Higher BMI increases risk of gallstones

Elevated body mass index (BMI) is tied to increased risk of gallstone disease, especially in women, a new study has claimed.
Researchers led by Dr Anne Tybjaerg-Hansen from Rigshospitalet, Copenhagen University Hospital in Denmark studied 77,679 participants from the general population, employing a Mendelian randomisation approach.
Its a method using genetic variation to study the impact of modifiable risk factors as the cause of a disease. There were 4,106 participants who developed symptomatic gallstone disease during the 34 years of follow-up.
The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) in US describe gallstones as pebble-like material, which can develop when there is excess cholesterol - accounting for 80 per cent of all gallstones - bile salts or bilirubin in bile stored in the gallbladder.

Prior studies have shown that greater BMI is associated with increased risk of gallstone disease; however it is unclear if it is the cause of the disease.
Participants with gallstone disease in the new study were more likely to be older, female, and less physically active. Researchers found that those with gallstones often used hormone replacement therapy and drank less alcohol than those without the disease.

Analyses show that increased BMI was associated with gallstone disease risk with an overall hazard ratio (HR) of 2.84.
When looking at BMI and gender, the team found that women had a higher risk of developing gallstone disease than men (HR=3.36 and 1.51, respectively).

Findings indicate that gallstone disease risk increased 7 per cent for every 1 kg/M2 increase in BMI.
"Obesity is a known risk factor for gallstone disease and our study suggests that elevated BMI likely contributes to the development of this disease," concluded Tybjaerg-Hansen.
"These data confirm that obesity adversely affects health, and lifestyle interventions that promote weight loss in overweight and obese individuals are warranted," Tybjaerg-Hansen said.
The study was published in Hepatology, a journal of the American Association for the Study of Liver Diseases.