Search
What are you looking for?
Start main content

Press Releases

Press Releases

https://www.med.cuhk.edu.hk/press-releases/a-joint-hku-cuhk-study-confirms-smoking-and-obesity-increase-risk-of-severe-covid-19-by-65-81
https://www.med.cuhk.edu.hk/press-releases/a-joint-hku-cuhk-study-confirms-smoking-and-obesity-increase-risk-of-severe-covid-19-by-65-81

A joint HKU-CUHK study confirms smoking and obesity increase risk of severe COVID-19 by 65%-81%

Researchers from the School of Public Health, LKS Faculty of Medicine of The University of Hong Kong (HKUMed), in collaboration with The Chinese University of Hong Kong (CUHK)’s Faculty of Medicine (CU Medicine), confirmed smoking, obesity and lower socioeconomic position (SEP) [1]likely increase the risk of contracting mild to severe COVID-19, using data from large scale genome-wide association studies. Other exposures thought to be related to COVID-19 risk, such as glycaemic traits, type 2 diabetes, and vitamin D, are likely unrelated. The researchers also found angiotensin-converting enzyme 2 (ACE2), the key receptor of SARS-CoV-2, mediates part of the detrimental effect of obesity and SEP. The findings have been published in the Journal of Medical Virology, a peer-reviewed virology journal.

 

Background

 

Epidemiologic studies show a variety of factors related to increased risk of COVID-19, such as type 2 diabetes[2], although paradoxical findings have also been reported, such as an inverse association of smoking with COVID-19 severity[3]. However, these associations may not be causal due to limitations in observational studies. Using better designs to understand the determinants of COVID-19 risk would be particularly important to devise effective mitigation measures to reduce the risk of COVID-19 in the population.

 

In this regard, the research team conducted a comprehensive assessment of the role of multiple risk factors (vitamin D, glycaemic traits, blood pressure, smoking, obesity and SEP) in various severities of COVID-19 risk using a method called Mendelian randomisation. As genetic variants are used, this approach might circumvent some of the limitations of conventional observational epidemiologic studies. The research team also explored whether ACE2 mediates any of these detrimental effects.

 

Research methods and findings

 

Using Mendelian randomisation, researchers extracted genetic variants related to the various risk factors described above (N<=3,037,499), and assessed their relationship with COVID-19 risk using large genetic summary data from genome-wide association studies (N<=2,942,817). The use of such large datasets also helps assess if previous negative findings on risk factors reported in smaller Mendelian randomisation studies, such as type 2 diabetes and vitamin D[4], were due to the small sample size.

 

The research team found that smoking, obesity and lower SEP likely increase the risk of COVID-19.

 

For example, one standard deviation increase (SD) of body mass index (BMI) likely

  • increases risk of severe COVID-19 by 81%
  • Increases risk of COVID-19 hospitalisation by 55%
  • increases risk of contracting COVID-19 by18%

Strong social gradations were also found in COVID-19 risks, with people of lower SEP tending to have a higher risk of all forms of COVID-19. Previous findings on the harms associated with smoking were also confirmed. ‘Using a less biased design, our study confirms the importance of smoking and obesity in increasing the risk of contracting all forms of COVID-19. Our study also shows that targeting ACE2 may be a way to mitigate the risk of COVID-19 among those who are obese or overweight, or of low SEP, and may help inform corresponding drug development,’ said Dr Ryan Au Yeung Shiu-lun, Assistant Professor, Division of Epidemiology and Biostatistics of the School of Public Health, HKUMed.

 

‘SARS-CoV-2 enters the host cells via ACE2. Recently, various therapeutic approaches have been developed for COVID-19 patients with the utilisation of ACE2-modulating medications to effectively control viral entry. Our findings will enhance research into several therapeutic targets for COVID-19 treatment,’ said Professor Kwok Kin-on, Assistant Professor, the Jockey Club School of Public Health and Primary Care, CU Medicine.

 

Research significance

 

This is one of the largest studies to explore the role of various risk factors in different severities of COVID-19 using Mendelian randomisation. It reiterates the relevance of obesity and smoking, which are key factors contributing to disease burden, according to the World Health Organization. ‘The strong social gradient associated with COVID-19 risk highlights clearly the inequalities embedded in societies that need to be urgently addressed, and it is likely relevant to other diseases too,’ added Dr Au Yeung.

