The Ideal Proportion of the Auricle Exposure via a Morphometric Analysis in Asian Women.

BACKGROUND: Ears are an important aesthetic feature that is vital to the overall attractiveness of the face. Although there have been many studies on the aesthetics of the auricle, there is currently a lack of consensus on the ideal proportion of auricle exposure for Asian women in frontal view. OBJECTIVES: This study aimed to investigate ideal proportion of auricle exposure in Asian women. METHODS: An observational study was carried out on the photographs of 84 women on the list of the 100 most beautiful faces in Asia (published by TCC Asia in 2020). The proportion of the distance between the outer canthus and the outermost point of auricle to the distance between the inner canthus and the outermost point of auricle was calculated as the auricle exposure proportion. Evaluators were asked to rank a set of photographs of the volunteer with varying auricle exposure proportions from most attractive to least attractive. RESULTS: Measurements of the photographs of the 84 women showed a mean ear exposure proportion of 0.600. With 487 questionnaire responses received, the proportion of auricle exposure that the evaluators considered most attractive was 0.600. People with aesthetic experience considered 0.625 the most attractive proportion, while the general group considered 0.600 the most attractive. CONCLUSIONS: The ideal proportion of the auricle exposure for Asian women is in the range of 0.60-0.625, which may help surgeons reconstruct aesthetically pleasing ears. LEVEL OF EVIDENCE V: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The Auricular Injection Technique: A New Treatment for Lying Ear.

SUMMARY: Lying-ear deformity refers to an auricle that bends backward excessively, is excessively folded against the head, and has a very prominent antihelix. It usually requires experienced surgeons to perform surgical treatment and a prolonged postoperative recovery process. This article proposes a simple and effective hyaluronic acid injection technique that significantly improves the shape of the outer ear and enhances perceived facial aesthetics. Twenty patients underwent treatment with multiple injections. Measure-related parameters were used to evaluate the postoperative effect, and the results were graded using a visual analog scale. Interrater reliability among graders was evaluated using intraclass correlation coefficients. After treatment, no serious complications, such as infection or embolism, occurred. Six months after the procedure, the average auriculocephalic angle increased from 25.11 ± 9.46 to 32.72 ± 8.29 degrees, the average conchoscaphal angle increased from 87.69 ± 9.06 to 95.94 ± 7.11 degrees, and patients' average visual analog scale score increased from 4.40 ± 1.14 to 8.57 ± 0.68. Interrater reliability was fair to good for visual analog scale before injection and 6 months after injection (intraclass correlation coefficients, 0.49 and 0.45, respectively; both P < 0.001). The patients were satisfied with the injection process and results. This injection protocol improved the shape of the outer ear, resulting in excellent postoperative outcomes.

Peeling mechanism of tomato induced by HHAIB: Microscopic, ultrastructure, chemical, physical and mechanical properties perspectives.

In order to better manage the peeling degree and avoid unnecessary losses, the current work aimed to explore the peeling mechanism of a novel peeling technology, high-humidity hot air impingement blanching (HHAIB). The relationships between HHAIB peeling performance and the changes in skin temperature, skin structure, water state, pectin fractions content, and skin mechanical properties of tomatoes were analyzed. Results showed, after HHAIB treatment, the epicuticular wax was disrupted, the skin exhibited more and longer random cracks, the degradation of inner skin tissue was observed by transmission electron microscopy, the free water percentage increased resulting in water loss in the whole tomato, the water-soluble pectin contents decreased in tomato fleshes, while the contents of chelate-soluble pectin and sodium-carbonate-soluble pectin increased. HHAIB heating reduced the elongation at break, and increased Young's Modulus of tomato peel. This study revealed the HHAIB peeling mechanism and provided new insights for developing HHAIB peeling technology.

Deep Temporal Artery Anatomy: Implications for Improving the Safety of Deep Temporal Injections.

