Ultrahigh-energy photons up to 1.4 petaelectronvolts from 12 γ-ray Galactic sources.

The extension of the cosmic-ray spectrum beyond 1 petaelectronvolt (PeV; 1015 electronvolts) indicates the existence of the so-called PeVatrons-cosmic-ray factories that accelerate particles to PeV energies. We need to locate and identify such objects to find the origin of Galactic cosmic rays1. The principal signature of both electron and proton PeVatrons is ultrahigh-energy (exceeding 100 TeV) γ radiation. Evidence of the presence of a proton PeVatron has been found in the Galactic Centre, according to the detection of a hard-spectrum radiation extending to 0.04 PeV (ref. 2). Although γ-rays with energies slightly higher than 0.1 PeV have been reported from a few objects in the Galactic plane3-6, unbiased identification and in-depth exploration of PeVatrons requires detection of γ-rays with energies well above 0.1 PeV. Here we report the detection of more than 530 photons at energies above 100 teraelectronvolts and up to 1.4 PeV from 12 ultrahigh-energy γ-ray sources with a statistical significance greater than seven standard deviations. Despite having several potential counterparts in their proximity, including pulsar wind nebulae, supernova remnants and star-forming regions, the PeVatrons responsible for the ultrahigh-energy γ-rays have not yet been firmly localized and identified (except for the Crab Nebula), leaving open the origin of these extreme accelerators.

Stringent Tests of Lorentz Invariance Violation from LHAASO Observations of GRB 221009A.

On 9 October 2022, the Large High Altitude Air Shower Observatory (LHAASO) reported the observation of the very early TeV afterglow of the brightest-of-all-time gamma-ray burst 221009A, recording the highest photon statistics in the TeV band ever obtained from a gamma-ray burst. We use this unique observation to place stringent constraints on the energy dependence of the speed of light in vacuum, a manifestation of Lorentz invariance violation (LIV) predicted by some quantum gravity (QG) theories. Our results show that the 95% confidence level lower limits on the QG energy scales are E_{QG,1}>10 times the Planck energy E_{Pl} for the linear LIV effect, and E_{QG,2}>6×10^{-8}E_{Pl} for the quadratic LIV effect. Our limits on the quadratic LIV case improve previous best bounds by factors of 5-7.

Constraints on Ultraheavy Dark Matter Properties from Dwarf Spheroidal Galaxies with LHAASO Observations.

In this Letter we try to search for signals generated by ultraheavy dark matter at the Large High Altitude Air Shower Observatory (LHAASO) data. We look for possible γ rays by dark matter annihilation or decay from 16 dwarf spheroidal galaxies in the field of view of the LHAASO. Dwarf spheroidal galaxies are among the most promising targets for indirect detection of dark matter that have low fluxes of astrophysical γ-ray background while having large amount of dark matter. By analyzing more than 700 days of observational data at LHAASO, no significant dark matter signal from 1 TeV to 1 EeV is detected. Accordingly we derive the most stringent constraints on the ultraheavy dark matter annihilation cross section up to EeV. The constraints on the lifetime of dark matter in decay mode are also derived.

Measurements of All-Particle Energy Spectrum and Mean Logarithmic Mass of Cosmic Rays from 0.3 to 30 PeV with LHAASO-KM2A.

We present the measurements of all-particle energy spectrum and mean logarithmic mass of cosmic rays in the energy range of 0.3-30 PeV using data collected from LHAASO-KM2A between September 2021 and December 2022, which is based on a nearly composition-independent energy reconstruction method, achieving unprecedented accuracy. Our analysis reveals the position of the knee at 3.67±0.05±0.15 PeV. Below the knee, the spectral index is found to be -2.7413±0.0004±0.0050, while above the knee, it is -3.128±0.005±0.027, with the sharpness of the transition measured with a statistical error of 2%. The mean logarithmic mass of cosmic rays is almost heavier than helium in the whole measured energy range. It decreases from 1.7 at 0.3 PeV to 1.3 at 3 PeV, representing a 24% decline following a power law with an index of -0.1200±0.0003±0.0341. This is equivalent to an increase in abundance of light components. Above the knee, the mean logarithmic mass exhibits a power law trend towards heavier components, which is reversal to the behavior observed in the all-particle energy spectrum. Additionally, the knee position and the change in power-law index are approximately the same. These findings suggest that the knee observed in the all-particle spectrum corresponds to the knee of the light component, rather than the medium-heavy components.