 

‘It is understandable that smokers and people who have high BMI may have difficulty in quitting smoking or losing weight immediately to reduce their COVID-19 risk. Therefore, these high-risk groups are strongly encouraged to receive the booster dose of the COVID-19 vaccine as soon as possible to mitigate any severe COVID-19 outcomes. This study highlights the importance of genomics and big data analytics in understanding the causes of diseases. In particular, it is an exemplar of enhancing the understanding of the interaction between infectious diseases and non-communicable diseases,” said Professor Kwok.

 

infographic
About the research team

 

The research was conducted by a team co-led by Dr Ryan Au Yeung Shiu-lun, Assistant Professor, Division of Epidemiology and Biostatistics, School of Public Health, HKUMed; and Professor Kwok Kin-on, Assistant Professor, the Jockey Club School of Public Health and Primary Care, CU Medicine. Other members of the research team from the School of Public Health of HKUMed include Dr Tommy Wong Hon-ting, Senior Research Assistant; Dr He Baoting, Post-doctoral Fellow; and Dr Luo Shan, Post-doctoral Fellow.

 

About the School of Public Health, HKUMed

 

The School of Public Health, LKS Faculty of Medicine of The University of Hong Kong has a long and distinguished history in public health education and high-impact research. With world-leading research in infectious diseases as well as on non-communicable diseases of both local and global importance, the School has made significant contributions through its research and advocacy to improve the health of populations and individuals, both locally and globally. The School is a leading research and teaching hub in public health on influenza and other emerging viruses, control of non-communicable and infectious diseases, tobacco control, air pollution, psycho-oncology, behavioural sciences, exercise science, life-course epidemiology, population mental health, and health economics, health services planning and management. This work has informed international (e.g. the US Food and Drug Administration, Health Canada, the World Health Organization), national and local public health policies.

 

About the Jockey Club School of Public Health and Primary Care, CU Medicine

 

The Jockey Club School of Public Health and Primary Care of the Faculty of Medicine at The Chinese University of Hong Kong is a leading centre of public health education and research that was established in 2001 to provide the broad-based education in public health, primary care, and family medicine. The School currently provides advanced professional training across a comprehensive range of public health disciplines that include Epidemiology, Biostatistics, Environmental Health, Health Policy, Health Services Management, Social Behaviour and Global Health. Our ongoing mission is to improve the health of populations through cutting-edge research and collaboration with leading research institutions around the world.


[1] Socioeconomic position is a measure of a person’s income, education and occupation in relation to others.

[2]Williamson, E.J., Walker, A.J., Bhaskaran, K. et al. Factors associated with COVID-19-related death using OpenSAFELY. Nature 584, 430–436 (2020). https://doi.org/10.1038/s41586-020-2521-4

[3]Min Gao, Paul Aveyard, Nicola Lindson, Jamie Hartmann-Boyce, Peter Watkinson, Duncan Young, Carol Coupland, Ashley K Clift, David Harrison, Doug Gould, Ian D Pavord, Margaret Smith, Julia Hippisley-Cox, Association between smoking, e-cigarette use and severe COVID-19: a cohort study, International Journal of Epidemiology, Volume 51, Issue 4, August 2022, Pages 1062–1072, https://doi.org/10.1093/ije/dyac028

[4]Shan Luo, Ying Liang, Tommy Hon Ting Wong, Catherine Mary Schooling, Shiu Lun Au Yeung, Identifying factors contributing to increased susceptibility to COVID-19 risk: a systematic review of Mendelian randomization studies, International Journal of Epidemiology, Volume 51, Issue 4, August 2022, Pages 1088–1105, https://doi.org/10.1093/ije/dyac076

More Press Releases

A joint HKU-CUHK study finds that smoking  increases the risk of COVID-19

A joint HKU-CUHK study finds that smoking increases the risk of COVID-19

Research
CUHK study advises residential care homes for the elderly to maintain current infection control practices

CUHK study advises residential care homes for the elderly to maintain current infection control practices

Research
HKUMed-CU Medicine joint study shows that vaccinated individuals develop more robust and broadly reactive antibody responses against SARS-CoV-2 variants than the unvaccinated after an Omicron infection

