New Study Shows Bariatric Surgery Turns Back Kidney Disease In Severely Obese Patients

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SAN DIEGO, CA – JUNE 20, 2012 – Severely obese patients with chronic kidney disease (CKD) saw significant improvements in kidney function within one year of bariatric surgery, according to a new study* presented here at the 29thAnnual Meeting of the American Society for Metabolic & Bariatric Surgery (ASMBS). The study found patients went from having either moderate disease to mild or mild disease to normal, within a span of one year.

“With bariatric surgery we are attacking the two main culprits of chronic kidney disease – high blood sugar and high blood pressure,” said study co-author Wei-Jei Lee, MD, PhD from Min-Sheng General Hospital and National Taiwan University Hospital. “However, this study suggests the earlier we treat CKD in the disease process with bariatric surgery, the more favorable the impact on the kidney.”

The study, conducted by researchers from Min-Sheng General Hospital and National Taiwan University Hospital, included 233 patients who, on average, were 33-years-old and had a body mass index (BMI) of 39.5 (about 80 pounds overweight). About 20 percent had mild to moderate CKD and another 25 percent of patients had a precursor to the disease. More than 90 percent had Type 2 diabetes and nearly half had hypertension.

According to the National Kidney Foundation (NKF), the two main causes of CKD are diabetes and high blood pressure, which are responsible for up to two-thirds of the 26 million CKD cases in the United States.[1]

After undergoing bariatric surgery, patients lost more than 60 percent of their excess weight, and their glomerular filtration rate (GFR), a test used to check how well the kidneys are working, improved no matter which stage of CKD the patient had. GFR went from 81.0 to 98.6 ml/min in the mild disease group, and from 49.3 to 66.8 ml/min in the moderate disease group. Type 2 diabetes went into remission for nearly 60 percent of patients in these groups.

The NKF says normal GFR ranges from 90 to 120 ml/min.1 Those with hyperfiltration, an early sign of potential kidney disease where the kidneys filter larger than normal quantities of blood, saw rates drop from 146.5 to 133 ml/min. This group saw a diabetes remission rate of more than 83 percent. Those with normal kidney function before surgery remained that way and diabetes improved in nearly three out of four patients.

In addition to Dr. Lee, study co-authors from Min-Sheng General Hospital and National Taiwan University Hospital include Chun-Cheng Hou, MD, Shu-Chu Chen, RN, Professor Yi-Chih Lee, Jung-Chien Chen, MD, and

Kong-Han Ser, MD.

About Obesity and Metabolic and Bariatric Surgery

Obesity is one of the greatest public health and economic threats facing the United States.[2] Approximately 72 million Americans are obese[3] and, according to the ASMBS, about 18 million have morbid obesity. Obese individuals with a BMI greater than 30 have a 50 to 100 percent increased risk of premature death compared to healthy weight individuals as well as an increased risk of developing more than 40 obesity-related diseases and conditions including Type 2 diabetes, heart disease and cancer.[4],[5] The federal government estimated that in 2008, annual obesity-related health spending reached $147 billion,[6] double what it was a decade ago, and projects spending to rise to $344 billion each year by 2018.[7]

Metabolic/bariatric surgery has been shown to be the most effective and long lasting treatment for morbid obesity and many related conditions and results in significant weight loss.[8],[9],[10] In the United States, about 200,000 adults have metabolic/bariatric surgery each year.[11] The Agency for Healthcare Research and Quality (AHRQ) reported significant improvements in the safety of metabolic/bariatric surgery due in large part to improved laparoscopic techniques.[12] The risk of death is about 0.1 percent[13] and the overall likelihood of major complications is about 4 percent.[14]

About the ASMBS

The ASMBS is the largest organization for bariatric surgeons in the world. It is a non-profit organization that works to advance the art and science of bariatric surgery and is committed to educating medical professionals and the lay public about bariatric surgery as an option for the treatment of morbid obesity, as well as the associated risks and benefits. It encourages its members to investigate and discover new advances in bariatric surgery, while maintaining a steady exchange of experiences and ideas that may lead to improved surgical outcomes for morbidly obese patients. For more information, visit


*PL-108: Improved Renal Function 12 Months After Bariatric Surgery

Dr. Wei-Jei Lee; Chun-Cheng Hou, MD; Shu-Chu Chen, RN; Prof. Yi-Chih Lee; Jung-Chien Chen, MD; Kong-Han Ser, MD


[1]The National Kidney Foundation. (2012). About chronic kidney disease. Accessed May 2012 from

[2]Flegal, K. M., Carroll, M. D., Ogden, C. L., et al. (2002). Prevalence and trends in obesity among US adults, 1999-2000. Journal of the American Medical Association. 288(14) pp. 1723-1727. Accessed March 2012 from

[3]Chronic Disease Prevention and Health Promotion – Centers for Disease Control and Prevention. (2011). Obesity; halting the epidemic by making health easier at a glance 2011. Accessed February 2012 from

[4]Office of the Surgeon General – U.S. Department of Health and Human Services. Overweight and obesity: health consequences. Accessed March 2012 from

[5]Kaplan, L. M. (2003). Body weight regulation and obesity. Journal of Gastrointestinal Surgery. 7(4) pp. 443-51. Doi:10.1016/S1091-255X(03)00047-7. Accessed March 2012 from

[6]Finkelstein, E. A., Trogdon, J. G., Cohen, J. W., et al. (2009). Annual medical spending attributable to obesity: payer- and service-specific estimates. Health Affairs. 28(5) pp. w822-w831. Accessed February 2012 from

[7]Thorpe, K (2009). The future costs of obesity: national and state estimates of the impact of obesity on direct health care expenses. America’s Health Rankings. Accessed June 2012 from

[8]Weiner, R. A. (2010). Indications and principles of metabolic surgery. U.S. National Library of Medicine. 81(4) pp.379-394.

[9]Chikunguw, S., Patricia, W., Dodson, J. G., et al. (2009). Durable resolution of diabetes after roux-en-y gastric bypass associated with maintenance of weight loss. Surgery for Obesity and Related Diseases. 5(3) p. S1

[10]Torquati, A., Wright, K., Melvin, W., et al. (2007). Effect of gastric bypass operation on framingham and actual risk of cardiovascular events in class II to III obesity. Journal of the American College of Surgeons. 204(5) pp. 776-782. Accessed March 2012 from

[11]American Society for Metabolic & Bariatric Surgery. (2009). All estimates are based on surveys with ASMBS membership and bariatric surgery industry reports.

[12]Poirier, P., Cornier, M. A., Mazzone, T., et al. (2011). Bariatric surgery and cardiovascular risk factors. Circulation: Journal of the American Heart Association. 123 pp. 1-19. Accessed March 2012 from

[13]Agency for Healthcare Research and Quality (AHRQ). Statistical Brief #23. Bariatric Surgery Utilization and Outcomes in 1998 and 2004. Jan. 2007.

[14]Flum, D. R. et al. (2009). Perioperative safety in the longitudinal assessment of bariatric surgery. New England Journal of Medicine. 361 pp.445-454. Accessed June 2012 from

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