Relationship between respiratory function assessed by spirometry and mild cognitive impairment among community-dwelling older adults.

AIM: Aging is a major cause of cognitive dysfunction. It has also been reported that respiratory function may influence cognitive dysfunction. However, few studies have examined the relationship between cognitive function and respiratory function among community-dwelling older adults. This study aims to determine the relationship between respiratory function, assessed using spirometry, and mild cognitive impairment (MCI) in community-dwelling older adults. METHODS: This study included 419 participants aged 73 ± 1 years and 348 participants aged 83 ± 1 years from the SONIC cohort study (Septuagenarians Octogenarians Nonagenarians Investigation with Centenarians Study). Respiratory function was evaluated using %Vital Capacity (%VC), Forced Expiratory Volume 1 s (FEV1)/Forced Vital Capacity (FVC), and %Peak Expiratory Flow (%PEF). Airflow-limitation presence and stages were classified using FEV1/FVC. Cognitive function and MCI were assessed using the Japanese version of the Montreal Cognitive Assessment (MoCA-J). RESULTS: The MoCA-J score exhibited a declining trend as the airflow-limitation stage increased among study participants in the 83 ± 1 age group. The presence of airflow limitation was associated with MCI in the 83 ± 1 age group. Among the indicators of each respiratory function, low %PEF was found to be associated with an increased rate of MCI. Furthermore, low %VC has also been suggested to be associated with an increased rate of MCI in the 83 ± 1 age female group. CONCLUSIONS: Advanced airflow-limitation stages may exacerbate cognitive dysfunction in community-dwelling older adults. The presence of airflow limitation and low %VC may also be associated with cognitive dysfunction in older women. Consequently, reduced respiratory function may potentially be associated with MCI in community-dwelling older adults. Geriatr Gerontol Int 2024; ••: ••-••.

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; ••: ••-••.

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.

Usefulness of the serum creatinine/cystatin C ratio as a blood biomarker for sarcopenia components among age groups in community-dwelling older people: The SONIC study.

AIM: The serum creatinine/cystatin C ratio (CCR) or sarcopenia index is considered a useful marker of muscle mass. However, its usefulness in late-stage older adults remains unclear. We aimed to determine the usefulness of CCR as an indicator of sarcopenia in community-dwelling Japanese adults aged >75 years. METHODS: Our study recruited participants aged 70, 80, and 90 ± 1 years during the baseline years, and included a 3-year follow-up in the Septuagenarians, Octogenarians, Nonagenarians, Investigation with Centenarians study. From 2015 to 2018, 955 participants were eligible: 367 in their 70s, 304 in their 80s, and 284 in their 90s. The diagnostic components of sarcopenia, including "low muscle mass, plus low muscle strength, and/or low physical performance," were evaluated using the bioelectrical impedance analysis-measured skeletal muscle mass index (SMI), handgrip strength, and short physical performance battery (SPPB) score, respectively, in accordance with the Asia Working Group for Sarcopenia 2019 criteria. Separate analyses were performed between each component and CCR, adjusting for sex, body mass index, and other blood biomarkers in each group. RESULTS: The relationship between CCR and sarcopenia components was significant for handgrip strength (ß = 0.21, 0.13, 0.19, and P < 0.0001, =0.0088, <0.0001, for the 70s, 80s, and 90s age groups, respectively); however, it was limited for SMI (ß = 0.14; P = 0.0022, only for the 90s) and not significant for the SPPB score. CONCLUSION: CCR is a limited indicator of sarcopenia in late-stage older adults. Although its association with muscle strength was significant, its relationship with muscle mass and physical performance was less pronounced. Geriatr Gerontol Int 2024; 24: 529-536.

Actual conditions for returning home after hospitalization among older patients receiving home medical care in Japan: OHCARE Study.

AIM: To examine the actual conditions of older patients receiving home medical care after hospitalization over a period of 2 years in Japan. METHODS: The study population included 102 participants, aged ≥65 years, receiving home medical care, who consented to participate in the Osaka Home Care Registry (OHCARE) study in Japan over a period of 2 years. We investigated the actual conditions for returning home after hospitalization. RESULTS: The median age of the 102 participants was 84 years, and 61 (59.8%) were women. In the group that returned home, 42 (55.3%) of the respondents desired to recuperate in a familiar place, as in advanced care planning (ACP). During the 2-year follow-up period, the group that did not return home had significantly more deaths. A multivariate analysis showed the association in the presence of ACP (odds ratio: 4.72, 95% confidence interval: 1.60-13.86) and cardiac disease (odds ratio: 0.25, 95% confidence interval: 0.08-0.76). The lack of ACP in the medical records when the patient was admitted to the hospital may have prevented the return home. CONCLUSION: In older patients who had difficulty returning home after hospitalization, the lack of ACP in home medical care may have been an influencing factor. ACP could help continue with home medical care. Geriatr Gerontol Int 2024; 24: 320-326.