As hundreds of thousands of diabetics get health coverage under the federal law, insurance companies are aggressively targeting this glut of new patients. That's because they are expensive to treat and often lax in taking medications and following their diet. Insurers are calling diabetics when they don't pick up prescriptions or miss appointments. They are arranging transportation to get them to the doctor's office and some are even sending nurses on house calls. It's all part of an effort to avoid costly complications that will have a big impact on the insurance companies' bottom lines.