BENGALURU: Males who contract Covid-19 are at greater risk of being admitted to an intensive care unit and death, according to a study of three million Covid-19 patients from across the world. Doctors in Karnataka too have observed this pattern among the patients they have treated.
According to a meta-analysis of 3,111,714 infections reported by sex from 47 countries (not including India), that was published in the open access journal Nature Communications, males who contract the disease have almost a three times higher chance of requiring intensive care treatment and higher odds of death, compared to females. The study found that both males and females have an equal chance of being infected by SARS-CoV-2.
“The trend of biological sex as a factor affecting mortality and morbidity has been seen across various countries and a similar pattern can be seen in the Karnataka data set as well. Given that it is a meta-analysis of a large number of cases, there is some credence (to it),” said Dr Anoop Amarnath, member of Karnataka’s Critical Care Support Team.
Indeed, a sex-wise break up of fatalities in Karnataka shows that mortality was higher among males. As of December 11, males accounted for 71% (8,552) of the 11,928 total deaths. While the sex-bias in the prognosis of the disease is evident, its causes are not fully understood. “The various theories for the male preponderance (in severity of the disease), include X chromosome-related immune genes, estradiol-related effect, or ACE receptor-mediated effect. They can be factors, but need more study,” Dr Amarnath said.
Research so far on biological sex and outcomes of various diseases suggests that biological factors do influence the strength of immune response, severity of disease and mortality. Other factors at play in the instance of Covid-19 could include the high number of ACE (Covid) receptors in men, and smoking.
Somnath Chatterjee, medical director of Prakriya Hospitals said that in his experience, male patients tend to outnumber females by six. “Of 421 admissions to the ICU, only 110 were females, and of the 54 deaths, only 12 were that of females,” he said.
Official data up to December 9 for Bengaluru shows that 3,25,999 males and 1,40,993 females contracted Covid-19 of whom 2,876 males and 1,334 females died. “The cause could be due to increased exposure (to situations where they could contract the disease) due to work. Smoking may also have contributed to the greater number of males affected,” Dr Chatterjee said.
The pattern in mortality is likely to be a combination of both social and biological factors, said Dr Chinnadurai R, lead consultant for critical care at Aster RV Hospital. In his experience, around 90% of patients who died were male. “Females generally have better immunity, and by nature, more survival capacity from birth. Men also tend to ignore their early symptoms,” he said.