Steven M. Willi, BA, MD

faculty photo
Associate Professor of Pediatrics at the Children's Hospital of Philadelphia
Department: Pediatrics

Contact information
Division of Endocrinology
and Diabetes
The Children's Hospital
of Philadelphia
34th & Civic Center Blvd.
Philadelphia, PA 19104
Office: (215) 590-3618
Fax: (215) 590-3053
BA (Chemistry)
Johns Hopkins University, 1981.
MD (Medicine)
Johns Hopkins University, 1985.
Permanent link
> Perelman School of Medicine   > Faculty   > Details

Description of Research Expertise

I am full-time faculty member at the University of Pennsylvania, a Pediatric Endocrinologist with a clinical research interest in the areas of pediatric diabetes and obesity. My ongoing research trials are designed to delay the progression of type 1 diabetes in new onset patients, assess new developments in type 1 diabetes treatment and examine the safety and pharmacokinetics of various medications for the treatment of type 2 diabetes and obesity in children. I am also conducting a number of observational clinical trials assessing trends in diabetes treatment and complications in pediatric and young adult populations. I received a Clinical Associate Physician Award from NIH to study the mechanisms of insulin resistance in type 2 diabetes, and have reviewed career development award grants for NIH for many years.
My contributions to the field of medicine are summarized below:

Optimization of T1DM therapy: Patients with T1DM are at risk for acute complications including severe hypoglycemia and diabetic ketoacidosis. In addition, long-term elevated blood glucose is associated with microvascular complications including retinopathy, neuropathy, and nephropathy. I have leveraged large cooperative databases of T1DM patients to investigate risk factors for acute complications and have demonstrated that non-white race and socioeconomic deprivation are significant barriers to optimal care. In addition, I have demonstrated in clinical trials that continuous insulin pump therapy leads to improved glucose control compared with traditional injection therapy.

Immunomodulatory therapies in new-onset T1DM: While T1DM can be managed as a chronic disease with subcutaneous insulin administration, this therapy is challenging and burdensome for patients and their families. Few patients are able to consistently attain good glycemic control, putting them at risk for long-term complications. I have been a co-investigator in several trials designed to modulate the immune attack in T1DM, with the goal of preserving β-cell function. In particular, therapies that specifically target T cells show promise and are now being evaluated in high-risk relatives of patients with T1DM.

. Type 2 diabetes in youth: While historically, type 2 diabetes (T2DM) has been thought of as an adult disease, the ongoing obesity epidemic is leading to an increased prevalence of T2DM in youth. Emerging evidence suggests that the course of T2DM is more aggressive in children than in adults. I am a co-investigator in the Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) study which demonstrated superior efficacy of metformin plus rosiglitazone compared with metformin plus lifestyle or metformin alone in maintaining target glycemic control. In a secondary analysis, my work led to the demonstration that this difference in efficacy is due to improved insulin sensitivity in the combined therapy group, while baseline insulin secretion is an independent predictor of disease progression. We also demonstrated that all three treatment modalities were safe and well-tolerated in youth, and that outcomes are strongly related to parental obesity and associated co-morbidities. In addition, leveraging data from the Pediatric Diabetes Consortium, I have helped define the presenting signs and symptoms of T2DM in youth, with notable findings including that 13% present in severe distress with either DKA or hyperglycemic hyperosmolar state and that children with T2DM quite often have significant social vulnerability due to poverty and low educational attainment of family members.

The role of pediatric obesity in CVD: Cardiovascular disease (CVD) generally presents during adulthood, but the antecedents of this adult disease may be detectable in childhood. Elevated lipid and blood pressure levels have been associated with an increased risk of cardiovascular disease, and these risk factors track from childhood into adulthood. Poor nutrition, a sedentary lifestyle, and genetic factors predispose to multiple CVD risk factors, including obesity, hyperlipidemia, and hypertension. CVD is the leading cause of mortality in the United States and is associated with the recent increase in obesity rates, which have tripled in youth since 1980. I have been interested in clinical and lifestyle interventions to ameliorate the effects of obesity on CVD risk for many years. My role as coinvestigator in the HEALTHY study has afforded the opportunity to examine the antecedents of cardiovascular disease in an at risk population, and explore the efficacy of a primary prevention strategy. My goal has been to increase knowledge of these risks in the hope of encouraging healthy behaviors for the purpose of improving cardiovascular health.