HKUMed-CU Medicine joint study shows that vaccinated individuals develop more robust and broadly reactive antibody responses against SARS-CoV-2 variants than the unvaccinated after an Omicron infection

Research
CUHK-HKU collaborative research finds a new inflammatory activation pathway in  blood vessels after SARS-CoV-2 infection

CUHK-HKU collaborative research finds a new inflammatory activation pathway in blood vessels after SARS-CoV-2 infection

Research
HKUMed-CU Medicine joint study finds that third dose of Comirnaty has better protection from COVID-19 variant Omicron

HKUMed-CU Medicine joint study finds that third dose of Comirnaty has better protection from COVID-19 variant Omicron

Research
A Global Study Led by CU Medicine and HKUMed Discovers  a Hepatitis C Virus Drug as Potent Treatment for COVID-19

A Global Study Led by CU Medicine and HKUMed Discovers a Hepatitis C Virus Drug as Potent Treatment for COVID-19

Research
CU Medicine Announces the Community Response Study Results During the Early Phase of the COVID-19 Outbreak in Hong Kong

CU Medicine Announces the Community Response Study Results During the Early Phase of the COVID-19 Outbreak in Hong Kong

Research
CU Medicine finds benign prostatic hyperplasia patients suffer from up to five times the risk of urological complications after COVID-19 infection

CU Medicine finds benign prostatic hyperplasia patients suffer from up to five times the risk of urological complications after COVID-19 infection

Research
CUHK study estimates half of COVID-19 infections went unrecognised during the Omicron epidemic in Hong Kong

CUHK study estimates half of COVID-19 infections went unrecognised during the Omicron epidemic in Hong Kong

Research
CU Medicine study published in The Lancet Infectious Diseases concludes that a novel oral microencapsulated live bacteria consortia (SIM01) alleviates long COVID symptoms

CU Medicine study published in The Lancet Infectious Diseases concludes that a novel oral microencapsulated live bacteria consortia (SIM01) alleviates long COVID symptoms

Research
CU Medicine discovers gut microbiome and metabolome markers that predict long-term COVID-19 vaccine effectiveness

CU Medicine discovers gut microbiome and metabolome markers that predict long-term COVID-19 vaccine effectiveness

Research
CUHK study reveals prevalence of myopia in children has reached record high in Hong Kong Number of myopic children aged six is double after COVID-19 restrictions Low-concentration atropine eyedrops with red light therapy study launched

CUHK study reveals prevalence of myopia in children has reached record high in Hong Kong Number of myopic children aged six is double after COVID-19 restrictions Low-concentration atropine eyedrops with red light therapy study launched

Research
CUHK-PWH research confirms Paxlovid can benefit patients with severe kidney disease

CUHK-PWH research confirms Paxlovid can benefit patients with severe kidney disease

Research
Joint Study Unveils How COVID-19  Adversely Impacts Placenta During Pregnancy

Joint Study Unveils How COVID-19 Adversely Impacts Placenta During Pregnancy

Research
T-cell responses elicited by COVID-19 vaccines Comirnaty and CoronaVac provide effective protection against severe disease from different SARS-CoV-2 variants

T-cell responses elicited by COVID-19 vaccines Comirnaty and CoronaVac provide effective protection against severe disease from different SARS-CoV-2 variants

Research
CU Medicine proves oral antivirals for COVID-19 can lower the risk of hospitalisation and  inpatient progression in older patients living in nursing homes

CU Medicine proves oral antivirals for COVID-19 can lower the risk of hospitalisation and inpatient progression in older patients living in nursing homes

Research
A randomised placebo-controlled clinical trial by CU Medicine shows that modulation of gut microbiome using oral microencapsulated live bacteria (SIM01) improves long COVID symptoms

A randomised placebo-controlled clinical trial by CU Medicine shows that modulation of gut microbiome using oral microencapsulated live bacteria (SIM01) improves long COVID symptoms

Research
CUHK finds high intention in Hong Kong to keep wearing masks and using alcohol-based sanitiser but low intention to receive a booster shot in the current era of COVID-19 endemicity

CUHK finds high intention in Hong Kong to keep wearing masks and using alcohol-based sanitiser but low intention to receive a booster shot in the current era of COVID-19 endemicity

