Acts as a high affinity receptor for both nicotinic acid (also known as niacin) and (D)-beta-hydroxybutyrate and mediates increased adiponectin secretion and decreased lipolysis through G(i)-protein-mediated inhibition of adenylyl cyclase. This pharmacological effect requires nicotinic acid doses that are much higher than those provided by a normal diet. Mediates nicotinic acid-induced apoptosis in mature neutrophils. Receptor activation by nicotinic acid results in reduced cAMP levels which may affect activity of cAMP-dependent protein kinase A and phosphorylation of target proteins, leading to neutrophil apoptosis. Expressed in lungs, spleen, heart, skeletal muscle and adipose tissue. By interferon-gamma in macrophages. Niacin administration has no effect on serum adiponectin levels in contrast to wild-type mice where levels are decreased. Belongs to the G-protein coupled receptor 1 family.