CHICAGO – The risk of gallbladder disease was more than twice as high in pregnant women in the top quartile of carbohydrate consumption, compared with those in the bottom quartile, based on data from a prospective study of 3,070 pregnant women.
Female sex is a risk factor for gallstones, and pregnancy is an especially high-risk time for gallstone development, Dr. Alexander Wong of the University of Washington, Seattle, said at a press conference.
“Gallbladder disease is the most common nonobstetrical cause of maternal rehospitalization the first 60 days after delivery,” said Dr. Wong.
“Carbohydrate intake has been linked to increased risk of cholecystectomy in women.
“However, the effect of carbohydrate intake on gallbladder disease during pregnancy is unclear,” he commented.
To determine the effect of diet during pregnancy on gallstone formation, Dr. Wong and his colleages performed ultrasounds on pregnant women during each trimester and at 4–6 weeks post partum.
The average age of the women was 25 years, and each had at least two interpretable ultrasounds. Women who had gallstones at the first ultrasound and those with a history of gallstones were excluded.
Overall, the cumulative incidence of new gallstones or biliary sludge indicative of gallbladder disease was 10%. In addition, women in the highest quartile of starch consumption were 80% more likely than those in the lowest quartile to show signs of gallbladder disease.
In addition, those in the highest quartile of fructose consumption had double the risk, compared with the lowest quartile, of showing signs of gallbladder disease. Dietary factors were assessed using standard food composition data.
Women who formed sludge or stones were more likely to have a higher caffeine and alcohol intake, be of Hispanic origin, and gain less weight during pregnancy.
By contrast, the highest quartile of galactose intake was independently associated with a decreased risk of gallbladder disease, compared with the lowest quartile, noted coauthor Dr. Cynthia Ko, also of the university, who presented the study results at the press conference. The results held after control for variables including age, prepregnancy weight, ethnicity, smoking, diabetes, total calorie intake, alcohol intake, and weight gain during pregnancy.
“We believe that high carbohydrate intake during pregnancy may stimulate even more insulin release, therefore increasing the negative effects of hyperinsulinemia on bile composition,” Dr. Wong said.
“The fructose finding is fairly novel,” added Dr. Ko.
“We hypothesize that fructose is metabolized differently than many other carbohydrates,” she said.
High fructose intake can cause insulin resistance, which can predispose individuals to gallstone formation, she noted.
“The galactose finding is quite novel, and we don't have a good scientific explanation for why we found that,” Dr. Ko added. “This is a very preliminary finding that needs further confirmation and explanation.”
The results suggest that cutting down on refined, processed carbohydrates during pregnancy might reduce a woman's risk of gallstones, Dr. Ko commented.
Dr. Ko said she had no relevant financial disclosures.