Identification of novel anti-obesity saponins from the ovary of sea cucumber (Stichopus japonicus).

The potential anti-obesity effects of sea cucumber extract have been reported. However, the individual saponins responsible for these effects are yet to be isolated and characterized. This study aimed to identify the most effective sea cucumber body part for inhibiting lipid accumulation in adipocytes and to elucidate the compounds responsible for this effect using nuclear magnetic resonance (NMR) techniques. Sea cucumber ovary 80 % ethanol extract (SCOE) demonstrated remarkable efficacy in inhibiting adipocyte differentiation compared to other sea cucumber body parts with 50 % or 80 % ethanol extracts. SCOE anti-obesity effect was evaluated in C57BL/6 mice fed a high-fat diet, which revealed significant reductions in body weight, serum lipids, adipose tissue, and liver weight. Using column chromatography, eight saponins were isolated from the SCOE, four of which exhibited potent inhibitory effects on adipocyte differentiation. Of these, three active saponins, holotoxins A, B, and D1, were newly identified. These findings highlight the potential of SCOE and its saponins as effective anti-obesity agents.

A 3 month nutrition and exercise program improved hallux strength among senior daycare center users in Korea: a cluster randomized controlled trial.

Introduction: With a growing aging population, the focus on the health and well-being of older adults, especially in preventing falls, becomes crucial. This 3 month study, initiated in July 2022, aimed to assess the impact of a nutrition and exercise program in senior daycare centers in Chuncheon, South Korea. Methods: A 3 month study, beginning in July 2022, included 204 older adults from 10 senior daycare centers in Chuncheon, South Korea. Randomly assigned to intervention or control groups, the intervention involved nutrition, daily toe exercises, or both. Control centers received interventions post-measurements. Pre- and post-intervention analyses used paired t-tests and multiple linear regression, assessing metrics like toe grip strength for significance. While 204 were initially enrolled, the analysis included 151 participants due to dropouts. Results: Participants, with a mean age of 83.3 years (43.1% aged ≥ 85 years), exhibited mild to moderate cognitive impairment and multiple chronic illnesses. Health data indicated that 37.3% were obese, and the average BMI was 24.0 kg/m2. Both the intervention and control groups showed significant improvements in toe grip strength post-intervention. Specifically, the exercise-only and combined exercise-nutrition groups demonstrated significant differences in hallux strength compared to the control group after adjusting for age and gender. Conclusion: The study showed that a basic nutrition and exercise program increased toe strength in older adults with chronic diseases, including mild cognitive impairments. This intervention holds potential to prevent muscle strength decline and reduce fall risks in older individuals. As the first of its kind in Korean senior daycare centers, it emphasizes the need for future research and standardized programs for senior daycare users.

Erratum: Development of a frailty prevention program including nutrition and exercise interventions for older adults in senior daycare centers in South Korea using a mixed methods research design.

[This corrects the article on p. 372 in vol. 18, PMID: 38854475.].

Association of the dietary inflammatory index with sarcopenic obesity and frailty in older adults.

OBJECTIVES: This study examined whether a higher dietary inflammatory index (DII®) is associated with the risk of sarcopenic obesity (SO) and frailty among Korean older adults. METHODS: A total of 950 participants aged 70-84 years, who completed the baseline nutrition survey of the Korean Frailty and Aging Cohort Study, were included in the analysis. The DII, quantifying the dietary inflammatory potential, was calculated using 23 foods and nutrients as assessed by a 24-h dietary recall. SO was defined as the coexistence of sarcopenia (dual-energy X-ray absorptiometry-measured appendicular skeletal muscle mass index of < 7.0 for males; <5.4 for females) and abdominal obesity (waist circumference of ≥ 90 cm for males; ≥85 cm for females). Frailty status was assessed using the Fried frailty index (range, 0-5), a simple tool for defining frailty that consists of three or more of five frailty items. Multinomial logistic regression models were used to estimate odds ratios (ORs) with 95% confidence intervals (CIs), adjusting for confounders. RESULTS: The prevalence of SO and frailty was 9.8% and 10.8%, respectively. The DII was significantly higher in the frail group (2.7) compared to the robust and SO groups (2.0 vs. 1.8) (P < 0.001). Among nutrients and foods included in the DII, the frail group exhibited lower vitamin E, niacin, vitamin B6, energy, and protein intakes than the robust and SO groups. Multivariable-adjusted OR (95% CI) for frailty versus robust (comparing DII tertile 3 to tertile 1) was 2.3 (1.1-4.8; P-trend = 0.02). However, no significant association was observed between the DII and SO (OR, 1.1; 95% CI, 0.5-2.1; P-trend = 0.6). CONCLUSIONS: A higher DII score was associated with increased odds of frailty but not with SO in Korean older adults, suggesting that proinflammatory diets have a greater impact on frailty than that on SO in the older population.

