Sarcopenic obesity is the co‐existence of obesity and sarcopenia in individuals aged 40–75 years. The Japanese Working Group on Sarcopenic Obesity has developed diagnostic criteria tailored for the Japanese population, considering their unique characteristics compared with European populations. Our algorithm consists of two steps: screening and diagnosis. The screening of obesity mandates using waist circumference and/or body mass index (BMI) based on national standards, while screening for sarcopenia involves the “finger ring test” in addition to the Asian Working Group for Sarcopenia 2019 criteria. The final diagnosis of sarcopenia involves handgrip strength for low muscle strength, the five‐times chair stand test for low physical function, and limb skeletal muscle mass (corrected for BMI) for low muscle mass. Obesity is assessed by visceral fat area or body fat percentage. Sarcopenic obesity is then categorized into Stage I, with muscle weakness/loss of function, loss of muscle mass, and obesity; or Stage II, which includes complications. Further clinical validation is needed to refine the consensus and age range. Geriatr Gerontol Int 2024; ••: ••–••.

Objective Conventionally, knee extension strength is often used as the indicator for lower limb muscle strength; however, several recent studies have also used quadriceps setting strength. This study aimed to investigate and compare the association of quadriceps setting and knee extension strength with health-related physical fitness. Methods We evaluated quadriceps setting strength and isometric knee extension strength in 75 elderly subjects (mean age, 76.8±5.3 years) to determine their lower limb muscle strength. Health-related physical fitness was evaluated using the physical fitness test advocated by the Ministry of Education and Culture, Sports, Science and Technology in Japan. The test consists of the following components: grip strength, sit-up, sit and reach, one leg standing with eyes open, 10 m obstacle walk and 6 min walk. Results When adjusted for age, sex and body mass index, quadriceps setting strength was significantly correlated with grip strength, number of sit-ups, sit and reach distance, 10 m obstacle walking time and 6 min walking distance. In contrast, knee extension strength was associated only with grip strength and number of sit-ups. Conclusion More health-related physical fitness parameters with quadriceps setting strength than knee extension strength. Quadriceps setting strength may be superior to knee extension strength as a predictor of health-related physical fitness.

Objective: This study examined the relationship between neighborhood food and physical activity environment, and obesity among elementary and junior high school students in Japan. Methods: The participants were fifth- to ninth-grade children (n=7277), who were attending municipal schools in Japan. Percent overweight (POW) was calculated using their age, gender, height, and weight, which were collected through a questionnaire. A POW of < 20% was considered non-obese, while ≥ 20% was considered obese. Furthermore, using a geographic information system, we investigated the density of convenience stores, fast-food stores, casual restaurants, supermarkets and department stores, parks, sports facilities, stations, and intersections in the school district. Additionally, from the census, we obtained information regarding the population density of the municipality where the participants’ schools were located. Multiple logistic regression analysis was used to examine the relationship between obesity and food environment (the food environment model), between obesity and physical activity environment (the physical activity environment model), and among obesity, food, and physical activity environment (the food and physical activity environment model). Results: In the food environment model and the food and physical activity environment model, the density of convenience stores showed a significant positive association. In the physical activity environment model, the density of stations showed a significant negative association. Conclusion: This study’s findings can contribute to the development of appropriate community interventions for improving children’s health in Japan and similar areas.

Obesity with multiple metabolic syndrome (MetS) components and/or with skeletal muscle loss is at high risk of cardiovascular disease (CVD). This study aimed to clarify the utility of anthropometric indices for identifying patients with overweight/obese at high risk of CVD based on having multiple MetS components and skeletal muscle loss. This cross-sectional study included 188 overweight/obese (BMI ≥25 kg/m², Japanese patients; 73 men and 115 women, mean age 55.7 years). First, we performed correlation analysis among seven anthropometric indices, body mass index (BMI), percentage body fat, waist circumference (WC), waist-to-hip ratio (WHpR), waist-to-height ratio (WHtR), a body shape index (ABSI), and body roundness index (BRI). Unlike the others, only ABSI was not correlated with BMI. Then, we conducted receiver operating characteristic analysis to assess the predictive abilities of anthropometric indices for having multiple MetS components. WC, WHpR, WHtR, BRI, and ABSI had significant predictive abilities for having multiple MetS components. Furthermore, multiple regression analysis showed that only ABSI had significantly negative associations with all sarcopenia-evaluated indices (skeletal muscle mass index [SMI], handgrip strength [HGS], and muscle quality [MQ]), irrespective of sex and age. Finally, an analysis of covariance showed that the high ABSI group had significantly lower SMI and HGS than the low ABSI group, irrespective of sex and age. ABSI was deemed useful for BMI-independently identifying Japanese patients with overweight/obese at high risk of CVD based on having multiple MetS components and skeletal muscle loss. Clinical trials (the unique trial number and the name of the registry) ID: UMIN000042726.