Measurement of Ultra-High-Energy Diffuse Gamma-Ray Emission of the Galactic Plane from 10 TeV to 1 PeV with LHAASO-KM2A.

The diffuse Galactic γ-ray emission, mainly produced via interactions between cosmic rays and the interstellar medium and/or radiation field, is a very important probe of the distribution, propagation, and interaction of cosmic rays in the Milky Way. In this Letter, we report the measurements of diffuse γ rays from the Galactic plane between 10 TeV and 1 PeV energies, with the square kilometer array of the Large High Altitude Air Shower Observatory (LHAASO). Diffuse emissions from the inner (15°10 TeV). The energy spectrum in the inner Galaxy regions can be described by a power-law function with an index of -2.99±0.04, which is different from the curved spectrum as expected from hadronic interactions between locally measured cosmic rays and the line-of-sight integrated gas content. Furthermore, the measured flux is higher by a factor of ∼3 than the prediction. A similar spectrum with an index of -2.99±0.07 is found in the outer Galaxy region, and the absolute flux for 10≲E≲60 TeV is again higher than the prediction for hadronic cosmic ray interactions. The latitude distributions of the diffuse emission are consistent with the gas distribution, while the longitude distributions show clear deviation from the gas distribution. The LHAASO measurements imply that either additional emission sources exist or cosmic ray intensities have spatial variations.

Constraints on Heavy Decaying Dark Matter from 570 Days of LHAASO Observations.

The kilometer square array (KM2A) of the large high altitude air shower observatory (LHAASO) aims at surveying the northern γ-ray sky at energies above 10 TeV with unprecedented sensitivity. γ-ray observations have long been one of the most powerful tools for dark matter searches, as, e.g., high-energy γ rays could be produced by the decays of heavy dark matter particles. In this Letter, we present the first dark matter analysis with LHAASO-KM2A, using the first 340 days of data from 1/2-KM2A and 230 days of data from 3/4-KM2A. Several regions of interest are used to search for a signal and account for the residual cosmic-ray background after γ/hadron separation. We find no excess of dark matter signals, and thus place some of the strongest γ-ray constraints on the lifetime of heavy dark matter particles with mass between 10^{5} and 10^{9} GeV. Our results with LHAASO are robust, and have important implications for dark matter interpretations of the diffuse astrophysical high-energy neutrino emission.

Exploring Lorentz Invariance Violation from Ultrahigh-Energy γ Rays Observed by LHAASO.

Recently, the LHAASO Collaboration published the detection of 12 ultrahigh-energy γ-ray sources above 100 TeV, with the highest energy photon reaching 1.4 PeV. The first detection of PeV γ rays from astrophysical sources may provide a very sensitive probe of the effect of the Lorentz invariance violation (LIV), which results in decay of high-energy γ rays in the superluminal scenario and hence a sharp cutoff of the energy spectrum. Two highest energy sources are studied in this work. No signature of the existence of the LIV is found in their energy spectra, and the lower limits on the LIV energy scale are derived. Our results show that the first-order LIV energy scale should be higher than about 10^{5} times the Planck scale M_{Pl} and that the second-order LIV scale is >10^{-3}M_{Pl}. Both limits improve by at least one order of magnitude the previous results.

First Detection of sub-PeV Diffuse Gamma Rays from the Galactic Disk: Evidence for Ubiquitous Galactic Cosmic Rays beyond PeV Energies.

