Disclosed are fusion proteins that include albumin fused to a polypeptide that has insulin activity. The fusion proteins may include albumin fused to insulin or an insulin analog. In particular, the fusions proteins may include albumin fused to a single chain insulin analog. The fusion proteins may exhibit extended insulin activity in vivo or in vitro relative to insulin that is not fused to albumin. The fusion proteins may be formulated as aerosol compositions.
