- Blood
samples from Covid-19 patients in small-scale study indicate
what could be a testicle malfunction, researchers say
- Results
'not conclusive and require further investigation'
Doctors in
the central Chinese city of Wuhan plan to embark on a
long-term study of
the
effects of the coronavirus on the male
reproductive system, building on small-scale research
indicating that the
pathogen could affect sex hormone levels in men.
Though still
preliminary and not peer reviewed, the study is the first
clinical observation
of the potential impact of Covid-19, the disease caused by the
coronavirus, on
the male reproductive system, especially among younger groups.
, the
researchers – from Zhongnan Hospital of Wuhan University and
the Hubei Clinical
Research Centre for Prenatal Diagnosis and Birth Health – said
they analysed
blood samples from 81 men aged 20 to 54 who tested positive
for the coronavirus
and were hospitalised in January.
The median
age of the participants was 38 and roughly 90 per cent of them
had only mild
symptoms. The samples were collected in the last days of their
stay in
hospital.
Using the
samples, the team looked at the ratio of testosterone to
luteinising hormone
(T/LH). A low T/LH ratio can be a sign of hypogonadism, which
in men is a
malfunction of the testicles that could lead to lower sex
hormone production.
The average
ratio for the Covid-19 patients was 0.74, about half the
normal level.
Testosterone is the main male sex hormone
critical for the development of
primary and secondary sexual characteristics including testes,
muscle, bone
mass and body hair. Luteinising hormone is found in both men
and women, and
best known for its ability to trigger ovulation
Common
symptoms of hypogonadism in men include abnormally large
breasts and erectile
dysfunction.
The
condition can be cured. Erectile disorders caused by a T/LH
ratio lower than
0.87 can be relieved effectively by testosterone treatment,
according to a
study in peer-reviewed journal Archives of Sexual
Behaviour in 1997.
"Since more
than half of the people with Covid-19 were reproductive-aged,
more attention
should be paid to the effect of Sars-CoV-2 on the reproductive
system," the
Wuhan researchers said in their paper, referring to the
official name for the new
coronavirus.
They said
their results were not conclusive and the blood samples were
not direct proof
of reproductive problems with Covid-19 patients. Other
factors, such as
medication and immune system response, could also cause
changes in hormones.
The
researchers said they planned to launch a long-term study,
which might include
the collection and analysis of sperm samples and interviews
with coronavirus
patients.
Previous
studies have indicated that the new coronavirus could bind
with ACE2, a receptor
protein cell, a large number of which are concentrated in the
testicles.
Li Yufeng, a
professor of reproductive medicine at Tongji Hospital in
Wuhan, had predicted
in a study that the testicles could become a major target of
the coronavirus
attack.
Other
studies have also suggested that severe acute respiratory
syndrome, or Sars, a
distant relative of the new coronavirus, could also cause
inflammation in the
testicles.
A researcher
with the State Key Laboratory of Reproductive Medicine at
Nanjing Medical
University, said the new observations were "highly valuable
information" but a
bigger sample would be needed to clarify the results.
"Many
viruses can affect fertility, but not every virus can cause a
pandemic. If the
impact is long lasting, it can be a problem," the researcher
said, declining to
be named because of the sensitivity of the issue
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