Serum albumin/globulin ratio is associated with cognitive function in community-dwelling older people: The Septuagenarians, Octogenarians, Nonagenarians Investigation with Centenarians study.

AIM: The objective of this study was to clarify the relationship between cognitive function and the serum albumin/globulin ratio (A/G ratio) in community-dwelling Japanese older adults. METHODS: Randomly extracted residents in both urban and rural parts of Japan were enrolled in this study. A total of 1827 participants with a mean age of 70 or 80 years were recruited. A venue survey method was carried out with comprehensive studies, including interviews, blood collection, physical examination and cognitive function tests. RESULTS: Univariate analysis showed a significant positive correlation between the total Japanese version of the Montreal Cognitive Assessment score and the serum A/G ratio at the age of 70 and 80 years, in which better cognitive function was associated with a high serum A/G ratio. Multiple regression analysis with the total Japanese version of the Montreal Cognitive Assessment score as the dependent variable showed that the serum albumin level, serum globulin level, serum A/G ratio, C-reactive protein, years of formal education and sex were related to the Japanese version of the Montreal Cognitive Assessment total score at the age of 70 years, and that the serum albumin level, serum globulin level, serum A/G ratio, C-reactive protein, years of formal education and stroke were related at the age of 80 years. The serum A/G ratio showed a better correlation than the serum globulin levels at the age of 70 and 80 years (70 years: ß = 0.131 vs -0.111, 80 years: ß = 0.108 vs -0.071). CONCLUSIONS: We found a correlation between cognitive function and the serum A/G ratio in community-dwelling older people, suggesting that nutritional status and chronic inflammation might influence cognitive function. Geriatr Gerontol Int 2019; 19: 967-971.

Association between long-term care and chronic and lifestyle-related disease modified by social profiles in community-dwelling people aged 80 and 90; SONIC study.

BACKGROUND: Chronic and lifestyle-related diseases and social status were reported to be associated with long-term care (LTC). The social factors should be treated as social sub-groups of which characteristics show social profiles. However, few previous studies considered that. The present study aimed to investigate the associations between LTC and chronic and lifestyle-related diseases, and whether the associations were modified by the social sub-groups in the community-dwelling elderly. METHOD: A cross-sectional study was conducted among 1004 community-dwelling participants aged 80 and 90. LTC was used as the outcome. Chronic and lifestyle-related diseases (i.e., stroke, heart disease, joint pain, osteoporosis, lung disease, cancer, hypertension, dyslipidemia, and diabetes) were used as the predictors. Education, household income, residential area, and support environment were analyzed by latent class analysis (LCA) to derive social profiles. We obtained odds ratios (ORs) of LTC from those diseases and tested interactions between those diseases and the social profiles by logistic regression analyses. RESULT: The participants were categorized into two sub-groups of social factors (n = 675 and 329) by LCA. Logistic regression analyses showed ORs (95% CI) of LTC were 4.69 (2.49, 8.71) from stroke, 2.22 (1.46, 3.38) from joint pain, 1.99 (1.22, 3.25) from osteoporosis, and 2.05 (1.22, 3.40) from cancer adjusting for the social sub-groups. There were no significant interactions between the social subgroups and those diseases in relation to LTC except for osteoporosis. CONCLUSION: The associations between LTC and chronic and lifestyle-related diseases were significant with adjusting for the social sub-groups, and not modified by that except osteoporosis.

Angiotensin-converting enzyme 2 deficiency accelerates and angiotensin 1-7 restores age-related muscle weakness in mice.

BACKGROUND: A pharmacologic strategy for age-related muscle weakness is desired to improve mortality and disability in the elderly. Angiotensin-converting enzyme 2 (ACE2) cleaves angiotensin II into angiotensin 1-7, a peptide known to protect against acute and chronic skeletal muscle injury in rodents. Since physiological aging induces muscle weakness via mechanisms distinct from other muscle disorders, the role of ACE2-angiotensin 1-7 in age-related muscle weakness remains undetermined. Here, we investigated whether deletion of ACE2 alters the development of muscle weakness by aging and whether angiotensin 1-7 reverses muscle weakness in older mice. METHODS: After periodic measurement of grip strength and running distance in male ACE2KO and wild-type mice until 24 months of age, we infused angiotensin 1-7 or vehicle for 4 weeks, and measured grip strength, and excised tissues. Tissues were also excised from younger (3-month-old) and middle-aged (15-month-old) mice. Microarray analysis of RNA was performed using tibialis anterior (TA) muscles from middle-aged mice, and some genes were further tested using RT-PCR. RESULTS: Grip strength of ACE2KO mice was reduced at 6 months and was persistently lower than that of wild-type mice (p < 0.01 at 6, 12, 18, and 24-month-old). Running distance of ACE2KO mice was shorter than that of wild-type mice only at 24 months of age [371 ± 26 vs. 479 ± 24 (m), p < 0.01]. Angiotensin 1-7 improved grip strength in both types of older mice, with larger effects observed in ACE2KO mice (% increase, 3.8 ± 1.5 and 13.3 ± 3.1 in wild type and ACE2KO mice, respectively). Older, but not middle-aged ACE2KO mice had higher oxygen consumption assessed by a metabolic cage than age-matched wild-type mice. Angiotensin 1-7 infusion modestly increased oxygen consumption in older mice. There was no difference in a wheel-running activity or glucose tolerance between ACE2KO and wild-type mice and between mice with vehicle and angiotensin 1-7 infusion. Analysis of TA muscles revealed that p16INK4a, a senescence-associated gene, and central nuclei of myofibers increased in middle-aged, but not younger ACE2KO mice. p16INK4a and central nuclei increased in TA muscles of older wild-type mice, but the differences between ACE2KO and wild-type mice remained significant (p < 0.01). Angiotensin 1-7 did not alter the expression of p16INK4a or central nuclei in TA muscles of both types of mice. Muscle ACE2 expression of wild-type mice was the lowest at middle age (2.6 times lower than younger age, p < 0.05). CONCLUSIONS: Deletion of ACE2 induced the early manifestation of muscle weakness with signatures of muscle senescence. Angiotensin 1-7 improved muscle function in older mice, supporting future application of the peptide or its analogues in the treatment of muscle weakness in the elderly population.

