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1. Look Ma, no markers: holistic performance capture without the hassle

Author

Hewitt, Charlie, Saleh, Fatemeh, Aliakbarian, Sadegh, Petikam, Lohit, Rezaeifar, Shideh, Florentin, Louis, Hosenie, Zafiirah, Cashman, Thomas J, Valentin, Julien, Cosker, Darren, and Baltrusaitis, Tadas

Subjects
Computer Science - Computer Vision and Pattern Recognition, Computer Science - Graphics
Abstract

We tackle the problem of highly-accurate, holistic performance capture for the face, body and hands simultaneously. Motion-capture technologies used in film and game production typically focus only on face, body or hand capture independently, involve complex and expensive hardware and a high degree of manual intervention from skilled operators. While machine-learning-based approaches exist to overcome these problems, they usually only support a single camera, often operate on a single part of the body, do not produce precise world-space results, and rarely generalize outside specific contexts. In this work, we introduce the first technique for marker-free, high-quality reconstruction of the complete human body, including eyes and tongue, without requiring any calibration, manual intervention or custom hardware. Our approach produces stable world-space results from arbitrary camera rigs as well as supporting varied capture environments and clothing. We achieve this through a hybrid approach that leverages machine learning models trained exclusively on synthetic data and powerful parametric models of human shape and motion. We evaluate our method on a number of body, face and hand reconstruction benchmarks and demonstrate state-of-the-art results that generalize on diverse datasets.

Published
2024
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4. VolTeMorph: Realtime, Controllable and Generalisable Animation of Volumetric Representations

Author

Garbin, Stephan J., Kowalski, Marek, Estellers, Virginia, Szymanowicz, Stanislaw, Rezaeifar, Shideh, Shen, Jingjing, Johnson, Matthew, and Valentin, Julien

Subjects
Computer Science - Graphics, Computer Science - Computer Vision and Pattern Recognition
Abstract

The recent increase in popularity of volumetric representations for scene reconstruction and novel view synthesis has put renewed focus on animating volumetric content at high visual quality and in real-time. While implicit deformation methods based on learned functions can produce impressive results, they are `black boxes' to artists and content creators, they require large amounts of training data to generalise meaningfully, and they do not produce realistic extrapolations outside the training data. In this work we solve these issues by introducing a volume deformation method which is real-time, easy to edit with off-the-shelf software and can extrapolate convincingly. To demonstrate the versatility of our method, we apply it in two scenarios: physics-based object deformation and telepresence where avatars are controlled using blendshapes. We also perform thorough experiments showing that our method compares favourably to both volumetric approaches combined with implicit deformation and methods based on mesh deformation., Comment: 18 pages, 21 figures

Published
2022

5. Offline Reinforcement Learning as Anti-Exploration

Author

Rezaeifar, Shideh, Dadashi, Robert, Vieillard, Nino, Hussenot, Léonard, Bachem, Olivier, Pietquin, Olivier, and Geist, Matthieu

Subjects
Computer Science - Machine Learning
Abstract

Offline Reinforcement Learning (RL) aims at learning an optimal control from a fixed dataset, without interactions with the system. An agent in this setting should avoid selecting actions whose consequences cannot be predicted from the data. This is the converse of exploration in RL, which favors such actions. We thus take inspiration from the literature on bonus-based exploration to design a new offline RL agent. The core idea is to subtract a prediction-based exploration bonus from the reward, instead of adding it for exploration. This allows the policy to stay close to the support of the dataset. We connect this approach to a more common regularization of the learned policy towards the data. Instantiated with a bonus based on the prediction error of a variational autoencoder, we show that our agent is competitive with the state of the art on a set of continuous control locomotion and manipulation tasks.

Published
2021

6. Offline Reinforcement Learning with Pseudometric Learning

Author

Dadashi, Robert, Rezaeifar, Shideh, Vieillard, Nino, Hussenot, Léonard, Pietquin, Olivier, and Geist, Matthieu

Subjects
Computer Science - Machine Learning
Abstract

Offline Reinforcement Learning methods seek to learn a policy from logged transitions of an environment, without any interaction. In the presence of function approximation, and under the assumption of limited coverage of the state-action space of the environment, it is necessary to enforce the policy to visit state-action pairs close to the support of logged transitions. In this work, we propose an iterative procedure to learn a pseudometric (closely related to bisimulation metrics) from logged transitions, and use it to define this notion of closeness. We show its convergence and extend it to the function approximation setting. We then use this pseudometric to define a new lookup based bonus in an actor-critic algorithm: PLOFF. This bonus encourages the actor to stay close, in terms of the defined pseudometric, to the support of logged transitions. Finally, we evaluate the method on hand manipulation and locomotion tasks., Comment: ICML 2021

Published
2021

7. Information bottleneck through variational glasses

Author

Voloshynovskiy, Slava, Kondah, Mouad, Rezaeifar, Shideh, Taran, Olga, Holotyak, Taras, and Rezende, Danilo Jimenez

Subjects
Computer Science - Computer Vision and Pattern Recognition
Abstract

Information bottleneck (IB) principle [1] has become an important element in information-theoretic analysis of deep models. Many state-of-the-art generative models of both Variational Autoencoder (VAE) [2; 3] and Generative Adversarial Networks (GAN) [4] families use various bounds on mutual information terms to introduce certain regularization constraints [5; 6; 7; 8; 9; 10]. Accordingly, the main difference between these models consists in add regularization constraints and targeted objectives. In this work, we will consider the IB framework for three classes of models that include supervised, unsupervised and adversarial generative models. We will apply a variational decomposition leading a common structure and allowing easily establish connections between these models and analyze underlying assumptions. Based on these results, we focus our analysis on unsupervised setup and reconsider the VAE family. In particular, we present a new interpretation of VAE family based on the IB framework using a direct decomposition of mutual information terms and show some interesting connections to existing methods such as VAE [2; 3], beta-VAE [11], AAE [12], InfoVAE [5] and VAE/GAN [13]. Instead of adding regularization constraints to an evidence lower bound (ELBO) [2; 3], which itself is a lower bound, we show that many known methods can be considered as a product of variational decomposition of mutual information terms in the IB framework. The proposed decomposition might also contribute to the interpretability of generative models of both VAE and GAN families and create a new insights to a generative compression [14; 15; 16; 17]. It can also be of interest for the analysis of novelty detection based on one-class classifiers [18] with the IB based discriminators.

