Diabetes, Cholesterol Meds Use Drops After Bariatric Surgery

Patients undergoing bariatric surgery for obesity showed significant declines in the use of lipid-lowering and antidiabetic medications up to 15 years after the procedure compared with patients with obesity who did not have such an operation. However, these declines didn't extend to cardiovascular medication use.

"In this study, undergoing bariatric surgery was associated with a substantial and long-lasting reduction in the use of lipid-lowering and antidiabetic medications compared with no surgery for obesity, while for cardiovascular medications this reduction was only transient," the authors report in research published this week in JAMA Surgery.

"The results can aid in informed decision-making when considering bariatric surgery for patients with morbid obesity and inform patients and professionals about the expected long-term effects of medication use for obesity-related comorbidities," they write.

The study "highlights the benefits of mandated databases that report metabolic bariatric surgery, obesity-related comorbidities, and medications," writes Paulina Salminen, MD, in an accompanying editorial.

However, key limitations include a lack of weight data, which is important in light of previous studies showing that suboptimal weight loss after bariatric surgery is linked to a higher incidence of type 2 diabetes, dyslipidemia, and hypertension, note Salminen, of the Department of Digestive Surgery, University Hospital, Turku, Finland, and colleagues.

Swedish, Finnish Obesity Data Probed

When significant weight loss is achieved, bariatric surgery has been well-documented to be associated with improvements in a variety of comorbidities, quality of life, and even life expectancy.

Key comorbidities shown to improve with the surgery include hyperlipidemia, cardiovascular disease, and type 2 diabetes.

However, data are lacking on the association between bariatric surgery and the use of medications for those conditions, particularly compared with people with obesity who don't have bariatric surgery.

To investigate, first author Joonas H. Kauppila, MD, PhD, of Upper Gastrointestinal Surgery, Karolinska University Hospital, Stockholm, Sweden, and colleagues conducted a population-based cohort study, evaluating data on 26,396 patients who underwent bariatric surgery with gastric bypass or sleeve gastrectomy in Sweden between 2005 and 2020 or Finland between 1995 and 2018.

Overall, 66.4% of patients were women and their median age was 50.

They were compared with five times as many matched controls with obesity who had not had bariatric surgery from the same population databases, representing a total of 131,980 patients who were matched based on age, country, sex, calendar year, and medication use.

In terms of lipid-lowering medication, rates of use after bariatric surgery decreased from 20.3% at baseline to 12.9% after 2 years and bounced back somewhat to 17.6% after 15 years. Comparatively, in the no surgery group, baseline lipid-lowering medication use of 21.0% increased to 44.6% after 15 years, more than twice the rate of usage in the bariatric surgery group in the same period.

Antidiabetic medications were used by 27.7% of patients in the bariatric surgery group at baseline, with a drop to 10.0% after 2 years, followed by an increase to 23.5% after 15 years. In the no surgery group, the rate of antidiabetic medication use steadily increased from 27.7% at baseline to 54.2% after 15 years, which again was nearly double the rate of antidiabetic medication use in the bariatric surgery group at 15 years.

Meanwhile, cardiovascular medications were used by 60.2% of patients receiving bariatric surgery at baseline, with the rate decreasing to 43.2% after 2 years, but increasing to 74.6% after 15 years. Among the nonbariatric surgery patients, use of cardiovascular medications increased from 54.4% at baseline to 83.3% after 15 years.

Causes?

As for the cause of the lack of any decline in use of cardiovascular medications versus other medications in the surgery patients, the authors speculate that the effect "may be related to aging and regain of weight over time after bariatric surgery, a phenomenon caused by hormonal, dietary, physical, and behavioral factors."

"In contrast, as expected, a gradual increase in the use of all three medication groups was observed over time among the patients treated with no surgery for obesity," they note.

The lower medication use with bariatric surgery can also translate to economic benefits, the authors add.

"Economically, the long-lasting reductions in medication use for hyperlipidemia, cardiovascular morbidity, and diabetes suggest that surgical treatment of morbid obesity may infer savings in medication expenses for patients, healthcare, and society," they report.

"Future research may focus on subgroups that are most likely to benefit from bariatric surgery, including resolution and severity of comorbidities," they continue.

In their editorial, Salminen and colleagues note that previous research has shown remission of dyslipidemia in up to 70% of patients after bariatric surgery that was independent of weight loss, which appears to support the sustained reduction in lipid-lowering medications following surgery observed in the current study, suggesting some benefits on lipids beyond weight loss.

Other limitations, however, include that the bariatric surgery group in the study was older and had more comorbidities than those in previous bariatric surgery studies.

"Future studies should assess this in a younger cohort with less disease at baseline and differentiation within cardiovascular disease regarding at least hypertension, ischemic heart disease, and heart failure," the authors conclude.

The authors have reported no relevant financial relationships. Salminen has reported receiving grants from the Sigrid Jusélius Foundation, Academy of Finland, Government Research Grant Foundation (EVO), and the University of Turku.

JAMA Surg. Published May 24, 2023. Full text, Editorial

For more diabetes and endocrinology news, follow us on Twitter and Facebook.

Comments

Commenting is limited to medical professionals. To comment please Log-in.

Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.