Physical performance reference values for Japanese oldest old: a SONIC study.

BACKGROUND: The oldest old, defined as those aged 90 or over, is now the fastest-growing population sector. This study aimed to determine reference values for several physical performance measures (PPMs) among 90-year-olds using internationally standardized measurements and to clarify the characteristics of these indices by comparing their results for 90-year-olds with those for older people 70 and 80. METHODS: We used the Septuagenarians, Octogenarians, and Nonagenarians Investigation with Centenarians (SONIC) study data from 2010 to 2018. The study subjects were 70, 80, and 90-year-olds in the target area eligible to participate in the venue. Excluding those certified for long-term care, the final number of eligible persons is 70s cohort 1000 (2010), 80s cohort 973 (2011), and 90s cohort 690. 90s cohort only consisted of three survey waves: 2012, 2015, and 2018. We used hand grip strength and score on the Short Physical Performance Battery (SPPB) for our physical performance measurements. In addition, we statistically analyzed sex and age differences. RESULT: The simple mean ± standard deviation (SD) for the 90-year-old respondents were in men, 24.1 ± 5.4 kg in hand grip strength, 0.80 ± 0.22 m/s in usual gait speed, 17.2 ± 6.73 s in 5times chair stand, 5.89 ± 4.42 s in tandem balance, and 8.3 ± 2.2 in SPPB respectively and in women, 14.4 ± 4.0 kg in hand grip strength, 0.72 ± 0.20 m/s in usual gait speed, 17.8 ± 7.89 s in 5times chair stand, 4.72 ± 4.35 s in tandem balance, and 7.5 ± 2.4 in SPPB, respectively. For all PPMs, the age 90 cohort was statistically significantly different from the age 70 and 80 cohorts (all trends P <  0.001). Hand grip strength decreased with a similar gradient with age cohort increase of 10 years for both sexes. In contrast, SPPB lower limb score showed a larger drop between the age 80 and 90 cohorts than between the age 70 and 80 cohorts. We also constructed sex-specific appraisal standards according to quintiles. CONCLUSIONS: Our study yielded inclusive sex-specific reference values and appraisal standards for major physical performance measures not certified as requiring long-term care, community-dwelling, oldest old Japanese. The characteristics of age-related decline in physical performance differed between the upper and lower extremity assessments.

Effects of multimorbidity and polypharmacy on physical function in community-dwelling older adults: A 3-year prospective cohort study from the SONIC.

BACKGROUND: We prospectively examined the effect of baseline multimorbidity and polypharmacy on the physical function of community-dwelling older adults over a three-year period. METHODS: The analysis included 1,401 older adults (51.5 % women) who participated in both wave 1 and wave 2 (3-year follow-up) of the Septuagenarians, Octogenarians, and Nonagenarians Investigation with Centenarians (SONIC) study. Grip strength and walking speed were binarized into poor/not poor physical function according to the frailty definition. The number of chronic conditions and the number of prescribed medications were categorized into 3 and 4 groups, respectively. Multivariable logistic regression was used to examine associations between the number of chronic conditions, medication use at baseline, and poor physical function over a three-year period. RESULTS: After adjusting for confounding factors, hyperpolypharmacy (≥ 10 medications) demonstrated associations with weak grip strength (adjusted odds ratio [aOR] = 2.142, 95 % confidence interval [CI] = 1.100-4.171) and slow walking speed (aOR = 1.878, 95 % CI = 1.013-3.483), while co-medication (1-4 medications) was negatively associated with slow walking speed (aOR = 0.688, 95 % CI = 0.480-0.986). There was no significant association between the number of chronic conditions and physical function. CONCLUSION: The findings suggest that the number of medications can serve as a simple indicator to assess the risk of physical frailty. Given that many older individuals receive multiple medications for extended durations, medical management approaches must consider not only disease-specific treatment outcomes but also prioritize drug therapy while actively avoiding the progression towards frailty and geriatric syndromes.

Risk factors predicting subtypes of physical frailty incidence stratified by musculoskeletal diseases in community-dwelling older adults: The SONIC study.

