Multilevel model estimation of age-dependent individual-specific trajectories for left ventricular echocardiographic indexes in an asymptomatic elderly cohort
| Autor: | Fang-fang Qiao, Shan-Shun Luo, Yu-ping Jiang, Yu-hong Wang, Hui Han |
|---|---|
| Rok vydání: | 2012 |
| Předmět: |
Male
Aging medicine.medical_specialty Physiology Heart Ventricles Age dependent Asymptomatic Ventricular Function Left Cohort Studies Physiology (medical) Internal medicine medicine Humans Longitudinal Studies Aged Aged 80 and over Estimation Likelihood Functions Models Statistical business.industry Multilevel model Linear model Surgery Echocardiography Cohort Linear Models Cardiology Female medicine.symptom business Cohort study |
| Zdroj: | Journal of Applied Physiology. 112:1128-1134 |
| ISSN: | 1522-1601 8750-7587 |
| DOI: | 10.1152/japplphysiol.01256.2011 |
| Popis: | Few studies have been performed on the individual-specific trajectory of left ventricular aging as assessed by echocardiography in an asymptomatic elderly cohort. In the present study, a representative cohort of elderly men, who were long-term asymptomatic for cardiovascular issues, were selected from an ongoing observational aging study. Annual echocardiographic data were used to establish an age-dependent hierarchical model. Based on two-level linear regression results, four echocardiographic indexes [left ventricular mass (LVmass; −1.872 g/yr), posterior ventricular wall thickness (−0.048 mm/yr), fraction shortening (0.097/yr), and transmitral peak A velocity (−0.006 m·s−1·yr−1)] changed significantly with increasing age and were age- and subject-dependent. The most characterized results of the study were the significant, age-related, within-individual variances in echocardiographic results, which were observed using the likelihood ratio test at an occasion-dependent level. Of these, fluctuated amplitudes of two systolic variables [i.e., LVmass (con/age = −0.012 ± 0.004; P = 0.0007) and fraction shortening (con/age = −0.001 ± 0.004; P = 0.05)] were significantly attenuated with increasing age within individuals. On the other hand, the age-related variability of four diastolic Doppler variables [i.e., peak A velocity (con/age = 0.003 ± 0.002; P = 0.0009), peak E velocity (con/age = 0.004 ± 0.003; P = 0.01), E/A ratio (con/age = 0.007 ± 0.003; P = 0.0002), and deceleration time of E wave (con/age = 0.025 ± 0.007; P < 0.0001)] significantly increased with increasing age within individuals. The age-related individual variability of left ventricular indexes observed in this continuous asymptomatic cohort may reflect the mechanism of preclinical, individualized heart aging. In conclusion, successfully fitted multilevel models were applied as a valuable tool to determine the mechanism of individual cardiac aging in the elderly. |
| Databáze: | OpenAIRE |
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