3D nanofabricated soft microrobots with super-compliant picoforce springs as onboard sensors and actuators.

Microscale organisms and specialized motile cells use protein-based spring-like responsive structures to sense, grasp and move. Rendering this biomechanical transduction functionality in an artificial micromachine for applications in single-cell manipulations is challenging due to the need for a bio-applicable nanoscale spring system with a large and programmable strain response to piconewton-scale forces. Here we present three-dimensional nanofabrication and monolithic integration, based on an acrylic elastomer photoresist, of a magnetic spring system with quantifiable compliance sensitive to 0.5 pN, constructed with customized elasticity and magnetization distributions at the nanoscale. We demonstrate the effective design programmability of these 'picospring' ensembles as energy transduction mechanisms for the integrated construction of customized soft micromachines, with onboard sensing and actuation functions at the single-cell scale for microrobotic grasping and locomotion. The integration of active soft springs into three-dimensional nanofabrication offers an avenue to create biocompatible soft microrobots for non-disruptive interactions with biological entities.

Guiding bone cell network formation in 3D via photosensitized two-photon ablation.

A long-standing challenge in skeletal tissue engineering is to reconstruct a three-dimensionally (3D) interconnected bone cell network in vitro that mimics the native bone microarchitecture. While conventional hydrogels are extensively used in studying bone cell behavior in vitro, current techniques lack the precision to manipulate the complex pericellular environment found in bone. The goal of this study is to guide single bone cells to form a 3D network in vitro via photosensitized two-photon ablation of microchannels in gelatin methacryloyl (GelMA) hydrogels. A water-soluble two-photon photosensitizer (P2CK) was added to soft GelMA hydrogels to enhance the ablation efficiency. Remarkably, adding 0.5 mM P2CK reduced the energy dosage threshold five-fold compared to untreated controls, enabling more cell-compatible ablation. By employing low-energy ablation (100 J/cm2) with a grid pattern of 1 µm wide and 30 µm deep microchannels, we induced dendritic outgrowth in human mesenchymal stem cells (hMSC). After 7 days, the cells successfully utilized the microchannels and formed a 3D network. Our findings reveal that cellular viability after low-energy ablation was comparable to unablated controls, whereas high-energy ablation (500 J/cm2) resulted in 42 % cell death. Low-energy grid ablation significantly promoted network formation and >40 µm long protrusion outgrowth. While the broad-spectrum matrix metalloproteinase inhibitor (GM6001) reduced cell spreading by inhibiting matrix degradation, cells invaded the microchannel grid with long protrusions. Collectively, these results emphasize the potential of photosensitized two-photon hydrogel ablation as a high-precision tool for laser-guided biofabrication of 3D cellular networks in vitro. STATEMENT OF SIGNIFICANCE: The inaccessible nature of osteocyte networks in bones renders fundamental research on skeletal biology a major challenge. This limit is partly due to the lack of high-resolution tools that can manipulate the pericellular environment in 3D cultures in vitro. To create bone-like cellular networks, we employ a two-photon laser in combination with a two-photon sensitizer to erode microchannels with low laser dosages into GelMA hydrogels. By providing a grid of microchannels, the cells self-organized into a 3D interconnected network within days. Laser-guided formation of 3D networks from single cells at micron-scale resolution is demonstrated for the first time. In future, we envisage in vitro generation of bone cell networks with user-dictated morphologies for both fundamental and translational bone research.

Glycemic control, HbA1c variability, and major cardiovascular adverse outcomes in type 2 diabetes patients with elevated cardiovascular risk: insights from the ACCORD study.

