STUDY ROUNDUP

Published in November 2013 Issue             


Perinatal Outcomes After Bariatric Surgery: Nationwide Population Based Matched
Cohort Study


Women who previously had bariatric surgery and subsequently become pregnant face increased risks of preterm birth, as well as an increased risk of for a low birth weight, according to a study published in the November 12 edition of BMJ. Using the Swedish birth register, researchers analyzed 1,742,702 births between 1992 and 2009, and coordinated each birth to a mother with a history of bariatric surgery with up to five non-surgery patients. Researchers found post-surgery births were more likely to be preterm than births to mothers who did not have surgery – 9.7 percent of surgical patients compared to 6.1 percent. Women who had bariatric surgery were also more likely to have a small for gestational age birth (5.2% vs. 3.0%) and a lower risk of a large for gestational age birth (4.2% compared to 7.3%). Researchers did not find differences in stillbirth or neonatal death rates. The authors concluded that women who have had bariatric surgery should be considered a risk group during pregnancy.


Bariatric Surgery Risk Increases with Kidney Disease


Patients with kidney disease experience high rates of harmful side effects and death when they have bariatric surgery, according to a new study presented during Kidney Week at the American Society of Nephrology meeting from November 5-10. The study analyzed 74 patients with obesity and kidney disease who had bariatric surgery. One year after surgery, 61 percent of the patients had lost weight, but surgical complications resulted in 16 adverse events, including two deaths. Four percent of patients experienced acute kidney damage, while 3 percent of patients experienced leak, acidosis, elevated blood potassium levels, postoperative chest infection, or vitamin B12/iron deficiency. One percent of patients had a heart attack.


Shortening of the QT Interval is Observed Soon after Sleeve Gastrectomy in Morbidly Obese Patients


Patients with morbid obesity who have sleeve gastrectomy procedures may have a reduced risk of sudden cardiac death, a study published online on November 9 in Obesity Surgery found. Researchers analyzed the EKGs of 28 sleeve gastrectomy patients before and three months after their surgeries over the course of six months. The study found the patients’ QT interval, or electrical lactivity levels in the heart, was 427 ± 18.6 ms prior to surgery, and was significantly lower three months after surgery, at 398.6 ± 15.5 ms. The QT interval decreased in all individual patients, however, weight loss was not significantly correlated with decreased levels. Obesity prolongs QT intervals, which may cause ventricular arrhythmia and sudden cardiac death.


Risk for Congenital Malformations in Offspring of Women who have Undergone Bariatric Surgery. A National Cohort


Women who have bariatric surgery and later become pregnant are not at a higher risk for having babies with congenital malformations, but women with high or very high BMIs do have an increased risk, according to a study published in the November edition of BJOG: An International Journal of Obstetrics and Gynaecology. The study analyzed all firstborn children to women born between 1973 and 1983. Researchers concluded the risk for congenital malformation in firstborn children was positively correlated with maternal BMI – the adjusted odds ratio for congenital malformation among children whose mothers’ BMI ranged from 25 to 29 was 1.09, while children whose mothers' BMI was between 30 and 34 was 1.14, and those whose mothers' BMI was greater than 35 was 1.30, compared to those whose mothers had a normal BMI.


Improvement of Exercise Capacity and Peripheral Metaboreflex After
Bariatric Surgery


Bariatric surgery patients who lose weight after their procedure experience increased exercise capacity and reduced peripheral metaboreflex, heart rate and blood pressure, according to a study published in Obesity Surgery. Researchers reviewed the cases of 17 patients with severe obesity before and three months after bariatric surgery, and found peripheral metaboreflex activity, expressed by the area under the curve of vascular resistance, was reduced following bariatric surgery. Patients’ heart rate, blood pressure and vascular resistance also significantly decreased. Researchers measured exercise capacity by assessing distance walked in six minutes, and patients improved on this test after bariatric surgery, as well. However, there was not a significant correlation between change in distance walked and change in peripheral metaboreflex activity.


Click here to see the top 10 studies presented at ObesityWeek.