Secure Triggering Frame-Based Dynamic Power Saving Mechanism against Battery Draining Attack in Wi-Fi-Enabled Sensor Networks.

Wireless local area networks (WLANs) have recently evolved into technologies featuring extremely high throughput and ultra-high reliability. As WLANs are predominantly utilized in Internet of Things (IoT) and Wi-Fi-enabled sensor applications powered by coin cell batteries, these high-efficiency, high-performance technologies often cause significant battery depletion. The introduction of the trigger frame-based uplink transmission method, designed to enhance network throughput, lacks adequate security measures, enabling attackers to manipulate trigger frames. Devices receiving such frames must respond immediately; however, if a device receives a fake trigger frame, it fails to enter sleep mode, continuously sending response signals and thereby increasing power consumption. This problem is specifically acute in next-generation devices that support multi-link operation (MLO), capable of simultaneous transmission and reception across multiple links, rendering them more susceptible to battery draining attacks than conventional single-link devices. To address this, this paper introduces a Secure Triggering Frame-Based Dynamic Power Saving Mechanism (STF-DPSM) specifically designed for multi-link environments. Experimental results indicate that even in a multi-link environment with only two links, the STF-DPSM improves energy efficiency by an average of approximately 55.69% over conventional methods and reduces delay times by an average of approximately 44.7% compared with methods that consistently utilize encryption/decryption and integrity checks.

Helmet wearing and related factors among electric personal mobility device users in Korea.

Using data from the 2022 Korea Community Health Survey (n = 13 320), this study investigated helmet use and related factors among Korean adults using personal mobility devices, without distinguishing between private and hired users. Among mobility device users, 32.1% responded that they always wore a helmet. The proportion of helmet use was 35.2% among men, 25.8% among women, 29.2% among those aged 19-44 years, 42.3% among those aged 45-64 years and 26.6% among those aged 65 years or older. Furthermore, those who drank less frequently and were physically active were more likely to wear helmets. Moreover, people who always wore a seat belt when driving a car or sitting in the rear seat and people who always wore a helmet when riding a motorcycle were more likely to wear a helmet while using electric personal mobility devices. Approximately one-third of users always wore a helmet. The helmet-wearing rate was related to general characteristics such as gender and education level, and to safety behaviors such as wearing a seat belt when driving a car, sitting in the rear seat of a car, or when riding a motorcycle. In addition to considering personal characteristics investigated in this study, the helmet-wearing rate should be improved through policies or systems at the national or regional levels.

Daily Supplementation with Bifidobacterium longum KACC91563 Alleviates Allergic Contact Dermatitis in an Animal Model.

Allergic contact dermatitis (ACD) is the most common chronic inflammatory skin disease (or immune-mediated disease), causing disruption to our psychological condition and life quality. In this study, the therapeutic properties of probiotic Bifidobacterium longum (B. longum) was investigated by using an ACD-induced animal model. For ACD induction, BALB/c mice ear and dorsal skin were sensitized with 240 µL of 1% (w/v) 2,4-dinitrochlorobenzene (DNCB) twice (3-day intervals). After a week of the first induction, the mice were re-sensitized by painting on their dorsal skin and ear with 0.4% (w/v) DNCB for a further three times (once per week). Before the ACD induction of 2 weeks and throughout the trial period, the BALB/c mice were supplemented daily with 1 mL of 1.0 × 109 CFU or 5.0 × 109 CFU B. longum using an intragastric gavage method. The ACD-induced mice without B. longum supplementation were used as a control. Results show that B. longum supplementation significantly alleviated ACD symptoms (e.g., ear swelling, epidermal damage) and immune response (e.g., reduced immune cell recruitment, serum IgE level, and cytokine production). The therapeutic efficiency of B. longum increased as the supplementation dose increased. Thus, daily supplementation with 5.0 × 109 CFU probiotic B. longum could be an effective method for the prevention and treatment of ACD.

