Chronic glucolipotoxic conditions in vitro reduce GSIS. Rat islets were cultured under normal conditions (control) or with 16.7 mM glucose and 500 μM palmitate for 72 h (GL). Post 72 h, islets were treated with 2 mM glucose (LG) or 11 mM glucose (HG) for 2 h and secreted insulin was measured. Data are expressed as mean±SEM and statistical analysis was performed using the unpaired Student’s t-test. (*P<0.05, **P<0.01 and ***P<0.001, n=4).