Pioglitazone for Idiopathic Gastroparesis

Objective • The principal objective of this pilot study will be to evaluate whether 8 weeks of treatment of pioglitazone will improve symptoms as measured by the Gastrointestinal Symptom Index Daily Diary (GCSI-DD) in patients with Idiopathic Gastroparesis Secondary objectives of this study include: * To determine the effects of pioglitazone on other symptoms associated with gastroparesis using the Patient Assessment of Upper Gastrointestinal Symptom Severity Index (PAGI-SYM) and the Gastrointestinal Symptom Rating Scale (GSRS), * To determine the effects of pioglitazone on gastric emptying as measured by the 13C- Spirulina breath test, * To determine the effects of pioglitazone on satiety as measured by a liquid caloric test * To determine the effects of pioglitazone on depression and anxiety using the Beck Depression Inventory and State-Trait Anxiety Scores, * To determine the effects of pioglitazone on Quality of Life using the PAGI-QoL and Short Form (SF)-36 questionnaire, * To determine the effects of pioglitazone on markers of inflammation (CRP and ESR) and serum cytokine levels * To determine the nature and incidence of adverse effects from a 12-week course of pioglitazone. Treatment group • Pioglitazone (30 mg po qd) Population • Age 18 years or older at registration with nausea, vomiting, and other symptoms suggestive of patients with chronic nausea and vomiting of presumed gastric origin, with symptomatic gastroparesis. Study duration * Up to 4 weeks of screening prior to pioglitazone treatment * 8 weeks of treatment starting at initial dose of pioglitazone * 4 weeks of washout period * Length of recruitment: 16 months Sample size justification * Total of 23 patients * Primary comparison: Baseline PAGI-SYM score versus 4, 8, and 12 weeks. Number of clinical centers • Johns Hopkins Bayview Medical Center.