Prevalence and factors influencing long COVID among primary healthcare workers after epidemic control policy adjustment in Jiangsu, China.

OBJECTIVE: The persistent symptoms arising from COVID-19 infection pose a substantial threat to patients' health, carrying significant implications. Amidst the evolving COVID-19 control strategies in China, healthcare workers (HCWs) endure considerable stress. This study aims to evaluate the prevalence of long COVID infections and their influencing factors among primary HCWs after epidemic control policy adjustment in Jiangsu. METHODS: A self-designed questionnaire was administered through on-site surveys among primary HCWs in five counties and districts within Jiangsu Province from July 4 to July 20, 2023. Logistic regression analysis was employed to identify factors associated with long COVID. RESULTS: The prevalence of long COVID among primary HCWs stood at 12.61%, with a 95% confidence interval (CI) of 11.67-13.55%. Among those affected, the most common long COVID symptoms were hypomnesia (4.90%, 95%CI: 4.29-5.51%), sleep difficulties (2.73%, 95%CI: 2.27-3.19%), fatigue (2.35%, 95%CI: 1.92-2.78%), disturbances in the reproductive system (1.93%, 95%CI: 1.54-2.32%), hair loss (1.85%, 95%CI: 1.47-2.23%), and myalgia/arthralgia (1.51%, 95%CI: 1.16-1.86%). Multivariate logistic regression revealed that older age groups (30-45 years (adjusted odds ratio (aOR) = 1.93, 95%CI: 1.44-2.58), 45-60 years (aOR = 2.82, 95%CI: 2.07-3.84)), females (aOR = 1.26, 95%CI: 1.03-1.55), and higher work stress (high stress (aOR = 1.52, 95%CI: 1.24-1.86), extremely high stress (aOR = 1.37, 95%CI: 1.03-1.82)) were more prone to long COVID. Conversely, individuals with educational attainment below the bachelor's degree (aOR = 0.67, 95%CI: 0.55-0.82) and those who received four or more doses of the COVID-19 vaccine (aOR = 0.55, 95%CI: 0.33-0.92) were at a reduced risk. CONCLUSION: This study investigates the prevalence of long COVID among primary HCWs and identifies key influencing factors. These findings are crucial for assisting in the early identification of COVID-19 patients at risk for long-term complications, developing targeted interventions aimed at optimizing healthcare resource allocation and enhancing the work conditions and quality of life of HCWs. To mitigate the prevalence of long COVID, healthcare providers and local authorities should implement effective measures, such as optimizing work-rest schedules and actively advocating for vaccination.

Screening for frailty and its association with activities of daily living, cognitive impairment, and falls among community-dwelling older adults in China.

OBJECTIVES: Frailty is a prevalent geriatric condition that significantly impacts the health of older adults. This study aimed to examine the prevalence of frailty among older Chinese adults aged ≥ 65 years and to assess its association with adverse geriatric outcomes. METHOD: This study included 20,724 older adults aged ≥ 65 years in Jiangsu Province, China, utilizing a random, stratified, multistage cluster sampling approach. Frailty was assessed using the 5-item FRAIL scale. Geriatric outcomes, such as independence in activities of daily living (ADL), cognitive impairment, and frequent fall events (occurring four or more times in the preceding year), were evaluated. Logistic regression models were employed to evaluate the association between frailty and geriatric outcomes, with results presented as odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: The mean age of the participants was 73.4 ± 6.4 years. The standardized prevalence of prefrailty and frailty was 35.2% and 10.3%, respectively. Individuals identified as prefrail or frail tended to live in rural areas, have lower educational levels, be widowed, have lower incomes, and engage in less physical activity. Prefrailty and frailty were associated with an increased risk of limitations in BADL (OR: 9.62, 95% CI: 7.43-12.46; and OR: 29.25, 95% CI: 22.42-38.17, respectively) and IADL (OR: 2.54, 95% CI 2.35-2.74; and OR: 5.19, 95% CI 4.66-5.78, respectively), positive cognitive impairment screening (OR: 1.23, 95% CI: 1.16-1.31; and OR: 1.72, 95% CI: 1.56-1.91, respectively), and frequent falls (occurring four or more times in the preceding year) (OR: 3.38, 95% CI: 2.50-4.56; and OR: 8.37, 95% CI: 6.01-11.65). The association between frailty and both limitations in BADL and falls was notably more pronounced among the younger age groups (p for interaction < 0.001). CONCLUSIONS: According to the 5-item FRAIL scale, frailty was associated with limitations in BADLs and IADLs, positive cognitive impairment screening, and recent falls among older adults living in the community. Screening for frailty in younger age groups has the potential to prevent declines in physical function and falls.

