Matrix metalloproteinases and hypertension: a link between left ventricular hypertrophy and diastolic dysfunction?

Differences in Left Ventricular Diastolic Dysfunction between Eccentric and Concentric Left Ventricular Hypertrophy in Hypertensive Patients with Preserved Systolic Function

Left ventricular (LV) hypertrophy (LVH) may be eccentric or concentric (2 × LV posterior wall thickness relative to LV end-diastolic dimension ≤ 0.42 or > 0.42, respectively). The LV diastolic function between age-matched hypertensive patients with eccentric and concentric LVH was compared in the present study. Echocardiography was used to measure LV mass index (LV mass/body surface area; LVMI) as an index of LVH. LV diastolic function was assessed by measurements of peak early transmitral flow velocity ( E)/peak late transmitral flow velocity ( A) (the E/A ratio), peak early diastolic mitral annular velocity ( e′) and the E/e′ ratio. Although LVMI, E/A and e′ did not differ between the two groups, E/e′ was significantly higher (worse) in patients with concentric LVH (13.4 ± 5.4) than in those with eccentric LVH (11.1 ± 3.6). Among hypertensive patients with LVH, those with concentric LVH may, therefore, have more severe LV diastolic dysfunction than those with eccentric LVH even if their LVMIs, which reflect the degree of LVH, are similar.

Metalloproteinase-3 genotype as a predictor of cardiovascular risk in hypertensive adolescents

Background and Objectives

Hypertension develops as a result of cardiac hypertrophy and fibrosis or as a result of exchange of the extracellular matrix. In particular, matrix metalloproteinase (MMP)-3 is a major enzyme involved in the reconstruction of the arterial intima through activation of other MMPs. We analyzed MMP-3 genotypes in hypertensive and normotensive adolescents and sought to determine if a particular genotype is a predictor of cardiovascular complications.

Subjects and Methods

Forty-four hypertensive adolescents and 59 healthy adolescents were included in this study. Serum aldosterone, renin, insulin, angiotensin converting enzyme (ACE), insulin, homocysteine, vitamin B₁₂, folate, MMP-1, MMP-2, MMP-3, MMP-9, tissue inhibitors of matrix metalloproteinases (TIMP)-1, and TIMP-2 were measured. MMP-3 genotypes were analyzed using a polymerase chain reaction (PCR) primer. The carotid intima media thickness (IMT), diameter, and brachial ankle pulse wave velocity (baPWV) were evaluated using ultrasound.

Results

In hypertensive adolescents, blood pressure, anthropometric data, carotid IMT, baPWV, serum pro-MMP-1, MMP-2, MMP-9, TIMP-1, and TIMP-2 were no different between the 6A/6A group and the 5A/6A group. Serum MMP-9 was higher in the 5A/6A group than in the control group. Aldosterone, insulin, and homocysteine were higher in the 6A/6A group than in the control group, and vitamin B₁₂ and folate were lower in the 6A/6A group than in the control group.

Conclusion

In conclusion, serum MMP-3 levels were not significantly different in different MMP-3 genotypes in hypertensive adolescents. However, few patients were included in this study. Further investigation is necessary to clarify the relationship between MMP-3 genotype and cardiovascular risk.