BACKGROUND: Knowledge of the anatomy of the deep temporal artery (DTA) is critical to ensure safe filling of the deep temporal region. However, current treatment guidelines still focus on how to avoid the superficial temporal artery and the middle temporal vein, and an understanding of the safety of avoiding DTA injury is lacking. OBJECTIVE: The purpose of this study was to determine the positioning and course of the DTA to help clinicians safely perform the injection and filling in the temporal region. METHODS: Computed tomography (CT) scans and dissections of the skulls of 34 fresh frozen cadavers perfused with lead oxide were performed. Reconstruction and trajectory analysis of all DTA branches were performed using Mimics and MATLAB software. RESULTS: In this study, the DTA was identified in all samples, which originated from the maxillary artery of the external carotid artery system. According to image reconstruction and anatomical observations, the distribution of the anterior and posterior branches of the DTA had two different distribution patterns. The anatomical level of the DTA is located between the temporal muscle and the periosteal layer. Compared with observations in previous studies, the anterior branch of the DTA is slightly different, and we found that its course is closer to the frontal area in Asian specimens. CONCLUSION: The anatomical information on the DTA described in this study may help improve awareness of the safety of temporal injection by aesthetic physicians. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine Ratings, please refer to Table of Contents or online Instructions to Authors www.springer.com/00266. .

Geographical distribution of Ixodes persulcatus and associated pathogens: Analysis of integrated data from a China field survey and global published data.

The increasing incidence and range expansion of tick-borne diseases have caused global threats to human and animal health under the background of climate and socioeconomic changes. As an efficient vector in transmission of tick-borne diseases, a growing burden caused by Ixodes persulcatus and associated pathogens could not be underestimated. This study summarized the distribution, hosts, and pathogens of I. persulcatus, and predicted the suitable habitats of this tick species worldwide. An integrated database involving a field survey, reference book, literature review, and related website was constructed. Location records of I. persulcatus and associated pathogens were incorporated into distribution maps using ArcGIS software. Positive rates for I. persulcatus-associated agents were estimated by meta-analysis. The global distribution of the tick species was predicted using Maxent model. I. persulcatus was distributed in 14 countries across the Eurasian continent, involving Russia, China, Japan, and several Baltic Sea states, which ranged between 21°N to 66°N. The tick species fed on 46 species of hosts, and 51 tick-borne agents could be harbored by I. persulcatus. The predictive model showed that I. persulcatus could be predominantly distributed in northern Europe, western Russia, and northern China. Our study fully clarified the potential public health risks posed by I. persulcatus and I. persulcatus-borne pathogens. Surveillance and control measures of tick-borne diseases should be enhanced to promote the health of humans, animals, and ecosystems.

Zygomatico-Orbital Artery: A Reevaluation of the Temporal Blood Vessels.

BACKGROUND: The current anatomical description of the zygomatico-orbital artery (ZOA) is mainly based on cadaver head studies and does not accurately reflect the complete anatomical information of the ZOA. The purpose of this study was to reveal the anatomical characteristics of the ZOA and to provide an anatomical basis for relevant operations in the temporal area. METHODS: Computed tomographic scans and autopsies were performed on 78 cadaver heads perfused with lead oxide. Mimics software was used to construct a three-dimensional image based on the bilateral intertragic notches and the right inferior orbital margin for a detailed analysis of the ZOA. RESULTS: The occurrence rate of ZOA in the 101 qualified hemisectioned cadaver heads was 86.14% (87 of 101). According to our observations, 46 of 87 (52.87%) originated from the superficial temporal artery above the zygomatic arch, 23 of 87 (26.44%) from the superficial temporal artery under the zygomatic arch, and 18 of 87 (20.69%) from the frontal branch of the superficial temporal artery. The ZOA communicates with the deep and superficial arches of the supraorbital artery, transverse facial artery, and ophthalmic artery. CONCLUSIONS: This study describes the anatomical characteristics of the ZOA. Moreover, these findings may guide skin flap transplantation and prevent associated injection complications.

Metavirome of 31 tick species provides a compendium of 1,801 RNA virus genomes.

The increasing prevalence and expanding distribution of tick-borne viruses globally have raised health concerns, but the full repertoire of the tick virome has not been assessed. We sequenced the meta-transcriptomes of 31 different tick species in the Ixodidae and Argasidae families from across mainland China, and identified 724 RNA viruses with distinctive virome compositions among genera. A total of 1,801 assembled and complete or nearly complete viral genomes revealed an extensive diversity of genome architectures of tick-associated viruses, highlighting ticks as a reservoir of RNA viruses. We examined the phylogenies of different virus families to investigate virome evolution and found that the most diverse tick-associated viruses are positive-strand RNA virus families that demonstrate more ancient divergence than other arboviruses. Tick-specific viruses are often associated with only a few tick species, whereas virus clades that can infect vertebrates are found in a wider range of tick species. We hypothesize that tick viruses can exhibit both 'specialist' and 'generalist' evolutionary trends. We hope that our virome dataset will enable much-needed research on vertebrate-pathogenic tick-associated viruses.

