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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 = 6.95 × 10-23). 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 (28-30) 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. [ABSTRACT FROM AUTHOR]

Objectives: This research analyzed the body mass index (BMI) level and rate of change, and their association with socio-economic status among older Japanese adults. Methods: Data came from a national sample of over 4,800 Japanese adults aged 60 and older at baseline, with up to 7 repeated observations over a period of 19 years (1987-2006). Hierarchical linear modeling was used to analyze the intrap-ersonal and interpersonal differences in BMI. Results: Average BMI among older Japanese was 22.26 at baseline and decreased with an accelerating rate over time. Relative to those with less education, BMI among older Japanese with more education was lower and it declined linearly at a faster rate over time. In contrast, higher household income at baseline was associated with a higher level of BMI but similar rates of decline over time. Furthermore, we found no evidence for age variations in the SES-BMI linkage as predicted by prior investigators. Discussion: These findings provide new insights into the complex relationship between socioeconomic factors and BMI, and help to inform the design of health policies and interventions related to weight control among older adults with diverse socioeconomic backgrounds. [ABSTRACT FROM AUTHOR]

Few studies have focused on the relationship between the trajectories of long-term changes in body mass index (BMI; weight (kg)/height (m)2) and all-cause mortality in old age, particularly in non-Western populations. We evaluated this association by applying group-based mixture models to data derived from the National Survey of the Japanese Elderly, which included 4,869 adults aged 60 or more years, with up to 7 repeated observations between 1987 and 2006. Four distinct BMI trajectories were identified: "low-normal weight, decreasing" (baseline BMI = 18.7; 23.8% of sample); "mid-normal weight, decreasing" (baseline BMI = 21.9; 44.6% of sample); "high-normal weight, decreasing" (baseline BMI = 24.8; 26.5% of sample); and "overweight, stable" (baseline BMI = 28.7; 5.2% of sample). Survival analysis with an average follow-up of 13.8 years showed that trajectories of higher BMI were associated with lower mortality. In particular, relative to those with a mid-normal weight, decreasing BMI trajectory, those with an overweight, stable BMI trajectory had the lowest mortality, and those with a low-normal, decreasing BMI trajectory had the highest mortality. In sharp contrast with prior observations from Western populations, BMI changes lie primarily within the normal-weight range, and virtually no older Japanese are obese. The association between BMI trajectories and mortality varies according to the distribution of BMI within the population. [ABSTRACT FROM AUTHOR]