Published
2019

8. $\rho$-VAE: Autoregressive parametrization of the VAE encoder

Author

Ferdowsi, Sohrab, Diephuis, Maurits, Rezaeifar, Shideh, and Voloshynovskiy, Slava

Subjects
Computer Science - Machine Learning, Computer Science - Computer Vision and Pattern Recognition, Statistics - Machine Learning
Abstract

We make a minimal, but very effective alteration to the VAE model. This is about a drop-in replacement for the (sample-dependent) approximate posterior to change it from the standard white Gaussian with diagonal covariance to the first-order autoregressive Gaussian. We argue that this is a more reasonable choice to adopt for natural signals like images, as it does not force the existing correlation in the data to disappear in the posterior. Moreover, it allows more freedom for the approximate posterior to match the true posterior. This allows for the repararametrization trick, as well as the KL-divergence term to still have closed-form expressions, obviating the need for its sample-based estimation. Although providing more freedom to adapt to correlated distributions, our parametrization has even less number of parameters than the diagonal covariance, as it requires only two scalars, $\rho$ and $s$, to characterize correlation and scaling, respectively. As validated by the experiments, our proposition noticeably and consistently improves the quality of image generation in a plug-and-play manner, needing no further parameter tuning, and across all setups. The code to reproduce our experiments is available at \url{https://github.com/sssohrab/rho_VAE/}., Comment: Submitted to NeurIPS workshop on Bayesian deep learning

Published
2019

9. Robustification of deep net classifiers by key based diversified aggregation with pre-filtering

Author

Taran, Olga, Rezaeifar, Shideh, Holotyak, Taras, and Voloshynovskiy, Slava

Subjects
Computer Science - Machine Learning, Computer Science - Cryptography and Security, Statistics - Machine Learning
Abstract

In this paper, we address a problem of machine learning system vulnerability to adversarial attacks. We propose and investigate a Key based Diversified Aggregation (KDA) mechanism as a defense strategy. The KDA assumes that the attacker (i) knows the architecture of classifier and the used defense strategy, (ii) has an access to the training data set but (iii) does not know the secret key. The robustness of the system is achieved by a specially designed key based randomization. The proposed randomization prevents the gradients' back propagation or the creating of a "bypass" system. The randomization is performed simultaneously in several channels and a multi-channel aggregation stabilizes the results of randomization by aggregating soft outputs from each classifier in multi-channel system. The performed experimental evaluation demonstrates a high robustness and universality of the KDA against the most efficient gradient based attacks like those proposed by N. Carlini and D. Wagner and the non-gradient based sparse adversarial perturbations like OnePixel attacks.

Published
2019

10. Reconstruction of Privacy-Sensitive Data from Protected Templates

Author

Rezaeifar, Shideh, Razeghi, Behrooz, Taran, Olga, Holotyak, Taras, and Voloshynovskiy, Slava

Subjects
Computer Science - Machine Learning, Computer Science - Cryptography and Security, Computer Science - Information Retrieval, Statistics - Machine Learning
Abstract

In this paper, we address the problem of data reconstruction from privacy-protected templates, based on recent concept of sparse ternary coding with ambiguization (STCA). The STCA is a generalization of randomization techniques which includes random projections, lossy quantization, and addition of ambiguization noise to satisfy the privacy-utility trade-off requirements. The theoretical privacy-preserving properties of STCA have been validated on synthetic data. However, the applicability of STCA to real data and potential threats linked to reconstruction based on recent deep reconstruction algorithms are still open problems. Our results demonstrate that STCA still achieves the claimed theoretical performance when facing deep reconstruction attacks for the synthetic i.i.d. data, while for real images special measures are required to guarantee proper protection of the templates., Comment: accepted at ICIP 2019

Published
2019

11. Defending against adversarial attacks by randomized diversification

Author

Taran, Olga, Rezaeifar, Shideh, Holotyak, Taras, and Voloshynovskiy, Slava

Subjects
Computer Science - Machine Learning, Computer Science - Cryptography and Security, Statistics - Machine Learning
Abstract

The vulnerability of machine learning systems to adversarial attacks questions their usage in many applications. In this paper, we propose a randomized diversification as a defense strategy. We introduce a multi-channel architecture in a gray-box scenario, which assumes that the architecture of the classifier and the training data set are known to the attacker. The attacker does not only have access to a secret key and to the internal states of the system at the test time. The defender processes an input in multiple channels. Each channel introduces its own randomization in a special transform domain based on a secret key shared between the training and testing stages. Such a transform based randomization with a shared key preserves the gradients in key-defined sub-spaces for the defender but it prevents gradient back propagation and the creation of various bypass systems for the attacker. An additional benefit of multi-channel randomization is the aggregation that fuses soft-outputs from all channels, thus increasing the reliability of the final score. The sharing of a secret key creates an information advantage to the defender. Experimental evaluation demonstrates an increased robustness of the proposed method to a number of known state-of-the-art attacks.

Published
2019

13. Classification by Re-generation: Towards Classification Based on Variational Inference

Author

Rezaeifar, Shideh, Taran, Olga, and Voloshynovskiy, Slava

Subjects
Computer Science - Computer Vision and Pattern Recognition
Abstract

As Deep Neural Networks (DNNs) are considered the state-of-the-art in many classification tasks, the question of their semantic generalizations has been raised. To address semantic interpretability of learned features, we introduce a novel idea of classification by re-generation based on variational autoencoder (VAE) in which a separate encoder-decoder pair of VAE is trained for each class. Moreover, the proposed architecture overcomes the scalability issue in current DNN networks as there is no need to re-train the whole network with the addition of new classes and it can be done for each class separately. We also introduce a criterion based on Kullback-Leibler divergence to reject doubtful examples. This rejection criterion should improve the trust in the obtained results and can be further exploited to reject adversarial examples.

Published
2018

14. Bridging machine learning and cryptography in defence against adversarial attacks

Author

Taran, Olga, Rezaeifar, Shideh, and Voloshynovskiy, Slava

Subjects
Computer Science - Cryptography and Security, Computer Science - Machine Learning, Statistics - Machine Learning
Abstract

In the last decade, deep learning algorithms have become very popular thanks to the achieved performance in many machine learning and computer vision tasks. However, most of the deep learning architectures are vulnerable to so called adversarial examples. This questions the security of deep neural networks (DNN) for many security- and trust-sensitive domains. The majority of the proposed existing adversarial attacks are based on the differentiability of the DNN cost function.Defence strategies are mostly based on machine learning and signal processing principles that either try to detect-reject or filter out the adversarial perturbations and completely neglect the classical cryptographic component in the defence. In this work, we propose a new defence mechanism based on the second Kerckhoffs's cryptographic principle which states that the defence and classification algorithm are supposed to be known, but not the key. To be compliant with the assumption that the attacker does not have access to the secret key, we will primarily focus on a gray-box scenario and do not address a white-box one. More particularly, we assume that the attacker does not have direct access to the secret block, but (a) he completely knows the system architecture, (b) he has access to the data used for training and testing and (c) he can observe the output of the classifier for each given input. We show empirically that our system is efficient against most famous state-of-the-art attacks in black-box and gray-box scenarios.

