Circulating adiponectin levels differ between patients with multiple myeloma and its precursor disease

OBJECTIVE: An increased risk of multiple myeloma (MM) has been observed among individuals with low pre-diagnostic circulating levels of adiponectin, a metabolic hormone that is typically underexpressed among those who are overweight or obese. To assess whether adiponectin may influence myeloma development or progression to frank MM, we compared circulating adiponectin levels across patients with different stages of MM and its precursor, monoclonal gammopathy of undetermined significance (MGUS). METHODS: We measured adiponectin in 213 patients with MGUS, smoldering MM, or fully developed MM. Differences in adiponectin levels across patient groups were assessed using multivariate linear regression. RESULTS: Relative to MGUS patients, adiponectin levels were statistically significantly lower among those with smoldering and fully developed MM, both overall (16–20% decrease; P=0.048) and among those with IgG/IgA isotypes (26–28% decrease; P=0.004). Among MGUS patients, adiponectin levels were significantly lower for those with the higher risk IgM isotype compared with those who had IgG/IgA isotypes (42% decrease; P=0.036). CONCLUSIONS: The findings of this study, the largest to investigate adiponectin levels in patients with different stages of MM and the first to evaluate associations with clinical characteristics, suggest that reduced expression of adiponectin may be associated with progression from MGUS to MM.