We report, for the first time, the long-awaited detection of diffuse gamma rays with energies between 100 TeV and 1 PeV in the Galactic disk. Particularly, all gamma rays above 398 TeV are observed apart from known TeV gamma-ray sources and compatible with expectations from the hadronic emission scenario in which gamma rays originate from the decay of π^{0}'s produced through the interaction of protons with the interstellar medium in the Galaxy. This is strong evidence that cosmic rays are accelerated beyond PeV energies in our Galaxy and spread over the Galactic disk.

Gamma-Ray Observation of the Cygnus Region in the 100-TeV Energy Region.

We report observations of gamma-ray emissions with energies in the 100-TeV energy region from the Cygnus region in our Galaxy. Two sources are significantly detected in the directions of the Cygnus OB1 and OB2 associations. Based on their positional coincidences, we associate one with a pulsar PSR J2032+4127 and the other mainly with a pulsar wind nebula PWN G75.2+0.1, with the pulsar moving away from its original birthplace situated around the centroid of the observed gamma-ray emission. This work would stimulate further studies of particle acceleration mechanisms at these gamma-ray sources.

Extended Very-High-Energy Gamma-Ray Emission Surrounding PSR J0622+3749 Observed by LHAASO-KM2A.

We report the discovery of an extended very-high-energy (VHE) gamma-ray source around the location of the middle-aged (207.8 kyr) pulsar PSR J0622+3749 with the Large High-Altitude Air Shower Observatory (LHAASO). The source is detected with a significance of 8.2σ for E>25 TeV assuming a Gaussian template. The best-fit location is (right ascension, declination) =(95.47°±0.11°,37.92°±0.09°), and the extension is 0.40°±0.07°. The energy spectrum can be described by a power-law spectrum with an index of -2.92±0.17_{stat}±0.02_{sys}. No clear extended multiwavelength counterpart of the LHAASO source has been found from the radio to sub-TeV bands. The LHAASO observations are consistent with the scenario that VHE electrons escaped from the pulsar, diffused in the interstellar medium, and scattered the interstellar radiation field. If interpreted as the pulsar halo scenario, the diffusion coefficient, inferred for electrons with median energies of ∼160 TeV, is consistent with those obtained from the extended halos around Geminga and Monogem and much smaller than that derived from cosmic ray secondaries. The LHAASO discovery of this source thus likely enriches the class of so-called pulsar halos and confirms that high-energy particles generally diffuse very slowly in the disturbed medium around pulsars.

First Detection of Photons with Energy beyond 100 TeV from an Astrophysical Source.

We report on the highest energy photons from the Crab Nebula observed by the Tibet air shower array with the underground water-Cherenkov-type muon detector array. Based on the criterion of a muon number measured in an air shower, we successfully suppress 99.92% of the cosmic-ray background events with energies E>100 TeV. As a result, we observed 24 photonlike events with E>100 TeV against 5.5 background events, which corresponds to a 5.6σ statistical significance. This is the first detection of photons with E>100 TeV from an astrophysical source.

Evaluation of the Interplanetary Magnetic Field Strength Using the Cosmic-Ray Shadow of the Sun.

We analyze the Sun's shadow observed with the Tibet-III air shower array and find that the shadow's center deviates northward (southward) from the optical solar disk center in the "away" ("toward") interplanetary magnetic field (IMF) sector. By comparing with numerical simulations based on the solar magnetic field model, we find that the average IMF strength in the away (toward) sector is 1.54±0.21_{stat}±0.20_{syst} (1.62±0.15_{stat}±0.22_{syst}) times larger than the model prediction. These demonstrate that the observed Sun's shadow is a useful tool for the quantitative evaluation of the average solar magnetic field.

Analysis of metabolic profiles of generalized aggressive periodontitis.

