Prevalence and diagnostic agreement of sarcopenic obesity with different definitions among Chinese community-dwelling older adults.

OBJECTIVE: this retrospective study aims to compare the prevalence and diagnostic agreement of sarcopenic obesity (SO) using different obesity diagnostic methods among Chinese community-dwelling older adults. METHODS: SO was diagnosed with sarcopenia and obesity diagnostic methods. Sarcopenia was defined using the Asian Working Group for Sarcopenia criteria 2019 (AWGS2019). Four widely used indicators were used to define obesity: body mass index (BMI), waist circumference (WC), percent of body fat (PBF) and visceral fat area (VFA). Cohen's kappa was used to analyse the diagnosis agreement of SO between different diagnostic methods. RESULTS: a total of 1,050 participants were included, including 347 men (71.3 ± 7.4 years) and 703 women (69.9 ± 7.5 years). The prevalence of sarcopenia was 25% in total participants, there was no difference between men (24.2%) and women (25.5%), (P = 0.705). With different obesity diagnostic methods, the obesity prevalence ranged from 4.1 to 42.2%, the SO prevalence was 0.1-7.9%. The diagnosis agreement of SO was poor-to-moderate (κ ranged from -0.002 to 0.682). Among the four diagnostic methods, AWGS combined with BMI had the poorest agreement (κ = -0.002 with other methods), AWGS combined with VFA had the best agreement (κ = 0.641 and 0.682 with AWGS combined with PBF and with AWGS combined with WC, respectively). CONCLUSION: the prevalence of SO vary considerably and the diagnostic agreement is poor-to-moderate with non-uniform diagnostic methods. BMI has the lowest sensitivity, whereas VFA has the highest sensitivity in diagnosis of SO, and VFA has a relatively good diagnostic agreement with other diagnostic methods.

Development and Validation of a Nomogram for Predicting Sarcopenia in Community-Dwelling Older Adults.

OBJECTIVE: To establish and validate a nomogram that predicts the risk of sarcopenia for community-dwelling older residents. DESIGN: Retrospective study. SETTING AND PARTICIPANTS: A total of 1050 community-dwelling older adults. METHODS: Data from a survey of community-dwelling older residents (≥60 years old) in Hunan, China, from June to September 2019 were retrospectively analyzed. The survey included general demographic information, diet, and exercise habits. Sarcopenia diagnosis was according to 2019 Asian Working Group for Sarcopenia criteria. Participants were randomly divided into the development group and validation groups. Independent risk factors were screened by multivariate logistic regression analysis. Based on the independent risk factors, a nomogram model was developed to predict the risk of sarcopenia for community-dwelling older adults. Both in the development and validation sets, the discrimination, calibration, and clinical practicability of the nomogram were verified using receiver operating characteristic curve analysis, Hosmer-Lemeshow test, and decision curve analysis, respectively. RESULTS: Sarcopenia was identified in 263 (25.0%) participants. Age, body mass index, marital status, regular physical activity habit, uninterrupted sedentary time, and dietary diversity score were significant contributors to sarcopenia risk. A nomogram for predicting sarcopenia in community-dwelling older adults was developed using these factors. Receiver operating characteristic curve analysis showed that the area under the curve was 0.827 (95% CI 0.792-0.860) and 0.755 (95% CI 0.680-0.837) in the development and validation sets, respectively. The Hosmer-Lemeshow test yielded P values of .609 and .565, respectively, for the 2 sets. The nomogram demonstrated a high net benefit in the clinical decision curve in both sets. CONCLUSIONS AND IMPLICATIONS: This study developed and validated a risk prediction nomogram for sarcopenia among community-dwelling older adults. Sarcopenia risk was classified as low (<11%), moderate (11%-70%), and high (>70%). This nomogram provides an accurate visual tool to medical staff, caregivers, and older adults for prediction, early intervention, and graded management of sarcopenia.

Comparison of Three Screening Methods for Sarcopenia in Community-Dwelling Older Persons.