AIM: This study aims to identify the key risk factors that lead to subtypes of physical frailty assessed by walking speed and grip strength among community-dwelling Japanese individuals, stratified by the presence of musculoskeletal diseases (MSDs) and age group. METHODS: We included 302 participants aged 70 or 80 years who did not exhibit subtypes of physical frailty at baseline through the Septuagenarians, Octogenarians, Nonagenarians, Investigation with Centenarians (SONIC) study. Our study was a longitudinal study. The outcome was the incidence of subtypes of physical frailty after 3 years. Subtypes of physical frailty were defined as a weak grip strength or slow walking speed, or both, based on the Japanese version of the Cardiovascular Health Study Index. The risk factors for subtypes of physical frailty incidence were examined by age group and MSD, using multivariate logistic regressions. RESULTS: Of the 302 participants, 110 (36.4%) had MSD. Those with MSD were significantly more likely to have subtypes of physical frailty after 3 years compared with those without MSD. Among all participants, older age was a risk factor of subtypes of physical frailty (P < 0.05). Without MSD, older age and dissatisfied financial status were risk factors (P < 0.05). With MSD, older age was a risk factor (P < 0.05). By age group, in individuals aged 70 years old, a dissatisfied financial status was a risk factor for those without MSD (P < 0.05), and a higher BMI was one for those with MSD (P < 0.05). CONCLUSIONS: Older age was a risk factor for subtypes of physical frailty, but other risk factors differed according to the presence of MSD and age. Geriatr Gerontol Int 2024; 24: 797-805.

Association between serum vitamin D levels and skeletal muscle indices in an older Japanese population: The SONIC study.

AIM: Vitamin D (VD) affects skeletal muscles. The high prevalence of VD deficiency in Japan may lead to decreased skeletal muscle mass and strength, increasing the prevalence of sarcopenia. Therefore, we aimed to investigate the association between serum VD levels and skeletal muscle indices in a Japanese community-dwelling older population. METHODS: We extracted data from the Septuagenarians, Octogenarians, Nonagenarians Investigation with Centenarians (SONIC) study. We analyzed the data for participants in the 70s and 90s age groups. Skeletal mass index (SMI) using bioimpedance analysis, grip strength, walking speed, and serum VD levels using 25-hydroxyvitamin D [25(OH)D] were measured. RESULTS: We analyzed the data of 310 participants in their 70s and 48 in their 90s. Mean serum 25(OH)D levels were 21.6 ± 5.0 ng/mL in the 70s group and 23.4 ± 9.1 ng/mL in the 90s group. In the 70s group, serum 25(OH)D levels correlated with SMI (r = 0.21, P < 0.0001) and grip strength (r = 0.30, P < 0.0001). Serum 25(OH)D levels were independently associated with SMI after adjusting for sex, body mass index, and serum albumin levels. In the 90s group, serum 25(OH)D levels were correlated with SMI (r = 0.29, P = 0.049) and grip strength (r = 0.34, P = 0.018). However, the multivariate analysis showed no independent association between SMI, grip strength, and serum 25(OH)D levels. CONCLUSION: In a cross-sectional analysis of an older population, serum VD levels were associated with SMI and grip strength, and this association was more pronounced in the 70s group than in the 90s group. Our results suggest that serum VD levels maintain skeletal muscle mass and grip strength. Geriatr Gerontol Int 2024; ••: ••-••.

Associations between salivary testosterone levels and cognitive function among 70-year-old Japanese elderly: A cross-sectional analysis of the SONIC study.

AIM: This cross-sectional study aimed to investigate the associations between salivary testosterone concentrations and cognitive function in 70-year-old Japanese elderly people without dementia and stroke. METHODS: Participants were 197 Japanese community-dwelling people aged 69-71 years. Their salivary samples were collected, and their cognitive function was assessed using the Japanese version of the Montreal Cognitive Assessment (MoCA-J). Participants were also administered a 10-item recall and a 24-item recognition test. The data for 179 (106 men and 73 women) individuals were analyzed, excluding individuals with a past history of stroke and dementia. Multivariate logistic regression analyses were performed after adjusting for lifestyle factors and analyzing data separately for men and women. RESULTS: MoCA-J scores showed that men with low testosterone concentrations had a significantly greater risk of low cognitive performance than those with high testosterone concentrations (adjusted odds ratio: 4.72, 95% confidence interval: 1.06-21.00), while no significant association was found in women. The 10-item recall test scores showed that higher testosterone concentrations were significantly associated with greater recall in the second trial in women (standardized beta = 0.24, P = 0.040), whereas no significant association was found in men. Salivary testosterone concentrations were positively associated with better cognitive performance in older men and women. CONCLUSIONS: The associations between salivary testosterone concentrations and cognitive function were shown by different tasks for men and women. Geriatr Gerontol Int 2022; 22: 1040-1046.