PEER REVIEW
INSULIN DOSING AFTER BARIATRIC SURGERY: PREDICTABLE DOSE DECREASES? AUTHORS
Katherine Hadsall, M.S. Kathryn Vollmer, Drake University College of Pharmacy and Health Sciences Natalie Ake, Drake University College of Pharmacy and Health Sciences Lynn Kassel, PharmD, BCPS, Associate Professor of Clinical Sciences, Drake University College of Pharmacy and Health Sciences, Acute Care Pharmacist, MercyOne West Des Moines Medical Center Jamie Pitlick, PharmD, BCPS, BC-ADM, Associate Professor of Pharmacy Practice, Drake University College of Pharmacy and Health Sciences, Clinical Pharmacist, MercyOne Diabetes and Endocrinology Center Michael Daly, PharmD, MSCI, BCPS, Associate Professor of Clinical Sciences, Drake University College of Pharmacy and Health Sciences, Informatics Pharmacist, The Iowa Clinic Joel Rand, MPAS, PA-C, Des Moines Bariatric Surgery, MercyOne West Des Moines Medical Center Mark Smolik, MD, FACS, FASMBS, Medical Director Des Moines Bariatric Surgery, MercyOne West Des Moines Medical Center
Conflict of interest: The authors declare no conflict of interest. A preliminary assessment of the project was presented at the 2019 ACCP Annual Meeting in New York, NY.
ABSTRACT Introduction: The prevalence of obesity is increasing in the United States and worldwide, and obesity is associated with chronic diseases such as type 2 diabetes. Bariatric surgery, including procedures such as laparoscopic sleeve gastrectomy (LVSG) or Roux-en-Y (RYGB), represent one solution to reduce weight, hemoglobin A1c, and insulin doses in patients who are overweight or obese. However, the long-term data and predictability of decreasing insulin doses in the individuals who have received these surgeries is limited. Methods: This was a retrospective study of individuals, ages 18-89 years with type 1 or 2 diabetes (n=39), who underwent LVSG or RYGB at MercyOne West Des Moines Medical Center and followed up at MercyOne Des Moines Endocrinology Care between March 1, 2012 and September 30, 2018. Descriptive statistics were used to analyze data. Results: Of the 40 patients included, almost half (45% (n=18)) remained on insulin in the immediate post-op period. At 12-months post-op, 20% (n=8) of patients remained on insulin. Even though fewer patients were on insulin at 12-months post-op, the mean A1c increased from 7.01 ± 0.83 to 7.93 ± 1.42. On average, bariatric surgery reduced mean weight by 19.2% (or a mean of 24.6 kg) at 12-months post-op. Conclusion: Bariatric surgery decreases weight and insulin requirements over 12 months in individuals with obesity and type 1 or 2 diabetes. However, insulin doses required were not predictable for the entire population. Key Points: • Insulin doses often decrease following bariatric surgery, and can cure diabetes.
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| The Journal of the Iowa Pharmacy Association
• Insulin doses immediately drop following surgery and up to the 12-months after. • Glucose control, by A1c, returned to baseline within 12-months of surgery. • The time frame of insulin dose decreases are not predictable following LVSG or RYGB.
INTRODUCTION
Diabetes is currently the 7th leading cause of death in the United States, with the economic burden on the healthcare system costing an estimated $327 billion annually for diagnosed individuals1,2. The prevalence of diabetes continues to grow, due in part to the obesity epidemic3, as obesity is the leading risk factor for the development of type 2 diabetes mellitus4,5. Weight loss, as low as 5 to 15% of total weight, can help decrease the number of risk factors for the development of diabetes in individuals with obesity5. Bariatric surgery is recommended as a treatment option for type 2 diabetes in adults with a BMI greater than or equal to 40 kg/m2 and with a BMI 35.0 – 39.9 kg/m2 who do not achieve weight loss with non-surgical methods. Several studies have compared health outcomes in patients undergoing surgical versus non-surgical interventions. Two studies demonstrated that patients who underwent bariatric surgery had a higher remission rate of type 2 diabetes, greater reductions in A1c, and decreased body weight compared to patients receiving no surgical intervention6,7. The surgical group had a significant decrease in body weight that continued four years post-op, while the A1c decreased until two years post-op6. Bariatric surgeries are classified as either restrictive, malabsorptive, or a combination of both8. Two of the most common bariatric surgeries are Roux-en-Y Gastric Bypass (RYGB) and laparoscopic sleeve gastrectomy (LVSG). The RYGB is considered a mixed procedure because it restricts stomach volume and affects how nutrients are absorbed into the bloodstream. The RYGB alters the gastrointestinal tract, causing food to bypass most of the stomach and upper small intestine. This type of surgery has been shown to induce remission of type 2 diabetes mellitus
