Serena Anna Ravelli, Elisa Maseroli, Linda Vignozzi
Male hypogonadism is increasingly prevalent with advancing age and is particularly frequent among men with obesity, type 2 diabetes mellitus, and other cardiometabolic comorbidities (functional hypogonadism), whereas it remains relatively uncommon in younger men except in the presence of congenital or acquired disorders affecting the hypothalamic-pituitary-testicular axis (organic hypogonadism). Historically, the relationship between testosterone decline and aging per se, as well as the contribution of comorbidities, has been debated. Similarly, uncertainty has persisted regarding the management of obesity-associated functional hypogonadism, and diagnostic thresholds remain insufficiently standardized across different guidelines. Therefore, this narrative review addresses unresolved issues in diagnostic criteria, etiological assessment, and the impact of treatment on symptoms and long-term health outcomes in older men. It was based on a literature search conducted in PubMed using combinations of keywords such as obesity, testosterone, male hypogonadism, functional and organic hypogonadism, aging men, metabolic syndrome, diabetes, and comorbidities. Original research articles, systematic reviews, meta-analyses, and clinical guidelines published in English were screened, and the most relevant and high-quality publications were selected to provide a comprehensive overview of the current evidence. Additional relevant studies were identified through the reference lists of retrieved articles.