Macrophage cholesterol efflux may be decreased in metabolic syndrome, due to low plasma HDL, the acceptor for cholesterol efflux, or hyperglycemia, which decreases Abca1 and Abcg1 expression in monocytes and macrophages.61,62 Our data suggest that decreased SMC cholesterol efflux in metabolic syndrome could link adverse metabolic conditions, including diabetes and low HDL cholesterol, with urinary bladder distension, a major cause of LUTS. Here, ABCG1 is linked to diabetes mellitus.