Research
CU Medicine’s population-based long COVID-19 survey estimates that over 400,000 recovered COVID-19 patients suffer from sexual dysfunction and reproductive problems

CU Medicine’s population-based long COVID-19 survey estimates that over 400,000 recovered COVID-19 patients suffer from sexual dysfunction and reproductive problems

Research
Large-scale clinical study shows CU Medicine (SIM01) microbiome formula reduces risk of infections including COVID-19

Large-scale clinical study shows CU Medicine (SIM01) microbiome formula reduces risk of infections including COVID-19

Research
CUHK-HKU collaborative study finds about 80% lower risk of death among COVID-19 inpatients prescribed oral medication and the risk of hospital admission in outpatients is significantly reduced by nearly 90%

CUHK-HKU collaborative study finds about 80% lower risk of death among COVID-19 inpatients prescribed oral medication and the risk of hospital admission in outpatients is significantly reduced by nearly 90%

Research
CUHK develops a real-time bioinformatics platform to predict COVID-19 vaccine effectiveness against SARS-CoV-2 variants with 95% accuracy

CUHK develops a real-time bioinformatics platform to predict COVID-19 vaccine effectiveness against SARS-CoV-2 variants with 95% accuracy

Research
CU Medicine supported by the Hospital Authority to launch HK’s first large-scale Long COVID survey, aiming to inform the government on impact of long COVID on healthcare services

CU Medicine supported by the Hospital Authority to launch HK’s first large-scale Long COVID survey, aiming to inform the government on impact of long COVID on healthcare services

Research
COVID-19 pandemic disrupted the daily lives of schoolchildren in Hong Kong; Proportion of overweight and obese kids more than doubled

COVID-19 pandemic disrupted the daily lives of schoolchildren in Hong Kong; Proportion of overweight and obese kids more than doubled

Research
CUHK finds that a booster vaccine dose is effective in retriggering antibodies in breast milk that protect babies

CUHK finds that a booster vaccine dose is effective in retriggering antibodies in breast milk that protect babies

Research
CUHK study suggests COVID-19 booster shot is key to protecting against infection among high-risk populations and from variants of concern

CUHK study suggests COVID-19 booster shot is key to protecting against infection among high-risk populations and from variants of concern

Research
CUHK Clinical Trial Centre collaborates with CUHK Medical Centre to conduct Hong Kong’s first clinical trial of novel oral treatment specifically developed for COVID-19

CUHK Clinical Trial Centre collaborates with CUHK Medical Centre to conduct Hong Kong’s first clinical trial of novel oral treatment specifically developed for COVID-19

Research
CUHK researchers discover distinct gut microbial signatures for prediction, diagnosis and treatment of long COVID

CUHK researchers discover distinct gut microbial signatures for prediction, diagnosis and treatment of long COVID

Research
CU Medicine study shows a higher prevalence of dry eye disease  among post-COVID-19 patients

CU Medicine study shows a higher prevalence of dry eye disease among post-COVID-19 patients

Research
CU Medicine and Kowloon City District Office co-organise community COVID-19 vaccination programme targeting 2,000 residents, especially young children

CU Medicine and Kowloon City District Office co-organise community COVID-19 vaccination programme targeting 2,000 residents, especially young children

Health Campaign
CU Medicine study shows distinct gut microbial profile associated with long COVID

CU Medicine study shows distinct gut microbial profile associated with long COVID

Research
Assessment of Omicron outbreak in Hong Kong after reimplementation of some of the toughest social distancing measures effective from 7 January

Assessment of Omicron outbreak in Hong Kong after reimplementation of some of the toughest social distancing measures effective from 7 January

Research
HKUMed-CU Medicine joint study finds COVID-19 variant Omicron significantly reduces virus neutralisation ability of BioNTech vaccine

HKUMed-CU Medicine joint study finds COVID-19 variant Omicron significantly reduces virus neutralisation ability of BioNTech vaccine

Research
Joint CUHK-HKU study discovers efficacy of COVID-19 vaccines correlates with a probiotic bacterium, Bifidobacterium adolescentis

Joint CUHK-HKU study discovers efficacy of COVID-19 vaccines correlates with a probiotic bacterium, Bifidobacterium adolescentis

Research
CUHK study sheds light on novel mechanism and treatment of acute kidney injury in COVID-19 patients