BACKGROUND: Although recent guidelines advocate for HbA1c target individualization, a comprehensive criterion for patient categorization remains absent. This study aimed to categorize HbA1c variability levels and explore the relationship between glycemic control, cardiovascular outcomes, and mortality across different degrees of variability. METHODS: Action to Control Cardiovascular Risk in Diabetes study data were used. HbA1c variability was measured using the HbA1c variability score (HVS) and standard deviation (SD). K-means and K-medians clustering were used to combine the HVS and SD. RESULTS: K-means clustering was the most stable algorithm with the lowest clustering similarities. In the low variability group, intensive glucose-lowering treatment significantly reduced the risk of adverse cardiovascular outcomes (HR: 0·78 [95% CI: 0·63, 0·97]) without increasing mortality risk (HR: 1·07 [0.81, 1·42]); the risk of adverse cardiovascular events (HR: 1·33 [1·14, 1·56]) and all-cause mortality (HR: 1·23 [1·01,1·51]) increased with increasing mean HbA1c. In the high variability group, treatment increased the risk of cardiovascular events (HR: 2.00 [1·54, 2·60]) and mortality (HR: 2·20 [1·66, 2·92]); a higher mean HbA1c (7·86%, [7·66%, 8·06%]) had the lowest mortality risk, when the mean HbA1c was < 7·86%, a higher mean HbA1c was associated with a lower mortality risk (HR: 0·63 [0·42, 0·95]). In the medium variability group, a mean HbA1c around 7·5% was associated with the lowest risk. CONCLUSIONS: HbA1c variability can guide glycemic control targets for patients with type 2 diabetes. For patients with low variability, the lower the HbA1c, the lower the risk. For those with medium variability, controlling HbA1c at 7·5% provides the maximum benefit. For patients with high variability, a mean HbA1c of around 7·8% presents the lowest risk of all-cause mortality, a lower HbA1c did not provide cardiovascular benefits but instead increased the mortality risk. Further studies, especially those with patients that reflect the general population with type 2 diabetes undergoing the latest therapeutic approaches, are essential to validate the conclusions of this study.

Stimuli-Responsive Functional Micro-/Nanorobots: A Review.

Stimuli-responsive functional micro-/nanorobots (srFM/Ns) are a class of intelligent, efficient, and promising microrobots that can react to external stimuli (such as temperature, light, ultrasound, pH, ion, and magnetic field) and perform designated tasks. Through adaptive transformation into the corresponding functional forms, they can perfectly match the demands depending on different applications, which manifest extremely important roles in targeted therapy, biological detection, tissue engineering, and other fields. Promising as srFM/Ns can be, few reviews have focused on them. It is therefore necessary to provide an overview of the current development of these intelligent srFM/Ns to provide clear inspiration for further development of this field. Hence, this review summarizes the current advances of stimuli-responsive functional microrobots regarding their response mechanism, the achieved functions, and their applications to highlight the pros and cons of different stimuli. Finally, we emphasize the existing challenges of srFM/Ns and propose possible strategies to help accelerate the study of this field and promote srFM/Ns toward actual applications.

3D-printed PNAGA thermosensitive hydrogelbased microrobots: An effective cancer therapy by temperature-triggered drug release.

Hydrogels with temperature-responsive capabilities are increasingly utilized and researched owing to their prospective applications in the biomedical field. In this work, we developed thermosensitive poly-N-acryloyl glycinamide (PNAGA) hydrogels-based microrobots by using the advanced two-photon polymerization printing technology. N-acryloyl glycinamide (NAGA) concentration-dependent thermosensitive performance was presented and the underlying mechanism behind was discussed. Fast swelling behavior was achieved by PNAGA-100 at 45°C with a growth rate of 22.5%, which is the highest value among these PNAGA hydrogels. In addition, a drug release test of PNAGA-100-based thermosensitive hydrogels was conducted. Our microrobots demonstrate higher drug release amount at 45°C (close to body temperature) than at 25°C, indicating their great potential to be utilized in drug delivery in the human body. Furthermore, PNAGA-100-based thermosensitive microrobots are able to swim along the route as designed under the magnetic actuator after incubating with Fe@ZIF-8 crystals. Our biocompatible thermosensitive magnetic microrobots open up new options for biomedical applications and our work provides a robust pathway to the development of high-performance thermosensitive hydrogel-based microrobots.