High plasma adiponectin levels are associated with frailty in a general old-old population: The Septuagenarians, Octogenarians, Nonagenarians Investigation with Centenarians study.

AIM: The objective of the present study was to investigate the association between frailty and plasma adiponectin levels in a general population of Japanese older adults. METHODS: The volunteer older adults, aged approximately 83 years, were recruited randomly from a general population in the Japanese Septuagenarians, Octogenarians, Nonagenarians Investigation with Centenarians study. We used the modified Cardiovascular Health Study criteria to assess the frailty status of the study participants. The study participants were classified as non-frail, pre-frail and frail according to their physical activities. We compared plasma adiponectin levels among these three groups and applied a multivariate logistic regression analysis including plasma adiponectin levels to clarify the factors associated with frailty status in the cross-sectional design. RESULTS: The mean age of the participants was 83.1 ± 0.9 years, and 51.8% were men. The frailty index was available to assess 353 participants, of whom 24.6% were classified as non-frail, 62.3% as prefrail and 13.0% as frail. The log-transformed plasma adiponectin levels increased stepwise in the following order: non-frail, pre-frail and frail. A multivariate logistic regression analysis showed that higher plasma adiponectin levels, a higher estimated glomerular filtration rate and lower hemoglobin levels were independent determinants for pre-frail/frail status compared with non-frail status. CONCLUSIONS: The present study showed that higher plasma adiponectin levels were associated with frailty status in older Japanese adults in the general population. Further longitudinal study is essential to clarify the role of plasma adiponectin in the progression of frailty. Geriatr Gerontol Int 2018; 18: 839-846.

Occlusal force is correlated with cognitive function directly as well as indirectly via food intake in community-dwelling older Japanese: From the SONIC study.

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.

Longitudinal association of hypertension and diabetes mellitus with cognitive functioning in a general 70-year-old population: the SONIC study.

Both hypertension and diabetes in middle-aged individuals have been suggested to be predictive indicators of cognitive decline. However, the association of hypertension, diabetes and their combination with cognitive functioning is still controversial in older people. The purpose of this study was to investigate the association between cognitive decline and hypertension, diabetes, and their combination in 70-year-old people based on a 3-year longitudinal analysis. Four hundred and fifty-four people aged 70 (±1) years who participated in the Japanese longitudinal cohort study of Septuagenarians, Octogenarians and Nonagenarians Investigation with Centenarians (SONIC) were recruited randomly from a general population and were monitored for 3 years. The data, including most of the demographics, cognitive functioning measured by the Montreal Cognitive Assessment Japanese version (MoCA-J), blood pressure, blood chemistry and other medical histories, were collected at baseline and during the follow-up. The prevalence of hypertension noted in the follow-up survey was significantly higher than than noted at baseline. The mean MoCA-J score at follow-up was not significantly different from the score obtained at baseline. However, the participants with diabetes, especially combined with hypertension at baseline, had significantly lower MoCA-J scores than those without lifestyle-related diseases. The combination of hypertension and diabetes was still a significant risk factor for cognitive decline, considering the MoCA-J scores obtained during the follow-up after adjustments at baseline, relative to sex, body mass index, dyslipidemia, smoking, excessive alcohol intake, antihypertensive treatment and education level (ß=-0.14; P<0.01). Our findings indicate that diabetes and the combination of hypertension and diabetes are clear risk factors for future cognitive decline in elderly individuals who are 70 years of age.

Modified forelimb grip strength test detects aging-associated physiological decline in skeletal muscle function in male mice.

