Published papers

© 2018 Oxford University Press. All rights reserved. Growth hormone (GH)/insulin-like growth factor-1 (IGF-1)/insulin signaling is one of the most plausible biological pathways regulating aging and longevity. Previous studies have demonstrated that several single nucleotide polymorphisms (SNPs) in the GH/IGF-1/insulin signaling-associated genes influence both longevity and adult height, suggesting the possibility of a shared genetic architecture between longevity and height. We therefore examined the relationship between 30 height-associated SNPs and extreme longevity in a Japanese population consisting of 428 centenarians and 4,026 younger controls. We confirmed that height-increasing genetic scores (HGSs) constructed based on 30 SNPs were significantly associated with height in the controls (p = 6.951023). HGS was significantly and inversely associated with extreme longevity in women (p = .011), but not in men, although no SNPs were significantly associated with extreme longevity after Bonferroni correction. The odds ratio for extreme longevity in the lowest HGS group (=27) and the second lowest HGS group (2830) relative to the highest HGS group (=37) was 1.71 (p = .056) and 1.69 (p = .034), respectively, for women. In conclusion, the present study demonstrated an inverse association between height-increasing alleles with extreme longevity in Japanese women, providing novel insight into the genetic architecture of longevity and aging.

© 2018 Ikebe et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Background Growing evidence suggests that oral health may be an important factor associated with cognitive function in aged populations. However, many previous studies on this topic used insensitive oral indicators or did not include certain essential covariates. Thus, we examined the association between occlusal force and cognitive function in a large sample of older adults, controlling for dietary intake, vascular risk factors, inflammatory biomarkers, depression, and genetic factors. Methods In this cross-sectional study of older community-dwelling Japanese adults, we examined data collected from 994 persons aged 70 years and 968 persons aged 80 years. Cognitive function was measured using the Japanese version of the Montreal Cognitive Assessment (MoCA-J). Oral status and function were evaluated according to the number of remaining teeth, periodontal pocket depth, and maximal occlusal force. Associations between MoCA-J scores and occlusal force were investigated via bivariate and multivariate analyses. Results Education level, financial status, depression score, and intake of green and yellow vegetables, as well as number of teeth and occlusal force, were significantly correlated with MoCA-J scores in both age groups. Among individuals aged 80 years, CRP and periodontal status were weakly but significantly associated with MoCA-J score. After controlling for all significant variables via bivariate analyses, the correlation between maximal occlusal force and cognitive function persisted. A path analysis confirmed the hypothesis that cognitive function is associated with occlusal force directly as well as indirectly via food intake. Conclusions After controlling for possible factors, maximal occlusal force was positively associated with cognitive function directly as well as indirectly through dietary intake.

© 2018, Springer Nature Switzerland AG. Purpose: The purpose of this study was to compare centenarians in the United States and Japan on sensory, cognitive, and physical functioning and to evaluate a model that tests the interrelationship between physical function, cognition, and sensory impairment in these two unique samples of the oldest old. Methods: The sample of U. S. centenarians included 245 centenarians, the sample of Japanese centenarians included 304 centenarians. Sensory impairment was assessed by general assessments of vision and hearing, and physical function was assessed with six physical activities of daily living (i.e., eating, grooming, dressing, transporting, bathing, and walking). Results: The results suggest that centenarians from the Georgia study showed higher levels of functioning in all domains when compared to the Tokyo sample. A structural equation model yielded stronger associations between cognitive and sensory function with physical function for the Tokyo sample. Conclusions: Functional differences may be due, in part, to different care patterns for the oldest old in the United States when compared to Japan.