Positions of the Glabellar Arteries: Implications for Glabellar Injection.

BACKGROUND: Glabellar filler injection is linked to an increased risk of blindness. A thorough understanding of vascular changes in the glabellar area is critical for safety. The study's goal was to precisely determine the three-dimensional placements of the arteries in the glabellar area. METHODS: In 117 cadavers, the vascular structures in the glabellar area were examined. There were four segments (S1/S1'-S4/S4') and five points (P1-P5) specified. The number of identified arteries found in each section and at each position was tallied. Additionally, the depth of the underlying identified artery under each site was measured. RESULTS: One to three named arteries per glabellar segment were found. Each segment had at least one named artery, and the number of named arteries detected between S1/S1' and S4/S4' decreased. The chance of encountering identified arteries at the 5 designated locations, P1-P5, was 7/117 (6.0%), 6/117 (5.1%), 7/117 (6.0%), 6/117 (5.1%), and 16/117 (13.7%), respectively. At P1-P5, the major artery trunk was 1.8 ± 0.3 mm, 1.6 ± 0.3 mm, 1.4 ± 0.2 mm, 1.3 ± 0.3 mm, and 1.1 ± 0.2 mm below the skin. CONCLUSIONS: The site of the glabellar arteries was clearly shown in this investigation; these arteries were met at a rate of 14% from P1 to P5. We demonstrated that a single entry site through the glabella via cannula could readily keep the needle deep enough for safe glabellar filler injection. LEVEL OF EVIDENCE V: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

7,8-Dihydroxyflavone protects retinal ganglion cells against chronic intermittent hypoxia-induced oxidative stress damage via activation of the BDNF/TrkB signaling pathway.

PURPOSE: Chronic intermittent hypoxia (CIH) plays a key role in the complications of obstructive sleep apnea (OSA), which is strongly associated with retinal and optic nerve diseases. Additionally, the brain-derived neurotrophic factor (BDNF)/tropomyosin receptor kinase B (TrkB) signaling pathway plays an important protective role in neuronal injury. In the present study, we investigated the role of 7,8-dihydroxyflavone (7,8-DHF) in regulating CIH-induced injury in mice retinas and rat primary retinal ganglion cells (RGCs). METHODS: C57BL/6 mice and in vitro primary RGCs were exposed to CIH or normoxia and treated with or without 7,8-DHF. The mice eyeballs or cultured cells were then taken for histochemistry, immunofluorescence or biochemistry, and the protein expression of the BDNF/TrkB signaling pathway analysis. RESULTS: Our results showed that CIH induced oxidative stress (OS) in in vivo and in vitro models and inhibited the conversion of BDNF precursor (pro-BDNF) to a mature form of BDNF, which increased neuronal cell apoptosis. 7,8-DHF reduced the production of reactive oxygen species (ROS) caused by CIH and effectively activated TrkB signals and downstream protein kinase B (Akt) and extracellular signal-regulated kinase (Erk) survival signaling pathways, which upregulated the expression of mature BDNF. ANA-12 (a TrkB specific inhibitor) blocked the protective effect of 7,8-DHF. CONCLUSION: In short, the activation of the BDNF/TrkB signaling pathway alleviated CIH-induced oxidative stress damage of the optic nerve and retinal ganglion cells. 7,8-DHF may serve as a promising agent for OSA related neuropathy.

Distribution of Dermacentor silvarum and Associated Pathogens: Meta-Analysis of Global Published Data and a Field Survey in China.

Dermacentor silvarum is an obligate blood sucking arthropod and transmits various pathogens to humans and domestic animals. Recently several new viruses were detected in D. silvarum as an emerging disease threat. In this study, we aimed to analyze its geographical distribution and associated pathogens. Data were collected from multiple sources, including a field survey, reference book, and literature review. We searched various electronic databases with the terms "Dermacentor silvarum" OR "D. silvarum" for studies published since 1963 and the positive rates for Dermacentor silvarum-associated pathogens were estimated by meta-analysis. D. silvarum was found only in four countries in Eurasia, ranging from 22° N to 57° N latitude. At least 20 human pathogens were associated with D. silvarum, including five species of spotted fever group rickettsiae, three species in the family of Anaplasmataceae, three genospecies in the complex Borrelia burgdorferi sensu lato, Francisella tularensis, Babesia venatorum, Coxiella buenetii, Borrelia miyamotoi, and five species of virus. Among them, Rickettsia raoultii was widely detected in D. silvarum, showing the highest pooled positive rate (25.15%; 95% CI 13.31-39.27). Our work presents the most comprehensive data and analysis (to our knowledge) for the geographical distribution of D. silvarum and associated pathogens, revealing an emerging threat to public health and stocking farming. Continued surveillance and further investigations should be enhanced.

