The present invention discloses that diabetic rats showed a reduction in nitrergic relaxation of the gastric, impaired nNOS dimerization, decreased BH4 and GTPCH1 levels and thus, are more susceptible to develop diabetic gastroparesis. The use of tetrahydrobiopterin and its derivatives and sex steroid hormones as disclosed herein provides a novel strategy for therapeutic intervention of diabetic gastroparesis and any other gut-related diseases. Additionally, the present invention also discloses methods to determine risk of developing gastroparesis in an individual that are drawn to detecting variations in the activity and levels of GCH gene and in gene encoding sex steroid hormone receptor.
