Methods are disclosed for determining progression of a condition, onset of a condition, or efficacy of treatment of a condition characterized by an adipocyte imbalance in a patient. In addition, methods are disclosed of treating diabetes, abnormal adipocyte activity, and insulin resistance using monomeric, homodimeric, and heterodimeric forms of certain C-terminal fragments of adiponectin receptor. In addition, methods of treating abnormal adipocyte activity, treating metabolic syndrome, causing insulin secretion, increasing insulin levels, inhibiting insulin degradation enzyme, treating Alzheimer's disease, treating cardiovascular disease associated with adiponectin levels, inhibiting ADAM-17 enzyme, inhibiting a protease, treating a condition associated with TNF-alpha, and treating a condition associated with HER2-neu are disclosed. Compositions, dosage forms, and kits are also disclosed.