In post-menopausal women, aged individuals, and patients with diabetes mellitus or chronic renal disease, bone mineral density (BMD) decreases while the vasculature accumulates arterial calcifications (ACs). AC can be found in the tunica intima and/or in the tunica media. Prospective studies have shown that patients with initially low BMD and/or the presence of fragility fractures have at follow-up a significantly increased risk for coronary and cerebrovascular events and for overall cardiovascular mortality. Similarly, patients presenting with abdominal aorta calcifications (an easily quantifiable marker of vascular pathology) show a significant decrease in the BMD (and an increase in the fragility) of bones irrigated by branches of the abdominal aorta, such as the hip and lumbar spine. AC induction is an ectopic tissue biomineralization process promoted by osteogenic transdifferentiation of vascular smooth muscle cells as well as by local and systemic secreted factors. In many cases, the same regulatory molecules modulate bone metabolism but in reverse. Investigation of animal and in vitro models has identified several potential mechanisms for this reciprocal bone–vascular regulation, such as vitamin K and D sufficiency, advanced glycation end-products–RAGE interaction, osteoprotegerin/RANKL/RANK, Fetuin A, oestrogen deficiency and phytooestrogen supplementation, microbiota and its relation to diet, among others. Complete elucidation of these potential mechanisms, as well as their clinical validation via controlled studies, will provide a basis for pharmacological intervention that could simultaneously promote bone and vascular health.

Multiple endocrine neoplasia type 1 (MEN1) is a rare, inherited cancer syndrome characterized by the development of multiple endocrine and non-endocrine tumors. MEN1 patients show a reduction of bone mass and a higher prevalence of early onset osteoporosis, compared to healthy population of the same age, gender, and ethnicity. During the monitoring and follow-up of MEN1 patients, the attention of clinicians is primarily focused on the diagnosis and therapy of tumors, while the assessment of bone health and mineral metabolism is, in many cases, marginally considered. In this study, we retrospectively analyzed bone and mineral metabolism features in a series of MEN1 patients from the MEN1 Florentine database. Biochemical markers of bone and mineral metabolism and densitometric parameters of bone mass were retrieved from the database and were analyzed based on age ranges and genders of patients and presence/absence of the three main MEN1-related endocrine tumor types. Our evaluation confirmed that patients with a MEN1 diagnosis have a high prevalence of earlyonset osteopenia and osteoporosis, in association with levels of serum and urinary markers of bone turnover higher than the normal reference values, regardless of their different MEN1 tumors. Fifty percent of patients younger than 26 years manifested osteopenia and 8.3% had osteoporosis, in at least one of the measured bone sites. These data suggest the importance of including biochemical and instrumental monitoring of bone metabolism and bone mass in the routine medical evaluation and follow-up of MEN1 patients and MEN1 carriers as important clinical aspects in the management of the syndrome.