BACKGROUND AND OBJECTIVE: The specific pathogenesis of generalized aggressive periodontitis (GAgP) has not yet been clarified, and few studies have focused on the association between GAgP and metabolomics. To elucidate the roles of metabolic profiles in the status of GAgP, this study aimed to identify the differential metabolic profiles between patients with GAgP and healthy controls using an untargeted metabolomic profiling method. MATERIAL AND METHODS: Serum and gingival crevicular fluid samples were collected from healthy controls (n = 20) and patients with GAgP (n = 20) in this cross-sectional study. The relative levels of biomarkers in the samples were measured by gas chromatography-mass spectrometry. Principal components analysis and orthogonal partial least-squares discriminant analysis were used for statistical analysis. Metabolites were analysed qualitatively using the FiehnLib and NIST databases. Full-mouth probing depth and clinical attachment loss were recorded as indexes of periodontal disease. RESULTS: A total of 349 metabolites were qualitatively detected in the gingival crevicular fluid samples, and 200 metabolites were detected in the serum samples. Compared with healthy controls, patients with GAgP showed significant increases in serum urea and allo-inositol levels. In contrast, glutathione, 2,5-dihydroxybenzaldehyde, adipic acid and 2-deoxyguanosine levels were decreased in patients with GAgP. In the gingival crevicular fluid samples, noradrenaline, uridine, α-tocopherol, dehydroascorbic acid, xanthine, galactose, glucose-1-phosphate and ribulose-5-phosphate levels were increased in patients with GAgP, while thymidine, glutathione and ribose-5-phosphate levels were decreased. CONCLUSION: The metabolomics analysis by gas chromatography-mass spectrometry is an effective and minimally non-invasive way to differentiate the metabolites characteristic of patients with GAgP. Both serum and gingival crevicular fluid metabolomics are significantly different between patients with GAgP and healthy controls. These metabolic profiles have great potential in detecting GAgP and helping to understand its underlying mechanisms.

Risk of epilepsy in surgical patients undergoing general or neuraxial anaesthesia.

Limited information is available on the risks of epilepsy after surgery in patients receiving general or neuraxial anaesthesia. Using Taiwan's National Health Insurance Research Database, we identified 1,478,977 patients aged ≥ 20 years who underwent surgery (required general or neuraxial anaesthesia with hospitalisation for more than one day) between 2004 and 2011. We selected 235,066 patients with general anaesthesia and 235,066 patients with neuraxial anaesthesia using a frequency-matching procedure for age and sex. We did not study those with co-existing epilepsy-related risk factors. The adjusted rate ratios (RRs) and 95% confidence intervals (CIs) of newly diagnosed epilepsy 1 year after surgery associated with general anaesthesia were analysed in the multivariate Poisson regression model. The one-year incidence of postoperative epilepsy for patients with general anaesthesia and neuraxial anaesthesia were 0.41 and 0.32 per 1000 persons, respectively, and the corresponding RR was 1.27 (95%CI 1.15-1.41). The association between general anaesthesia and postoperative epilepsy was significant in men (RR = 1.22; 95%CI 1.06-1.40), women (RR = 1.33; 95%CI 1.15-1.55) and 20-39-year-old patients. The risk of postoperative epilepsy increased in patients with general anaesthesia who had co-existing medical conditions and postoperative complications.

[Clinical observation of postprandial hypotension in patients with hypertensive and coronary heart disease].

