After Bariatric Surgery, Renal Nutrition Vital

— Expert: dietitians must address these patients' special needs

MedicalToday

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ORLANDO -- Diet is a vital component to improved outcomes post-bariatric surgery, and particularly for patients with kidney disease, an expert nutritionist said here.

Due to the physiologic changes a patient experiences after bariatric surgery, overall dietary requirements in addition to specific renal nutrition needs must be met to improve post-surgical outcomes, explained , of the University of Washington in Seattle, during an oral session at the National Kidney Foundation's spring clinical meeting.

Patients should begin changing their diet prior to surgery, as preoperative weight loss, specifically at least a 5% loss in total body weight, is associated with fewer post-surgical complications as well as predicting greater weight loss following the procedure.

And among patients who undergo bariatric followed by renal transplant surgery, one of the most important contributors to improved outcomes is dietary follow-up, Clancy said. A particular challenge for patients who have undergone kidney transplant following bariatric surgery is staying hydrated with enough fluid intake, with around 2.5-3 liters of liquid suggested each day for improved kidney outcomes.

Frequent lab checks are required for all post-bariatric surgery patients, but particularly for those with chronic kidney disease or on dialysis to monitor vitamin and mineral deficiencies very closely. Calcium, folic acid, and iron are among some of the most common deficiencies, even prior to surgery, mainly due to lack of food intake during the first six months post-surgery, Clancy suggested.

She recommended the American Society of Bariatric and Metabolic Surgery's latest , which were co-sponsored by the American Association of Clinical Endocrinologists and The Obesity Society. These guidelines recommend checking lab values particularly for vitamins A, E, K, serum copper, B12 as methylmalonic acid, folate, as well as others.

The ASMBS is expected to release updated, integrated clinical practice guidelines later this year. Clancy anticipates these new guidelines will recommend patients take about 200% of daily value of vitamins and minerals for at least the first three to six months after surgery, which is about two multivitamins daily. However, she said there are currently "no great guidelines" in terms of the specific nutritional values specifically for post-bariatric surgery patients with chronic kidney disease, calling for additional research in this area. Although, she adds, they will most likely required a modified regimen of the same supplements as patients without CKD.

To mitigate post-surgical deficiencies, Clancy recommended complete, water-soluble multivitamin tablet supplements, rather than gummies and liquid vitamins, adding that most renal vitamins are lacking minerals. However, some higher quality bariatric-specific formulas are recommended, though often at a high cost. Vitamin patches should be avoided, Clancy said, noting that they have only been tested in non-obese people. Quality of the vitamins a patient is taking is also crucial, Clancy states. Hormonal issues post-surgery, such as hair loss, can also arise if the supplement quality is low, and particularly if the patient loses a large among of weight very rapidly.

Other hormonal issues that may arise post-surgery include dumping syndrome, which is an endocrine response within the first fifteen minutes after eating due to food dumping from the pouch to the small intestine, resulting in serious, flu-like side effects. Reactive hypoglycemia, which is becoming more common according to Clancy, is also important to look for in patients following surgery. She recommends patients stop drinking liquids with meals, but states that if patients experience this, a referral to an endocrinologist is advised, as medication might be required. Phosphate binders generally aren't needed following bariatric surgery, mainly due to the small portion sizes of meals.

"All vitamins, all minerals are for the rest of their life," Clancy said in response to a question posed by an audience member, though dosages can vary. She also noted that dialysis patients on renal supplements will be guaranteed to have deficiencies in some minerals, and these patients will require additional supplementation. In order to improve patient adherence to dietary plans, Clancy recommended the free app "" that patients can use after bariatric surgery.

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    Kristen Monaco is a senior staff writer, focusing on endocrinology, psychiatry, and nephrology news. Based out of the New York City office, she’s worked at the company since 2015.

Disclosures

Clancy disclosed no relevant relationships with industry.