RBP4 promotes denervation-induced muscle atrophy through STRA6-dependent pathway.

BACKGROUNDS: Fat infiltration of skeletal muscle has been recognized as a common feature of many degenerative muscle disorders. Retinol binding protein 4 (RBP4) is an adipokine that has been demonstrated to be correlated with the presence and severity of sarcopenia in the elderly. However, the exact role and the underlying mechanism of RBP4 in muscle atrophy remains unclear. METHODS: Denervation-induced muscle atrophy model was constructed in wild-type and RBP4 knockout mice. To modify the expression of RBP4, mice were received intramuscular injection of retinol-free RBP4 (apo-RBP4), retinol-bound RBP4 (holo-RBP4) or oral gavage of RBP4 inhibitor A1120. Holo-RBP4-stimulated C2C12 myotubes were treated with siRNAs or specific inhibitors targeting signalling receptor and transporter of retinol 6 (STRA6)/Janus kinase 2 (JAK2)/Signal transducer and activator of transcription 3 (STAT3) pathway. Fat accumulation, myofibre cross-sectional area, myotube diameter and the expression of muscle atrophy markers and myogenesis markers were analysed. RESULTS: The expression levels of RBP4 in skeletal muscles were significantly up-regulated more than 2-fold from 7 days and sustained for 28 days after denervation. Immunofluorescence analysis indicated that increased RBP4 was localized in the infiltrated fatty region in denervated skeletal muscles. Knockout of RBP4 alleviated denervation-induced fatty infiltration and muscle atrophy together with decreased expression of atrophy marker Atrogin-1 and MuRF1 as well as increased expression of myogenesis regulators MyoD and MyoG. By contrast, injection of retinol-bound holo-RBP4 aggregated denervation-induced ectopic fat accumulation and muscle atrophy. Consistently, holo-RBP4 stimulation also had a dose-dependent effect on the reduction of C2C12 myotube diameter and myofibre cross-sectional area, as well as on the increase of Atrogin-1and MuRF1 expression and decrease of MyoD and MyoG expression. Mechanistically, holo-RBP4 treatment increased the expression of its membrane receptor STRA6 (>3-fold) and promoted the phosphorylation of downstream JAK2 and STAT3. Inhibition of STRA6/JAK2/STAT3 pathway either by specific siRNAs or inhibitors could decrease the expression of Atrogin-1 and MuRF1 (>50%) and decrease the expression of MyoD and MyoG (>3-fold) in holo-RBP4-treated C2C12 myotube. RBP4 specific pharmacological antagonist A1120 significantly inhibited the activation of STRA6/JAK2/STAT3 pathway, ameliorated ectopic fat infiltration and protected against denervation-induced muscle atrophy (30% increased myofibre cross-sectional area) in mice. CONCLUSIONS: In conclusion, our data reveal that RBP4 promotes fat infiltration and muscle atrophy through a STRA6-dependent and JAK2/STAT3 pathway-mediated mechanism in denervated skeletal muscle. Our results suggest that lowering RBP4 levels might serve as a promising therapeutic approach for prevention and treatment of muscle atrophy.

A novel predictive model for optimizing diabetes screening in older adults.