CUHK study sheds light on novel mechanism and treatment of acute kidney injury in COVID-19 patients

Research
CUHK Study Suggests a Standardised Experimental Setup is the Key to Optimise  Performance of COVID-19 Nucleic Acid Tests

CUHK Study Suggests a Standardised Experimental Setup is the Key to Optimise Performance of COVID-19 Nucleic Acid Tests

Research
CUHK Study Demonstrates a 2.5-fold Increase in Myopia Incidence in Children  During COVID-19 Pandemic Due to Less Time Outdoors and More Time on Screens

CUHK Study Demonstrates a 2.5-fold Increase in Myopia Incidence in Children During COVID-19 Pandemic Due to Less Time Outdoors and More Time on Screens

Research
CU Medicine Survey Shows Only 25% of Unvaccinated People Intend to Get Inoculated in the Coming Six Months “Multiple Incentives” are Urgently Needed

CU Medicine Survey Shows Only 25% of Unvaccinated People Intend to Get Inoculated in the Coming Six Months “Multiple Incentives” are Urgently Needed

Research
CU Medicine Estimates 20,000 COVID-19 Hidden Infections in Hong Kong  All Vaccinated Persons in HK Developed Neutralising Antibody After Two Doses  Urgent Call for the Largely Unprotected Population to Get Vaccinated

CU Medicine Estimates 20,000 COVID-19 Hidden Infections in Hong Kong All Vaccinated Persons in HK Developed Neutralising Antibody After Two Doses Urgent Call for the Largely Unprotected Population to Get Vaccinated

Research
CU Medicine Study Shows Recovered Mothers Transfer COVID-19 Antibodies to Newborn Babies

CU Medicine Study Shows Recovered Mothers Transfer COVID-19 Antibodies to Newborn Babies

Research
CU Medicine Study Suggests Toddlers are at High Risk of Being  “Silent Spreaders of SARS-CoV2 Infection”

CU Medicine Study Suggests Toddlers are at High Risk of Being “Silent Spreaders of SARS-CoV2 Infection”

Research
CU Medicine Study Shows Modulation of Gut Microbiota  Helps Enhance Safety and Efficacy of COVID-19 Vaccine

CU Medicine Study Shows Modulation of Gut Microbiota Helps Enhance Safety and Efficacy of COVID-19 Vaccine

Research
CU Medicine and International Surgeons Suggest Patients with Positive COVID-19 Results Should Delay Surgery for Seven Weeks to Reduce Death Risk

CU Medicine and International Surgeons Suggest Patients with Positive COVID-19 Results Should Delay Surgery for Seven Weeks to Reduce Death Risk

International collaboration
CU Medicine Finds New Evidence for Link between Gut Microbiome and COVID-19 Severity Microbiome Imbalance Might Influence “Long COVID” Risk

CU Medicine Finds New Evidence for Link between Gut Microbiome and COVID-19 Severity Microbiome Imbalance Might Influence “Long COVID” Risk

Research
CU Medicine Survey Shows Government Recommendation as the Strongest Driver for COVID-19 Vaccine Acceptance

CU Medicine Survey Shows Government Recommendation as the Strongest Driver for COVID-19 Vaccine Acceptance

Research
CUHK Introduces Nasal Strip Sampling for COVID-19 Test As a Superior Tool for Surveillance in a Wide Age-Range Population

CUHK Introduces Nasal Strip Sampling for COVID-19 Test As a Superior Tool for Surveillance in a Wide Age-Range Population

Research
40% of Hong Kong People Show Gut Dysbiosis Comparable to that of COVID-19 Patients CUHK Microbiome Immunity Formula Hastens Recovery of COVID-19 Patients and Offers Hope to Boost Immunity

40% of Hong Kong People Show Gut Dysbiosis Comparable to that of COVID-19 Patients CUHK Microbiome Immunity Formula Hastens Recovery of COVID-19 Patients and Offers Hope to Boost Immunity

Research
CUHK Study Shows Exposure Settings Impact COVID-19 Transmission With Entertainment Setting Showing Propensity for Widespread Dispersion

CUHK Study Shows Exposure Settings Impact COVID-19 Transmission With Entertainment Setting Showing Propensity for Widespread Dispersion

