KUALA LUMPUR, Dec 8 — About 94 per cent of active smokers with Covid-19 in a Malaysian study experienced mild illness, while chronic kidney disease and chronic pulmonary disease were associated with severe Covid-19.
The research by Benedict Lim Heng Sim et al, published on November 2 in The Lancet Regional Health – Western Pacific journal — which studied 5,889 Covid-19 patients admitted to hospitals nationwide and recruited from 18 designated Covid-19 hospitals between February 1 and May 30 — showed that active smokers comprised 9 per cent of their study sample.
Of these 529 active smokers, 496 had mild Covid-19 disease, while 33 smokers had severe disease. Active smokers comprised 9.2 per cent and 7 per cent of mild and severe Covid-19 cases respectively in the study. Researchers did not offer an explanation on why most active smokers in Malaysia experienced mild symptoms of Covid-19, a respiratory disease.
A vast majority, or 92 per cent, of Covid-19 cases in the study on clinical characteristics and risk factors for severe Covid-19 infections in Malaysia were mild, while 3.3 per cent required intensive care. Covid-19 patients are categorised based on five clinical stages — Stage 1 is asymptomatic, Stage 2 is symptomatic without pneumonia, Stage 3 refers to pneumonia without hypoxia, Stage 4 patients have pneumonia with hypoxia; while Stage 5 patients are critically ill. Hypoxia is a condition when tissues of the body don’t receive sufficient oxygen supply. The study classified Stages 1 to 3 as mild, and Stages 4 to 5 as severe.
“In our cohort, underlying comorbidities such as chronic kidney disease and chronic pulmonary disease were associated with severe Covid-19 disease,” wrote researchers from Sungai Buloh Hospital’s Infectious Disease Department, the Institute for Clinical Research’s Digital Health Research and Innovation Unit, and Seberang Jaya Hospital’s Clinical Research Centre.
About a quarter of admitted Covid-19 patients in the study had at least one underlying medical condition, while 20 per cent had a history of medication for chronic diseases. High blood pressure was the most common comorbidity at 15.8 per cent of participants, followed by diabetes (9.8 per cent), asthma (3.3 per cent), chronic cardiac disease (3.2 per cent), obesity (1.6 per cent), chronic kidney disease (1.6 per cent), and chronic pulmonary disease except asthma (0.5 per cent).
“The prevalence of chronic diseases amongst Covid-19 cases was below the national average, which suggests that public health preventive measures might have a role in reducing the risk of transmission to this vulnerable population,” said researchers.
“Older groups were mostly symptomatic, and for those with comorbidities, the likelihood of progressing to poorer outcomes was high.”
Among the 471 severe Covid-19 cases in the study, which represented 8 per cent of total participants, the median age was 58 years. People with high blood pressure comprised nearly half of the severe Covid-19 disease category at 48.6 per cent, followed by diabetes (39.1 per cent), chronic cardiac disease (14 per cent), chronic kidney disease (11.3 per cent), asthma (4.2 per cent), obesity (4.2 per cent), and chronic pulmonary disease except asthma (3.6 per cent).
The majority of Covid-19 patients with chronic kidney disease and chronic pulmonary disease except asthma had severe Covid-19 disease at 57.6 per cent and 53.1 per cent respectively.
However, the majority of Covid-19 patients with hypertension, or 75.4 per cent, experienced mild Covid-19 disease, followed by those with diabetes (68.2 per cent), asthma (89.8 per cent), chronic cardiac disease (65.3 per cent), and obesity (78.7 per cent).
The median age in the overall Malaysian Covid-19 study was 34 years (cases aged below 12 years were excluded), while 72 per cent of participants were male. In terms of ethnic breakdown, 58.4 per cent of the 5,889 Covid-19 cases in the study were Malaysian Malay, followed by non-nationals (23.8 per cent), other ethnic groups in Sabah and Sarawak and indigenous people from the peninsula (8.9 per cent), Malaysian Chinese (6.7 per cent), and Malaysian Indian (2.3 per cent).
According to the study, the three most common complications from Covid-19 were liver injuries (6.7 per cent), kidney injuries (4 per cent), and acute respiratory distress syndrome (2.3 per cent). The lower incidence of acute respiratory distress syndrome compared to acute kidney and liver injuries was attributed to possibly milder disease in the study’s young participants.
Among severe Covid-19 cases, 7.7 per cent developed secondary bacteraemia, 8.3 per cent developed cardiac arrhythmia, and 2.1 per cent were affected by deep vein thrombosis and pulmonary embolism. The Malaysian study’s Covid-19 case fatality rate was 1.2 per cent, recording 73 in-hospital deaths.
In the Malaysian study, malaria drug hydroxychloroquine was prescribed for more than 37 per cent of Covid-19 cases, mainly people with severe disease. Antiviral agents, especially lopinavir/ ritonavir, were used for 77 per cent of severe Covid-19 cases. Steroids and tocilizumab (an immunosuppressive drug that is used mainly to treat rheumatoid arthritis) were prescribed sparingly, mostly to severe Covid-19 patients.
“Clinical decisions on the use of medications were made by physicians in-charge with reference to national guideline,” said researchers.
The World Health Organization (WHO) said in a statement last July 4 that it was dropping hydroxychloroquine and lopinavir/ ritonavir from its global Solidarity Trial investigating treatments for Covid-19, after interim results showed these medications failed to reduce deaths of hospitalised Covid-19 patients compared to standard of care.
STAT reported last June that rigorous studies have shown hydroxychloroquine — previously touted by United States president Donald Trump to treat Covid-19 — did not show benefits for Covid-19 patients or prevent people who had been exposed to the coronavirus from falling ill.