Medium-Enhanced cc[over ¯] Radiation.

We show that the same QCD formalism that accounts for the suppression of high-p_{T} hadron and jet spectra in heavy-ion collisions predicts medium-enhanced production of cc[over ¯] pairs in jets. We demonstrate that this phenomenon, which cannot be accessed by traditional jet-quenching observables, can be directly observed using D^{0}D[over ¯]^{0}-tagged jets in nuclear collisions.

Efficacy of Empirical 131 I Radioiodine Therapy in Well-Differentiated Thyroid Carcinoma Patients With Thyroglobulin-Elevated Negative Iodine Scintigraphy Syndrome : A Systematic Review and Meta-analysis.

OBJECTIVES: This study aimed to perform a systematic review and meta-analysis on the efficacy of empirical high-dose radioiodine therapy in treating differentiated thyroid cancer patients with thyroglobulin (Tg)-elevated negative iodine scintigraphy (TENIS) syndrome. METHODS: We searched PubMed, EMBASE, and the Cochrane Library to identify relevant studies published until April 2022. This systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist and registered in an international prospective register of systematic reviews (PROSPERO). Meta-analyses of proportions and odds ratios were performed to assess the beneficial effect of empirical high-dose radioiodine therapy in patients with TENIS syndrome. Subgroup analysis was also performed according to the presence of micrometastasis or macrometastasis. RESULTS: We identified 14 studies including 690 patients who received empirical high-dose radioiodine therapy for TENIS syndrome. Those who had micrometastasis exhibited additional lesions not previously observed on diagnostic whole-body scan (prop = 0.64, 95% confidence interval [CI], 0.51-0.77) and had reduced serum Tg levels (prop = 0.69; 95% CI, 0.52-0.84) after empirical radioiodine treatment. No such findings were observed among patients with macrometastasis. Moreover, we found that the empirical radioiodine treatment group had lower serum Tg levels than did controls (odds ratio = 0.27; 95% CI, 0.09-0.87), which suggests a lower risk of disease progression. CONCLUSIONS: Our findings indicate that empirical high-dose radioiodine therapy promoted beneficial effects and could be recommended for patients with TENIS syndrome, especially those with micrometastasis.

Association between dietary carotenoid intake and breast cancer risk: a case-control study among Korean women.

The association between dietary carotenoids and breast cancer (BC) risks were inconsistent. Therefore, this study investigated the association between dietary carotenoid and BC risks among Korean women. We recruited participants from the National Cancer Centre of Korea. Odds ratios and 95% confidence intervals were calculated with a logistic regression model. There was an inverse association between dietary carotenoid subclasses and BC risks; in particular, a higher intake of ß-carotene and lutein/zeaxanthin was associated with reduced BC risks. After subgroup analysis with estrogen receptor (ER)/progesterone receptor (PR) status, there was similar trend among ER-/PR- women. We further investigated which foods contribute to the carotenoid intake. A higher intake of radish leaves, kale, and bracken was associated with lowered BC risks. Accordingly, dietary carotenoid, particularly ß-carotene and lutein/zeaxanthin, appears to be associated with a lower risk of BC among Korean women.

Development of a frailty prevention program including nutrition and exercise interventions for older adults in senior daycare centers in South Korea using a mixed methods research design.

BACKGROUND/OBJECTIVES: The growing aging population has led to an increased utilization of senior daycare centers. This study was conducted to design a program to enhance the health of older adults in senior daycare centers in Chuncheon City, South Korea. SUBJECTS/METHODS: The study explored the health conditions and dietary patterns of older adults in senior daycare centers. Participants included staff and older adults from senior daycare centers in Chuncheon City. A mixed methods research design was used to obtain both qualitative and quantitative data. Qualitative insights were obtained through in-depth interviews with 26 staff members and older adults, coupled with observations made at 10 senior daycare centers. The quantitative component comprised structured questionnaires and physical measurements of 204 older adults at these centers. RESULTS: Many of the older adults relied on the meals provided by the center due to their limited cooking abilities. Dental health issues and dysphagia were common. Interviews highlighted the budgetary constraints of the centers in providing wholesome meals and the need for government support to alleviate meal expenses and enhance quality. A structured survey of older adults showed that the average age was 83.3 yrs, with an average of 2 chronic conditions per participant. Frailty analysis of the participants revealed that 56.2% were prefrail and 32.0% were frail. Almost half of the participants (47.0%) used dentures. Based on these findings, a preventive intervention program was proposed, addressing the specific needs and challenges of older adults while promoting overall well-being and preventing frailty. CONCLUSION: Tailored health promotion strategies are crucial in senior daycare centers. Recommended interventions include staff nutrition education, improved dietary plans, and cost-effective strength training programs. These interventions aim to reduce frailty and enhance the quality of life of older adults in the community via interventions in daycare centers.