OBJECTIVE: The 2019 Asian Working Group on Sarcopenia in Older People (AWGS 2019) recommends using either calf circumference or the strength, assistance in walking, rising from a chair, climbing stairs, and falls (SARC-F) or SARC-F combined with calf circumference (SARC-CalF) questionnaires for sarcopenia screening. The aim of this study was to compare the ability and applicability of calf circumference, SARC-F, and SARC-CalF for screening sarcopenia among community-dwelling older adults. DESIGN: Cross-sectional study. SETTING AND PARTICIPANTS: A total of 1050 community-dwelling older people were enrolled. METHODS: Sarcopenia was diagnosed according to the AWGS 2019 criteria: bioimpedance analysis for appendicular skeletal muscle index, hand grip, and 6-m gait speed test. Participants also completed the SARC-F questionnaire and calf circumference measurement. The screening tools' performances were evaluated through receiver operating characteristic (ROC) curves, area under the ROC curves (AUC), and sensitivity/specificity analyses. RESULTS: Sarcopenia was identified in 263 (25.0%) participants by the AWGS 2019 criteria. Calf circumference had a sensitivity of 81.4% and a specificity of 77.0%. Sensitivity and specificity of SARC-F for screening sarcopenia were 17.9% and 93.7%, respectively. SARC-CalF improved the sensitivity of SARC-F (47.5%) while keeping similar specificity (92.0%). The AUCs of calf circumference, SARC-F, and SARC-CalF were 0.79 [95% confidence interval (CI), 0.77-0.82], 0.56 (95% CI, 0.52-0.59), and 0.70 (95% CI, 0.67-0.73), respectively. The differences across ROC curves were statistically significant among 3 screening tools (P < .001). CONCLUSIONS AND IMPLICATIONS: The overall screening ability of calf circumference was better than that of SARC-F and SARC-CalF for sarcopenia in community-dwelling older persons despite gender, age, and cognitive function. SARC-F and SARC-CalF have high specificity but are susceptible to the preceding factors.

[Expression of recombinant VP2 gene in insect sf9 cells and screening of clinical specimens].

OBJECTIVE: To clone and express VP, gene from HBoV, and the expressed VP, protein was as the antigen in order to detect serum from children in Wenling area with lower respiratory tract infections. METHODS: The VP, gene was recombined with the genome of Baculovirus, which infected the insect cell. The fusion protein with HA tag was applied to confirm the specificity of expressed protein. Furthermore, the recombinant protein was observed using electron microscopy. The 176 serum from children in Wenling area with lower respiratory tract infections was screened using Western blot. RESULTS: The expressed VP2 protein was more than 60% in total proteins from insect cell, and MWt about 60 x 10(3). The virus-like particle (VLP) was observed using electron microscopy, and size about 20 nm. The 176 serum from children in wenling area with lower respiratory tract infections was screened using Western blot. The HBoV positive rate was 2.28% (4/176). CONCLUSION: The VP2 protein from human bocavirus was expressed in insect cell successfully. Through HA tag the VP2 protein was specific, and then the assay using SDS-PAGE with Western blot could detect and screen the antibody in serum from children with lower respiratory tract infections rapidly and accurately.

[Isolation and cell culture of human bocavirus (HBoV) by human bronchial epithelial cell lines].

OBJECTIVE: To investigate pave a way for studying pathogenicty of HBoV. METHODS: Isolation and cell culture of HBoV by human bronchial epithelial cell line, which was founded in our laboratory. The morphology of the virus were primarily studied with a transmission electron microscope. In addition, transcript mRNA was detected in human bronchial epithelial cells, which was passaged and infected within HBoV, using the reverse-transcription polymerase chain reaction (RT-PCR). The amplified products nucleotide sequence of HBoV were sequencing and sequence analysis. RESULTS: Cytopathic effect (CPE) was observed after the aseptic residue of filtration of 2 case sputum specimens with HBoV, which was inoculated to the human bronchial epithelial cell line. The virus particles were observed in the cytoplasm, which were hexagonal or spherical in shape and 18-26 nm in diameter,bulk was 20 nm. cDNA amplicon obtained 295 bp fragment results of electrophoresis bands as same as NS1 region of the conserved matrix gene of publish sequence of HboV. PCR products nucleotide sequence of HboV were compared with corresponding HboV GeneBank sequences. The comparison/alignment and construction of phylogenetic trees also point to an affiliation of the parvovirus to the species HBoV. CONCLUSION: Isolation and identification of HBoV could be done in the human bronchial epithelial cell, and we found some characterizing CPE in the human bronchial epithelial cell after HBoV infection. The above studies pave a way for studying pathogenicty of human bocavirus.

[Characterization of the cytopathic effect in human bronchial epithelial cell after Human Bocavirus Infection (HBoV)].

OBJECTIVE: In this study, human bronchial epithelial cells were inoculated with positive sputum specimens of HBoV. After four days' infection, cytopathic effects (CPE) were observed by inverted microscopy. These viruses all cause typical cell damages such as rounded and shrivelled, fusion and fallout. These damages got quick following increased future degenerations. The other assay result of CPE within the infected cells were observed by inverted microscopy, have typical "owl's eye" plaque and above 90 percent hemadsorption within the infected cells by erythrocytes for hemadsorption technique. The typical fluorescence lump of nucleus within the infected cells was found by indirect immunofluorescence technique. CONCLUSION: Isolation and identification of HBoV could be done in the human bronchial epithelial cell, and we found some characterizing CPE in the human bronchial epithelial cell after HBoV infection. The above studies pave a way for studying pathogenicity of human bocavirus.