LAS VEGAS — Adults who undergo bariatric surgery may be more likely to be readmitted to the hospital, have more trips to the ICU and have a higher rate of overall morbidity if they have an HbA1c of more than 7% before surgery, according to findings presented at ObesityWeek.
“While bariatric surgery represents an opportunity to improve glycemic control, it is also well known that poor glycemic control is a risk factor for adverse outcomes during many certain different surgeries. We have no reason to believe that bariatric surgery is any different,” Michael Mazzei, MD, MPH, MS, a resident physician in the department of surgery at Temple University Hospital in Philadelphia, said during a presentation. “As such, there’s a bit of a paradox here. Poor glycemic control may represent a potentially modifiable risk factor prior to or after bariatric surgery, but bariatric surgery may be the best way to modify it.”
Mazzei and colleagues evaluated data from 20,287 adults with diabetes who had Roux-en-Y gastric bypass or sleeve gastrectomy and were included in the MBSAQIP database from 2017. Among the total cohort, 9,945 (mean age, 50.29 years; 68.97% women) had a baseline HbA1c of greater than 7%, which Mazzei defined as “poor glycemic control.” The remaining participants (n = 10,342; mean age, 49.2 years; 75.24% women) had a baseline HbA1c of 7% or less, which Mazzei defined as “good glycemic control.” Postoperative outcomes and complications in the 30 days following surgery were identified in the database.
Comorbidities and complications
Mazzei noted that the percentages of participants with a history of myocardial infarction (3.43% vs. 2.02%; P < .001), prior cardiovascular surgery (2.78% vs. 1.63%; P < .001), hypertension (77.23% vs. 70.09%; P < .001), hyperlipidemia (55.57% vs. 46.18%; P < .001), history of smoking (8.53% vs. 7.29%; P = .001) and use of therapeutic anticoagulation (5.48% vs. 4.79%; P = .025) were higher for those with poor glycemic control vs. those with good glycemic control.
“I do not think it is a surprise to find that patients with poor glycemic control have a higher preponderance of most comorbidities,” Mazzei said.
Adults who undergo bariatric surgery may be more likely to be readmitted to the hospital, have more trips to the ICU and have a higher rate of overall morbidity if they have an HbA1c of more than 7% before surgery.
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The average length of hospital stay was 3.96 days among those with poor baseline glycemic control compared with an average stay of 1.73 days among those with good glycemic control (P < .001). The researchers also found that 1.32% of those with poor glycemic control had an unplanned trip to the ICU compared with a rate of 0.92% among those with good glycemic control (P = .007). In addition, the rate of readmission was 4.99% among those with poor glycemic control and 4.05% among those with good glycemic control (P = .001) while the overall morbidity rate was 6.65% among those with poor glycemic control and 5.53% among those with good glycemic control (P = .001).
The rate of total infections was 2.42% among those with poor glycemic control compared with a rate of 1.8% among those with good glycemic control (P = .002). Mazzei noted that other complications “trended toward higher in poorly controlled diabetes.”
“It is unclear, however, if the increased rate of certain adverse outcomes is mediated by the poor control itself or other comorbidities associated with poor control,” Mazzei said.
Mediating and predictive factors
Mazzei and colleagues matched participants via propensity scoring to elucidate this potential mediating effect.
The rates of unplanned ICU visits (1.28% vs. 0.93%; P = .026), readmission (5.06% vs. 4.23%; P = .009) and overall morbidity (6.67% vs. 5.76%; P = .013) were all greater for those with poor glycemic control compared with those with good glycemic control.
Mazzei said insulin use did not affect the results and that ambulatory dysfunction, a history of MI, prior bariatric surgery and poor glycemic control were among the factors that independently predicted poor outcomes after surgery, although poor glycemic control was “mild” compared with the other factors.
“An effort should be made to establish adequate glycemic control prior to surgery,” Mazzei said. “The decision to perform bariatric surgery in the setting of poor glycemic control must balance increased risk by understanding that delaying may contribute to worsening of comorbidities and these in turn may ultimately have a more deleterious effect on outcomes.” – by Phil Neuffer
Mazzei M. A143. Presented at: ObesityWeek 2019; Nov. 3-7, 2019; Las Vegas.
Disclosure: Mazzei reports no relevant financial disclosures.