Bai Xiaojuan, Han Lulu, Liu Jing, Zhang Weiguang, Zhou Hongyu, Dong Shaochen, Sun Ying, Chen Xiangmei
Department of Gerontology and Geriatrics, First Affiliated Hospital of China Medical University, Shenyang, 110001, People's Republic of China.
Curr Aging Sci. 2010 Dec;3(3):188-97. doi: 10.2174/1874609811003030188.
Aging process reduces kidney function, glomerular filtration rate (GFR) and/or creatinine clearance rate (Ccr), and also significantly increases the risk level for cardiovascular diseases. The classical Framingham risk equation provides a method for predicting cardiovascular risk, but it does not include the kidney function indexes. In this study, we investigated the relationship between age-related kidney function and Framingham risk score (FRS) in healthy Chinese people, and validated to assess the risk factor by GFR/Ccr.
This community-based cross-sectional study recruited 505 healthy subjects (age from 35 to 93 yr.) with both gender is during September 2007 to June 2008 in Shenyang. Framingham risk equation was used to evaluate cardiovascular risk factors and generate FRS. GFR and Ccr were calculated with Cockcroft-Gault (CG) equation (GFR(CG)), abbreviated Modification of Diet in Renal Disease Study (MDRD) equation (GFR(MDRD1)) and modified MDRD equation (GFR(MDRD2)). All data were sorted according to FRS (low, moderate and high) risk levels, and five different age groups (≤44 yr; 45-54 yr; 55-64 yr; 65-74 yr and ≥75 yr). The ANOVA, correlation, partial correlation between GFR/Ccr and FRS, as well as other risk factors were analyzed with SPSS16.0 statistical package.
As the FRS level increased, GFR(CG), GFR(MDRD1), GFR(MDRD2) and Ccr decreased about 10 to 30% (low>moderate> high risk group, p<0.01). While the subjects were getting older, GFR(CG), GFR(MDRD1), GFR(MDRD2) and Ccr showed significant reduction (P<0.001). Ccr decreased about 50% from the young to oldest group (p<0.001). There was a significantly inverse correlation between FRS and GFR with Ccr having the Pearson correlation coefficient -0.586 (GFR(CG), P<0.001), - 0.449 (GFR(MDRD1) and GFR(MDRD2), P<0.001), -0.459 (Ccr, P<0.001). However, the relationship between FRS and Ccr was lost after controlling for age and other confounding variables.
In healthy population, we found inverse correlations between Framingham risk score and GFR, Ccr and GFR were independently related to the FRS with similar correlation coefficient among three equations. With the increase of FRS, the GFR and Ccr decrease. Aging is the major factor of GFR and Ccr reduction in the healthy population. We suggest that GFR/Ccr could be used as risk indexes for cardiovascular diseases.
衰老过程会降低肾功能、肾小球滤过率（GFR）和/或肌酐清除率（Ccr），同时也会显著增加心血管疾病的风险水平。经典的弗雷明汉风险方程提供了一种预测心血管风险的方法，但它不包括肾功能指标。在本研究中，我们调查了健康中国人中与年龄相关的肾功能与弗雷明汉风险评分（FRS）之间的关系，并通过GFR/Ccr验证评估风险因素。
这项基于社区的横断面研究于2007年9月至2008年6月在沈阳招募了505名年龄在35至93岁之间的健康受试者，男女皆有。使用弗雷明汉风险方程评估心血管风险因素并生成FRS。用Cockcroft-Gault（CG）方程（GFR(CG)）、简化的肾脏病膳食改良研究（MDRD）方程（GFR(MDRD1)）和改良的MDRD方程（GFR(MDRD2)）计算GFR和Ccr。所有数据根据FRS（低、中、高）风险水平以及五个不同年龄组（≤44岁；45 - 54岁；55 - 64岁；65 - 74岁和≥75岁）进行分类。使用SPSS16.0统计软件包分析GFR/Ccr与FRS以及其他风险因素之间的方差分析、相关性、偏相关性。
随着FRS水平升高，GFR(CG)、GFR(MDRD1)、GFR(MDRD2)和Ccr降低约10%至30%（低风险组>中风险组>高风险组，p<0.01）。随着受试者年龄增长，GFR(CG)、GFR(MDRD1)、GFR(MDRD2)和Ccr显著降低（P<0.001）。Ccr从最年轻组到最年长组降低约50%（p<0.001）。FRS与GFR以及Ccr之间存在显著的负相关，Pearson相关系数分别为 -0.586（GFR(CG)，P<0.001）、 -0.449（GFR(MDRD1)和GFR(MDRD2)，P<0.001）、 -0.459（Ccr，P<0.001）。然而，在控制年龄和其他混杂变量后，FRS与Ccr之间的关系消失。
在健康人群中，我们发现弗雷明汉风险评分与GFR、Ccr之间存在负相关，且GFR与FRS独立相关，三个方程的相关系数相似。随着FRS升高，GFR和Ccr降低。衰老是健康人群中GFR和Ccr降低的主要因素。我们建议GFR/Ccr可作为心血管疾病的风险指标。