An Optimal Nucleic Acid Testing Strategy for COVID-19 during the Spring Festival Travel Rush in Mainland China: A Modelling Study.

Western countries are experiencing surges in COVID-19 cases and deaths due to increasing public transportation during holiday seasons. This study aimed to explore whether mainland China will face an epidemic rebound during the Spring Festival holiday, when millions of Chinese people travel across the country, and investigate which nucleic acid testing (NAT) strategy is optimal to contain the epidemic. A microsimulation model was used to simulate SARS-CoV-2 transmission among railway travelers and evaluated the effects of various NAT strategies. An extended susceptible-exposed-infectious-recovered (SEIR) model was built to forecast local transmission during the Spring Festival period under different scenarios of testing strategies. The total number of infections, testing burden, and medical expenditure were calculated to devise an optimal strategy during the Spring Festival travel rush. Assuming the daily incidence of 20 per 10 million persons, our model simulated that there would be 97 active infections on the day of travel among 10 million railway passengers without NAT and symptom screening. Pre-travel testing could reduce the number of active infections. Compared with no NAT, testing passengers from risk tier 2-4 regions 3 days before travelling could significantly reduce the risk of transmission, and it is more economical and efficient than testing for all passengers.

Detection of Novel Spotted Fever Group Rickettsiae (Rickettsiales: Rickettsiaceae) in Ticks (Acari: Ixodidae) in Southwestern China.

Spotted fever group rickettsiae, mainly maintained and transmitted by ticks, are important etiological agents of (re)emerging zoonotic diseases worldwide. It is of great significance to investigate spotted fever group rickettsiae in ticks in different areas for the prevention and control of rickettsioses. In this study, a total of 305 ticks were collected from wild and domestic animals in Chongqing, Guizhou, Yunnan, and Guangxi provinces of southwestern China during 2017-2019 and examined for the presence of spotted fever group rickettsiae by PCR with primers targeting the partial gltA, ompA, rrs, and htrA genes. Results showed that two spotted fever group rickettsiae species, including the pathogenic Candidatus Rickettsia jingxinensis (Rickettsiales: Rickettsiaceae) and a potential novel species Rickettsia sp. sw (Rickettsiales: Rickettsiaceae), were identified. The Ca. R. jingxinensis sequences were recovered from Rhipicephalus microplus (Ixodida: Ixodidae) and Haemaphysalis longicornis (Ixodida: Ixodidae) ticks and phylogenetically clustered with previous Ca. R. jingxinensis, Ca. R. longicornii (Rickettsiales: Rickettsiaceae), and Rickettsia sp. XY118 (Rickettsiales: Rickettsiaceae) strains. Rickettsia sp. sw was detected in Amblyomma geoemydae (Ixodida: Ixodidae) and Rh. microplus. Interestingly, as far as we know, this was the first report of Rickettsia (Rickettsiales: Rickettsiaceae) in A. geoemydae. Phylogenetic analyses indicated that this potential novel species was closely related to R. aeschlimannii (Rickettsiales: Rickettsiaceae) with gltA and ompA genes and grouped in a cluster composed of R. montanensis (Rickettsiales: Rickettsiaceae), R. raoultii (Rickettsiales: Rickettsiaceae), R. aeschlimannii, R. massiliae (Rickettsiales: Rickettsiaceae), and R. rhipicephali (Rickettsiales: Rickettsiaceae) with htrA, while formed a separate clade with rrs. The pathogenicity of Rickettsia sp. sw should be further confirmed. These results expand the knowledge of the geographical distribution and vector distribution of spotted fever group rickettsiae in China and are useful for assessing the potential public health risk.

Prevalence of Multiple Tick-Borne Pathogens in Various Tick Vectors in Northeastern China.