Magnetic Microrobots with Folate Targeting for Drug Delivery.

Untethered microrobots can be used for cargo delivery (e.g., drug molecules, stem cells, and genes) targeting designated areas. However, it is not enough to just reach the lesion site, as some drugs can only play the best therapeutic effect within the cells. To this end, folic acid (FA) was introduced into microrobots in this work as a key to mediate endocytosis of drugs into cells. The microrobots here were fabricated with biodegradable gelatin methacryloyl (GelMA) and modified with magnetic metal-organic framework (MOF). The porous structure of MOF and the hydrogel network of polymerized GelMA were used for the loading of enough FA and anticancer drug doxorubicin (DOX) respectively. Utilizing the magnetic property of magnetic MOF, these microrobots can gather around the lesion site with the navigation of magnetic fields. The combination effects of FA targeting and magnetic navigation substantially improve the anticancer efficiency of these microrobots. The result shows that the cancer cells inhibition rate of microrobots with FA can be up to 93%, while that of the ones without FA was only 78%. The introduction of FA is a useful method to improve the drug transportation ability of microrobots, providing a meaningful reference for further research.

Association Between the Frailty and Cognitive Impairment Among Patients With Hypertension-A Post Hoc Analysis of the SPRINT Trial.

Background Frailty and cognitive impairment are common in the elderly, with various shared risk factors like hypertension. Frailty is a marker for future cognitive function. Moreover, whether intensive blood pressure interacted with frailty and cognitive impairment is unknown. Methods and Results We performed a post hoc analysis of data from SPRINT (Systolic Blood Pressure Intervention Trial). The relationship between frailty and a composite of probable dementia (PD) and mild cognitive impairment (MCI) was analyzed. Also, we evaluated the interaction of intensive blood pressure lowering in the relationship between frailty and cognitive impairment. A total of 8537 patients were included in our study, and 35.1% were women. The mean age of these participants was 67.9±9.3 years. According to the baseline frailty index, 1670, 4637, and 2230 patients were in fit, less fit, and frail statuses, respectively. During a mean follow-up of 4.61 years, 871 cases of PD or MCI occurred. Compared with those in fit status, those with less fit (hazard ratio [HR], 2.14 [95% CI, 1.65-2.77]) and frailty (HR, 4.28 [95% CI, 3.26-5.61]) status had a higher incidence of a composite of PD and MCI. Blood pressure control strategy interacted with the correlation between frailty and cognitive impairment. Intensive blood pressure control (HR, 2.4 [95% CI, 2.0-2.8]) accelerated the relationship between frailty and incidence of PD and MCI compared with the standard treatment group (HR, 1.8 [95% CI, 1.5-2.1]; P for interaction=0.009). Conclusions This study found that the baseline frailty status was a possible marker for the incidence of a composite of PD and MCI. Intensive blood pressure control may strengthen this correlation. Registration URL: https://clinicaltrials.gov/; Unique identifier: NCT01206062.

High-resolution and high-speed 3D tracking of microrobots using a fluorescent light field microscope.

Background: Imaging and tracking are crucial for microrobots which navigate through complex 3D environments. Fluorescent imaging (FI) by microscope offers a high-resolution and high-sensitive imaging method to study the property of microrobots. However, conventional microscope suffers from shallow depth of field (DOF) and lacks 3D imaging capability. Methods: We proposed a high-resolution and high-speed 3D tracking method for microrobots based on a fluorescent light field microscope (FLFM). We designed the FLFM system according to the size of a representative helical microrobot (150 µm body length, 50 µm screw diameter), and studied the system's performance. We also proposed a 3D tracking algorithm for microrobots using digital refocusing. Results: We validated the method by simulations and built an FLFM system to perform the tracking experiments of microrobots with representative size. Our 3D tracking method achieves a 30 fps data acquisition rate, 10 µm lateral resolution and approximately 40 µm axial resolution over a volume of 1,200×1,200×326 µm3. Results indicate that the accuracy of the method can reach about 9 µm. Conclusions: Compared with the FI by a conventional microscope, the FLFM-based method gains wider DOF and 3D imaging capability with a single-shot image. The tracking method succeeds in providing the trajectory of the microrobot with a good lateral resolution.