Published
2018

23. Durable functional limitation in patients with coronavirus disease-2019 admitted to intensive care and the effect of intermediate-dose vs standard-dose anticoagulation on functional outcomes

Author

Sadeghipour, P., Talasaz, A.H., Barco, S., Bakhshandeh, H., Rashidi, F., Rafiee, F., Rezaeifar, P., Jamalkhani, S., Matin, S., Baghizadeh, E., Tahamtan, O., Sharif-Kashani, B., Beigmohammadi, M.T., Farrokhpour, M., Sezavar, S.H., Payandemehr, P., Dabbagh, A., Moghadam, K.G., Jimenez, D., Monreal, M., Maleki, M., Siegerink, B., Spatz, E.S., Piazza, G., Parikh, S.A., Kirtane, A.J., Tassell, B.W. van, Lip, G.Y.H., Goldhaber, S.Z., Klok, F.A., Krumholz, H.M., Bikdeli, B., and Inspiration Investigators

Subjects
Hospitalization, Male, The post-COVID-19 functional status scale, Patient health questionnaire-2, Anticoagulation, Critical Care, SARS-CoV-2, Internal Medicine, Anticoagulants, Humans, COVID-19, Female, Middle Aged
Abstract

Introduction: Patients affected with severe forms of coronavirus disease 2019 (COVID-19) suffer from a wide range of sequelae, from limited airway diseases to multiple organ failure. These sequelae may create exercise limitation, impair the daily activity and thus impact the mental health and the social life. However, the extent of functional limitations and depressive symptoms are understudied especially in patients with COVID-19 after intensive care unit (ICU) hospitalization. Methods: The Intermediate versus Standard-dose Prophylactic anticoagulation In cRitically-ill pATIents with COVID-19: An opeN label randomized controlled trial (INSPIRATION) was a clinical trial that randomized ICU patients with COVID-19 to intermediate-dose vs standard-dose anticoagulation. In the current study, we assessed the interval change in 30-day and 90-day functional limitations based on the post-COVID-19 functional status scale (PCFS) and depressive symptoms based on the Patient Health Questionnaire-2 (PHQ-2) in the trial participants. We also assessed the effect of intermediate-dose vs standard-dose prophylactic anticoagulation on the functional outcomes and depressive symptoms. Results: Of 600 randomized patients in INSPIRATION, 375 (age: 62 years; 42% women) participated in the functional status study. 195 patients died during the 90-day follow up (191 by day 30). Among survivors, between day 30 and day 90, the proportion of patients with moderate-to-severe functional limitation (PCSF grade 3-or-4) decreased from 20.0% to 4.8% (P = 3 decreased from 25.5% to 16.6% (P = 0.05). The proportion of patients with no functional limitations (PCFS grade 0) increased (4.2% to 15.4%, P= 3 (17.9% vs 15.3%; OR, 1.14, [95% CI, 0.79-1.65]; P = 0.14), with similar results when accounting for study center. Conclusion: In patients with COVID-19 admitted to the ICU, functional limitations and depressive symptoms were common at 30-day follow-up and had some improvement by 90-day follow-up among survivors. Intermediate-dose compared to standard-dose prophylactic anticoagulation did not improve functional outcomes.

Published
2022
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27. Intermediate-Dose versus Standard-Dose Prophylactic Anticoagulation in Patients with COVID-19 Admitted to the Intensive Care Unit: 90-Day Results from the INSPIRATION Randomized Trial

Author

Bikdeli, Behnood, Talasaz, Azita H., Rashidi, Farid, Bakhshandeh, Hooman, Rafiee, Farnaz, Rezaeifar, Parisa, Baghizadeh, Elahe, Matin, Samira, Jamalkhani, Sepehr, Tahamtan, Ouria, Sharif-Kashani, Babak, Beigmohammadi, Mohammad Taghi, Farrokhpour, Mohsen, Sezavar, Seyed Hashem, Payandemehr, Pooya, Dabbagh, Ali, Moghadam, Keivan Gohari, Khalili, Hossein, Yadollahzadeh, Mahdi, Riahi, Taghi, Abedini, Atefeh, Lookzadeh, Somayeh, Rahmani, Hamid, Zoghi, Elnaz, Mohammadi, Keyhan, Sadeghipour, Pardis, Abri, Homa, Tabrizi, Sanaz, Mousavian, Seyed Masoud, Shahmirzaei, Shaghayegh, Amin, Ahmad, Mohebbi, Bahram, Parhizgar, Seyed Ehsan, Aliannejad, Rasoul, Eslami, Vahid, Kashefizadeh, Alireza, Dobesh, Paul P., Kakavand, Hessam, Hosseini, Seyed Hossein, Shafaghi, Shadi, Ghazi, Samrand Fattah, Najafi, Atabak, Jimenez, David, Gupta, Aakriti, Madhavan, Mahesh V., Sethi, Sanjum S., Parikh, Sahil A., Monreal, Manuel, Hadavand, Naser, Hajighasemi, Alireza, Maleki, Majid, Sadeghian, Saeed, Piazza, Gregory, Kirtane, Ajay J., Van Tassell, Benjamin W., Stone, Gregg W., Lip, Gregory Y. H., Krumholz, Harlan M., Goldhaber, Samuel Z., and Sadeghipour, Parham

Published
2022
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29. Hot-electron emission processes in waveguide-integrated graphene

Author

Rezaeifar, Fatemeh, Ahsan, Ragib, Lin, Qingfeng, Chae, Hyun Uk, and Kapadia, Rehan

Abstract

Photoemission plays a central role in a wide range of fields, from electronic structure measurements to free-electron laser sources. In metallic emitters, single-photon1, multiphoton2–5or strong-field emission6–10processes are the primary photoemission mechanisms. Here, using a sub-work-function 3.06 eV continuous-wave laser, photoemission from waveguide-integrated monolayer graphene is observed to occur at peak power densities >5 orders of magnitude lower than reported multiphoton and strong-field emission6,11,12. The behaviour is explained by the emission of hot electrons in graphene. In monolayer graphene, the need for photoelectrons to be transported to an emitting surface is eliminated, dramatically enhancing the probability of emission before thermalization. These results indicate that integrated-photonics-driven hot-electron emission provides a rich new area of exploration for both electron emission and integrated photonics.

