The subject invention provides materials and methods for modulating a variety of biological factors to treat biological conditions associated with the factors. In one embodiment of the invention, a cysteamine compound is administered to a patient to treat hypercholesterolemia and/or complications associated with hypercholesterolemia. In another embodiment, a cysteamine compound is administered to a patient to prevent the onset of diabetes in an at-risk patient and/or treat or prevent the onset of diabetes-associated complications.