INTRODUCTION: The fasting blood glucose test is widely used for diabetes screening. However, it may fail to detect early-stage diabetes characterized by elevated postprandial glucose levels. Hence, we developed and internally validated a nomogram to predict the diabetes risk in older adults with normal fasting glucose levels. MATERIALS AND METHODS: This study enrolled 2,235 older adults, dividing them into a Training Set (n = 1,564) and a Validation Set (n = 671) based on a 7:3 ratio. We employed the least absolute shrinkage and selection operator regression to identify predictors for constructing the nomogram. Calibration and discrimination were employed to assess the nomogram's performance, while its clinical utility was evaluated through decision curve analysis. RESULTS: Nine key variables were identified as significant factors: age, gender, body mass index, fasting blood glucose, triglycerides, alanine aminotransferase, the ratio of alanine aminotransferase to aspartate aminotransferase, blood urea nitrogen, and hemoglobin. The nomogram demonstrated good discrimination, with an area under the receiver operating characteristic curve of 0.824 in the Training Set and 0.809 in the Validation Set. Calibration curves for both sets confirmed the model's accuracy in estimating the actual diabetes risk. Decision curve analysis highlighted the model's clinical utility. CONCLUSIONS: We provided a dynamic nomogram for identifying older adults at risk of diabetes, potentially enhancing the efficiency of diabetes screening in primary healthcare units.

DNA methylation of skeletal muscle function-related secretary factors identifies FGF2 as a potential biomarker for sarcopenia.

BACKGROUND: Sarcopenia is characterized by progressive loss of muscle mass and function due to aging. DNA methylation has been identified to play important roles in the dysfunction of skeletal muscle. The aim of our present study was to explore the whole blood sample-based methylation changes of skeletal muscle function-related factors in patients with sarcopenia. METHODS: The overall DNA methylation levels were analysed by using MethlTarget™ DNA Methylation Analysis platform in a discovery set consistent of 50 sarcopenic older adults (aged ≥65 years) and 50 age- and sex-matched non-sarcopenic individuals. The candidate differentially methylated regions (DMRs) were further validated by Methylation-specific PCR (MSP) in another two independent larger sets and confirmed by pyrosequencing. Receiver operating characteristic (ROC) curve analysis was used to determine the optimum cut-off levels of fibroblast growth factor 2 (FGF2)_30 methylation best predicting sarcopenia and area under the ROC curve (AUC) was measured. The correlation between candidate DMRs and the risk of sarcopenia was investigated by univariate analysis and multivariate logistic regression analysis. RESULTS: Among 1149 cytosine-phosphate-guanine (CpG) sites of 27 skeletal muscle function-related secretary factors, 17 differentially methylated CpG sites and 7 differentially methylated regions (DMRs) were detected between patients with sarcopenia and control subjects in the discovery set. Further methylation-specific PCR identified that methylation of fibroblast growth factor 2 (FGF2)_30 was lower in patients with sarcopenia and the level was decreased as the severity of sarcopenia increased, which was confirmed by pyrosequencing. Correlation analysis demonstrated that the methylation level of FGF2_30 was positively correlated to ASMI (r = 0.372, P < 0.001), grip strength (r = 0.334, P < 0.001), and gait speed (r = 0.411, P < 0.001). ROC curve analysis indicated that the optimal cut-off value of FGF2_30 methylation level that predicted sarcopenia was 0.15 with a sensitivity of 84.6% and a specificity of 70.1% (AUC = 0.807, 95% CI = 0.756-0.858, P < 0.001). Multivariate logistic regression analyses showed that lower FGF2_30 methylation level (<0.15) was significantly associated with increased risk of sarcopenia even after adjustment for potential confounders including age, sex, and BMI (adjusted OR = 9.223, 95% CI: 6.614-12.861, P < 0.001). CONCLUSIONS: Our results suggest that lower FGF2_30 methylation is correlated with the risk and severity of sarcopenia in the older adults, indicating that FGF2 methylation serve as a surrogate biomarker for the screening and evaluation of sarcopenia.

Association of volatile organic compound exposure with metabolic syndrome and its components: a nationwide cross-sectional study.

