The pressor response to acute hyperlipidemia is enhanced in lean normotensive offspring of hypertensive parents

Abstract

Family history is an important predictor of the cardiovascular risk factor cluster associated with insulin resistance. The dyslipidemia associated with insulin resistance may contribute to elevated blood pressure (BP). This study was undertaken to further explore the link between family history, dyslipidemia, and BP regulation. Twenty-three lean normal volunteers with a negative family history (FH−, n = 11) or positive family history (FH+, n = 12) of hypertension were evaluated under baseline conditions and during a 4-h infusion of intralipid and heparin (acute hyperlipidemia). Fasting blood was drawn for lipids including nonesterified fatty acids (NEFA). After 2 and 4 h of intralipid and heparin, blood was drawn for NEFA. The BP was measured at baseline and every 30 min after starting the intralipid and heparin infusion. Baseline triglycerides and very low density lipoprotein cholesterol concentrations were higher in FH+ than FH− subjects ( P < .05). However, NEFA increased similarly in both groups during the infusion of intralipid and heparin. The BP and heart rate increased with acute hyperlipidemia in all subjects combined ( P < .05). Despite the similar increase of NEFA, mean BP, pulse pressure, and pressure–rate product increased significantly in FH+ subjects but not in FH− volunteers with acute hyperlipidemia. Although systolic BP increased in both groups, the increase was greater in FH+ than in FH− volunteers during acute hyperlipidemia (14 ± 2 v 10 ± 2 mm Hg, P < .05). These results suggest that higher plasma lipids combined with a greater pressor response to hyperlipidemia may contribute to the development of high BP in subjects with a family history of hypertension.