Chemotaxis along local chemical gradients enhanced bacteria dispersion and PAH bioavailability in a heterogenous porous medium.

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous, EPA-designated priority pollutants for soil and groundwater, remaining recalcitrant to bioremediation because of limited bioavailability. In this work, we used naphthalene as a model PAH and soil bacteria Pseudomonas putida G7 to investigate the potential role of chemotaxis to enhance access to PAHs in heterogenous porous media. To this aim, we conducted transport experiments and numerical simulations with chemotactic bacteria and naphthalene trapped within a non-aqueous phase liquid (NAPL) mainly in low permeable areas of a dual-permeability microfluidic device. Microscopic imaging showed higher accumulations of chemotactic bacteria, about eight times that of nonchemotactic bacteria, at the junctures between high and low permeability regions. Pore-scale simulations for fluid flow and naphthalene revealed that the junctures are stagnant areas of fluid flow, which generated strong and temporally persistent naphthalene gradients. The landscape and densities of bacterial accumulation at the junctures were strongly regulated by flow profiles and naphthalene gradients especially those transverse to flow. We conducted macroscale simulations using convective dispersion equations with an added chemotactic velocity to account for directed migration toward naphthalene. Simulated results showed good consistency with experiments and pore-scale simulation as normalized bacterial accumulation per mm of NAPL was 7.80, 7.84 and 7.71 mm-1 for experiments, pore-scale and macroscale simulations, respectively. Macroscale simulations indicated that in the absence of grain-boundary restrictions associated with the pore structure bacterial dispersion needed to be increased by 50 % to account for the interplay between chemotactic response and naphthalene gradients at the pore-scale level. Our work details the mechanism of pore-scale chemotaxis in enhancing bioavailability of PAHs and its impact on biomass retention at the system level, which provides a potential solution toward more efficient bioremediation for contaminants such as PAHs with limited bioavailability.

Mechanically Interlocked Hydrogel-Elastomer Strain Sensor with Robust Interface and Enhanced Water-Retention Capacity.

Hydrogels are stretchable ion conductors that can be used as strain sensors by transmitting strain-dependent electrical signals. However, hydrogels are susceptible to dehydration in the air, leading to a loss of flexibility and functions. Here, a simple and general strategy for encapsulating hydrogel with hydrophobic elastomer is proposed to realize excellent water-retention capacity. Elastomers, such as polydimethylsiloxanes (PDMS), whose hydrophobicity and dense crosslinking network can act as a barrier against water evaporation (lost 4.6 wt.% ± 0.57 in 24 h, 28 °C, and ≈30% humidity). To achieve strong adhesion between the hydrogel and elastomer, a porous structured thermoplastic polyurethane (TPU) is used at the hydrogel-elastomer interface to interlock the hydrogel and bond the elastomer simultaneously (the maximum interfacial toughness is over 1200 J/m2). In addition, a PDMS encapsulated ionic hydrogel strain sensor is proposed, demonstrating an excellent water-retention ability, superior mechanical performance, highly linear sensitivity (gauge factor = 2.21, at 100% strain), and robust interface. Various human motions were monitored, proving the effectiveness and practicability of the hydrogel-elastomer hybrid.

Relationship between orthostatic blood pressure changes and intensive blood pressure management in patients with hypertension.

