other two groups. IR hypertensives had lower LE (even after adjusting for BMI and waist/hip ratio) and among LV diastolic indexes, lower E peak velocity (P < .05) and longer isovolumic relaxation time (IVRT) (P < .001) in comparison to IR hypertensives. IR hypertensives had the lowest E/A ratio (0.88 +/- 0.2) compared to IS patients (1.03 +/- 0.1 P < .05) and controls (1.31 +/- 10.2 P < .001). By multiple linear regression analyses performed both in the overall population and hypertensives, LV mass index and LE were independently associated to IVRT (R2 = 0.41 in overall population, R2 = 0.42 in hypertensives, both P < .0001), whereas age, heart rate, diastolic and systolic blood pressure (BP), BMI, waist/hip ratio, and insulin action were not significant. CONCLUSIONS: Our study underscores an independent association of increased plasma LE and lengthening of isovolumic relaxation in uncomplicated hypertension. Further studies will need to understand the conditions underlying both these phenomena.
BACKGROUND: On the basis of evidence of plasma leptin (LE) effects on cardiovascular system, we assessed possible association of LE and Doppler-derived left ventricular (LV) diastolic function in arterial hypertension. METHODS: Doppler echocardiography, blood sample for fasting plasma LE levels, and euglycemic hyperinsulinemic glucose clamp were performed on 15 healthy insulin-sensitive men and 40 newly diagnosed hypertensivemen, who were divided into two groups according to insulin sensitivity degree: 15 insulin sensitive (IS) and 25 insulin resistant (IR) individuals (whole body glucose disposal >33.3 and <33.3 micromol/kg, respectively). RESULTS: The IR hypertensives had significantly higher body mass index (BMI), waist/hip ratio, LE and LV mass index than the other two groups. IR hypertensives had lower LE (even after adjusting for BMI and waist/hip ratio) and among LV diastolic indexes, lower E peak velocity (P < .05) and longer isovolumic relaxation time (IVRT) (P < .001) in comparison to IR hypertensives. IR hypertensives had the lowest E/A ratio (0.88 +/- 0.2) compared to IS patients (1.03 +/- 0.1 P < .05) and controls (1.31 +/- 10.2 P < .001). By multiple linear regression analyses performed both in the overall population and hypertensives, LV mass index and LE were independently associated to IVRT (R2 = 0.41 in overall population, R2 = 0.42 in hypertensives, both P < .0001), whereas age, heart rate, diastolic and systolic blood pressure (BP), BMI, waist/hip ratio, and insulin action were not significant. CONCLUSIONS: Our study underscores an independent association of increased plasma LE and lengthening of isovolumic relaxation in uncomplicated hypertension. Further studies will need to understand the conditions underlying both these phenomena.
Authors: Wolfgang Lieb; Lisa M Sullivan; Jayashri Aragam; Tamara B Harris; Ronenn Roubenoff; Emelia J Benjamin; Ramachandran S Vasan Journal: Am J Cardiol Date: 2009-06-18 Impact factor: 2.778