Description of Clinical Expertise

Steven M. Willi, MD, received his undergraduate and medical degrees from Johns Hopkins University, and completed residency and fellowship training at the Children’s Hospital of Philadelphia. Dr. Willi has been Associate Professor of Pediatrics at the University of Pennsylvania and Director of the Diabetes Center for Children (DCC) at the Children’s Hospital of Philadelphia (CHOP) since 2004. He has been designing clinical diabetes programming and conducting clinical diabetes research for over 25 years. During that time, he has been the recipient of a number of research grants from NIH as well as from the FDA, industry and private foundations. He was also a principal investigator on the CDC/NIH sponsored SEARCH Pediatric Diabetes Registry (the largest pediatric diabetes registry in the US to date).
Before taking his current position as Director of the Diabetes Center at CHOP, he was the Chief of Pediatric Endocrinology at the Medical University of South Carolina in Charleston. As Division Chief, he developed the first Pediatric Endocrinology Fellowship Program in South Carolina, and was its program director until his departure in 2004. His clinical and research interests were in the areas of a) the counterregulatory effects of GH, b) the contribution of genetic abnormalities to human disease, and c) hypothalamic-pituitary-adrenal axis function in the neonate. However, Dr. Willi’s major interest was in the area of pediatric obesity and diabetes, for which he received a Clinical Associate Physician award from NIH.
Dr. Willi’s current clinical and research focus is still in the areas of diabetes and obesity, including intensive management of, and novel therapies for, type 1 diabetes. He remains active in the management and use of novel treatments for type 2 diabetes in children. Notable past efforts include the use of a very low calorie diet (VLCD) to treat morbid obesity and T2DM in adolescence. Dr. Willi's expertise extends to the optimal use of insulin pump therapy in type 1 diabetes, including a study utilizing the sensor augmented insulin pump, which was published in the New England Journal of Medicine. He has served on the Safety and Monitoring Committee for a multicenter, national pediatric T2D treatment trial (the TODAY study), and on the Publications and Presentations Committee for a multicenter, national pediatric T2D prevention trial (the "Healthy" study). He also served as Medical Monitor for the SEARCH Study (through its third funding cycle) and chaired the Data Safety Monitoring Board for an NIH trial designed to improve diabetes outcomes in children with T1D.
Dr. Willi's ongoing efforts focused in T1D include three trials designed to prevent or delay the progression of T1D, as well as trials utilizing new developments in T1D therapy. These include the use of inhaled insulin (Afrezza®) and a sensor augmented insulin pump with an automated blood sugar threshold suspend feature. Dr. Willi is also conducting early phase pediatric PK/PD trails examining the use of T2D therapies recently approved for use in adults. He has been lead investigator on two of these successfully completed trials. Under his direction, CHOP is among the largest participating centers in the Type 1 Diabetes Exchange, and the Pediatric Diabetes Consortium for Type 2 Diabetes. These consortia are the largest collaborative efforts of their kind to examine relevant diabetes issues through an analysis of prospectively collected clinical and biochemical data.
During his tenure as Director of the Diabetes Center for Children, Dr. Willi has spearheaded the development of an ADA certified Diabetes Education "Center of Excellence" at the Children's Hospital of Philadelphia. He has furthermore initiated several evidence-based practice initiatives within the Center. This effort has led to the formation of numerous teams of physicians, nurses, nutritionists and social workers. These teams collaborate to develop practice guidelines, which are then assessed through clinical data analysis and enhanced to improve outcomes.
Recognition of Dr. Willi's clinical expertise is evident from his inclusion in "The Best Doctors in America", Marquis Who's Who, Castle Connolly’s Top Doctors and the Consumer Research Council of America's Guide to America's Top Pediatrician's. He has been recognized as a clinical researcher by being asked to serve on four NIH/NIDDK Special Emphasis Panels, an individual Fellowship Scientific Review Group at NHLBI, and a Special Advisory Panel to the United States Office of Human Research Protection (OHRP).

