Factors Influencing Bariatric Patients’ Level of Compliance with Supplement Recommendations And Bioavailability of Iron Supplement Formulations in Roux-en-y Gastric Bypass Patients

Haley Snell-Sparapany, Purdue University

Abstract

Morbid obesity is on the rise, and bariatric surgery is the most effective weight loss intervention. After bariatric surgery, patients often experience improvements in chronic conditions such as hypertension, hyperlipidemia, and type 2 diabetes mellitus. Although there are numerous benefits to the procedure, patients often experience nutritional complications post-bariatric surgery. Nutrient deficiency is common in bariatric patients prior to surgery, and the rate of deficiency is exacerbated after the procedures. It is estimated that 80% of the bariatric population has at least one nutrient deficiency. Dietary supplement guidelines were designed to prevent and reverse nutrient deficiency, but compliance with supplement recommendations is low. Only around 46% of bariatric patients report following the supplement recommendations all the time. There is limited research exploring the barriers patients face when it comes to post-surgery supplement recommendations. Iron deficiency (ID) is one of the most common nutrient deficiencies, impacting as high as 50% of the bariatric population. Ferrous Sulfate (FS) is considered the gold-standard iron supplement for improving iron status. Even though ID is common, compliance with iron supplement recommendations is only around 50%, and one proposed explanation is the poor tolerability of iron supplements. Nearly one-third of patients experience gastrointestinal (GI) symptoms like constipation, diarrhea, and nausea. Improving the tolerability of iron supplements may help increase compliance with the iron supplement recommendations. Our research group aimed to address these issues by exploring the barriers to adhering to post-bariatric surgery dietary supplement recommendations and exploring the efficacy and tolerability of AspironTM(ASP), an iron supplement suspected to have improved tolerability as a slow-release form of iron. In our first study, we explored the barriers to complying with iron supplement recommendations using focus groups. We recruited adults, ages 18-75 years, who have had bariatric surgery at least two months previously to participate in one of four 90-minute focus groups. Participants filled out a survey asking for information on demographics and supplement use, and a facilitator asked a set of pre-determined questions to each group. Responses were written, recorded, transcribed using TranscribeMe (San Francisco CA), and analyzed using NVivo (QSR International Pty Ltd, Doncaster, Victoria). The focus groups contained nineteen participants, five of which had sleeve gastrectomy (SG) and fourteen had Roux-en-Y gastric bypass (RYGB). The average age of the participants was 49.3 ± 9.4 years, and they had undergone surgery 3.9 ± 3.6 years previously. The key factors that influenced participants’ adherence to supplement guidelines were cost, tolerability, and palatability of the supplement, level of knowledge and support from healthcare providers, and convenience of the supplementation regime. The second study was a prospective observational study to determine the bioavailability of ASP compared to FS. Iron deficient RYGB patients ages 18-65 years, who had surgery at least 6 months previously, participated in 8-hour iron absorption tests. Participants received a low-iron breakfast with 65 mg ASP (N=7) or FS (N=3). We assessed serum iron every 30 minutes for 8 hours following the supplementation using a colorimetric assay (South Bend Medical Foundation, South Bend, IN). In participants administered FS, serum iron increased 96.0 ± 27.2 µg/dL compared to baseline, whereas with ASP, serum iron increased 5.8 ± 4.7 µg/dL compared to baseline (P= 0.02). These data indicate that ASP is not as bioavailable as FS in RYGB patients. At the conclusion of these studies, we learned strategies for improving compliance to supplementation should address the barriers encountered by bariatric surgery patients such as high cost, poor tolerability and palatability, lack of clarity regarding recommendations and inconvenience with their daily routine. Moreover, we observed that FS is still the preferred supplemental source for improving iron status post-bariatric surgery.

Degree

M.Sc.

Advisors

Gletsu-Miller, Purdue University.

Subject Area

Medicine|Nutrition|Public health|Surgery

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