Published
2019
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30. High Quantum Efficiency Hot Electron Electrochemistry

Author

Chae, Hyun Uk, Ahsan, Ragib, Lin, Qingfeng, Sarkar, Debarghya, Rezaeifar, Fatemeh, Cronin, Stephen B., and Kapadia, Rehan

Abstract

Using hot electrons to drive electrochemical reactions has drawn considerable interest in driving high-barrier reactions and enabling efficient solar to fuel conversion. However, the conversion efficiency from hot electrons to electrochemical products is typically low due to high hot electron scattering rates. Here, it is shown that the hydrogen evolution reaction (HER) in an acidic solution can be efficiently modulated by hot electrons injected into a thin gold film by an Au–Al2O3–Si metal–insulator–semiconductor (MIS) junction. Despite the large scattering rates in gold, it is shown that the hot electron driven HER can reach quantum efficiencies as high as ∼85% with a shift in the onset of hydrogen evolution by ∼0.6 V. By simultaneously measuring the currents from the solution, gold, and silicon terminals during the experiments, we find that the HER rate can be decomposed into three components: (i) thermal electron, corresponding to the thermal electron distribution in gold; (ii) hot electron, corresponding to electrons injected from silicon into gold which drive the HER before fully thermalizing; and (iii) silicon direct injection, corresponding to electrons injected from Si into gold that drive the HER before electron–electron scattering occurs. Through a series of control experiments, we eliminate the possibility of the observed HER rate modulation coming from lateral resistivity of the thin gold film, pinholes in the gold, oxidation of the MIS device, and measurement circuit artifacts. Next, we theoretically evaluate the feasibility of hot electron injection modifying the available supply of electrons. Considering electron–electron and electron–phonon scattering, we track how hot electrons injected at different energies interact with the gold–solution interface as they scatter and thermalize. The simulator is first used to reproduce other published experimental pump–probe hot electron measurements, and then simulate the experimental conditions used here. These simulations predict that hot electron injection first increases the supply of electrons to the gold–solution interface at higher energies by several orders of magnitude and causes a peaked electron interaction with the gold–solution interface at the electron injection energy. The first prediction corresponds to the observed hot electron electrochemical current, while the second prediction corresponds to the observed silicon direct injection current. These results indicate that MIS devices offer a versatile platform for hot electron sources that can efficiently drive electrochemical reactions.

Published
2024
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33. Secure and privacy-aware traffic information as a service in VANET-based clouds.

Author

Hussain, Rasheed, Rezaeifar, Zeinab, Lee, Yong-Hwan, and Oh, Heekuck

Subjects
VEHICULAR ad hoc networks, CLOUD computing, AD hoc computer networks, INTELLIGENT transportation systems, TECHNOLOGY
Abstract

The multitude of applications and services in Vehicular Ad hoc NETwork (VANET) and cloud computing technology that are dreamed of in the near future, are visible today. VANET applications are set to explode in the next couple of years as a result of the advancements in the wireless communication technologies and automobile industry. Nevertheless, it is speculated that future high-end vehicles will potentially under-utilize their on-board storage, computation, and communication resources. This phenomenon sets the ground for the evolution of traditional VANET to a rather more applications-rich paradigm referred to as VANET-based clouds. In this paper, we aim at a framework of VANET-based clouds namely VANET using Clouds (VuC) and propose a novel secure and privacy-aware service referred to as Traffic Information as a Service (TIaaS) atop the cloud computing services stack. TIaaS provides vehicles (more precisely subscribers) with fine-grained traffic information from the cloud as a result of subscribers’ cooperation with the cloud in a privacy-preserving way. Legitimate VANET users share their frequent whereabouts information referred to as Mobility Vectors (MV) with the cloud infrastructure through gateways (static Road Side Units—RSUs and mobile vehicles with 3/4 G Internet). The gateways forward coarse-grained traffic information (MVs) from vehicles to the cloud whereas after processing, cloud modules construct and re-forward the fine-grained traffic information along with location-based warnings to the subscribers based on their physical locations and moving directions. The communication among vehicles, gateways, and the cloud infrastructure is carried out in a privacy-preserving way. More precisely vehicles share their MVs with cloud infrastructure anonymously. The MVs are hard to link to the sender, until and unless necessary, otherwise. Similarly every vehicle receives fine-grained traffic information in a privacy-preserving manner. The proposed TIaaS keeps the adversaries at bay from abusing users’ privacy and/or constructing profiles against targeted users. Moreover for location confidentiality and privacy, we also propose a novel location-based encryption technique that keeps the insider and outsider adversaries at bay from manipulating the contents of the message. Furthermore, the proposed TIaaS preserves conditional privacy and with the help of an efficient revocation mechanism, revocation authorities can revoke any node in case of a dispute. The proposed TIaaS also introduces the thin-client concept for vehicles where most of the time-consuming processing is offloaded to the cloud and the processing resources of the vehicles can be used elsewhere, for instance for the critical safety related applications. More precisely the cloud processes the big traffic data (BTD) and produces timely, decisive, and meaningful results. [ABSTRACT FROM AUTHOR]

Published
2015
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34. Atorvastatin versus Placebo in ICU Patients with COVID-19: Ninety-day Results of the INSPIRATION-S Trial

Author

Talasaz, Azita H., Sadeghipour, Parham, Bakhshandeh, Hooman, Sharif-Kashani, Babak, Rashidi, Farid, Beigmohammadi, Mohammad Taghi, Moghadam, Keivan Gohari, Rezaian, Somaye, Dabbagh, Ali, Sezavar, Seyed Hashem, Farrokhpour, Mohsen, Abedini, Atefeh, Aliannejad, Rasoul, Riahi, Taghi, Yadollahzadeh, Mahdi, Lookzadeh, Somayeh, Rezaeifar, Parisa, Matin, Samira, Tahamtan, Ouria, Mohammadi, Keyhan, Zoghi, Elnaz, Rahmani, Hamid, Hosseini, Seyed Hossein, Mousavian, Seyed Masoud, Abri, Homa, Sadeghipour, Pardis, Baghizadeh, Elahe, Rafiee, Farnaz, Jamalkhani, Sepehr, Amin, Ahmad, Mohebbi, Bahram, Parhizgar, Seyed Ehsan, Soleimanzadeh, Mahshid, Aghakouchakzadeh, Maryam, Eslami, Vahid, Payandemehr, Pooya, Khalili, Hossein, Talakoob, Hamed, Tojari, Taranom, Shafaghi, Shadi, Tabrizi, Sanaz, Kakavand, Hessam, Kashefizadeh, Alireza, Najafi, Atabak, Jimenez, David, Gupta, Aakriti, Madhavan, Mahesh V., Sethi, Sanjum S., Parikh, Sahil A., Monreal, Manuel, Hadavand, Naser, Hajighasemi, Alireza, Ansarin, Khalil, Maleki, Majid, Sadeghian, Saeed, Barco, Stefano, Siegerink, Bob, Spatz, Erica S., Piazza, Gregory, Kirtane, Ajay J., Tassell, Benjamin W. Van, Lip, Gregory Y. H., Klok, Frederikus A., Goldhaber, Samuel Z., Stone, Gregg W., Krumholz, Harlan M., and Bikdeli, Behnood

Published
2023
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36. Shrapnel splinter in the common bile duct.