INTRODUCTION: The Systolic Blood Pressure Intervention Trial (SPRINT) demonstrated that closely controlling blood pressure (BP) could decrease cardiovascular outcome risk without increasing the orthostatic hypotension rate. We aimed to evaluate the association between baseline orthostatic BP change and major adverse cardiovascular event (MACE) occurrence. METHODS: We conducted a post hoc analysis using SPRINT data including 9329 patients with hypertension. The SPRINT trial was a two-arm, multicentre, randomised clinical trial designed to test whether an intensive treatment aimed at reducing systolic BP (SBP) to <120 mm Hg would reduce cardiovascular disease risk. Orthostatic BP change was defined as baseline standing systolic BP (SBP)-baseline mean seated SBP, or diastolic BP (DBP)-baseline mean seated DBP. RESULTS: We found a U-shaped relationship between orthostatic BP changes and MACE occurrence. All lowest risk points were around 0 mm Hg. On the left side of the inflection point, MACE risk decreased with orthostatic BP change decrease (HR=0.99, 95% CI (0.98 to 1.00), p=0.04, SBP change) (HR=0.97, 95% CI (0.95 to 0.99), p<0.01, DBP change); on the right side, MACE risk increased with orthostatic BP change increase (HR=1.02, 95% CI (1.01 to 1.06), p<0.01, SBP change) (HR=1.01, 95% CI (1.00 to 1.03), p=0.16, DBP change). There was no significant interaction effect between orthostatic SBP (p for interaction=0.37) or DBP changes (p for interaction=0.33) and intensive BP management. CONCLUSIONS: Orthostatic DBP increase and SBP decrease were associated with an increased MACE risk. The benefits of intensive BP management were also consistent across different orthostatic BP change ranges.

Effect of body size and intensive blood pressure management on cardiovascular and serious adverse events.

BACKGROUND: Previous studies have shown that obese hypertensive patients have a lower risk of cardiovascular events than normal-weight patients, and that the performed hypertension treatment affects cardiovascular outcomes depending on the patient's body size. This study aimed to investigate the relationship between the BMI and cardiovascular outcomes and safety endpoints in hypertensive patients with intensive or standard blood pressure (BP) management. METHODS: We used data from the Systolic Blood Pressure Intervention Trial (SPRINT). Cox proportional hazards models were used to analyze the data. The primary endpoint was cardiovascular disease (CVD) death, and the safety endpoint was serious adverse events. RESULTS: In total, 9284 patients were included in our analysis. Thirty-seven patients in the intensive arm and 65 patients in the standard arm had CVD death. After multivariable adjustment, the BMI was not associated with the incidence of CVD death in the standard arm [hazard ratio 0.96, 95% confidence interval (CI) 0.91-1.02]. In the intensive arm, the incidence of CVD death decreased (hazard ratio 0.86, 95% CI 0.78-0.96) first and, then, increased (hazard ratio 1.15, 95% CI 1.07-1.25) with an increase in the BMI (inflection point, 32.33 kg/m2). CONCLUSION: Intensive BP management in overweight, class I, and class II obese patients significantly reduced the cardiovascular outcomes without increasing the safety risks. Nevertheless, further clinical evidence is needed to verify the effectiveness of intensive BP management in patients with normal weight and class III obesity.

Gut bacterial metabolite Urolithin A inhibits myocardial fibrosis through activation of Nrf2 pathway in vitro and in vivo.

BACKGROUND: Myocardial fibrosis after myocardial infarction (MI) is one of the leading causes of cardiovascular diseases. Cardiac fibroblasts (CFs) are activated and promoted by MI to undergo myofibroblast transformation (CMT). Urolithin A (UA) is an active and effective gut metabolite derived from polyphenolics of berries and pomegranate fruits, which has been reported to have anti-inflammatory and anti-oxidant functions. However, whether UA affects the CMT process during myocardial fibrosis remains unclear. METHODS: TGF-ß1-treated primary rat cardiac fibroblasts were used for in vitro study. Cell proliferation ability was evaluated by MTT assay. Cell migration and invasion abilities were tested by wound healing and Transwell assays. The expression of CMT process-related markers were measured by qRT-PCR and western blot. The rat MI model was established by left anterior descending coronary artery (LAD) ligation and evaluated by H&E and Masson staining. RESULTS: Our data demonstrated that UA treatment could inhibit the CMT process in TGF-ß1-induced CFs, including cell proliferation, migration and invasion abilities. Knocking down of Nrf2, which was activated by UA treatment, could mitigate the effects of UA treatment on CMT process. Moreover, in vivo administration of UA in rat MI model successfully up-regulated Nrf2 expression and improved the myocardial damage and fibrosis. CONCLUSIONS: The study discovered the function and mechanism of UA on myocardial fibrosis and demonstrated the protective effects of UA administration through activation of Nrf2 pathway.

