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Research Summary
Clinical studies of patients with pituitary tumors. Current research is investigating new approaches to the evaluation of disease status and treatment of acromegaly.
Research Activities
One series of studies focuses on patients with acromegaly, a rare disease characterized by excess GH and IGF-I and their multi-system adverse effects. For these studies we utlize our large cohort of newly diagnosed and postoperative patients with acromegaly. We are examining a novel GH-IGF-I excess specific dysregulation of adipose tissue (AT) and lipodystrophy, which we believe contributes to insulin resistance, adipokine and appetite hormone dysregulation, endothelial cell dysfunction and ultimately increased CV risk in active acromegaly. During treatment, as GH/IGF-I normalize, reversal of the lipodystrophy markedly increases central AT, macrophage infiltration and inflammation in AT and systemic inflammation. We are testing these hypotheses utilizing techniques novel to the study of acromegaly and the GH/IGF-I axis including examinations of muscle lipid by MRI and 1HMRS, hepatic lipid by 1HMRS, adipose tissue for macrophage infiltration and inflammation and function of biopsied endothelial cells. We will also relate these clinical endpoints to our modern biochemical markers of acromegaly and thereby establish clinically validated biochemical guidelines for acromegaly therapy.
Our other multi-disciplinary collaborative study is first comprehensive prospective study of clinically non-functioning pituitary adenomas (CNFA). In this project we will prospectively study asymptomatic pituitary lesions that do not require surgical intervention in order to determine the appropriate initial evaluation and follow up as well as the safety of their conservative, non-surgical management. We will also prospectively assess the outcome of symptomatic CNFAs treated with surgery, the initial treatment of choice, assess the safety of conservative follow up for patients with small tumor remnants after surgery and determine in which of these patients RT is needed by examining the risks vs. benefits of post-operatively RT for residual/recurrent tumors. This project will also examine for the first time, prospectively, the impact of the disease and our therapies on quality of life and neurocognitive function in patients with CNFAs and establish a novel bank of pituitary tumor specimens from our cohort that will be linked to the extensive clinical data collected in our prospective study.
Positions & Appointments
| 2005-present |
Associate Professor of Medicine |
Columbia University, College of Physicians & Surgeons |
New York, NY |
| 1999-2005 |
Florence Irving Assistant Professor of Clinical Medicine |
Columbia University, College of Physicians & Surgeons |
New York, NY |
| 1997-2005 |
Assistant Professor of Clinical Medicine |
Columbia University, College of Physicians & Surgeons |
New York, NY |
| 1997-present |
Assistant Attending in Medicine |
Presbyterian Hospital |
New York, NY |
| 1994-1996 |
Instructor in Medicine |
Columbia University, College of Physicians & Surgeons |
New York, NY |
Education and Training
| 1980-1984 |
AB History & Science |
Harvard College, Cambridge, MA |
| 1984-1988 |
MD , Medicine |
Columbia University, College of P & S, New York, NY |
| 1988-1991 |
Residency, Internal Medicine |
Presbyterian Hospital, New York, NY |
| 1991-1994 |
Endocrinology Fellowship |
Columbia University, College of P & S, New York, NY |
Honors and Awards
1999-2002 Irving Scholar Award
Committees and Society Memberships
The Endocrine Society
The Pituitary Society, Board of Directors
Clinical Director, Neuroendocrine Unit, Columbia University College of Physicians & Surgeons.
Member, Clinical Trials Office Scientifc Advisory Committee, Columbia-Presbyterian Medical Center
Member, Herbert Irving Comprehensive Cancer Center
Member, Endocrine Society Self-Assessment Committee
Member, Columbia University Diabetes and Endocrinology Research Center (DERC)
Member, Standing Committee on Recruitment & Retention for Clinical and Epidemiological Research, Department of Medicine
Favorite Websites
http://www.ColumbiaDeptMedicine.org/dept/medicine/neuroendo/
Selected Publications:
1. Freda PU, Shen, W, Reyes-Vidal CM, Geer EB, Arias-Mendoza F, Gallagher D, Heymsfield SB. (2009) Skeletal Muscle Mass in Acromegaly Assessed by Magnetic Resonance Imaging and Dual Photon X-ray Absorptiometry. PMCID: PMC2730874 J Clin Endocrinol Metabolism
94(8):2880-6
2. Freda PU, Reyes CS, Conwell IM, Sundeen RS and Wardlaw SL. (2003) Serum ghrelin levels in acromegaly: Effects of surgical and long-acting octreotide therapy. J Clin Endocrinol Metab
88:2037-44
3. Freda PU, Shen W, Heymsfield SB, Geer EB, Reyes-Vidal CM, Gallagher D. (2008) Lower visceral and subcutaneous, but higher intermuscular adipose tissue depots in patients with GH and IGF-I excess due to
acromegaly. PMCID: PMC2435633
J Clin Endocrinol Metab
93(6):32334-2343
4. Freda PU, Nuruzzaman AT, Reyes CM, Sundeen RE, Post KD. (2004) Significance of "abnormal" nadir GH levels after oral glucose in postoperative patients with acromegaly in remission with normal IGF-I levels. J Clin Endocrinol Metab
89:495-500
5. Trainer PJ, Drake WM, Katznelson L, Freda PU, Herman-Bonert V, Van der Lely AJ et al. (2000) Treatment of acromegaly with the growth hormone-receptor antagonist
pegvisomant. N Engl J Med
342:1171-7
6. Freda PU, Post KD, Powell JS and Wardlaw SL. (1998) Evaluation of disease status with sensitive measures of GH secretion in 60 postoperative patients with acromegaly. J Clin Endocrinol Metab
83:3808-16
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