Gastric Bypass Associated with Greater Medication Discontinuation than Sleeve Gastrectomy

Ryan Howard, MD

An analysis of Medicare claims data is providing clinicians with new insight into the rate of long-term discontinuation of medications for obesity-related comorbidities following sleeve gastrectomy or gastric bypass.

A comparative effectiveness study of adult Medicare beneficiaries with up to 5 years of follow-up data, results of the study suggest both procedures were associated with medication discontinuation, but gastric bypass was associated with a greater cumulative incidence of medication discontinuation and a lower incidence of medication restart.

“We believe these results demonstrate that both procedures are associated with long-term discontinuation of obesity-related medication and suggest that patients who underwent gastric bypass may be slightly more likely to remain free from their diabetes, antihypertensive, and lipid-lowering medications,” wrote investigators.

As the obesity epidemic has grown, so has the role of bariatric surgery in obesity management. To better inform clinical decision-making in patients with obesity, a team led by Ryan Howard, MD, of the Department of Surgery at the University of Michigan, designed their study to compare rates of medication discontinuation and restart of diabetes, hypertension, and lipid-lowering medications up to 5 years after gastric bypass or sleeve gastrectomy.

Using fee-for-service Medicare claims for patients who underwent laparoscopic sleeve gastrectomy or laparoscopic Roux-en-Y gastric bypass from 2012-2018. For the purpose of analysis, investigators created 3 study cohorts to assess effects on medication discontinuation in cohorts defined by use of diabetes, hypertension, and lipid-lowering medications, respectively.

The primary outcome of interest for the study was the discontinuation of diabetes, hypertension, or hyperlipidemia medications, with discontinuation defined as a lapse in claims for a medication refill of 6 months or longer. The secondary outcome of interest was the restart of medication after discontinuation.

Investigators identified a cohort of 95,405 patients for inclusion in their analyses. This cohort had a mean age of 56.6 (SD, 11.8) years and 74.8% (n=71,348) were female. Of the 95,405 patients in the overall study cohort, 30,588 were included in the diabetes cohort, 52,081 were included in the hypertension cohort, and 35,055 were included in the hyperlipidemia cohort.

In the diabetes cohort, the median follow-up time was 307 (IQR, 160-795) days for 16,809 patients who underwent sleeve gastrectomy and 260 (IQR, 158-702) days for 13,779 patients who underwent gastric bypass. In the hypertension cohort, the median follow-up time was 545 (IQR, 250-1091) days for 31,126 patients who underwent sleeve gastrectomy and 613 (IQR, 265-1349) days for 20,955 patients who underwent gastric bypass. In the hyperlipidemia cohort, the median follow-up time was 487 (IQR, 218-963) days for 20,654 patients who underwent sleeve gastrectomy and 419 (IQR, 172-1006) days for 14,401 patients who underwent gastric bypass.

Results of the analysis suggested gastric bypass, when compared with sleeve gastrectomy, was associated with a greater 5-year cumulative incidence of medication discontinuation in the diabetes cohort (74.7% [95% CI, 74.6-74.9] vs 72.0% [95% CI, 71.8-72.2]), the hypertension cohort (53.3% [95% CI, 53.2-53.4] vs 49.4% [95% CI, 49.3-49.5]), and the hyperlipidemia cohort (64.6% [95% CI, 64.5-64.8] vs 61.2% [95% CI, 61.1-61.3]). Similarly, further analysis indicated gastric bypass, when compared with sleeve gastrectomy, was associated with a lower incidence of medication restart in the diabetes cohort (30.4% [95% CI, 30.2-30.5] vs 35.6% [95% CI, 35.4-35.9]), the hypertension cohort (67.2% [95% CI, 66.9-67.4] vs 70.6% [95% CI, 70.3-70.9]), and the hyperlipidemia cohort (46.2% [95% CI, 46.2-46.3] vs 52.5% [95% CI, 52.2-52.7]).

“Long-term prospective trials are needed to explain the mechanisms and factors associated with the differences in medication discontinuation and comorbidity resolution after bariatric surgery,” noted investigators in their conclusion.

This study, “Medication Use for Obesity-Related Comorbidities After Sleeve Gastrectomy or Gastric Bypass,” was published in JAMA Surgery.