Hiroshi Akasaka

Aim: Sarcopenia increases the risk of long‐term care, disease development, and mortality in older adults. It is also a risk factor for cardiovascular disease and vice versa. Using cross‐sectional and longitudinal cohort study designs, we investigated the association between the carotid intima‐media thickness (CIMT) and sarcopenia in older adults. Methods: Data were extracted from the Septuagenarians, Octogenarians, Nonagenarians Investigation with Centenarians (SONIC) study. Using data from Wave 3 of the SONIC participants, we examined the association between CIMT and sarcopenia using cross‐sectional analysis and the association between CIMT at baseline and sarcopenia status 3 years later (Wave 4) in a longitudinal study. Sarcopenia was diagnosed according to the Asian Working Group for Sarcopenia (AWGS) 2019 guidelines. Results: The cross‐sectional study included 735 participants (347 males, mean age: 76.0 ± 0.9 years); the longitudinal study included 498 participants (247 males, mean age: 75.9 ± 0.9 years). In the cross‐sectional study, 130 (17.7%) participants had sarcopenia; multiple logistic regression analysis revealed an odds ratio (OR) of 1.55 (95% confidence interval [CI]: 1.15–2.07) for sarcopenia for every 1 mm increase in the maximum CIMT. In the longitudinal study, 100 participants (20.1%) had sarcopenia at Wave 4. Multiple logistic regression analysis revealed an OR of 1.63 for sarcopenia (95% CI: 1.13–2.36) for each 1 mm increase from the baseline maximum CIMT. Conclusion: CIMT was associated with sarcopenia. These results help clarify the pathophysiology of sarcopenia and the possible use of the CIMT as a marker to identify individuals at high risk of sarcopenia.

Background:Few studies have specifically examined the relationship between social media use and uptake of COVID-19 booster. This study examined the association between social media use and COVID-19 booster vaccination uptake in Japan during the pandemic.Methods:A series of cross-sectional surveys was conducted using rapid online questionnaires among residents of Iwate Prefecture, Japan, from October 1 to 3, 2021, and from December 11 to 17, 2023 (n = 4,026). Vaccination status was assessed using a single question: “What is your vaccination status?”. Respondents were categorized into two groups: individuals with incomplete booster uptake (those who had received one or two doses; n = 226) and booster acceptors (those who had received at least three doses; n = 3,800). Social media use was defined as self-reported use of Twitter, Facebook, Instagram, YouTube, or other social networking services. Logistic regression analyses were conducted to examine the association between social media use and receipt of a COVID-19 booster vaccination.Results:Social media use was significantly associated with higher odds of incomplete booster uptake of COVID-19 vaccination. This association remained statistically significant after adjustment for relevant covariates (odds ratio [OR] 1.70, 95% confidence interval [CI] 1.21–2.39). Individuals with a history of COVID-19 infection prior to the initiation of booster vaccinations were less likely to receive a booster dose in an exploratory analysis (OR 3.06, 95% CI 1.28–7.32).Conclusion:Differential associations between media use and COVID-19 booster uptake may provide important insights for designing effective communication strategies to improve vaccine acceptance in future pandemics.

Aim: To investigate the impact of preoperative exercise and nutritional interventions on postoperative complications, physical function, and activities of daily living ( ADL ) 1 year postoperatively in frail older patients with gastrointestinal cancer. Methods: This single‐center, randomized controlled trial enrolled 62 patients aged ≥ 70 years scheduled to undergo elective surgery for gastrointestinal cancer with decreased grip strength or walking speed between October 2017 and December 2022. Participants were randomly assigned to control ( n = 33) and intervention ( n = 29) groups; the latter performed resistance exercises and consumed amino acid‐containing jelly daily at home for 14 days. All participants were followed‐up for 1 year. Results: After exclusion, 27 and 18 patients were enrolled in the control and intervention groups, respectively. The average age was 80.4 years, and 37.8% were male. Postoperative complications were observed in 51.9% and 44.4% of the control and intervention groups, respectively (95% confidence interval [CI] 0.62–2.19), with postoperative delirium observed in 25.9% and 33.3%, respectively (95% CI 0.31–1.94). There were no significant inter‐group differences in grip strength, walking speed, or skeletal muscle index. However, the intervention group showed superior knee extension strength maintenance (preoperatively: 100.2% ± 18.3% vs. 119.1% ± 68.8%, p = 0.19; discharge: 86.7% ± 22.0% vs. 119.3% ± 72.0%, p = 0.044), and lower rates of decreased ADLs or death 1 year postoperatively (42.3% vs. 23.5%; RR 0.56, 95% CI 0.08–1.92). Conclusions: This 14‐day preoperative exercise and nutritional intervention program did not significantly reduce postoperative complications in frail older patients with gastrointestinal cancer; however, it aided in maintaining knee extension strength at discharge.