Author

Somi MH and Rezaeifar P

Abstract

Obstructive jaundice is infrequently caused by a foreign body. We report a 42-year-old man who presented with obstructive jaundice by an impacted shrapnel splinter in the common bile duct (CBD) 23 years after a combat injury. To our knowledge, this is the first case report of this type in Iranian literature, although there are a few reports of combat related injuries in other countries. This diagnosis should be considered in the assessment of any patient with jaundice and abdominal pain who has experienced a previous combat injury. [ABSTRACT FROM AUTHOR]

Published
2010

37. Tissue plasminogen activator for the treatment of adults with critical COVID-19: A pilot randomized clinical trial.

Author

Rashidi F, Barco S, Rezaeifar P, Sadeghipour P, Ghodrati S, Bakhshandeh H, Mousavi-Aghdas SA, Sadeghi A, Sharifi A, Valizadeh H, Mikaeili H, Rafiee F, Navarbaf Z, Farajian G, Mahmoodpoor A, Bikdeli B, and Ansarin K

Subjects
Adult, Fibrinolysis, Fibrinolytic Agents therapeutic use, Humans, Pilot Projects, SARS-CoV-2, Tissue Plasminogen Activator pharmacology, Tissue Plasminogen Activator therapeutic use, COVID-19 Drug Treatment
Published
2022
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38. The early start of hemoperfusion decreases the mortality rate among severe COVID-19 patients: A preliminary study.

Author

Mikaeili H, Taghizadieh A, Nazemiyeh M, Rezaeifar P, Zununi Vahed S, Safiri S, Ardalan M, and Ansarin K

Subjects
Humans, Renal Dialysis, Respiration, Artificial, SARS-CoV-2, COVID-19 therapy, Hemoperfusion
Abstract

Background: Coronavirus disease-2019 (COVID-19)-related organ failure is partly related to a sepsis-like syndrome and extreme pro-inflammatory cytokine release, named cytokine storm. Therapeutic strategies that prevent the production of or remove the pro-inflammatory cytokines could potentially be an effective therapy in critically afflicted COVID-19 patients., Methods: In this clinical trial study, from April until June 2020, 68 COVID-19 patients (35 vs. 33 controls) with severe critical symptoms, and PaO 2 /FiO 2 (P/F) ratio less than 200 mmHg either received a single standard therapy or a combination of standard treatment for COVID-19 combined with hemoperfusion (hemofilter, HA330 D Javfron) for 4 h, in 3 consecutive days. The length of hospital stay and mechanical ventilation, the resolution of radiologic abnormalities, and the mortality rate were defined as the primary outcomes., Results: Demographic characteristics, the acute physiology, and chronic health evaluation score of both groups were similar (p > 0.05). Importantly, we noticed a significant mortality rate reduction in the perfused group compared with controls (37.1% vs. 63.6%, p = 0.02), this positive effect was stronger among those with a P/F ratio higher than 75 (mortality rate of 84.7% for P/F ratio < 75 vs. 15.4% for P/F ratio ≥ 75, p = 0.02)., Conclusions: The results imply that early start of hemoperfusion could be more effective and significantly reduce the mortality rate among COVID-19 patients with critical diseases., (© 2021 International Society for Hemodialysis.)

Published
2022
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39. Effect of Intermediate-Dose vs Standard-Dose Prophylactic Anticoagulation on Thrombotic Events, Extracorporeal Membrane Oxygenation Treatment, or Mortality Among Patients With COVID-19 Admitted to the Intensive Care Unit: The INSPIRATION Randomized Clinical Trial.

Author

Sadeghipour P, Talasaz AH, Rashidi F, Sharif-Kashani B, Beigmohammadi MT, Farrokhpour M, Sezavar SH, Payandemehr P, Dabbagh A, Moghadam KG, Jamalkhani S, Khalili H, Yadollahzadeh M, Riahi T, Rezaeifar P, Tahamtan O, Matin S, Abedini A, Lookzadeh S, Rahmani H, Zoghi E, Mohammadi K, Sadeghipour P, Abri H, Tabrizi S, Mousavian SM, Shahmirzaei S, Bakhshandeh H, Amin A, Rafiee F, Baghizadeh E, Mohebbi B, Parhizgar SE, Aliannejad R, Eslami V, Kashefizadeh A, Kakavand H, Hosseini SH, Shafaghi S, Ghazi SF, Najafi A, Jimenez D, Gupta A, Madhavan MV, Sethi SS, Parikh SA, Monreal M, Hadavand N, Hajighasemi A, Maleki M, Sadeghian S, Piazza G, Kirtane AJ, Van Tassell BW, Dobesh PP, Stone GW, Lip GYH, Krumholz HM, Goldhaber SZ, and Bikdeli B

Subjects
Aged, Anticoagulants adverse effects, COVID-19 mortality, Drug Administration Schedule, Enoxaparin adverse effects, Female, Hemorrhage chemically induced, Hospitalization, Humans, Intensive Care Units, Iran, Length of Stay statistics & numerical data, Male, Middle Aged, Odds Ratio, Outcome Assessment, Health Care, Pulmonary Embolism epidemiology, Thrombocytopenia chemically induced, Thrombosis etiology, Thrombosis mortality, Treatment Outcome, Venous Thrombosis epidemiology, Venous Thrombosis mortality, Anticoagulants administration & dosage, COVID-19 complications, Enoxaparin administration & dosage, Extracorporeal Membrane Oxygenation, Oxygen Inhalation Therapy methods, Thrombosis prevention & control
Abstract

