State officials are watching for a predicted increase in demand for addiction treatment services once Connecticut expands its Medicaid program and more people have insurance coverage next year because of the new federal health care law. It is not certain that the prospect of having health insurance coverage will spur more people to seek treatment, said Jim Siemianowski, spokesman for the state’s Department of Mental Health and Addiction Services. About 32,000 people are receiving substance abuse treatment annually in a facility or hospital in Connecticut, an Associated Press analysis of government data showed. That number is projected to climb to 44,588. Nationally, an estimated 3 million to 5 million people with drug and alcohol problems are expected to become eligible for insurance coverage under the new health care law.