Changes in food sufficiency among Korean adults in urban and rural areas during the COVID-19 pandemic: an analysis of the 7th and 8th Korea National Health and Nutrition Examination Survey.

OBJECTIVES: Understanding changes in food sufficiency within various demographic groups during emergency situations, such as the global coronavirus disease 2019 (COVID-19) pandemic, is crucial in formulating public health policies for future preparedness. This study investigated potential differences between urban and rural residents in food sufficiency trends during the COVID-19 pandemic and examined how these changes varied according to socio-demographic factors. METHODS: This cross-sectional study analyzed data from 19,724 adults aged 20 years and older, utilizing information from the 7th-8th Korea National Health and Nutrition Examination Survey (2018-2021). RESULTS: In urban areas, across all subpopulations, food sufficiency improved significantly during the COVID-19 period relative to pre-pandemic levels (p<0.001). However, in rural regions, a significant increase in food sufficiency during the COVID-19 era was observed only among female, with an odds ratio of 1.42 (95% confidence interval, 1.06 to 1.89). Nevertheless, no significant interaction terms were found between region and various socio-demographic factors regarding changes in food sufficiency during the COVID-19 period. CONCLUSIONS: During the COVID-19 pandemic, food sufficiency among urban residents improved compared to the pre-pandemic era, whereas their rural counterparts saw no such improvement. Additionally, no significant interaction was detected between urban versus rural areas and changes in food sufficiency during the COVID-19 period. These findings indicate the need for targeted food policies to prepare for potential future pandemics, particularly in rural areas, where food sufficiency did not improve.

SERS-based microdevices for use as in vitro diagnostic biosensors.

Advances in surface-enhanced Raman scattering (SERS) detection have helped to overcome the limitations of traditional in vitro diagnostic methods, such as fluorescence and chemiluminescence, owing to its high sensitivity and multiplex detection capability. However, for the implementation of SERS detection technology in disease diagnosis, a SERS-based assay platform capable of analyzing clinical samples is essential. Moreover, infectious diseases like COVID-19 require the development of point-of-care (POC) diagnostic technologies that can rapidly and accurately determine infection status. As an effective assay platform, SERS-based bioassays utilize SERS nanotags labeled with protein or DNA receptors on Au or Ag nanoparticles, serving as highly sensitive optical probes. Additionally, a microdevice is necessary as an interface between the target biomolecules and SERS nanotags. This review aims to introduce various microdevices developed for SERS detection, available for POC diagnostics, including LFA strips, microfluidic chips, and microarray chips. Furthermore, the article presents research findings reported in the last 20 years for the SERS-based bioassay of various diseases, such as cancer, cardiovascular diseases, and infectious diseases. Finally, the prospects of SERS bioassays are discussed concerning the integration of SERS-based microdevices and portable Raman readers into POC systems, along with the utilization of artificial intelligence technology.

Associations between short-term exposure to air pollution and thyroid function in a representative sample of the Korean population.

