Mary Leonard

Mary B. Leonard, MD, Arline and Pete Harman Professor and Chair, Department of Pediatrics, Division of Nephrology; Professor, Department of Medicine, Division of Nephrology; Professor (by courtesy), Department of Epidemiology and Population Health, Stanford University School of Medicine; Adalyn Jay Physician-in-Chief, Lucile Packard Children’s Hospital; Director, Stanford Maternal and Child Health Research Institute; Associate Dean of Maternal Child Health

Research Description: Dr. Leonard leads a multidisciplinary research program primarily focused on the impact of chronic diseases on bone metabolism and nutrition, with an emphasis on changes in body composition and skeletal density and structure during growth and aging, and in the context of inflammatory diseases, chronic kidney disease, glucocorticoid therapy, and bone marrow transplantation. Her lab identified unique windows of vulnerability for impaired bone accrual during early puberty, with a consequent detrimental impact on peak bone mass and likely implications for life long skeletal health and fracture risk. For example, they demonstrated that type 1 diabetes was associated with markedly increased fracture rates, evident in early adolescence and pronounced throughout adulthood. She and her students are currently using high resolution peripheral quantitative CT to characterize bone structure and strength in adolescents with type 1 diabetes, compared with healthy controls. Dr. Leonard was the Founding Director of the Stanford Assessment of Muscle and Bone across the Ages (SAMBA) Center in 2014. This Center permits state-of-the-art studies of bone metabolism and body composition in diabetes. For example, the whole body DXA scans in Dr. Maahs’ newly NIH funded DP3 study (Accelerating Solutions to Optimize Glycemic Control and Weight Management in Young Adults with Type 1 diabetes) are performed in the Center, as were the whole body DXA scans and measures of muscle strength in Dr. Palaniappan’s STRONG-D exercise RCT in normal weight diabetics. In 2016, Dr. Leonard was appointed Chair of the Department of Pediatrics, and Director of the Maternal and Child Health Research Institute (MCHRI). In these roles, she will continue to dedicate effort to support diabetes research at Stanford. She has supported the P&F program with co-funding support through her leadership role in MCHRI and Department of Pediatrics. Dr. Leonard also serves on SDRC Executive Committee.

Selected relevant publications or presentations (Stanford DRC Members in BOLD):

  1. Mostoufi-Moab S, Magland J, Isaacoff EJ, Sun W, Rajapakse CS, Zdemel B, Wehrli F, Shekdar K, Baker J, Long J, Leonard MB. Adverse Fat Depots and Marrow Adiposity Are Associated With Skeletal Deficits and Insulin Resistance in Long-Term Survivors of Pediatric Hematopoietic Stem Cell Transplantation. J Bone Miner Res. 2015; 30(9), 1657-66. PMID: 25801428; PMCID: PMC4540662. 

  2. Ziolkowski SL, Long J, Baker JF, Chertow GMLeonard MB. Chronic Kidney Disease and the Adiposity Paradox: Valid or Confounded? J Ren Nutr. 2019 Nov;29(6):521-528. doi: 10.1053/j.jrn.2018.11.011. PMID: 30709713; PMCID: PMC6663655. 

  3. DeBoer MD, Lee AM, Herbert K, Long J, Thayu M, Griffin LM, Baldassano RN, Denson LA, Zemel BS, Denburg MR, Herskovitz R, Leonard MB. Increases in IGF-1After Anti-TNF-α Therapy Are Associated with Bone and Muscle Accrual in Pediatric Crohn Disease. J Clin Endocrinol Metab. 2018 Mar 1;103(3):936-945. doi: 10.1210/jc.2017-01916. PMID: 29329430; PMCID: PMC6276706.

  4. Weber DR, Gordon RJ, Kelley JC, Leonard MB, Willi SM, Hatch-Stein J, Kelly A, Kosacci O, Kucheruk O, Kaafarani M, Zemel BS. Poor Glycemic Control Is Associated With Impaired Bone Accrual in the Year Following a Diagnosis of Type 1 Diabetes. J Clin Endocrinol Metab. 2019 Oct 1;104(10):4511-4520. doi: 10.1210/jc.2019-00035. PMID: 31034056; PMCID: PMC6736051.