Table 1.

Unmet needs in the setting of sarcopenia that require further investigations.

Definition	Sarcopenia among individuals with metabolic syndrome represents a separate entity from that occurring in ageing population. Is s concomitantly found with obesity (“sarcopenic obesity”) and/or other features of metabolic syndrome. Obesity by Body Mass Index may be under-classified in patients with sarcopenia. A proper definition of sarcopenia and the understanding of all concomitant diseases and afflictions (e.g. depression) needs to be carefully implemented.
Diagnosis	Comparative studies involving the different diagnostic tools (hand-grip strength, gait speed) and techniques (Computed Tomography, Magnetic Resonance, Body impedance analysis, Dual-energy X-ray absorptiometry, ultrasound) are needed, in order to assess their accuracy in different populations (age, ethnicity) and to improve non-invasive, radiation-free approaches.
Biomarkers	Sarcopenia is a major determinant for the metabolic status in individuals with metabolic syndrome and insulin resistance. Many involved tissues (adipose tissue, liver, hypothalamus) actively secrete cytokines that might be feasible as biomarkers, as emerged by pre-clinical studies and few human studies (leptin, irisin, myostatin, adiponectin, IGF-1). Their plausibility is affected by the different source of secretion and the pleiotropic effect of the molecules. More studies are needed to assess the accuracy of these cytokines as serum markers in specific populations (e.g. individuals with Non-Alcoholic Fatty Liver Disease, diabetic patients) for the detection of sarcopenia and the prediction of a more severe course.
Therapy	The management of sarcopenia resides on physical activity. The concomitant presence of other conditions (e.g. older age, obesity) and potential lack of long-term compliance requires other approaches. The evaluation of multiple cross-talks between insulin sensitive tissues and different disease pathways might bring to light optimal target for individualized therapy.