Objective: To explore the prevalence and clinical characteristics of postprandial hypotension(PPH) in patients with essential hypertension and coronary heart disease. Methods: A total of 197 patients with essential hypertension and coronary heart disease, who had been treated in the First Department of Cardiology of the Second Hospital of Hebei Medical University from December, 2013 to December, 2014 were included. The patients' blood pressure before breakfast, lunch and dinner and 30, 60, 90, 120 minutes after the meal were monitored. Subjects were classified into PPH group (n=37) and non-PPH group (NPPH, n=160) according to postprandial decrease in systolic blood pressure, to explore the clinical characteristics and related factors and the major adverse cardiac and cerebral vascular events of PPH. Results: Among 197 patients, 37 cases (18.8%) showed at least once postprandial decline in systolic blood pressure greater than and equal to 20 mmHg. The incidence of PPH after breakfast and dinner were higher than lunch (P<0.05). There was no significant difference in the incidence of PPH among different age groups, among patients accompanied with different diseases, and among patients with different dining position (all P>0.05). According to the baseline systolic blood pressure, patients can be divided into 4 groups(<120 mmHg, 120-129 mmHg, 130-139 mmHg, >140 mmHg), the higher the level of the baseline systolic blood pressure was, the higher the incidence of PPH was. And the incidence of major adverse cardiac and cerebral vascular events in patients during hospitalization were increased by PPH. Conclusions: The prevalence of PPH in the patients with essential hypertension and coronary heart disease is 18.8%. The incidence of PPH after breakfast and dinner is higher than lunch. The baseline systolic blood pressure is considered to be the risk factor of PPH. And PPH could lead to an increase of the incidence of major adverse cardiac and cerebral vascular events.

Risk and outcomes of fracture in peripheral arterial disease patients: two nationwide cohort studies.

Using national insurance claims data of Taiwan, we found that patients with peripheral arterial disease (PAD) had increased risk of fracture during the follow-up period of 2000-2013. History of PAD was also associated with adverse outcomes in hospitalized fracture patients. Prevention strategies were needed in this susceptible population. INTRODUCTION: Limited information was available on the association between PAD and fracture. The purpose of this study is to evaluate fracture risk and post-fracture outcomes in patients with PAD. METHODS: We identified 6647 adults aged ≥ 20 years with newly diagnosed PAD using the Taiwan National Health Insurance Research Database in 2000-2004. Comparison cohort consisted of 26,588 adults without PAD randomly selected with frequency matching in age and sex. Events of fracture were identified during the follow-up period from January 1, 2000 until December 31, 2013, to evaluate adjusted hazard ratios (HR) and 95% confidence interval (CI) of fracture associated with PAD. Another nested cohort study of 799,463 hospitalized fracture patients analyzed adjusted odds ratios (ORs) and 95% CIs of adverse events after fracture among patients with and without PAD in 2004-2013. RESULTS: Incidences of fracture in people with and without PAD were 22.1 and 15.5 per 1000 person-years, respectively (P < .0001). Compared with control, the adjusted HR of fracture was 1.59 (95% CI, 1.48-1.69) for PAD patients. In the nested cohort study, patients with PAD had higher post-fracture mortality (OR = 1.16; 95% CI, 1.09-1.25) and various complications. PAD patients also had comparatively higher medical expenditure (2691 vs. 2232 USD, P < .0001) and longer hospital stay (10.6 vs. 9.0 days, P < 0.0001) during fracture admission. CONCLUSIONS: Increased risk of fracture and post-fracture adverse outcomes were associated with PAD. This susceptible population needs care to prevent fracture and to minimize adverse outcomes after it occurs.

Birth month and risk of atopic dermatitis: a nationwide population-based study.

BACKGROUND: An individual's birth month has been associated with allergic diseases, but little is known about the association between birth month and atopic dermatitis (AD). OBJECTIVE: The aim of this study was to investigate the risk of AD in children born in various months. METHODS: Using Taiwan's National Health Insurance Research Database, we conducted a case-control study that included 31 237 AD cases and 124 948 age- and gender-matched controls without AD. Data regarding sociodemographic factors and coexisting medical conditions were collected and controlled in the multivariate logistic regression to determine the adjusted odds ratios and 95% confidence intervals for AD associated with the participant's birth month. RESULTS: Compared with people born in May, people born in December had the highest risk of AD (OR 1.17, 95% CI 1.10-1.25), followed by people born in October (OR 1.15, 95% CI 1.08-1.22) and November (OR 1.13, 95% CI 1.06-1.20). Low income (OR 1.28), asthma (OR 1.88), allergic rhinitis (OR 1.70), psoriasis (OR 2.36), vitiligo (OR 1.99), urticaria (OR 2.14), and systemic lupus erythematosus (OR 1.91) were significant coexisting medical conditions associated with AD. CONCLUSION: Being born in December, October, or November may be associated with an increased risk of AD. Future investigations are needed to evaluate the possible mechanism behind the association between birth month and AD.