BACKGROUND: Disruption of thyroid function can profoundly affect various organ systems. However, studies on the association between air pollution and thyroid function are relatively scarce and most studies have focused on the long-term effects of air pollution among pregnant women. OBJECTIVES: This study aimed to explore the associations between short-term exposure to air pollution and thyroid function in the general population. METHODS: Data from the Korea National Health and Nutrition Examination Survey (2013-2015) were analyzed (n = 5,626). Air pollution concentrations in residential addresses were estimated using Community Multiscale Air Quality models. The moving averages of air pollution over 7 days were set as exposure variables through exploratory analyses. Linear regression and quantile g-computation models were constructed to assess the effects of individual air pollutants and air pollution mixture, respectively. RESULTS: A 10-ppb increase in NO2 (18.8-µg/m3 increase) and CO (11.5-µg/m3 increase) was associated with 2.43% [95% confidence interval (CI): 0.42, 4.48] and 0.19% (95% CI: 0.01, 0.36) higher thyroid-stimulating hormone (TSH) levels, respectively. A 10-µg/m3 increase in PM2.5 and a 10-ppb increase in O3 (19.6-µg/m3 increment) were associated with 0.87% (95% CI: 1.47, -0.27) and 0.59% (95% CI: 1.18, -0.001) lower free thyroxine (fT4) levels, respectively. A simultaneous quartile increase in PM2.5, NO2, O3, and CO levels was associated with lower fT4 but not TSH levels. CONCLUSIONS: As the subtle changes in thyroid function can affect various organ systems, the present results may have substantial public health implications despite the relatively modest effect sizes. Because this was a cross-sectional study, it is necessary to conduct further experimental or repeated-measures studies to consolidate the current results.

Surface and Bulk Stabilization of Silicon Anodes with Mixed-Multivalent Additives: Ca(TFSI)2 and Mg(TFSI)2.

Silicon is drawing attention as an emerging anode material for the next generation of lithium-ion batteries due to its higher capacity compared with commercial graphite. However, silicon anions formed during lithiation are highly reactive with binder and electrolyte components, creating an unstable SEI layer and limiting the calendar life of silicon anodes. The reactivity of lithium silicide and the formation of an unstable SEI layer are mitigated by utilizing a mixture of Ca and Mg multivalent cations as an electrolyte additive for Si anodes to improve their calendar life. The effect of mixed salts on the bulk and surface of the silicon anodes was studied by multiple structural characterization techniques. Ca and Mg ions in the electrolyte formed relatively thermodynamically stable quaternary Li-Ca-Mg-Si Zintl phases in an in situ fashion and a more stable and denser SEI layer on the Si particles. These in turn protect silicon particles against side reactions with electrolytes in a coin cell. The full cell with the mixed cation electrolyte demonstrates enhanced calendar life performance with lower measured current and current leakage in comparison to that of the baseline electrolyte due to reduced side reactions. Electron microscopy, HR-XRD, and solid-state NMR results showed that electrodes with mixed cations tended to have less cracking on the electrode surface, and the presence of mixed cations enhances cation migration and formation of quaternary Zintl phases stabilizing the bulk and forming a more stable SEI in comparison to baseline electrolyte and electrolyte with single multivalent cations.

Microfluidics for disease diagnostics based on surface-enhanced raman scattering detection.

This review reports diverse microfluidic systems utilizing surface-enhanced Raman scattering (SERS) detection for disease diagnosis. Integrating SERS detection technology, providing high-sensitivity detection, and microfluidic technology for manipulating small liquid samples in microdevices has expanded the analytical capabilities previously confined to larger settings. This study explores the principles and uses of various SERS-based microfluidic devices developed over the last two decades. Specifically, we investigate the operational principles of documented SERS-based microfluidic devices, including continuous-flow channels, microarray-embedded microfluidic channels, droplet microfluidic channels, digital droplet channels, and gradient microfluidic channels. We also examine their applications in biomedical diagnostics. In conclusion, we summarize the areas requiring further development to translate these SERS-based microfluidic technologies into practical applications in clinical diagnostics.

Rhizobial oxidized 3-hydroxylbutanoyl glycan-based gelatin hydrogels with enhanced physiochemical properties for pH-responsive drug delivery.

Rhizobial exopolysaccharide (EPS) is an acidic polysaccharide involved in nitrogen fixation-related signal transduction in the rhizosphere, serving as a structural support for biofilms, and protecting against various external environmental stresses. Rhizobial EPS as a hydrogel biomaterial was used for a pH-responsive drug delivery system combing with gelatins. Pure gelatin (GA) hydrogels have limited practical applications due to their poor mechanical strength and poor thermal stability. We developed new GA hydrogels using oxidized 3-hydroxylbutanoyl glycan (OHbG) as a polymer cross-linking agent to overcome these limitations. OHbG was synthesized from sodium periodate oxidation of 3-hydroxylbutanoyl glycan directly isolated from Rhizobium leguminosarum bv. viciae VF39. The newly fabricated OHbG/GA hydrogels exhibited 21-fold higher compressive stress and 4.7-fold higher storage modulus (G') than GA at the same strain. This result suggested that OHbG provided mechanical improvement. In addition, these OHbG/GA hydrogels showed effective pH-controlled drug release for 5-fluorouracil, self-healable, and self-antioxidant capacity by uronic acids of OHbG. Cell viability tests using HEK-293 cells in vitro also showed that the OHbG/GA hydrogels were non-toxic. This suggests that the new OHbG/GA hydrogels can be used as a potentially novel biomaterial for drug delivery based on its self-healing ability, antioxidant capacity, and pH-responsive drug delivery.