Importance: Thrombotic events are commonly reported in critically ill patients with COVID-19. Limited data exist to guide the intensity of antithrombotic prophylaxis., Objective: To evaluate the effects of intermediate-dose vs standard-dose prophylactic anticoagulation among patients with COVID-19 admitted to the intensive care unit (ICU)., Design, Setting, and Participants: Multicenter randomized trial with a 2 × 2 factorial design performed in 10 academic centers in Iran comparing intermediate-dose vs standard-dose prophylactic anticoagulation (first hypothesis) and statin therapy vs matching placebo (second hypothesis; not reported in this article) among adult patients admitted to the ICU with COVID-19. Patients were recruited between July 29, 2020, and November 19, 2020. The final follow-up date for the 30-day primary outcome was December 19, 2020., Interventions: Intermediate-dose (enoxaparin, 1 mg/kg daily) (n = 276) vs standard prophylactic anticoagulation (enoxaparin, 40 mg daily) (n = 286), with modification according to body weight and creatinine clearance. The assigned treatments were planned to be continued until completion of 30-day follow-up., Main Outcomes and Measures: The primary efficacy outcome was a composite of venous or arterial thrombosis, treatment with extracorporeal membrane oxygenation, or mortality within 30 days, assessed in randomized patients who met the eligibility criteria and received at least 1 dose of the assigned treatment. Prespecified safety outcomes included major bleeding according to the Bleeding Academic Research Consortium (type 3 or 5 definition), powered for noninferiority (a noninferiority margin of 1.8 based on odds ratio), and severe thrombocytopenia (platelet count <20 ×103/µL). All outcomes were blindly adjudicated., Results: Among 600 randomized patients, 562 (93.7%) were included in the primary analysis (median [interquartile range] age, 62 [50-71] years; 237 [42.2%] women). The primary efficacy outcome occurred in 126 patients (45.7%) in the intermediate-dose group and 126 patients (44.1%) in the standard-dose prophylaxis group (absolute risk difference, 1.5% [95% CI, -6.6% to 9.8%]; odds ratio, 1.06 [95% CI, 0.76-1.48]; P = .70). Major bleeding occurred in 7 patients (2.5%) in the intermediate-dose group and 4 patients (1.4%) in the standard-dose prophylaxis group (risk difference, 1.1% [1-sided 97.5% CI, -∞ to 3.4%]; odds ratio, 1.83 [1-sided 97.5% CI, 0.00-5.93]), not meeting the noninferiority criteria (P for noninferiority >.99). Severe thrombocytopenia occurred only in patients assigned to the intermediate-dose group (6 vs 0 patients; risk difference, 2.2% [95% CI, 0.4%-3.8%]; P = .01)., Conclusions and Relevance: Among patients admitted to the ICU with COVID-19, intermediate-dose prophylactic anticoagulation, compared with standard-dose prophylactic anticoagulation, did not result in a significant difference in the primary outcome of a composite of adjudicated venous or arterial thrombosis, treatment with extracorporeal membrane oxygenation, or mortality within 30 days. These results do not support the routine empirical use of intermediate-dose prophylactic anticoagulation in unselected patients admitted to the ICU with COVID-19., Trial Registration: ClinicalTrials.gov Identifier: NCT04486508.

Published
2021
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40. Incidence of symptomatic venous thromboembolism following hospitalization for coronavirus disease 2019: Prospective results from a multi-center study.

Author

Rashidi F, Barco S, Kamangar F, Heresi GA, Emadi A, Kaymaz C, Jansa P, Reis A, Rashidi A, Taghizadieh A, Rezaeifar P, Moghimi M, Ghodrati S, Mozafari A, Foumani AA, Tahamtan O, Rafiee E, Abbaspour Z, Khodadadi K, Alamdari G, Boodaghi Y, Rezaei M, Muhammadi MJ, Abbasi M, Movaseghi F, Koohi A, Shakourzad L, Ebrahimi F, Radvar S, Amoozadeh M, Fereidooni F, Naseari H, Movalled K, Ghorbani O, and Ansarin K

Subjects
Adult, Aged, Aged, 80 and over, COVID-19 diagnosis, COVID-19 mortality, COVID-19 therapy, Female, Humans, Incidence, Iran epidemiology, Male, Middle Aged, Prospective Studies, Pulmonary Embolism diagnosis, Pulmonary Embolism mortality, Risk Factors, Time Factors, Venous Thromboembolism diagnosis, Venous Thromboembolism mortality, Venous Thrombosis diagnosis, Venous Thrombosis mortality, COVID-19 epidemiology, Patient Discharge, Pulmonary Embolism epidemiology, Venous Thromboembolism epidemiology, Venous Thrombosis epidemiology
Abstract

Background: Thrombosis and pulmonary embolism appear to be major causes of mortality in hospitalized coronavirus disease 2019 (COVID-19) patients. However, few studies have focused on the incidence of venous thromboembolism (VTE) after hospitalization for COVID-19., Methods: In this multi-center study, we followed 1529 COVID-19 patients for at least 45 days after hospital discharge, who underwent routine telephone follow-up. In case of signs or symptoms of pulmonary embolism (PE) or deep vein thrombosis (DVT), they were invited for an in-hospital visit with a pulmonologist. The primary outcome was symptomatic VTE within 45 days of hospital discharge., Results: Of 1529 COVID-19 patients discharged from hospital, a total of 228 (14.9%) reported potential signs or symptoms of PE or DVT and were seen for an in-hospital visit. Of these, 13 and 12 received Doppler ultrasounds or pulmonary CT angiography, respectively, of whom only one patient was diagnosed with symptomatic PE. Of 51 (3.3%) patients who died after discharge, two deaths were attributed to VTE corresponding to a 45-day cumulative rate of symptomatic VTE of 0.2% (95%CI 0.1%-0.6%; n = 3). There was no evidence of acute respiratory distress syndrome (ARDS) in these patients. Other deaths after hospital discharge included myocardial infarction (n = 13), heart failure (n = 9), and stroke (n = 9)., Conclusions: We did not observe a high rate of symptomatic VTE in COVID-19 patients after hospital discharge. Routine extended thromboprophylaxis after hospitalization for COVID-19 may not have a net clinical benefit. Randomized trials may be warranted., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Published
2021
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41. Clinical Utility of Red Cell Distribution Width in Patients with Pleural Effusion.

Author

Rezaeifar P, Nouri-Vaskeh M, Nazemiyeh M, Dorraji A, and Sharifi A

Abstract

Background: The red cell distribution width (RDW) value has been recently recognized as a valuable biomarker in clinical practice. The RDW value has not been evaluated so far in patients with pleural effusion. Thus, this study aimed to investigate whether RDW could distinguish between exudative and transudative pleural effusions., Materials and Methods: We measured protein and lactate dehydrogenase levels on both pleural fluids and serum samples from 223 cases and classified them as transudates or exudates based on the classic Light's criteria. We collected blood cell count elements such as RDW from the medical records. We also investigated the correlation between RDW and the nature of pleural effusion., Results: In 55.2% of the patients, pleural fluid was exudative. Although we found no significant association between RDW and the nature of the pleural fluid, we detected a significantly higher amount of RDW (14.9 ≤) in patients with exudative pleural effusion compared to transudate (66.7% vs. 33.3%; P= 0.01). In this category, neoplastic conditions were mostly observed in the patients (76.3%), followed by pulmonary thromboembolism (21.1%) and systemic lupus erythematous (2.6%)., Conclusion: The findings could not reveal any noticeable correlation between RDW and the Light criteria. However, it appears that elevated RDW levels give insights into the valuable nature of RDW in different conditions such as neoplastic diseases., Competing Interests: Conflict of interest No potential conflict of interest relevant to this article was reported., (Copyright© 2020 National Research Institute of Tuberculosis and Lung Disease.)

