Serum lipid concentrations in patients with cholesterol and pigment gallstones

Gallstones (GS) are formed as a result of impaired metabolic regulation of the human body. Abnormal lipid metabolism is partly responsible for the pathogenesis of GS mainly rich in cholesterol. Thus abnormalities of serum lipids would reflect the possibilities of the formation of cholesterol GS. This study aims to identify the significance of serum lipids on the development of GS disease.

Serum lipid profiles were estimated in 73 patients with symptomatic GS, admitted to the Teaching Hospital, Peradeniya, Sri Lanka for GS removal surgeries from May 2011 to December 2012. Patients with normal serum bilirubin level and not being on lipid lowering drugs were recruited for the study. Serum lipid profile of each patient was analyzed by enzymatic kit assays and the chemical composition of GS was analyzed by Fourier Transform Infrared spectroscopy.

Of the 73 patients, 37 (51%) had cholesterol GS while 36 (49%) had pigment GS. Serum lipid parameters of a majority of patients were within the normal range. Body mass index values of the patients with two types of GS were not significantly different (Two sample t test, p = 0.335). Out of the lipid parameters tested, only serum triglyceride concentration was significantly high in patients with cholesterol GS than that of pigment GS (Two sample t test, p = 0.038). None of the lipid parameters were significantly different between males and females (Two sample t test, p > 0.05). Compared to the patients with pigment GS who were aged below 50 years, mean total cholesterol and triglyceride concentrations were higher in the same age category patients with cholesterol GS.

Abnormal serum lipid profiles doesn't seem to be an essential feature in patients with cholesterol GS. However when the two groups of patients with cholesterol and pigment GS with no significant difference of body mass indexes were compared, patients with cholesterol GS are more likely to have serum lipid parameters towards the undesirable cutoff levels of their respective normal ranges. However an effect of serum lipid concentrations on high incidence of GS among females has not been identified.