Apelin pathway in cardiovascular, kidney, and metabolic diseases: Therapeutic role of apelin analogs and apelin receptor agonists.

The apelin/apelin receptor (ApelinR) signal transduction pathway exerts essential biological roles, particularly in the cardiovascular system. Disturbances in the apelin/ApelinR axis are linked to vascular, heart, kidney, and metabolic disorders. Therefore, the apelinergic system has surfaced as a critical therapeutic strategy for cardiovascular diseases (including pulmonary arterial hypertension), kidney disease, insulin resistance, hyponatremia, preeclampsia, and erectile dysfunction. However, apelin peptides are susceptible to rapid degradation through endogenous peptidases, limiting their use as therapeutic tools and translational potential. These proteases include angiotensin converting enzyme 2, neutral endopeptidase, and kallikrein thereby linking the apelin pathway with other peptide systems. In this context, apelin analogs with enhanced proteolytic stability and synthetic ApelinR agonists emerged as promising pharmacological alternatives. In this review, we focus on discussing the putative roles of the apelin pathway in various physiological systems from function to dysfunction, and emphasizing the therapeutic potential of newly generated metabolically stable apelin analogs and non-peptide ApelinR agonists.

Tensor Network-Encrypted Physical Anti-counterfeiting Passport for Digital Twin Authentication.

The trend of digitalization has produced rapidly increasing data interaction and authentication demand in today's internet of things ecosystem. To face the challenge, we demonstrated a micro-scale label by direct laser writing to perform as a passport between the physical and digital worlds. On this label, the user information is encrypted into three-dimensional geometric structures by a tensor network and then authenticated through the decryption system based on computer vision. A two-step printing methodology is applied to code the randomly distributed fluorescence from doped quantum dots, which achieved physical unclonable functions (PUFs) of the passport. The 105 bits/mm2 data storage density enables abundant encrypted information from physical worlds, for example, the biometric data of human users. This passport guarantees the strong correlation between the user's privacy data and the PUF-assisted codes, successfully overcoming the illegal transfer of authentication information. Due to its ultra-high security level and convenience, the printed passport has enormous potential in future digital twin authentication anytime anywhere, including personal identity, valuable certificates, and car networking.

Traditional Cardiovascular Risk Factors and Coronary Collateral Circulation: A Meta-Analysis.

Objective: Patients with well-developed coronary collateral circulation (CC) usually have low mortality, improved cardiac function, and reduced infarct size. Currently, there is conflicting evidence on the association between traditional cardiovascular risk factors (diabetes, hypertension, and smoking habit) and CC. Design: We performed a meta-analysis of case-control studies to better understand such associations. Data Sources: We searched the MEDINE, EMBASE, and Science Citation Index databases to identify relevant studies. Eligibility Criteria for Selecting Studies: Case control studies reporting data on risk factors (smoking habit, hypertension, and diabetes mellites) in comparing cases between poor CC and well-developed CC groups. Well-developed CC was the primary outcome of this meta-analysis Data Extraction and Synthesis: Relevant data were extracted by two independent investigators. We derived pooled odds ratios (ORs) with random effects models. We performed quality assessments, publication bias, and sensitivity analysis to ensure the reliability of our results. Results: In total, 18 studies that had 4,746 enrolled patients were analyzed. Our results showed that hypertension and smoking habit did not (OR = 0.94, 95% CI: 0.75-1.17, p = 0.564 and OR = 1.00, 95% CI: 0.84-1.18, p = 0.970, respectively), and diabetes did (OR = 0.50, 95% CI: 0.38-0.67, p = 0.00001) affect the development of CC. Conclusion: Unlike hypertension and smoking habit, diabetes was associated with poor CC formation. Trial Registration Number: https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=87821, identifier: CRD42018087821.