Chronic kidney disease (CKD) and atherosclerotic heart disease, frequently associated with dyslipidemia and hypertension, represent significant health concerns. We investigated the interplay among these conditions, focusing on the role of oxidized low-density lipoprotein (oxLDL) and angiotensin II (Ang II) in renal injury via G protein αq subunit (Gq) signaling. We hypothesized that oxLDL enhances Ang II-induced Gq signaling via the AT1 (Ang II type 1 receptor)-LOX1 (lectin-like oxLDL receptor) complex. Based on CHO and renal cell model experiments, oxLDL alone did not activate Gq signaling. However, when combined with Ang II, it significantly potentiated Gq-mediated inositol phosphate 1 production and calcium influx in cells expressing both LOX-1 and AT1 but not in AT1-expressing cells. This suggests a critical synergistic interaction between oxLDL and Ang II in the AT1-LOX1 complex. Conformational studies using AT1 biosensors have indicated a unique receptor conformational change due to the oxLDL-Ang II combination. In vivo, wild-type mice fed a high-fat diet with Ang II infusion presented exacerbated renal dysfunction, whereas LOX-1 knockout mice did not, underscoring the pathophysiological relevance of the AT1-LOX1 interaction in renal damage. These findings highlight a novel mechanism of renal dysfunction in CKD driven by dyslipidemia and hypertension and suggest the therapeutic potential of AT1-LOX1 receptor complex in patients with these comorbidities.

Chronic kidney disease (CKD) and atherosclerotic heart disease, frequently associated with dyslipidemia and hypertension, represent significant health concerns. We investigated the interplay among these conditions, focusing on the role of oxidized low-density lipoprotein (oxLDL) and angiotensin II (Ang II) in renal injury via G protein αq subunit (Gq) signaling. We hypothesized that oxLDL enhances Ang II-induced Gq signaling via the AT1 (Ang II type 1 receptor)-LOX1 (lectin-like oxLDL receptor) complex. Based on CHO and renal cell model experiments, oxLDL alone did not activate Gq signaling. However, when combined with Ang II, it significantly potentiated Gq-mediated inositol phosphate 1 production and calcium influx in cells expressing both LOX-1 and AT1 but not in AT1-expressing cells. This suggests a critical synergistic interaction between oxLDL and Ang II in the AT1-LOX1 complex. Conformational studies using AT1 biosensors have indicated a unique receptor conformational change due to the oxLDL-Ang II combination. In vivo, wild-type mice fed a high-fat diet with Ang II infusion presented exacerbated renal dysfunction, whereas LOX-1 knockout mice did not, underscoring the pathophysiological relevance of the AT1-LOX1 interaction in renal damage. These findings highlight a novel mechanism of renal dysfunction in CKD driven by dyslipidemia and hypertension and suggest the therapeutic potential of AT1-LOX1 receptor complex in patients with these comorbidities.

IL-15 gene deficiency can decrease autophagy induction. However, although IL-15 overexpression induced a decrease in muscle mass, it led to an improvement in muscle quality. Based on these results, understanding the role of IL-15 in regulating autophagy pathways within skeletal muscle may lead to the development of therapies for the autophagy-induced regulation of skeletal muscle mass and cellular quality control.

Sarcopenia is the core factor of frailty. This study specifically focused on lower limb muscle strength and examined muscle indices that indicate the risk of frailty or pre-frailty in older adults. The study included 327 community-dwelling individuals aged ≥65 years (43.7% male) who participated in the cohort. Frailty was defined based on five symptoms: weight loss, low activity level, exhaustion, weakness and slowness. Participants were classified into frail (three or more applicable), pre-frail (one to two applicable) and non-frail groups. Muscle strength (knee extension strength, toe grip strength and hand grip strength) were assessed, and appendicular muscle mass was assessed via a bioelectrical impedance analysis. The adjusted odds ratio (OR) of muscle indices for with frailty (frail group vs. pre-frail group) or pre-frailty (pre-frail group vs. non-frail group) were calculated. The prevalence of frail and pre-frail was 7% and 40%, respectively. Adjusted for age, sex, albumin and medical history, knee extension strength was significantly associated with frailty (odds ratio 0.95, 95% CI 0.92–0.98), while hand grip strength was associated with pre-frailty (odds ratio 0.92, 95% CI 0.88–0.97) but not with other muscle indices. This study is significant for identifying knee extension strength as a factor relevant to frailty in older adults considered pre-frailty, emphasizing the importance of this specific muscle measure in predicting and managing frailty.