Research
CU Medicine Found SARS-CoV2 in Infants' Stool A Coronavirus Testing Centre Is Established for Paediatric Population to Identify Silent Carriers

CU Medicine Found SARS-CoV2 in Infants' Stool A Coronavirus Testing Centre Is Established for Paediatric Population to Identify Silent Carriers

Research
Most Deaths from COVID-19 in Hong Kong are of 60 Years Old or Above CUHK Initiated International Effort in Devising Strategies to Protect Older People with Dementia amid COVID-19 Pandemic

Most Deaths from COVID-19 in Hong Kong are of 60 Years Old or Above CUHK Initiated International Effort in Devising Strategies to Protect Older People with Dementia amid COVID-19 Pandemic

Research
CU Medicine Study Shows Liver Injury is Common and Prognostic in COVID-19 Patients

CU Medicine Study Shows Liver Injury is Common and Prognostic in COVID-19 Patients

Research
CUHK Researchers Uncover Diabetes as a Potential Risk Factor for COVID-19,  and Possible Mechanisms

CUHK Researchers Uncover Diabetes as a Potential Risk Factor for COVID-19, and Possible Mechanisms

Research
CU Medicine Survey Shows Global Urological Services have been Significantly Deferred due to COVID-19 Pandemic

CU Medicine Survey Shows Global Urological Services have been Significantly Deferred due to COVID-19 Pandemic

Research
CU Medicine Develops a Probiotic Formula to Target Imbalance in Gut Microbiota in COVID-19

CU Medicine Develops a Probiotic Formula to Target Imbalance in Gut Microbiota in COVID-19

Research
CU Medicine Recruits 3,000 Persons to Investigate Hidden Infection and Break the Obstacles in Containing COVID-19 in Hong Kong

CU Medicine Recruits 3,000 Persons to Investigate Hidden Infection and Break the Obstacles in Containing COVID-19 in Hong Kong

Research
CU Medicine Offers Free Stool Screening Test for COVID-19 in Children arriving at Airport

CU Medicine Offers Free Stool Screening Test for COVID-19 in Children arriving at Airport

Clinical service
CUHK Finds that the Coronavirus Can Persist in Stool after Its Clearance in Respiratory Tract Will Conduct Stool Test for People in Quarantine Camps for Early Identification

CUHK Finds that the Coronavirus Can Persist in Stool after Its Clearance in Respiratory Tract Will Conduct Stool Test for People in Quarantine Camps for Early Identification

Research
10th Palliative Care Symposium for Healthcare Workers in Chinese Population: ‘Succession ‧ Innovation’

10th Palliative Care Symposium for Healthcare Workers in Chinese Population: ‘Succession ‧ Innovation’

Symposium
CUHK-HKU Study on Multi-gene Mutation-Drug Matching for Recurrent Ovarian Cancer Patients Providing Free Pharmacogenomic Analysis for 100 Patients in Hong Kong

CUHK-HKU Study on Multi-gene Mutation-Drug Matching for Recurrent Ovarian Cancer Patients Providing Free Pharmacogenomic Analysis for 100 Patients in Hong Kong

Research
The 9th Palliative Care Symposium for Health Care Workers in Chinese Population: ‘Integrating Palliative Care into General Care: Paving the Way for the Future’

The 9th Palliative Care Symposium for Health Care Workers in Chinese Population: ‘Integrating Palliative Care into General Care: Paving the Way for the Future’

Symposium
The 8th Palliative Care Symposium for Health Care Workers in Chinese Population: ‘Advancing Palliative Care in Hong Kong: Opportunities and Challenges’

The 8th Palliative Care Symposium for Health Care Workers in Chinese Population: ‘Advancing Palliative Care in Hong Kong: Opportunities and Challenges’

Symposium
The 6th Palliative Care Symposium for Health Care Workers in Chinese Population: ‘Palliative Care for Geriatric Cancer Patients’

The 6th Palliative Care Symposium for Health Care Workers in Chinese Population: ‘Palliative Care for Geriatric Cancer Patients’

Symposium
CUHK and HKU's Collaborative Research Discovers Novel Epilepsy Genetic Markers

CUHK and HKU's Collaborative Research Discovers Novel Epilepsy Genetic Markers

Research

Our Expert List

Many experts under the Faculty of Medicine are available for media interview.
Please click here for the expert list or contact us.