Evaluation of Biological Aging Process – A Population-Based Study of Healthy People in China

Abstract

Background: Although there have been cross-sectional and longitudinal studies examining biological age (BA) with chronological age (CA)-related changes in physical, physiological, biochemical, and hormonal variables, few studies have performed echocardiographic evaluation of the cardiovascular system and inflammatory biomarkers. Furthermore, little is known about biomarkers of aging and BA score (BAS) for healthy people in China. Objectives: The purpose of this study was to identify the biomarkers of healthy aging and to establish BAS for healthy people in China. Methods: We examined 2,876 men and women aged 30–98 years old in three Chinese cities, and 852 healthy subjects were assessed with 108 physical, morphological, physiological and biochemical variables. After excluding binary variables, variables that had a correlation coefficient with CA of ≤0.25 and redundant variables, eight variables including CA, arterial pulse pressure (PP), intima-media thickness (IMT), end diastolic velocity (EDV), ratio of peak velocity of early filling to atrial filling (E/A), mitral valve annulus lateral wall of peak velocity of early filling (MVEL), cystatin C (CYSC), and fibrinogen (FIB) were selected as candidate biomarkers of aging based on a factor-weighted BAS composite for predicting BA. Results: The BAS equation was 0.248 (CA) + 0.195 (IMT) – 0.196 (EDV) – 0.167 (E/A) – 0.166 (MVEL) + 0.188 (PP) + 0.182 (FIB) + 0.193 (CYSC). Individual BAS were significantly correlated with CA (r = 0.893, p < 0.001). Biological aging rate predicted by BAS was accelerated with increases in CA, and peaked when healthy men and women reached ≧75 years of age. Conclusions: Our data suggest that BAS is superior to CA in assessing the rate of aging in healthy Chinese people. The cardiovascular variables play a crucial role in the evaluation of biological aging. Biological aging rate appears to be age specific.

Atrial Dilation and Altered Function Are Mediated by Age and Diastolic Function But Not Before the Eighth Decade

“…The biological age score has been suggested to be superior to chronological age in assessing cardiovascular variables in healthy aging (44). However, derivation of a similar biological score was beyond the scope of our study.…”

Arteriosclerotic Changes after Intravitreal Injections of Anti-Vascular Endothelial Growth Factor Drugs in Patients with Exudative Age-Related Macular Degeneration

“…High CAVI values and high mean IMT are major risk factors for stroke [19,20]. It has also been reported that the CAVI, mean IMT, and cystatin C level increase with aging [21,22,23]. …”

Construction Formula of Biological Age Using the Principal Component Analysis

“…In early exploratory studies, the BA formulae of males and females were analyzed separately, and the sample size was usually small, which was often less than 100 people in most circumstances [7, 17, 18, 20, 21]. Then with the development of BA formula construction, the sample size was expanded accordingly [11, 12, 19, 23–25]. Meanwhile, both males and females were comparably included, and the ratio of two genders was near to 1 : 1 in many studies, which may avoid the sexual factors caused by the gender differences of ageing process [11, 12, 22–25].…”

“…Then with the development of BA formula construction, the sample size was expanded accordingly [11, 12, 19, 23–25]. Meanwhile, both males and females were comparably included, and the ratio of two genders was near to 1 : 1 in many studies, which may avoid the sexual factors caused by the gender differences of ageing process [11, 12, 22–25]. The expanding sample size and balanced ratio of two genders are required to give deeper view of BA in the whole population.…”

“…Statistical methods that have been used for BA formula construction include the multiple linear regression (MLR), the principal component analysis (PCA), Hochschild's method, and the Klemera and Doubal method (KDM) [7–15]. Although some new methods other than PCA have been proposed and tested [8, 16], researchers still use PCA as a stable and common statistical method in some studies [12]. For example, PCA is better than MLR in avoiding some statistical deficiencies [7, 17, 18].…”