Background: Tick-borne bacteria and protozoa can cause a variety of human and animal diseases in China. It is of great importance to monitor the prevalence and dynamic variation of these pathogens in ticks in ever-changing natural and social environment. Materials and Methods: Ticks were collected from Heilongjiang and Jilin provinces of northeastern China during 2018-2019 followed by morphological identification. The presence of Rickettsia spp., Anaplasma spp., Ehrlichia spp., Borrelia spp., Babesia spp., and Theileria spp. was examined by PCR and Sanger sequencing. The obtained sequences were subjected to phylogenetic analysis through Mega 7.0. Statistical analysis was performed using SPSS 24.0. Results: A total of 250 ticks from 5 species of 3 genera were collected. Ixodes and Haemaphysalis ticks carried more species of pathogens than Dermacentor, and the pathogens detected in Haemaphysalis japonica varied significantly among different sampling sites. The infection rates of Rickettsia spp., Anaplasma spp., Ehrlichia spp., Borrelia spp., Babesia spp., and Theileria spp. were 41.2%, 0, 2.0%, 7.2%, 1.2%, and 7.2%, respectively. Twelve pathogens were identified, among which Rickettsia raoultii (29.6%), Candidatus Rickettsia tarasevichiae (9.2%), and Theileria equi (4.4%) were the three most common ones. Rickettsia had its dominant vector, that is, R. raoultii had high infection rates in Dermacentor nuttalli and Dermacentor silvarum, Ca. R. tarasevichiae in Ixodes persulcatus, and Rickettsia heilongjiangensis in H. japonica. Interestingly, unclassified species were observed, including a Rickettsia sp., an Ehrlichia sp., a Borrelia sp., and a Babesia sp. Coinfections with different pathogens were identified in 9.2% of all tested ticks, with I. persulcatus most likely to be coinfected (23.8%) and Rickettsia spp. and Borrelia spp. as the most common combination (16.7%). Conclusions: The results of this study reflect high diversity and complexity of pathogens in ticks, which are useful for designing more targeted and effective control measures for tick-borne diseases in China.

Outbreak of COVID-19 and SARS in mainland China: a comparative study based on national surveillance data.

OBJECTIVE: To compare the epidemiological characteristics and transmission dynamics in relation to interventions against the COVID-19 and severe acute respiratory syndrome (SARS) outbreak in mainland China. DESIGN: Comparative study based on a unique data set of COVID-19 and SARS. SETTING: Outbreak in mainland China. PARTICIPANTS: The final database included 82 858 confirmed cases of COVID-19 and 5327 cases of SARS. METHODS: We brought together all existing data sources and integrated them into a comprehensive data set. Individual information on age, sex, occupation, residence location, date of illness onset, date of diagnosis and clinical outcome was extracted. Control measures deployed in mainland China were collected. We compared the epidemiological and spatial characteristics of COVID-19 and SARS. We estimated the effective reproduction number to explore differences in transmission dynamics and intervention effects. RESULTS: Compared with SARS, COVID-19 affected more extensive areas (1668 vs 230 counties) within a shorter time (101 vs 193 days) and had higher attack rate (61.8 vs 4.0 per million persons). The COVID-19 outbreak had only one epidemic peak and one epicentre (Hubei Province), while the SARS outbreak resulted in two peaks and two epicentres (Guangdong Province and Beijing). SARS-CoV-2 was more likely to infect older people (median age of 52 years), while SARS-CoV tended to infect young adults (median age of 34 years). The case fatality rate (CFR) of either disease increased with age, but the CFR of COVID-19 was significantly lower than that of SARS (5.6% vs 6.4%). The trajectory of effective reproduction number dynamically changed in relation to interventions, which fell below 1 within 2 months for COVID-19 and within 5.5 months for SARS. CONCLUSIONS: China has taken more prompt and effective responses to combat COVID-19 by learning lessons from SARS, providing us with some epidemiological clues to control the ongoing COVID-19 pandemic worldwide.

Impacts of transportation and meteorological factors on the transmission of COVID-19.

The ongoing pandemic of 2019 novel coronavirus disease (COVID-19) is challenging global public health response system. We aim to identify the risk factors for the transmission of COVID-19 using data on mainland China. We estimated attack rate (AR) at county level. Logistic regression was used to explore the role of transportation in the nationwide spread. Generalized additive model and stratified linear mixed-effects model were developed to identify the effects of multiple meteorological factors on local transmission. The ARs in affected counties ranged from 0.6 to 9750.4 per million persons, with a median of 8.8. The counties being intersected by railways, freeways, national highways or having airports had significantly higher risk for COVID-19 with adjusted odds ratios (ORs) of 1.40 (p = 0.001), 2.07 (p < 0.001), 1.31 (p = 0.04), and 1.70 (p < 0.001), respectively. The higher AR of COVID-19 was significantly associated with lower average temperature, moderate cumulative precipitation and higher wind speed. Significant pairwise interactions were found among above three meteorological factors with higher risk of COVID-19 under low temperature and moderate precipitation. Warm areas can also be in higher risk of the disease with the increasing wind speed. In conclusion, transportation and meteorological factors may play important roles in the transmission of COVID-19 in mainland China, and could be integrated in consideration by public health alarm systems to better prevent the disease.