Resistivity detection of perfluoroalkyl substances with fluorous polyaniline in an electrical lateral flow sensor.

Perfluoroalkyl substances (PFAS), known as "forever chemicals," are a growing concern in the sphere of human and environmental health. In response, rapid, reproducible, and inexpensive methods for PFAS detection in the environment and home water supplies are needed. We have developed a simple and inexpensive perfluoroalkyl acid detection method based on an electrically read lateral flow assay (e-LFA). Our method employs a fluorous surfactant formulation with undoped polyaniline (F-PANI) fabricated to create test lines for the lateral flow assay. In perfluoroalkyl acid sensing studies, an increase in conductivity of the F-PANI film is caused by acidification and doping of PANI. A conductivity enhancement by 104-fold can be produced by this method, and we demonstrate a limit of detection for perfluorooctanoic acid (PFOA) of 400 ppt and perfluorobutanoic acid of 200 ppt. This method for PFOA detection can be expanded for wide-scale environmental and at-home water testing.

Factors Associated with Sugar-Sweetened Beverage Intake Among Young Children - United States, 2021.

Introduction: Because limited data exist about factors related to sugar-sweetened beverage (SSB) intake among younger children, we investigated factors associated with SSB intake among US children aged 1 to 5 years. Methods: We examined SSB intake (0, 1-3, or ≥4 times/week) by using data from the 2021 National Survey of Children's Health. We performed a multinomial logistic regression to calculate adjusted odds ratios (aORs) for select sociodemographic and household factors associated with moderate (1-3 times/week) and high (≥4 times/week) SSB intake. Results: Overall, 36% of children consumed SSBs 1 to 3 times/week and 21% consumed 4 or more times/week. Both moderate and high SSB intake were associated with child's age, child's race and ethnicity, highest caregiver education level, household income, primary household language, and frequency of family meals. For example, children who lived in households with caregiver education level of high school graduate or less were significantly more likely to have moderate (aOR, 2.06) and high (aOR, 2.81) SSB intake than those who lived in households with caregiver education level of college degree or higher. High SSB intake was also associated with marginal household food sufficiency, nonmetropolitan statistical area status, and receipt of government food benefits. Conclusion: Several sociodemographic and household factors were significantly associated with SSB intake among children aged 1 to 5 years. Public health initiatives designed to address SSB intake among young children in various settings including pediatric health care, early care and education, and the child's home could consider key associated factors.

Level of happiness and its association with food literacy among Seoul citizens: results from Seoul Food Survey 2021.

BACKGROUND/OBJECTIVES: Happiness is an important factor in life, and food literacy (FL) has been emphasized as a core concept for a happy and healthy life. This study examined the level of happiness of Seoul citizens according to their sociodemographic factors and their association with FL. SUBJECTS/METHODS: This study used the data from the Seoul Food Survey, a cross-sectional study conducted on 4,039 Seoul citizens from September to October 2021. FL was measured using a validated questionnaire consisting of 33 items from 3 sub-domains: 14 items in the nutrition and safety domain, 8 items in the cultural and relational domain, and 11 items in the socio-ecological domain. Statistical analysis involved descriptive statistics and multivariate regression analysis. RESULTS: Various sociodemographic factors, such as household income, subjective health status, and food insecurity, were found to be associated with the level of happiness. The level of FL was also associated with the happiness scores. After adjusting for variables associated with happiness, the participants with the highest quartile FL scores were 7.32 times more likely to respond that they were happy than those with the lowest FL score. Three FL domains and total FL showed linear increases in overall happiness after controlling for subjective health status and sociodemographic factors (P < 0.001). CONCLUSIONS: After adjusting for the related covariates, higher levels of FL were associated with higher scores in happiness. Based on this study, it would be meaningful to evaluate ways to intervene in FL to improve the level of happiness among the general population.