BACKGROUND: Metabolic syndrome (MetS) is a health issue consisting of multiple metabolic abnormalities. The impact of exposure to volatile organic compounds (VOCs) on MetS and its components remains uncertain. This study aimed to assess the associations of individual urinary metabolites of VOC (mVOCs) and mVOC mixtures with MetS and its components among the general adult population in the United States. METHODS: A total of 5345 participants with eligible data were filtered from the 2011-2020 cycles of the National Health and Nutrition Examination Survey. Multivariate logistic regression models were applied to assess the associations of individual mVOCs with MetS and its components. The least absolute shrinkage and selection operator (LASSO) regression models were constructed to identify more relevant mVOCs. The weight quantile sum regression model was applied to further explore the links between mVOC co-exposure and MetS and its components. RESULTS: The results indicated positive associations between multiple mVOCs and MetS, including CEMA, DHBMA, and HMPMA. CEMA was found to be positively correlated with all components of MetS. HMPMA was associated with elevated triglyceride (TG), reduced high-density lipoprotein, and fasting blood glucose (FBG) impairment; 3HPMA was associated with an elevated risk of high TG and FBG impairment; and DHBMA had positive associations with elevated TG and high blood pressure. The co-exposure of LASSO-selected mVOCs was associated with an increased risk of elevated TG, high blood pressure, and FBG impairment. CONCLUSION: Positive associations of certain individual urinary mVOCs and mVOC mixtures with MetS and its components were observed by utilizing multiple statistical models and large-scale national data. These findings may serve as the theoretical basis for future experimental and mechanistic studies and have important implications for public health.

Urinary caffeine and its metabolites in association with advanced liver fibrosis and liver steatosis: a nationwide cross-sectional study.

Aim: This study used urinary caffeine and its metabolites to evaluate their relationships with liver steatosis and advanced liver fibrosis. Methods: A total of 2068 adult participants with required data were filtered from the 2009-2014 National Health and Nutrition Examination Survey (NHANES) cycles. Non-invasive scores were applied to define liver steatosis and advanced liver fibrosis. Logistic regression models, weighted quantile sum (WQS) regression models, quantile-based g-computation (QG-Comp) models, and restricted cubic spline (RCS) regression models were used to assess the associations of urinary caffeine and its metabolites with liver steatosis and advanced liver fibrosis. A series of additional analyses were conducted to examine the subgroup-specific differences and test the robustness of the observed results. Results: The major caffeine metabolite mixture and most individual caffeine metabolites were found to be negatively associated with the risk of advanced liver fibrosis with subgroup-specific variations. Only 7-MX consistently showed a negative association with liver steatosis in all analyses, while no association was observed between the major caffeine metabolite mixture and liver steatosis. Conclusion: The major caffeine metabolite mixture and most individual urinary caffeine metabolites exhibited inverse associations with advanced liver fibrosis with subgroup differences. Further prospective and experimental studies are urgently needed to verify our results and further identify the possible mechanisms.

Association of AST/ALT (De Ritis) ratio with sarcopenia in a Chinese population of community-dwelling elderly.

Background: The aspartate aminotransferase/alanine aminotransferase (AST/ALT) ratio, also known as De Ritis ratio, has been reportedly associated with malnutrition which plays a crucial role in sarcopenia. The aim of this study was to examine the relationship between AST/ALT ratio and sarcopenia in the Chinese community-dwelling elderly. Methods: A cross-sectional study with 2751 participants (1343 men and 1408 women) aged ≥60 years was performed. Appendicular skeletal muscle mass index (ASMI), grip strength, and gait speed were measured to diagnose sarcopenia according to the latest Asian Working Group for Sarcopenia (AWGS) consensus. The association of AST/ALT ratio with sarcopenia was examined using logistic regression analysis. Results: The prevalence of sarcopenia in the present study was 4.4%. AST/ALT ratio was higher in the sarcopenia group than in the non-sarcopenia group (1.30 ± 0.33 vs. 1.16 ± 0.62, P = 0.010). AST/ALT ratio was negatively correlated with the components of sarcopenia, including ASMI, grip strength, and gait speed. Logistic regression analysis indicated that high AST/ALT ratio (>1.20) was associated with increased risk of sarcopenia even after adjustment for potential confounders (adjusted OR = 2.33, 95%CI = 1.48-3.68, P < 0.001). Stratification analyses indicated that the association of high AST/ALT ratio with high risk of sarcopenia was more significant in males and the elderly with ≥70 years. Conclusions: Our findings demonstrate that high AST/ALT ratio is associated with increased risk of sarcopenia in a Chinese population of community-dwelling elderly.