Hypogonadism is frequent in very old men with multimorbidity and is associated with anemia and sarcopenia.

"Declarations Conflict of interestS. Schluessel, M. Bidlingmaier, S. Martini, M. Reincke, N. Reisch, A. Schaupp, G. Stalla,D. Teupser, R. Schmidmaier and M. Drey declare that they have no competing interests. All procedures performed in studies involving human participants or on human tissue were in accordance with the ethical standards of the institutional and/or national research committee and with the 1975 Helsinki declaration and its later amendments or comparable ethical standards. Since this study was retrospective in nature, it did not require informed consent from the participants. The study protocol received approval from the Ethical Review Committee of Ludwig-Maximilians-University under Ethical Vote No. 22‑0305. Conflict of interest S. Schluessel, M. Bidlingmaier, S. Martini, M. Reincke, N. Reisch, A. Schaupp, G. Stalla,D. Teupser, R. Schmidmaier and M. Drey declare that they have no competing interests."

"Funding This work was supported by the Deutsche Forschungsgemeinschaft (Heisenberg Professorship 325768017) to N.R. Funding Open Access funding enabled and organized by Projekt DEAL."