Cheung, BMY

Kumana, CR

Lau, CP

Leung, RYH

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Title Angiotensin-converting enzyme genotypes in hypertensivepatients with left ventricular hypertrophyAuthor(s) Cheung, BMY; Leung, RYH; Lau, CP; Kumana, CRCitation The 5th Medical Research Conference, Hong Kong, China,January 2000, v. 22 n. Supp 2, p. 35Issued Date 2000URL http://hdl.handle.net/10722/46872Rights Creative Commons: Attribution 3.0 Hong Kong LicenseS-CH-2ANGIOTENSIN-CONVERTING ENZYME GENOTYPES IN HYPERTENSIVE PATIENTS WITHLEFT VENTRICULAR HYPERTROPHYCheung BMY. Leung RYH, Lau CP, Kumana CR. Department of Medicine, University of Hong Kong, Hong KongObjective: Hypertension, left ventricular hypertrophy (LVH) and angiotensin-converting enzyme homozygousdeletional (DD) genotype are all cardiovascular risk factors which, if present together, may confer especiallyhigh risk. We and others previously reported a decrease with age in the prevalence of the DD genotype inhypertensive patients, which may be due to decreased survival. In this study, we hypothesise that there mightbe fewer patients with the DD genotype among patients with hypertensive LVH.Methods: 70 hypertensive patients and 102 normal healthy controls were studied. LVH was determined byechocardiography in hypertensive patients. DNA was extracted from leucocytes and amplified by PCR usingspecific primers. Insertion (I) or deletion (D) alleles were identified after electrophoresis of PCR products.Results: The left ventricular mass index (LVMI) in hypertensive patients with DD, ID and II genotypes were(mean ± SE) 111 + 6, 115±5 and 136± 8 g/m2 respectively (p = 0.03).n DD ID II D INormal controlsHypertensiveswithout LVHwith LVH10270333722%14%24%5%*32%37%36%38%46%49%39%57%0.380.330.420.24**0.620.670.580.76*X2 = 4.4, p = 0.04**X2 = 5.2, p = 0.02Conclusion: The lower LVMI in hypertensive DD patients and the lower prevalence of the DD genotype inhypertensive patients with LVH are consistent with increased cardiovascular mortality in patients withhypertension, LVH and DD genotype. The striking mortality reductions observed in the HOPE study may berelated to the ability of ACEI to address all of these risk factors.S-CH-3PLASMA BRADYKININ LEVEL AND ANGIOTENSIN-CONVERTING ENZYME GENEPOLYMORPHISM IN HYPERTENSIVE PATIENTSBMY Cheung. RYH Leung, AHK Cheung, KWT Tsang, CP Lau, CR Kumana. Department of Medicine,University of Hong Kong, Hong KongIntroduction: Bradykinin is a vasodilator which may be involved in the pathophysiology of hypertension. Itsdegradation is mediated by angiotensin converting enzyme (ACE). An insertion/deletion polymorphism of theACE gene is a marker of ACE activity. We previously observed for the first time that plasma bradykinin levelis related to the ACE genotype. Our aim was to confirm this novel finding in a larger group of patients.Methods: 52 patients with essential hypertension (21 men, 31 women; mean age 50, range 24-75) and 6normal subjects (3 men, 3 women; mean age 31, range 23-37) were studied with informed consent. Venousblood (3 ml) was drawn from a forearm vein and put into pre-chilled polypropylene tubes containing proteaseinhibitors. These samples were promptly centrifuged and the plasma stored at -40°C. Plasma bradykinin wasmeasured by radioimmunoassay. DNA was extracted from the buffy coat and amplified by polymerase chainreaction (PCR) using specific primers. The insertion and deletion alleles were identified as separate bandsafter electrophoresis of PCR products. Results: Mean plasma bradykinin level was 89.1 + 7.9 pmol/1 inhypertensive patients and 11.6+ 1.4 pmol/L in normal subjects (p < 0.001). Untreated hypertensive patientshad higher levels than those on treatment (136.5±26.6 vs. 82.9±7.9 pmol/L, p = 0.03). Plasma bradykininlevel correlated with ACE genotype (r = 0.30, p = 0.03) but was not related to age or gender. The levels inpatients with the DD, ID and II genotypes were 33.7± 12.2, 89.2± 12.2 and 100.4± 11.3 pmol/L respectively(p = 0.004). Conclusions: These results in a new series of patients confirm our previous finding that theinsertional genotype is associated with higher plasma bradykinin level in hypertensive patients. The higherlevel of bradykinin in hypertension may be a consequence of raised blood pressure as antihypertensive treatmentappears to reduce it. Further studies are needed to clarify the role of bradykinin in cardiovascular diseases inman.- 35 -

Angiotensin-converting enzyme genotypes in hypertensive patients with left ventricular hypertrophy

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Angiotensin-converting enzyme genotypes in hypertensive patients with left ventricular hypertrophy

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