The association of interferon-alpha with development of collateral circulation after artery occlusion.

BACKGROUND: Previous studies have demonstrated that interferon (IFN) signaling is enhanced in patients with poor collateral circulation (CC). However, the role and mechanisms of IFN-alpha in the development of CC remain unknown. METHODS: We studied the serum levels of IFN-alpha and coronary CC in a case-control study using logistics regression, including 114 coronary chronic total occlusion (CTO) patients with good coronary CC and 94 CTO patients with poor coronary CC. Restricted cubic splines was used to flexibly model the association of the levels of IFN-alpha with the incidence of good CC perfusion restoration after systemic treatment with IFN-alpha was assessed in a mice hind-limb ischemia model. RESULTS: Compared with the first IFN-alpha tertile, the risk of poor CC was higher in the third IFN-alpha tertile (OR: 4.79, 95% CI: 2.22-10.4, p < .001). A cubic spline-smoothing curve showed that the risk of poor CC increased with increasing levels of serum IFN-alpha. IFN-alpha inhibited the development of CC in a hindlimb ischemia model. Arterioles of CC in the IFN-alpha group were smaller in diameter than in the control group. CONCLUSION: Patients with CTO and with poor CC have higher serum levels of IFN-alpha than CTO patients with good CC. IFN-alpha might impair the development of CC after artery occlusion.

Hb Levels and Sex Differences in Relation to Short-Term Outcomes in Patients With Acute Myocardial Infarction.

Background: Women had worse outcomes after acute myocardial infarction (AMI), and physiologically, women had lower hemoglobin values. We examined whether there were sex-related differences in the relationship between hemoglobin levels and adverse outcomes in patients with acute myocardial infarction. Method: We conducted a post-hoc analysis of data from the Acute Coronary Syndrome Quality Improvement in Kerala (ACS-QUIK) Study. We explored the relationship between baseline hemoglobin level and 30-days adverse outcomes by logistic regression model, generalized additive model (GAM) and two-piecewise linear regression model. We used multiple imputation, based on five replications and a chained equation approach method in the R multiple imputation procedure, to account for missing data. The primary outcome were 30-day major adverse cardiovascular events (MACEs) defined as death, reinfarction, stroke, and major bleeding. The secondary outcomes were 30-day major bleeding, 30-day stroke and 30-day cardiovascular death (CVD death). Results: Twenty thousand, five hundred fifty-nine patients with AMI were included in our analysis. Baseline hemoglobin level was associated with major bleeding [OR: 0.74, 95%CI (0.60, 0.92) P < 0.01], CVD death [OR: 0.94, 95%CI (0.90, 0.99) P < 0.01], and MACEs [OR: 0.95, 95%CI (0.92, 0.99) P < 0.01]. There was no significant relationship between baseline hemoglobin level and stroke incidence in both men [OR: 1.02, 95%CI (0.90, 1.14) P = 0.77] and women [OR: 1.15, 95%CI (0.96, 1.37) P = 0.18]. Baseline hemoglobin level was associated with major bleeding [OR: 0.71, 95%CI (0.58, 0.85) P < 0.01] in male patients, however we did not find the same relationship in female patients [OR: 0.89, 95%CI (0.56, 1.41) P = 0.61]. GAM and two-piecewise linear regression model showed the relationships of hemoglobin level with major bleeding, CVD death, and MACEs were non-linear (non-linear P < 0.05), and the threshold value were 13, 14.8, and 14.3 g/dL for MACEs and CVD death, respectively. Conclusion: Baseline hemoglobin level was one of the independent predictors of prognosis in South Asia patients with acute myocardial infarction. Moreover, its impact on prognosis was largely different depending on the patients' sex.