A Cross-sectional Study Of Ageing Phenotypes In Elderly

Objective To know the distribution of ageing phenotype in Qingdao elderly; To examine the effects of age, sex and their interaction in ageing phenotype; To compare the age and sex patterns in ageing phenotype between Qingdao and Danish data.; To investigate the relationship among ageing variables and their comman latent factors.Methods2006Qingdao residents who aged50-74years participanted this survey. Individual’s self-rated health (SRH), hand grip strength,5sit-to-stand test time (STS), forced expiratory volumne in1second (FEV1), force vital capacity (FVC), near visual acuity, number of teeth lost, hearing threshold, cognitive function and despression were measured. Effects of age and sex on the changes in the ten ageing variables were assessed using multiple linear regression models, Logistic regression models, zero-inflated Poisson regression (ZIP) and general equation estimation (GEE) with age and sex interactions included. The Qingdao data were compared with the Danmark sample which in the same age group. Pair-wise correlations among the ten ageing variables were estimated. Structural equation model (SEM) was fited to explore the latent common factor for these ageing phenotype.Results After controlling sex, with increasing age, SRH, grip strength, FEV1, FVC, near visual acuity and cognitive function were declined, while STS time, number of teeth lost, hearing threshold and depression rised(|β|=0.011～0.848, p<0.001). After controlling age, there were sex differents in all of the measures (|β|=0.046～30.417, p=0.019). Males are better than females in all of the phenotypes except hearing level. There was age-sex interaction in grip strength (|β|=0.258,p<0.001), and no sex differences in age-related changes in other nine phenotypes (p>0.05). In both sexes, higher levels of ageing phenotypes were observed in Danes than Qingdao people(|β|=0.258, p=0.004). Most ageing variables were significantly associated with each other (|r|=0.055～0.714, p<0.05. SEM analysis supported a latent common factor protecting the ten phenotypes (|β|=0.012-5.513, p<0.024) except hearing threshold.Conclusions All the ageing phenotypes we have measured declined obviously with the increasing age. There were sex differents in levels of all the measures. Meanwhile, the sex differents in age-related changes in grip strength were observed. Our cross population analysis identified significant sex and population differences suggesting endogenous biological, physical and social environmental determinants in age related decline in general health. There is an latent common mechanism underlying the human healthy ageing.