The conventional forelimb grip strength test is a widely used method to assess skeletal muscle function in rodents; in this study, we modified this method to improve its variability and consistency. The modified test had lower variability among trials and days than the conventional test in young C57BL6 mice, especially by improving the variabilities in male. The modified test was more sensitive than the conventional test to detect a difference in motor function between female and male mice, or between young and old male mice. When the modified test was performed on male mice during the aging process, reduction of grip strength manifested between 18 and 24 months of age at the group level and at the individual level. The modified test was similar to the conventional test in detecting skeletal muscle dysfunction in young male dystrophic mice. Thus, the modified forelimb grip strength test, with its improved validity and reliability may be an ideal substitute for the conventional method.

Differences in the association between high blood pressure and cognitive functioning among the general Japanese population aged 70 and 80 years: The SONIC study.

High blood pressure in middle age (up to 64 years) has been proposed as a predictive indicator of dementia. However, the association between hypertension and the cognitive functioning is controversial in older age groups. The aim of this study was to investigate this association in 70-80-year-old participants in the Japanese study of Septuagenarians, Octogenarians and Nonagenarians Investigation with Centenarians (SONIC). Participants aged 70 (±1) and 80 (±1) years (n=1000 and 973, respectively) were randomly recruited from the general population in Japan. Cognitive functioning was measured by the Montreal Cognitive Assessment. Blood pressure and other medical and social variables were analyzed by multiple regression analyses. High systolic blood pressure (SBP) was significantly correlated with a reduced cognitive functioning only in participants aged 70 years. Additionally, this correlation became more marked in participants with uncontrolled blood pressure at age 70 years. In contrast, SBP was not significantly correlated with the cognitive functioning at age 80 years. Nutritional status indicators such as serum albumin and frequency of going outdoors were significantly associated with cognitive functioning at age 80 years. Our findings indicate that high SBP has a significant role in cognitive functioning at age 70 years; however, blood pressure is less important as a risk factor for cognitive decline at age 80 years.

Oxidized LDL (oxLDL) activates the angiotensin II type 1 receptor by binding to the lectin-like oxLDL receptor.

The angiotensin II type 1 receptor (AT1) is a 7-transmembrane domain GPCR that when activated by its ligand angiotensin II, generates signaling events promoting vascular dysfunction and the development of cardiovascular disease. Here, we show that the single-transmembrane oxidized LDL (oxLDL) receptor (LOX-1) resides in proximity to AT1 on cell-surface membranes and that binding of oxLDL to LOX-1 can allosterically activate AT1-dependent signaling events. oxLDL-induced signaling events in human vascular endothelial cells were abolished by knockdown of AT1 and inhibited by AT1 blockade (ARB). oxLDL increased cytosolic G protein by 350% in Chinese hamster ovary (CHO) cells with genetically induced expression of AT1 and LOX-1, whereas little increase was observed in CHO cells expressing only LOX-1. Immunoprecipitation and in situ proximity ligation assay (PLA) assays in CHO cells revealed the presence of cell-surface complexes involving LOX-1 and AT1. Chimeric analysis showed that oxLDL-induced AT1 signaling events are mediated via interactions between the intracellular domain of LOX-1 and AT1 that activate AT1. oxLDL-induced impairment of endothelium-dependent vascular relaxation of vascular ring from mouse thoracic aorta was abolished by ARB or genetic deletion of AT1. These findings reveal a novel pathway for AT1 activation and suggest a new mechanism whereby oxLDL may be promoting risk for cardiovascular disease.

Trigger-based mechanism of the persistence of atrial fibrillation and its impact on the efficacy of catheter ablation.

BACKGROUND: We investigated the possibility that a frequent trigger action might play a role in the development of persistent atrial fibrillation (PeAF) and the presence of a substrate. METHODS AND RESULTS: In 263 consecutive patients who underwent catheter ablation (CA) for PeAF, electric cardioversion was performed at the beginning of the procedure to determine the presence or absence of an immediate recurrence of AF (IRAF). We defined an IRAF as a reproducible AF recurrence within 90 s after restoration of sinus rhythm by electric cardioversion. We performed a mean±SD of 1.3±0.5 sessions of CA, including pulmonary vein isolation and ablation of the premature atrial contractions that triggered the IRAF (IRAF triggers), and observed the patients for 17 (10-27) months. An IRAF was observed in 70 patients (27%), but we could not ablate the IRAF triggers in 16 (23%) of these IRAF patients. The recurrence rate of PeAF was higher in patients with an unsuccessful IRAF trigger ablation than in those with successful IRAF trigger ablation (63% versus 11%; P<0.001). A multivariable analysis also revealed that an unsuccessful IRAF trigger ablation was 1 of the independent predictors of recurrent PeAF (odds ratio, 10.9; 95% CI, 3.4-36.7). CONCLUSIONS: In the PeAF patients with an IRAF, successful elimination of the IRAF triggers, in addition to pulmonary vein isolation, resulted in a successful CA. These results imply that such triggers play a major role in the AF persistence in these PeAF patients.