Gender May Make a Difference for Post-Bariatric Heart Risks

— Study raises questions on how men and women respond to weight loss surgery

MedicalToday

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NEW ORLEANS -- Men and women both showed improvement in a range of cardiac risk factors following bariatric surgery, though the improvements seemed to differ by sex, researchers said here.

Prior to surgery, men had significantly higher HDL levels, triglycerides, hemoglobin A1C, and homocysteine (an amino acid considered a marker of cardiac risk) versus women, while women had higher LDL, total cholesterol, and C-reactive protein (CRP) compared with men.

Action Points

  • Note that this study was published as an abstract and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.

Following surgery, men were able to normalize HbA1c, triglycerides, and waist circumferences better than women post-surgery, while women were able to normalize levels of CRP better, maintain higher HDL levels, and had a higher percent of excess weight loss following surgery compared with men, reported of Stanford University in Stanford, Calif., and colleagues.

There were no significant differences between the sexes in Framingham Risk Scores (FRS) following surgery, although women had an overall lower risk scores compared with men both before and after the procedure, they reported at Obesity Week, a joint meeting of The Obesity Society and the American Society for Metabolic and Bariatric Surgery (ASMBS).

Agrawal said that while bariatric surgery has been shown to improve nearly all cardiac risk factors and reduce mortality from heart disease, there has been "little investigation into how bariatric surgery might affect men and women differently."

, of the Cleveland Clinic and ASMBS president, pointed out that around 80% of all bariatric surgery patients are women, who will often come for surgery earlier in the course of their disease. On the other hand, men will present later with more advanced cardiac disease and will often come for treatment of their metabolic issues, he added.

"This suggests when we intervene with the genders, where they're at on that continuum of their cardiac risk may be represented by how well they do afterwards," Brethauer told . "Because the earlier you intervene, the more likely you are to get long-term success with the treatment."

Agrawal's group examined 1,220 patients from the Stanford Bariatric and Metabolic Interdisciplinary Clinic, who underwent Roux-en-Y gastric bypass or laparoscopic sleeve gastrectomy from 2000 to 2015. Women were younger than men (mean age 45 vs 49), while a greater portion of men had existing comorbidities, including hypertension, diabetes, hyperlipidemia, and sleep apnea.

The authors found that the average FRS remained significantly different between genders prior to surgery (17.4% for men and 8.6% for women, P<0.0001) and 1 year after surgery (11.2% for men and 5.1% for women, P<0.0001).

There were significant reductions in 10-year cardiovascular disease risk for both groups at 1 year after surgery (35.6% decrease for men and 41% decrease for women, P<0.0001 for all).

When the authors examined the portion of patients with abnormal levels of certain cardiac risk factors following surgery, the differences between men and women became non-significant for triglycerides, HbA1c, and CRP.

However, a significantly higher portion of men had abnormal HDL compared with women, while a significantly higher portion of women had abnormal waist circumference compared with men.

The authors also wanted to see if there was an effect of a patient's sex on the overall change in cardiac risk factors. They found that after controlling for several confounders, men were more likely to have reductions in HbA1c levels and triglycerides, while women were more likely to have reductions in CRP levels.

"Men were able to normalize HbA1c, triglycerides, and waist circumferences better than women post-surgery, so men may be more metabolically receptive to bariatric surgery," Agrawal said. "Women were able to normalize levels of CRP better, maintain higher HDL levels, and had a higher percent of excess weight loss following surgery compared to men."

Study limitations included the fact that not all patients had complete and that some patients were lost to follow-up.

Brethauer said the findings raised questions about differences in how men and women respond to bariatric surgery, which could be answered in a prospective cohort study.

"I think this is really an exploratory study [by Agarwal's group] about what questions we should be asking next...why do men and women have different responses? Is it patient selection? Is it genetics? Is it follow-up?" he stated. "There's lots of variables here, but it would be very interesting to find out what the differences are, so the next step would be to do this in a more prospective way, to really determine what causes these differences among genders."

Disclosures

Agarwal disclosed no relevant relationships with industry. One co-author disclosed relevant relationships with Coviden, Ethicon, Olympus, and Novo Nordisk.

Primary Source

Obesity Week

Agrawal P, et al "Are there gender disparities in cardiac outcomes following bariatric surgery?" Obesity Week 2016; Abstract A-144.