Risk and adverse outcomes of fractures in patients with Parkinson's disease: two nationwide studies.

UNLABELLED: The association between Parkinson's disease and fracture was not completely understood. This nationwide study investigated increased risk of fracture in patients with Parkinson's disease. In the nested cohort study, Parkinson's disease was associated with pneumonia, septicemia, stroke, urinary tract infection, and mortality after fracture admission. INTRODUCTION: Falls are a common complication in people with Parkinson's disease (PD). This study evaluated fracture risk and post-fracture outcomes in patients with PD. METHODS: We identified 1,423 adults aged 40 years and older newly diagnosed with PD using the Taiwan National Health Insurance Research Database from 2000 to 2003. Comparison cohort consisted of 5,692 adults without PD randomly selected from the same dataset, frequency matched in age and sex. Followed-up events of fracture from January 1, 2000, until December 31, 2008, were ascertained from medical claims. Adjusted hazard ratios (HR) and 95 % confidence interval (CI) of fracture associated with PD were evaluated. Another nested cohort study of 397,766 hospitalized fracture patients analyzed for adjusted odds ratios (ORs) and 95 % CIs of adverse events after fracture among patients with and without PD between 2004 and 2010. RESULTS: The incidences of fracture for people with and without PD were 39.5 and 23.9 per 1,000 person-years, respectively (p < 0.0001). Compared with control, the adjusted HR of fracture was 2.25 (95 % CI 1.97-2.58) for PD patients. Previous PD was associated with risks of pneumonia (OR 1.44, 95 % CI 1.36-1.52), septicemia (OR 1.41, 95 % CI 1.33-1.49), stroke (OR 1.40, 95 % CI 1.32-1.50), urinary tract infection (OR 1.53, 95 % CI 1.46-1.61), and mortality (OR 1.25, 95 % CI 1.15-1.35) after fracture. CONCLUSIONS: PD was associated with higher risk of fracture. Patients with PD had more complications and mortality after fracture. Fracture prevention and attention to post-fracture adverse events are needed for this susceptible population.

Outcomes after surgery in patients with previous stroke.

BACKGROUND: Limited information is available on the association between a medical history of stroke and postoperative outcomes. This study investigated the outcomes following non-neurological surgery in patients with previous stroke. METHODS: Using Taiwan's National Health Insurance Research Database, a nationwide cohort study was conducted of patients who underwent non-neurological surgery between 2008 and 2010 with a medical history of stroke in the 24-month period before operation. Patients who had non-neurological surgeries without previous stroke were selected as controls by the propensity score-matched pair method. Thirty-day postoperative complications and in-hospital mortality were compared between the two groups. RESULTS: Some 1 426 795 adults underwent major inpatient non-neurological surgery, of whom 45 420 had a medical history of previous stroke. Patients with previous stroke who underwent surgery had an increased risk of postoperative pneumonia, septicaemia, acute renal failure, acute myocardial infarction, pulmonary embolism and 30-day in-hospital mortality (adjusted rate ratio (RR) 1·79, 95 per cent c.i. 1·61 to 1·99). Compared with controls, patients with previous stroke due to intracerebral haemorrhage (RR 3·41, 2·97 to 3·91), and those who were treated in intensive care (RR 2·55, 2·24 to 2·90) or underwent neurosurgery (RR 2·49, 2·12 to 2·92), had an increased 30-day in-hospital mortality rate. Postoperative mortality also increased with stroke-related co-morbidities, and with stroke 1-6 months before surgery (RR 3·31, 2·91 to 3·75). CONCLUSION: Patients with previous stroke had a higher risk of adverse postoperative outcomes; their 30-day in-hospital mortality rate was nearly twice that of patients without previous stroke.