In fission yeast, the formation of centromeric heterochromatin is induced through the RNA interference (RNAi)-mediated pathway. Some pre-mRNA splicing mutants (prp) exhibit defective formation of centromeric heterochromatin, suggesting that splicing factors play roles in the formation of heterochromatin, or alternatively that the defect is caused by impaired splicing of pre-mRNAs encoding RNAi factors. Herein, we demonstrate that the splicing factor spPrp16p is enriched at the centromere, and associates with Cid12p (a factor in the RNAi pathway) and the intron-containing dg ncRNA. Interestingly, removal of the dg intron, mutations of its splice sites, or replacement of the dg intron with an euchromatic intron significantly decreased H3K9 dimethylation. We also revealed that splicing of dg ncRNA is repressed in cells and its repression depends on the distance from the transcription start site to the intron. Inefficient splicing was also observed in other intron-containing centromeric ncRNAs, dh and antisense dg, and splicing of antisense dg ncRNA was repressed in the presence of the RNAi factors. Our results suggest that the introns retained in centromeric ncRNAs work as facilitators, co-operating with splicing factors assembled on the intron and serving as a platform for the recruitment of RNAi factors, in the formation of centromeric heterochromatin. Formation of centromeric heterochromatin is required for correct segregation of sister chromatids during mitosis. In fission yeast, formation of heterochromatin at centromeres is performed through the RNA interference (RNAi) system, which involves processing of noncoding RNAs transcribed from the centromeres. We found that the intron in the centromeric dg ncRNAs facilitates formation of centromeric heterochromatin in fission yeast. We showed that the splicing factor spPrp16p associates with the RNAi factor and intron-containing dg ncRNA. Removal of or mutations in the dg intron significantly decreased H3K9 dimethylation, suggesting that the intron and associated splicing factors serve as a platform for recruitment of RNAi factors. Inefficient splicing is a hallmark of intron-containing centromeric ncRNAs. Such repression of splicing seems to be important for facilitation of heterochromatin formation. Introns in euchromatic regions are removed by splicing to generate functional RNAs, whereas centromeric introns are retained in ncRNAs by splicing repression and play roles in gene silencing. Our findings shed light on the novel roles of introns in epigenetic regulation of gene expression and heterochromatin formation.

Background: Sarcopenia is associated with an increased risk for dementia. This study aimed to elucidate the relationship between sarcopenia‐related indices and cognitive decline in the general population.Methods: This was a cross‐sectional study involving 263 participants (163 men with a median age of 60 years [interquartile range = 53–70] and 100 women with a median age of 58 years [interquartile range = 49–68]) who underwent a general health examination. Sarcopenia‐related indices included appendicular skeletal muscle mass (ASM)/height², ASM/body mass index, handgrip strength (HGS), HGS/upper extremity skeletal muscle mass and phase angle (PhA). We examined the associations between these indices and cognitive function using the Japanese version of the Montreal Cognitive Assessment (MoCA‐J).Results: Higher PhA, an indicator of muscle quality, was associated with a lower risk of mild cognitive impairment (MCI) in women (adjusted odds ratio = 0.28 [95% confidence interval, 0.10–0.78], p = 0.014), whereas the other sarcopenia‐related indices showed no significant association with MCI in both sexes. The PhA of women was positively associated with the MoCA‐J scores (β = 0.27, p = 0.005). Moreover, the PhA of women showed a positive correlation with cognitive subdomains, including memory (r = 0.22, p = 0.031), which is one of the earliest manifestations of cognitive impairment. The PhA in men was also positively correlated with memory (r = 0.24, p = 0.002).Conclusions: PhA is a potentially novel index for detecting the risk of sarcopenia and cognitive decline in the general population.