Selected Publications

Bjornstad P, Nehus E, El Ghormli L, Bacha F, Libman IM, McKay S, Willi SM, Laffel L, Arslanian S, Nadeau KJ; TODAY Study Group.: Insulin Sensitivity and Diabetic Kidney Disease in Children and Adolescents With Type 2 Diabetes: An Observational Analysis of Data From the TODAY Clinical Trial. Am J Kidney Dis. 71(1): 65-74, January 2018

Wong CA, Miller VA, Murphy K, Small D, Ford CA, Willi SM, Feingold J, Morris A, Ha YP, Zhu J, Wang W, Patel MS.: Effect of Financial Incentives on Glucose Monitoring Adherence and Glycemic Control Among Adolescents and Young Adults With Type 1 Diabetes: A Randomized Clinical Trial. JAMA Pediatr. 171(12): 1176-1183, December 2017

Jaser SS, Foster NC, Nelson BA, Kittelsrud JM, DiMeglio LA, Quinn M, Willi SM, Simmons JH: Sleep in children with type 1 diabetes and their parents the T1D Exchange. Sleep Medicine 39: 108-115, November 2017.

Bergenstal RM, Gal RL, Connor CG, Gubitosi-Klug R, Kruger D, Olson BA, Willi SM, Aleppo G, Weinstock RS, Wood J, Rickels M, DiMeglio LA, Bethin KE, Marcovina S, Tassopoulos A, Lee S, Massaro E, Bzdick S, Ichihara B, Markmann E, McGuigan P, Woerner S, Ecker M, Beck RW; T1D Exchange Racial Differences Study Group.: Racial Differences in the Relationship of Glucose Concentrations and Hemoglobin A1c Levels. Ann Intern Med. 167(2): 95-102, July 2017.

Nambam B, Silverstein J, Cheng P, Ruedy KJ, Beck RW, Paul Wadwa R, Klingensmith G, Willi, SM, Wood JR, Bacha F, Thomas IH, Tamborlane WV; Pediatric Diabetes Consortium: A cross-sectional view of the current state of treatment of youth with type 2 diabetes in the USA: enrollment data from the Pediatric Diabetes Consortium Type 2 Diabetes Registry. Pediatr Diabetes 18(33): 222-229, May 2017.

Arslanian S, El Ghormli L, Bacha F, Caprio S, Goland R, Haymond MW, Levitsky L, Nadeau KJ, White NH, Willi SM; TODAY Study Group.: Adiponectin, Insulin Sensitivity, β-Cell Function, and Racial/Ethnic Disparity in Treatment Failure Rates in TODAY. Diabetes Care 40: 85–93, January 2017.

Wood JR, Connor CG, Cheng P, Ruedy KJ, Tamborlane WV, Klingensmith G, Schatz D, Gregg B, Cengiz E, Willi S, Bacha F, Beck RW; Pediatric Diabetes Consortium.: Vitamin D status in youth with type 1 and type 2 diabetes enrolled in the Pediatric Diabetes Consortium (PDC) is not worse than in youth without diabetes. Pediatric Diabetes 17: 584–591 December 2016.

Isaacs CJ, Brigatti KW, Kucheruk O, Ratcliffe S, Sciascia T, McCormack SE, Willi SM, Lynch DR.: Effects of genetic severity on glucose homeostasis in Friedreich ataxia. Muscle Nerve 54(5): 887-894, November 2016.

Jago R, Drews KL, Otvos JD, Willi SM, Buse JB: Novel measures of inflammation and insulin resistance are related to obesity and fitness in a diverse sample of 11-14 year olds: The HEALTHY study. International Journal of Obesity (Lond) 40(7): 1157-63, July 2016.

Klingensmith GJ, Connor CG, Ruedy KJ, Beck RW, Kollman C, Haro H, Wood JR, Lee JM, Willi SM, Cengiz E, Tamborlane WV; Pediatric Diabetes Consortium: Presentation of youth with type 2 diabetes in the Pediatric Diabetes Consortium. Pediatr Diabetes 17(4): 266-73, June 2016.

back to top
Last updated: 01/16/2018
The Trustees of the University of Pennsylvania