Association of body mass index with COVID-19 related in-hospital death.

Dear Editor,

We thank Drs Ceylan and Balci for their insightful comments on our recently published analysis (ref [1]).

As pointed out, the proportion of patients older than 65 years was indeed higher in the low BMI than in the other BMI groups (table). However, the categories of age were included in the multivariable analysis. This latter analysis revealed that the overweight patients had still a significantly lower risk of in-hospital mortality than the underweight patients, implying that age was not residual confounding factor of the comparison between the categories of BMI.

The possible coexistence of sarcopenia and obesity suggested cannot be assessed, in the absence of report of muscle mass or strength. We agree that the prevalence of sarcopenia in the different groups of BMI would help to refine the interpretation of the results.

Author contribution

Conceptualization: Jason Bouziotis, Jean-Charles Preiser.

Methodology: Jason Bouziotis.

Formal analysis: Jason Bouziotis, Jean-Charles Preiser.

Visualization: Jason Bouziotis, Jean-Charles Preiser.

Writing - original draft: Jason Bouziotis, Jean-Charles Preiser.

BMI (kg/m2)	n	Age over 65 yn (%)
<18.5|20.5	319	240 (75.2)
18.5|20.5–<25	2325	1008 (43.3)
25–<30	3846	1560 (40.6)
≥30	4119	1257 (30.5)