Obesity is a pervasive public health issue, and is responsible for a growing prevalence of diverse comorbidites that increase mortality and reduce quality of life. Obesity is an important risk factor for the development and progression of chronic kidney disease (CKD), independent of other associated illnesses such as type 2 diabetes. Increased activation of the renin-angiotensin-aldosterone system (RAAS) is a principal mechanism of obesity-associated renal disease. RAAS blockers, specifically angiotensin converting enzyme inhibitors (ACE- Is) and angiotensin receptor blockers (ARBs), attenuate adverse renal outcomes in patients with both diabetic and non-diabetic nephropathies, with increased effect in patients with a higher degree of baseline proteinuria. RAAS blockers also delay the onset of microalbuminuria in diabetic patients without any baseline renal disease. Obese patients seem to be more sensitive to the hemodynamic effects of RAAS blockade than normal-weight individuals. However, little is known about the long-term renoprotective effects of RAAS blockade in obesity-associated, non-diabetic kidney disease. The objective of the proposed study is to perform a retrospective, population-based cohort study using The Health Improvement Network (THIN) to evaluate the effect of RAAS blockade on the development and progression of CKD in obese patients. We will employ marginal structural modeling for time-updated exposure to ACE-Is and ARBs, and will adjust for various key confounders, including number of antihypertensive medications and degree of blood pressure control. This study of obese, non-diabetic, hypertensive patients will determine 1) if RAAS blockade is protective against adverse renal outcomes compared to other antihypertensive therapies, and 2) if the presence of baseline renal dysfunction or 3) baseline proteinuria modifies the association between RAAS blockade and development of adverse renal outcomes. The proposed study will provide critical insights into the potential role of RAAS blockade in mitigating renal complication in the obese population. This work, together with the formal masters degree program described in the application, will provide the applicant, Dr. Jordana Cohen, with intensive training in biostatistics, clinical epidemiology, database management, and analytic methods that will allow her to establish a clinical research focus in obesity, hypertension, and CKD. The program will also involve multifaceted career development with complementary mentors with expertise in epidemiology, hypertension, obesity, and CKD-based research. The long-term objectives of Dr. Cohen for this grant are to analyze and interpret the data for this project, prepare manuscripts for publication, apply the results to the design of future studies in this area, and use the result as a foundation of a K award application.

Public Health Relevance

Obesity is an important public health issue, and is a major risk factor for the development and progression of kidney disease. Obese patients often sustain kidney damage from excessive blood flow into the kidney (due to increased activity of the renin-angiotensin-aldosterone system (RAAS)), however very little is known about the long-term effects of medications that block RAAS on obesity-associated kidney disease. The purpose of the proposed study is to use a large, population-based database to evaluate the effect of RAAS blockers on the development and progression of chronic kidney disease in obese, hypertensive, non-diabetic patients.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Postdoctoral Individual National Research Service Award (F32)
Project #
1F32DK103484-01
Application #
8782707
Study Section
Special Emphasis Panel (ZDK1)
Program Officer
Rankin, Tracy L
Project Start
2014-07-03
Project End
2016-07-02
Budget Start
2014-07-03
Budget End
2015-07-02
Support Year
1
Fiscal Year
2014
Total Cost
Indirect Cost
Name
University of Pennsylvania
Department
Type
Schools of Medicine
DUNS #
City
Philadelphia
State
PA
Country
United States
Zip Code
19104
Cohen, Jordana B; Stephens-Shields, Alisa J; Denburg, Michelle R et al. (2016) Obesity, Renin-Angiotensin System Blockade and Risk of Adverse Renal Outcomes: A Population-Based Cohort Study. Am J Nephrol 43:431-40
Cohen, Jordana B; Townsend, Raymond R (2016) Antihypertensive Medication in Patients Pre- and Postdialysis: Still Hazy After All These Years. Clin J Am Soc Nephrol 11:1327-9
Cohen, Jordana B; Hogan, Jonathan J (2016) Rethinking First-Line Immunosuppression for Idiopathic FSGS. Clin J Am Soc Nephrol 11:372-3
Cohen, Jordana B; Cohen, Debbie L (2015) Cardiovascular and renal effects of weight reduction in obesity and the metabolic syndrome. Curr Hypertens Rep 17:34
Cohen, Jordana B; Bloom, Roy D; Reese, Peter P et al. (2015) National outcomes of kidney transplantation from deceased diabetic donors. Kidney Int :