Gallstones and Gallbladder Disease - Risk Factors

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• The risk for gallstones is as high as 12% after eight to 16 weeks of restricted calorie diets.
• The risk is more than 30% within a year to 18 months after gastric by-pass surgery.

About one-third of gallstone cases in these situations are symptomatic. The risk for gallstones is highest in the following dieters:

• Those who lose more than 24% of their initial body weight.
• Those who lose more than 1.5 kg (3.3. lb.) a week.
• Those on very low-fat, low-calorie diets.

Weight cycling also puts people at risk for gallstones. For example, a 16-year study found that the risk for gallstone surgery was 68% higher for women who lost and then regained more than 20 pounds at least once than in women whose weight remained stable.

Metabolic Syndrome

Metabolic syndrome is a cluster of conditions that includes obesity (especially belly fat), low HDL (good) cholesterol, high triglycerides, high blood pressure, and high blood sugar. Research suggests that metabolic syndrome is a risk factor for gallstones.

Low HDL Cholesterol and High Triglycerides and Their Treatment

Although gallstones are formed from supersaturation of cholesterol in the bile, high total cholesterol levels themselves are not necessarily associated with gallstones. Gallstone formation, however, is associated with low HDL cholesterol (the so-called good cholesterol) levels and high triglyceride levels. Some evidence suggests that high triglyceride levels may impair emptying actions of the gallbladder.

Unfortunately some fibrates, drugs used to correct these conditions, actually increase the risk for gallstones by increasing the amount of cholesterol secreted into the bile. They include gemfibrozil (Lopid), fenofibrate (Tricor), and bezafibrate (Bezalip). (Other cholesterol-lowering agents do not have this effect at all.) [See In-Depth Report #23: Cholesterol.]

Other Risk Factors

Prolonged Intravenous Feeding. Prolonged intravenous feeding reduces the flow of bile and increases the risk for gallstones.

Crohn's Disease. Crohn's disease, an inflammatory bowel disorder, leads to poor reabsorption of bile salts from the digestive tract and substantially increases the risk of gallbladder disease. Patients over 60 and those who have had numerous bowel surgeries (particularly in the region where the small and large bowel meet) are at especially high risk.

Cirrhosis. Cirrhosis poses a major risk for gallstones, particularly pigment gallstones.

Organ Transplantation. Bone marrow or solid organ transplantation increases the risk.

Medications. Octreotide (Sandostatin) poses a risk for gallstones. In addition the cholesterol-lowering drugs known as fibrates and thiazide diuretics may slightly increase the risk for gallstones.

Blood Disorders. Chronic hemolytic anemia, including sickle cell anemia, increases the risk for pigment gallstones.

Review Date: 06/12/2006
Reviewed By: Harvey Simon, M.D., Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital