Cross-sectional association between high-sensitivity C-reactive protein and cognitive function in community-dwelling older adults: the SONIC study.

BACKGROUND: A decline in cognitive function is associated with inflammatory processes. However, the association between high-sensitivity C-reactive protein (hs-CRP) levels and cognitive decline in the Japanese population remains inconclusive. Thus, this study aimed to determine whether hs-CRP is associated with low cognitive function in 70- and 80-year-old community-dwelling Japanese individuals. METHODS: The participants in this cross-sectional study were 872 Japanese residents aged 70 and 80 years who voluntarily participated in the Septuagenarians, Octogenarians, Nonagenarians Investigation with Centenarians (SONIC) study between 2010 and 2011. Blood sample collection, cognitive assessment, and other measurements were performed at the venue. Low cognitive function was defined as a score of 25 points or lower on the Japanese version of the Montreal Cognitive Assessment. The odds ratio (OR) and 95% confidence interval (95% CI) for each hs-CRP quartile were calculated using logistic regression analysis. RESULTS: A total of 288 (69.9%) parsons in the 70-year-old group and 372 (80.9%) in the 80-year-old group exhibited low cognitive function. The association between hs-CRP levels and low cognitive function was significant among 70- and 80-year-old Japanese community-dwelling adults. In particular, the fourth quartile of hs-CRP (0.727-7.420 mg/L) in the 70-year-old group and the second and fourth quartiles (0.214-0.404 and 0.911-9.890 mg/L) in the 80-year-old group were associated with low cognitive function. Furthermore, the third quartile (0.409-0.892 mg/L) in the 80-year-old group was closely associated with low cognitive function. CONCLUSIONS: High hs-CRP levels were associated with lower cognitive function in 70- and 80-year-old Japanese community-dwelling individuals, suggesting that high hs-CRP levels may influence cognitive function.

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; 24: 1001-1007.

Preparation and Characterization of Reconstituted Lipid-Synthetic Polymer Discoidal Particles.

Discoidal high-density lipoproteins generated by the apolipoprotein-mediated solubilization of membrane lipids in vivo can be reconstituted with phospholipids and apolipoproteins in vitro. Recently, it has been reported that such particles can be prepared using the hydrolyzed acid form of styrene-maleic anhydride copolymer (SMAaf) instead of apolipoproteins, but characterization of its physicochemical properties has remained less elucidated. In the present study, with the aim of applying SMAaf-based lipid nanoparticles as novel delivery vehicles of drugs and/or imaging agents, we investigated the preparation conditions and evaluated the physicochemical properties of lipid-SMAaf complexes. SMAaf induced spontaneous turbidity clearance of dimyristoylphosphatidylcholine (DMPC) vesicles accompanied by the formation of smaller particles not only at the phase transition temperature of DMPC but also above it. Such reductions in the turbidity were not observed with some other amphiphilic synthetic polymers tested under the same experimental conditions. Size exclusion chromatography analyses showed that homogeneously sized particles were prepared at lipid to SMAaf weight ratios of less than 1/1.5. Dynamic light scattering and transmission electron microscopy revealed that gel-filtered DMPC-SMAaf complexes were approximately 8-10 nm in diameter and discoidal in shape. The DMPC-SMAaf complexes were relatively stable even after lyophilization but were sensitive to pH changes. Fluorescence techniques demonstrated that the gel to liquid-crystalline phase transition temperature of DMPC in the discoidal complexes broadened significantly relative to that of liposomes, despite their common bilayer structure, which is a typical feature of discoidal lipid nanoparticles. These results provide fundamental insights into discoidal SMAaf-based lipid nanoparticles for the development of novel delivery vehicles.