Published
2020

42. Intermediate versus standard-dose prophylactic anticoagulation and statin therapy versus placebo in critically-ill patients with COVID-19: Rationale and design of the INSPIRATION/INSPIRATION-S studies.

Author

Bikdeli B, Talasaz AH, Rashidi F, Sharif-Kashani B, Farrokhpour M, Bakhshandeh H, Sezavar H, Dabbagh A, Beigmohammadi MT, Payandemehr P, Yadollahzadeh M, Riahi T, Khalili H, Jamalkhani S, Rezaeifar P, Abedini A, Lookzadeh S, Shahmirzaei S, Tahamtan O, Matin S, Amin A, Parhizgar SE, Jimenez D, Gupta A, Madhavan MV, Parikh SA, Monreal M, Hadavand N, Hajighasemi A, Maleki M, Sadeghian S, Mohebbi B, Piazza G, Kirtane AJ, Lip GYH, Krumholz HM, Goldhaber SZ, and Sadeghipour P

Subjects
Anticoagulants adverse effects, Atorvastatin adverse effects, COVID-19 complications, COVID-19 diagnosis, Critical Illness, Double-Blind Method, Enoxaparin adverse effects, Humans, Hydroxymethylglutaryl-CoA Reductase Inhibitors adverse effects, Iran, Multicenter Studies as Topic, Randomized Controlled Trials as Topic, Thrombosis diagnosis, Thrombosis etiology, Time Factors, Treatment Outcome, Venous Thromboembolism diagnosis, Venous Thromboembolism etiology, Anticoagulants administration & dosage, Atorvastatin administration & dosage, Enoxaparin administration & dosage, Hydroxymethylglutaryl-CoA Reductase Inhibitors administration & dosage, Thrombosis prevention & control, Venous Thromboembolism prevention & control, COVID-19 Drug Treatment
Abstract

Background: Microvascular and macrovascular thrombotic events are among the hallmarks of coronavirus disease 2019 (COVID-19). Furthermore, the exuberant immune response is considered an important driver of pulmonary and extrapulmonary manifestations of COVID-19. The optimal management strategy to prevent thrombosis in critically-ill patients with COVID-19 remains unknown., Methods: The Intermediate versus Standard-dose Prophylactic anticoagulation In cRitically-ill pATIents with COVID-19: An opeN label randomized controlled trial (INSPIRATION) and INSPIRATION-statin (INSPIRATION-S) studies test two independent hypotheses within a randomized controlled trial with 2 × 2 factorial design. Hospitalized critically-ill patients with reverse transcription polymerase chain reaction confirmed COVID-19 will be randomized to intermediate-dose versus standard dose prophylactic anticoagulation. The 600 patients undergoing this randomization will be screened and if meeting the eligibility criteria, will undergo an additional double-blind stratified randomization to atorvastatin 20 mg daily versus matching placebo. The primary endpoint, for both hypotheses will be tested for superiority and includes a composite of adjudicated acute arterial thrombosis, venous thromboembolism (VTE), use of extracorporeal membrane oxygenation, or all-cause death within 30 days from enrollment. Key secondary endpoints include all-cause mortality, adjudicated VTE, and ventilator-free days. Key safety endpoints include major bleeding according to the Bleeding Academic Research Consortium definition and severe thrombocytopenia (platelet count <20,000/fL) for the anticoagulation hypothesis. In a prespecified secondary analysis for non-inferiority, the study will test for the non-inferiority of intermediate intensity versus standard dose anticoagulation for major bleeding, considering a non-inferiority margin of 1.8 based on odds ratio. Key safety endpoints for the statin hypothesis include rise in liver enzymes >3 times upper normal limit and clinically-diagnosed myopathy. The primary analyses will be performed in the modified intention-to-treat population. Results will be tested in exploratory analyses across key subgroups and in the intention-to-treat and per-protocol cohorts., Conclusions: INSPIRATION and INSPIRATON-S studies will help address clinically-relevant questions for antithrombotic therapy and thromboinflammatory therapy in critically-ill patients with COVID-19., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Published
2020
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44. Von Willebrand factor-cleaving protease activity in thrombotic microangiopathy: first report from iran.

Author

Ardalan M and Rezaeifar P

Abstract

Background: Thrombotic microangiopathy (TMA) is a rare but devastating small vessels disorder that is characterized by intravascular platelet thrombi, thrombocytopenia, and various degrees of organ ischemia and anemia, which is due to erythrocyte fragmentation in microcirculation., Objectives: The Aim of this study was to determine the von Willebrand factor-cleaving protease (ADAMTS13) activity during the acute phase of TMA. We also investigated inhibiting antibodies against ADAMTS13 in these patients., Patients and Methods: In a collaborative work with Mario-Negro institute of pharmacological research in Bergamo-Italy, we registered the clinical and laboratory data, collected the serum samples, and transferred the samples to the laboratories. Serum samples were taken before the start of plasmapheresis or at least 15 days after the final exchange., Results: We recruited 40 patients (14 males and 26 females) with the mean age of 46.12 ± 17.26 years. The mean activity of ADAMTS13 was 34.58% ± 21.83%. Two patients had inhibitory antibodies against ADAMTS13 with profound deficiency of ADAMTS13 activity (< 6%). Infectious diseases were the most common underlying condition, followed by systemic lupus erythematous., Conclusions: Majority of patients had an underlying condition and had various ADAMTS13 activity. The presence of inhibiting antibodies and accompanied complete deficiency of ADAMTS13 activity is an indicator of severity.

Published
2014
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45. Epidemiological and clinical characteristics of inflammatory bowel disease in patients from northwestern iran.