Large-Scale Comparative Analyses of Tick Genomes Elucidate Their Genetic Diversity and Vector Capacities.

Among arthropod vectors, ticks transmit the most diverse human and animal pathogens, leading to an increasing number of new challenges worldwide. Here we sequenced and assembled high-quality genomes of six ixodid tick species and further resequenced 678 tick specimens to understand three key aspects of ticks: genetic diversity, population structure, and pathogen distribution. We explored the genetic basis common to ticks, including heme and hemoglobin digestion, iron metabolism, and reactive oxygen species, and unveiled for the first time that genetic structure and pathogen composition in different tick species are mainly shaped by ecological and geographic factors. We further identified species-specific determinants associated with different host ranges, life cycles, and distributions. The findings of this study are an invaluable resource for research and control of ticks and tick-borne diseases.

Organocatalytic Asymmetric Aldol Reaction of Arylglyoxals and Hydroxyacetone: Enantioselective Synthesis of 2,3-Dihydroxy-1,4-diones.

A highly efficient quinine-derived primary-amine-catalyzed asymmetric aldol addition of hydroxyacetone to arylglyoxals is described. Structurally diverse anti-2,3-dihydroxy-1,4-diones were generated in high yields, with good diastereoselectivities and enantioselectivities.

Asymmetric Diels-Alder Reaction of 3-Vinylindoles and Nitroolefins Promoted by Multiple Hydrogen Bonds.

The first catalytic asymmetric Diels-Alder reaction of 3-vinylindole and nitroolefin is described. In the promotion of organocatalyst 3j, structurally diverse 1-nitro-hydrocarbazoles are produced in moderate-to-good yields and high-to-excellent enantioselectivities. All of these products are obtained as a single diastereoisomer. The 1-nitro-hydrocarbazole compounds can be converted into 1-amino-hydrocarbazole derivatives and structurally complex ring-fused indoles enantioseletively. Possible transition states were investigated by control experiments and DFT calculations.

Diabetes mellitus and the risk of gastrointestinal cancer in women compared with men: a meta-analysis of cohort studies.

BACKGROUND: The increasing epidemic proportions of diabetes mellitus (DM) are a major cause of premature illness and death. However, whether DM confers the same excess risk of gastrointestinal cancer for women as it does for men remains controversial. The purpose of this study was to estimate the relation between DM and gastrointestinal cancer in women compared with men after accounting for other major risk factors based on cohort studies. METHODS: We performed a meta-analysis of cohort studies published through May 2017 from PubMed, Embase, and the Cochrane Library. Studies with cohort designs were stratified by sex and reported the relation between DM and esophageal cancer (EC), gastric cancer (GC), colorectal cancer (CRC), colon cancer (CC), rectal cancer (RC), hepatocellular carcinoma (HCC), or pancreatic cancer (PC) risk. The ratio of relative risk (RRR) between men and women was employed to measure the sex differences in the relation between DM and gastrointestinal cancer with a random effects model with inverse variance weighting. RESULTS: We included 38 cohort studies reporting data on 18,060,698 individuals. The pooled RRR indicated DM women was associated with an increased risk of GC (RRR: 1.14; 95%CI: 1.06-1.22; p < 0.001), while the risk of HCC was lower (RRR: 0.88; 95%CI: 0.79-0.99; p = 0.031) as compared with DM men. Further, there was no evidence of sex differences in the RRR between participants who had DM compared with those without DM for EC (p = 0.068), CRC (p = 0.618), and PC (p = 0.976). In addition, the pooled RRR showed a statistically significant association between DM and the risk of CC in women compared with men (RRR: 0.93; 95%CI: 0.86-1.00; p = 0.050), and there was no evidence of sex differences for RC among participants with DM compared to those without DM (p = 0.648). Finally, the sex differences of the comparison between DM and non-DM for gastrointestinal cancer risk at different sites were variable after stratification for different effect estimates. CONCLUSIONS: The findings of this study suggested female-to-male RRR of DM was increased for GC, while reduced for HCC and CC. However, there were no sex differences for the relation between DM and the risk of EC, CRC, PC, and RC.