Eisenmann Joey C, Sarzynski Mark A, Glenn Kim, Rothschild Max, Heelan Kate A
Michigan State University, Department of Kinesiology, East Lansing, Michigan, USA.
Cardiovasc Diabetol. 2009 Mar 16;8:14. doi: 10.1186/1475-2840-8-14.
Angiotensin converting enzyme (ACE) is a possible candidate gene that may influence both body fatness and blood pressure. Although several genetic studies have been conducted in adults, relatively few studies have examined the contribution of potential candidate genes, and specifically ACE I/D, on adiposity and BP phenotypes in childhood. Such studies may prove insightful for the development of the obesity-hypertension phenotype early in life. The purpose of this study was to examine differences in body fatness and resting blood pressure (BP) by ACE I/D genotype, and determine if the association between adiposity and BP varies by ACE I/D genotype in children.
152 children (75 girls, 77 boys) were assessed for body composition (% body fat) using dual energy x-ray absorbtiometry and resting BP according to American Heart Association recommendations. Buccal cell samples were genotyped using newly developed PCR-RFLP tests for two SNPs (rs4341 and rs4343) in complete linkage disequilibrium with the ACE I/D polymorphism. Partial correlations were computed to assess the ociations between % body fat and BP in the total sample and by genotype. ANCOVA was used to examine differences in resting BP by ACE I/D genotype and fatness groups.
Approximately 39% of youth were overfat based on % body fat (>30% fat in girls, 25% fat in boys). Body mass, body mass index, and fat-free mass were significantly higher in the ACE D-carriers compared to the II group (p < 0.05). BP was not significantly different by ACE I/D genotypes. In the total sample, correlations between adiposity and BP ranged from 0.30 to 0.46, and were not significantly different between genotypes. When grouped by genotype and body fat category, the overfat D-carrier subjects had significantly higher SBP and MAP compared to the normal fat D-carrier and normal fat II groups (p < 0.05).
ACE D-carriers are heavier than ACE II children; however, BP did not differ by ACE I/D genotype but was adversely influenced in the overfat D-carriers. Further studies are warranted to investigate the genetics of fatness and BP phenotypes in children.
血管紧张素转换酶（ACE）是一个可能影响身体脂肪含量和血压的候选基因。虽然已经在成年人中进行了多项基因研究，但相对较少的研究考察了潜在候选基因，特别是ACE I/D基因多态性，对儿童肥胖和血压表型的影响。此类研究可能对生命早期肥胖 - 高血压表型的发展具有重要意义。本研究的目的是通过ACE I/D基因型检查身体脂肪含量和静息血压（BP）的差异，并确定儿童中肥胖与BP之间的关联是否因ACE I/D基因型而异。
根据美国心脏协会的建议，使用双能X线吸收法评估了152名儿童（75名女孩，77名男孩）的身体成分（体脂百分比）和静息血压。使用新开发的PCR - RFLP测试对与ACE I/D多态性处于完全连锁不平衡状态的两个单核苷酸多态性（rs4341和rs4343）进行颊细胞样本基因分型。计算偏相关性以评估总样本以及按基因型分组时体脂百分比与BP之间的关联。使用协方差分析来检查ACE I/D基因型和肥胖组之间静息血压的差异。
根据体脂百分比（女孩>30%脂肪，男孩>25%脂肪），约39%的青少年超重。与II组相比，ACE D等位基因携带者的体重、体重指数和去脂体重显著更高（p < 0.05）。ACE I/D基因型之间的BP没有显著差异。在总样本中，肥胖与BP之间的相关性范围为0.30至0.46，不同基因型之间没有显著差异。按基因型和体脂类别分组时，超重的D等位基因携带者受试者的收缩压和平均动脉压显著高于正常体重的D等位基因携带者和正常体重的II组（p < 0.05）。
ACE D等位基因携带者比ACE II儿童更重；然而，BP在ACE I/D基因型之间没有差异，但在超重的D等位基因携带者中受到不利影响。有必要进一步研究儿童肥胖和血压表型的遗传学。