Author

Shirazi KM, Somi MH, Bafandeh Y, Saremi F, Mylanchy N, Rezaeifar P, Abedi Manesh N, and Mirinezhad SK

Abstract

Background: There are few reports from Iran about the epidemiology and clinical features of inflammatory bowel disease (IBD). This study aims to determine the epidemiologic profile and clinical features of IBD in Northwest Iran referral centers., Methods: In a cross-sectional setting, we evaluated 200 patients with definitive diagnoses of IBD who referred to Tabriz educational hospitals during the period of 2005 to 2007. Demographic characteristics as well as patients' clinical profiles were evaluated. Disease activity and severity were determined by the Crohn's Disease Activity Index and Truelove and Witt's classification of ulcerative colitis (UC). The related probable demographic factors were tested., Results: Of the 200 IBD patients, 183 (91.5%) were diagnosed with UC and 17 (8.5%) with Crohn's disease (CD). There was a positive first degree relative of IBD in 10.9% of UC and 11.8% of CD patients. Abdominal pain was the primary presenting symptom in 25.7% of UC patients and in 58.8% of those with CD. Among UC patients, left-sided colitis was the main feature (52.5%); while in patients with CD, colon involvement was predominant (52.9%). There was no significant contributor for activity or severity of disease noted among demographic factors., Conclusion: The occurrence of UC was much higher than CD. The onset of IBD occurred in younger ages with a predominance in males. Left-sided colitis in UC and colon involvement in CD was common. Mostly, the pattern of IBD was mild to moderate with good response to pharmacotherapy. Disease activity and severity were unaffected by demographic features.

Published
2013

46. Effects of low dose zinc supplementation on biochemical markers in non-alcoholic cirrhosis: a randomized clinical trial.

Author

Somi MH, Rezaeifar P, Ostad Rahimi A, and Moshrefi B

Subjects
Adult, Aged, Biomarkers blood, Double-Blind Method, Female, Humans, Liver Cirrhosis blood, Male, Middle Aged, Young Adult, Dietary Supplements, Liver Cirrhosis prevention & control, Zinc administration & dosage
Abstract

Background: The present study aimed to evaluate the effects of low dose zinc (Zn) supplementation on biochemical markers and underlying disease status in non-alcoholic cirrhotic patients., Methods: We enrolled 60 cirrhotic patients in a double-blind, placebo-controlled, randomized clinical trial. All patients in the interventional group (n = 30) received long-term, low dose Zn supplementation (50 mg elemental Zn sulfate daily). The control group (n = 30) received placebo (starch). Child-Pugh scores and biochemical markers were assessed for both interventional and control groups at the first day and the end of the 90th day of the interventional period. A per-protocol analysis was performed after excluding all participants who did not receive or complete the randomized intervention. The mean differences of quantitative variables between and within groups were evaluated by independent samples t-test and paired-samples t-test, respectively. SPSS version 13.00 was used for statistical analysis., Results: In the initial evaluation, 16 (53.30%) patients from the interventional group had a Child-Pugh score of 5-8 and 14 (46. 70%) had a score of 9-12. In the control group 18 (60.00%) had a Child-Pugh score of 5-8 and 12 (40.00%) scored 9-12. After three months the mean Child-Pugh score in the interventional group showed a significant improvement (from 6.56 ± 0.21 to 5.72 ± 0.22, P = 0.001) whereas in the control group despite no significant decline, the mean Child-Pugh score increased slightly (from 6.25 ± 0.27 to 6.67 ± 0.31, P = 0.14). Zn supplementation significantly decreased copper (Cu; P = 0.01) and creatinine (Cr; P < 0.0001) levels., Conclusion: In this study, we determined that low dose Zn supplementation could prevent deterioration of clinical status of cirrhosis and prevent excess Cu accumulation in non-alcoholic cirrhotic patients. Zn supplementation produces metabolic effects and trends towards improvements in liver function, hepatic encephalopathy, and nutritional status. Registration ID in IRCT: IRCT201106122017N4.

Published
2012
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47. Bone density and bone metabolism in patients with inflammatory bowel disease.

Author

Shirazi KM, Somi MH, Rezaeifar P, Fattahi I, Khoshbaten M, and Ahmadzadeh M

Subjects
Absorptiometry, Photon, Adolescent, Adult, Age Factors, Aged, Bone Density, Bone Diseases, Metabolic diagnosis, Bone Diseases, Metabolic metabolism, Cohort Studies, Colitis, Ulcerative pathology, Crohn Disease pathology, Cross-Sectional Studies, Diet, Female, Humans, Iran, Male, Middle Aged, Risk Factors, Sex Factors, Young Adult, Bone Diseases, Metabolic epidemiology, Colitis, Ulcerative complications, Colitis, Ulcerative metabolism, Crohn Disease complications, Crohn Disease metabolism
Abstract

Background/aims: Patients with inflammatory bowel disease (IBD) are at high risk for low bone mineral density (BMD). This study aimed to evaluate BMD in IBD patients and its relationship with bone metabolism in a group of Iranian patients., Patients and Methods: A cross-sectional study was conducted on patients with IBD to assess BMD status and serum biochemical factors. After getting the demographic data from 200 patients, they were screened using dual-energy X-ray absorptiometry of the lumbar spine (L2-L4) and femoral neck for BMD status. Serum levels of calcium, phosphate, alkaline phosphatase (ALP), and 25-hydroxyvitamin D (25-OH vitamin D) were measured to assess the bone metabolism status., Results: Two hundred patients with IBD were enrolled in the study. One hundred and eighty three (91.5%) patients were identified as having ulcerative colitis (UC) and 17 (8.5%) as having Crohn's disease (CD). Based on the lumbar and femoral neck bone mass densitometry, 148 (74.4%) patients had low BMD at either lumbar spine or femoral neck. Of these, 100 patients (50.3%) were osteopenic and 48 patients (24.1%) were osteoporotic. A 58.6% and 61% of patients with UC had low BMD in the lumbar and femoral neck, respectively. These results for those with CD were 76.5% and 70.6%, respectively. The mean of femoral neck and lumbar T-scores in patients with UC were -1.14 and -1.38, and in patients with CD were -1.24 and -1.47, respectively (P > 0.05). The mean (±SD) levels for calcium (Ca) in UC and CD were in the normal range. The mean (±SD) levels of ALP and 25-OH vitamin D in both the groups were in the normal range, and in comparison between groups (UC and CD), no significant differences were observed (P = 0.20 for ALP and P = 0.44 for 25-OH vitamin D). In the assessment of correlation between biochemical markers and BMD, an inverse correlation between lumbar T-score and ALP or 25-OH vitamin D only in patients with UC was observed., Conclusions: The high prevalence of low BMD in the Iranian population with IBD needs attention. The subclinical vitamin D deficiency may contribute to bone loss in IBD patients, which is more pronounced in patients with UC in this study because of the small population of patients with CD.

Published
2012
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