Use of Low Dose Pioglitazone to Treat Autosomal Dominant Polycystic Kidney Disease

Inclusion Criteria: * Male or female patients with autosomal dominant polycystic kidney disease (ADPKD) aged 18-55 * estimate glomerular filtration rate (GFR) at or above ≥ 50 ml/min/1.73 m2 by any GFR formula * Normal liver enzymes (ALT/AST) * fasting blood glucose between 70 and120 * for female patients, a willingness to use double contraception to avoid pregnancy while in study * able to give informed consent * In the opinion of the investigator, high likelihood of progressive kidney disease Exclusion Criteria: * diabetes, defined as any of the following: fasting blood sugar \> 130 times two, HgbA1C \> 7, on any blood sugar lowering medication, or past diagnosis of diabetes not occurring during pregnancy * uncontrolled hypertension as determined by the examining physician * history of impaired systolic function (ejection fraction \< 50%) by previous echocardiogram or known ischemic cardiovascular disease * findings suggestive of a kidney disease other than ADPKD * systemic illness requiring immunosuppressive or anti-inflammatory agents * congenital absence of a kidney or history of a total nephrectomy * history of cyst reduction or partial nephrectomy * history of renal cyst aspiration within the previous year * History of bladder cancer, or gross hematuria * inability to undergo MRI due to implantable devices or foreign objects that preclude MRI * active renal transplant * allergy or sensitivity to any of the components of the test materials * institutionalized * currently pregnant or plans to become pregnant during the study