[Prevalence of frailty and related factors in middle-aged and elderly people in island and mountainous areas of Taizhou, Zhejiang Province].

Objective: To compare the prevalence of frailty and related factors in middle-aged and elderly people aged ≥45 years in island and mountainous areas of Taizhou, Zhejiang Province. Methods: Based on cross-sectional design, stratified cluster sampling and quota sampling methods were adopted. One administrative district was randomly selected from each of six coastal and three inland administrative districts in Taizhou during July to August, representing two different geographical terrains. In the island area (Jiaojiang District), all residents aged ≥45 years were included by cluster sampling. In the mountainous area (Xianju County), participants were selected through quota sampling, with same gender and age distributions. Data about their demographic characteristics, lifestyle and health-related factors were collected through questionnaire surveys and laboratory examinations. The prevalence of frailty was assessed using the Fried frailty phenotype scale. Hierarchical analysis and multivariate logistic regression analysis were used to compare the influencing factors of frailty. Results: A total of 1 011 local residents were studied, in whom island and mountainous residents accounted for 48.1% (486/1 011) and 51.9% (525/1 011) respectively; men and women accounted for 45.9% (464/1 011) and 54.1% (547/1 011) respectively. Middle-aged (45-49 years), younger elderly (60-74 years), and older elderly (≥75 years) residents accounted for 38.6% (390/1 011), 44.6% (451/1 011), and 16.8% (170/1 011) respectively. The overall prevalence rate of frailty was 3.6% (36/1 011), the prevalence rate was 3.7% (17/464) in men and 3.5% (19/547) in women. The prevalence rates in age groups 45-59,60-74 years and ≥75 years were 0.3% (1/390), 2.2% (10/451), and 14.7% (25/170), respectively. The prevalence rates of frailty and pre-frailty in island area were 6.0% (29/486) and 39.1% (190/486), respectively, which was higher than those in mountainous area (1.3%, 7/525) and (30.9%, 162/525). After adjusting for potential confounding factors, the risk for frailty in island residents was significantly higher than that in mountainous residents (aOR=1.55,95%CI: 1.07-2.25,P=0.019). In island area, older age (60-74 years:aOR=2.52,95%CI: 1.56-4.13; ≥75 years:aOR=11.65,95%CI:5.38-26.70), being women (aOR=1.94,95%CI: 1.20-3.17), suffering from depression (aOR=1.09,95%CI:1.02-1.17) were associated with frailty symptoms. In mountainous area, older age was also associated with an increased risk of frailty symptoms, but the OR value was lower than those in island area (60-74 years: aOR=1.74,95%CI:1.04-2.94;≥75 years: aOR=4.78,95%CI:2.45-9.50). Polydrug use (aOR=2.08,95%CI: 1.14-3.80) and suffering from depression (aOR=1.10,95%CI: 1.02-1.18) had significant positive association with frailty symptoms. Higher education level had significant negative association with frailty symptoms (junior high school: aOR=0.40,95%CI: 0.21-0.75; senior high school and technical secondary school: aOR=0.29,95%CI: 0.15-0.53; college or above:aOR=0.22,95%CI: 0.11-0.42). Conclusions: The prevalence of frailty in middle-aged and elderly community residents was significantly higher in island area than in mountainous area in Taizhou. The frailty-related factors varied with area. The elderly people (≥75 years) and women in island area had higher risk for frailty. Older age and suffering from depression were the independent risk factors for frailty. It is necessary to pay attention to the health risk factors and special environment in island area, and take comprehensive intervention measures to delay the process of debilitation and improve the quality of life of middle-aged and elderly people.