Data on young adults with COVID-19 are lacking. Although one study from China reported a median age of 41 years, the overall population ranged from 41 to 65 years and it included even older patients (10).
Data from European countries describe patients who are generally older than those reported from Asiatic countries (11) (12) . Despite this, older age represents an independent risk factor for mortality in all reports. For this reason, this study focused on clinical characteristics, management and health related quality of life in young adults with COVID 19 admitted to the ED of Pesaro Hospital. During the epidemic, Marche, and particularly the Province of Pesaro-Urbino, was one of the most affected regions in Italy.
Overall, our data highlight distinctive features of COVID 19 in young patients.
First, as many as 26% of the patients was hospitalized upon arrival to the ED. This is a remarkable percentage considering the age. Even if there is a lack of data describing the management of patients after ED access, it is reasonable to think, looking at the regional prevalence of SARS CoV2, that many patients with mild symptoms were managed at home according to WHO indications (13). Second, in contrast to many reports in which SARS CoV2 seems to affect more males then females, our population included approximately an equal number of men and women. Conversely, we observed a slightly higher number of men (57%) requiring hospitalization after ED access. It has been demonstrated that for SARS-CoV2, as for other similar infections (i.e.: MERS and SARS-CoV1), the male gender is more affected than female thereby reflecting sex predisposition associated with genetic factors (14). Third, several coexisting conditions were quite frequent in this population. In concert with other studies focused on patients with COVID-19 without age selection, an increase of BMI even in young adults has been observed. As it has been already demonstrated in Influenza A virus (15), obesity may worsen the severity of respiratory diseases. One study showed that SARS-CoV2 patients having BMI ≥35 are at higher risk of mechanical ventilation, compared to those with BMI <25 (16). This could be due to multiple factors. Accumulation of adipose tissue in the mediastinum and in the abdominal cavities seen in obese subjects determines lung mechanical dysfunction (17). Additionally, fat causes an abnormal cytokine production and an increasing inflammatory pathway activation thereby favouring the infection per se and worsening its clinical course. (18)
Hypertension is one of the most frequent underlying diseases in patients with COVID-19 (19). In our study, 11% of young patients suffered from this clinical condition. Although hypertension has been commonly described to increase the severity illness in patients with COVID 19 (20), it is still unclear whether hypertensive subjects are more likely to be infected by coronavirus. It is reasonable to think that angiotensin-converting enzyme 2 expression, frequently increased in these patients, and the activation of the renin-angiotensin system can be involved either in the entrance of the virus into the cell or in the inflammatory response (21). Further studies are warranted to elucidate this issue.
Thyroid dysfunction was seen in 8% of our patients. Little is known about the correlation between COVID-19 and thyroid dysfunction. Thyroid hormones play an important role in regulating the immune response and in modulating pulmonary system and alveolar ventilation. Hypothyroid patients can have a decreased lung function (22) but there is no evidence that those who have a thyroid disorder, unless they are under immunosuppressive treatment, are at higher risk to be infected by coronavirus (23).
Fourth, we identified several features more frequently associated with young patients requiring ICU admission, namely the respiratory distress syndrome, the hypokalaemia and neurological diseases and mental disorders. While the more severe respiratory syndrome the greater risk of mechanical ventilation is easily explained, the relationship between the other two parameters and ICU admission is less clear.
Hypokalaemia has been already reported among patients with COVID-19 with progressive disease (24). It can occur first through virus action on angiotensin-converting enzyme 2 with an increased potassium excretion by the kidneys and secondly through loss, with vomiting or diarrhoea, in patients with gastrointestinal symptoms (25). Hypokalemia might worsen acute respiratory distress syndrome and acute cardiac injury, which are common complications in COVID-19 (24) (25) .
There are no data on underlying mental health disease and higher risk of developing SARS Cov-2 pneumonia. Similarly, no information on the effect of chronic benzodiazepines use in patients with COVID-19 infection is available. It is interesting to note how four out of six patients, who underwent mechanical ventilation, were taking benzodiazepines. The mechanism of action of these drugs is enhancing the effect of γ-amino-butyric acid type A (GABAA) at the GABAA receptors. Chronic benzodiazepine exposure could be associated with an increased risk of developing pneumonia (26) as GABA can play an important role in regulating the secretion of a great number of cytokines (27) (28).
A severe respiratory infection generally affects HRQoL. This has been demonstrated in subjects recovering from MERS (8), SARS-CoV-1 (9) and H1N1 (29). Batawi et al. (8) demonstrated that subjects with MERS experiencing ICU admission scored low values for physical function, general health, vitality, emotional role and physical components. To our knowledge, there are still no studies considering the impact of COVID-19 on mental health and quality of life among these patients. Despite the young age population analysed in this study and the majority of patients who were discharged early after ED arrival, we observed lowest rating scores in items regarding physical role, vitality, social functioning and emotional role. It is interesting to note how the quality of life reported by hospitalized patients did not differ from non-hospitalized ones, as shown by similar physical and mental component summary scores (around 50 in both groups). This can be due by the fact that patients discharged early from ED experienced the lockdown period, so their psychological and physical spheres were possibly affected as the ones hospitalized.
The present study has some limitations. First, being a single-centre study, the number of patients considered is low. The suspected but undiagnosed cases were ruled out in the analyses. This feature has certainly weakened the statistical power of the study. Nevertheless, we considered all patients admitted to the ED of Pesaro Hospital in a very limited time which represented the period with highest COVID-19 incidence in our country. Second, this was a retrospective analysis. Although we tried to collect as many clinical data as possible, we may have still missed useful information for the management of these patients. In particular, due to the massive burden of patients admitted at the ED, several laboratory parameters (i.e.: D-dimer, ferritin, IL-6 etc.) or second level radiological examinations (i.e.: CT scan) were not always performed, mainly at the beginning of the pandemic period. Third, we performed only one early SF-36 survey (within one month from hospital discharge), while late and repeated surveys (i.e.: three or six months thereafter) might be more useful either in differentiating HRQoL based on severity illness or showing a quality of life improvement.