Association Between Serum Concentration of Apolipoproteins A-I and B with Gallbladder Disease

Abstract

Background. A total of 1,255 subjects attending a private health care facility in Mexico City were studied to evaluate the association of serum concentration of Apo A-I and Apo B with presence of gallbladder disease (gallstones or cholecystectomy).

Methods. A cross-sectional study was carried out. All participants provided data on sociodemographic status and previous diagnoses of type 2 diabetes, hypertension, cardiovascular events, alcohol consumption, and smoking habits. Women additionally reported their obstetric-gynecologic history. Weight and height were measured; liver and biliary tract ultrasound assessed gallbladder disease. Plasma levels of total cholesterol, triglycerides, high-density lipoproteins (HDL) cholesterol, and apolipoproteins A-I (Apo A-I) and B (Apo B) were determined after a 12-h fasting period.

Results. In multivariate models, Apo A-I ≥120 mg/dL was positively associated with gallbladder disease with odds ratio (OR) = 1.64, 95% confidence interval (95% CI) = 1.03–2.62, whereas Apo B ≥120 mg/dL showed an inverse association (OR = 0.71, 95% CI = 0.48–1.05). Ratio of Apo B/Apo A-I ≥1 was inversely associated with risk of gallbladder disease (OR = 0.54, 95% CI = 0.37–0.80). All models were adjusted for age, gender, body mass index (BMI), previous diagnosis of type 2 diabetes, triglycerides, alcohol consumption, tobacco, and contraceptive use, as well as for total cholesterol in HDL-cholesterol and Apo A-I models.

Conclusions. Our results suggested the relationship between serum concentration of apolipoproteins and gallbladder disease. These findings support the hypothesis of increased biliary catabolism of cholesterol in subjects with gallbladder disease characterized by lower Apo B and higher Apo A-I serum concentrations.

Introduction

Association between plasma lipids and gallbladder disease is controversial and often contradictory 1., 2., 3., 4., 5., 6., 7., 8., 9., 10., 11., 12.. Some epidemiologic studies showed inverse association between plasma cholesterol and presence of gallbladder disease 2., 5., 9., 13., 14., 15.. Gallstones were identified more frequently in autopsy examinations of men following a cholesterol-lowering diet for several years (11). Furthermore, administration of some lipid-lowering drugs raised cholesterolsaturation index, hence the possibility of gallstone formation (16). However, association between total serum cholesterol and gallbladder disease may reflect joint effect of opposed influences of low-density lipoproteins (LDL) cholesterol (LDL-C) and high-density lipoproteins (HDL) cholesterol (HDL-C) levels, as well as of their corresponding majorapolipoproteins, apolipoprotein B (Apo B) and apoliprotein A-I (Apo-I) 17., 18..

Absolute mass of cholesterol fluxing through liver into bile acids or biliary cholesterol depends mainly on energy intake and lipoprotein cholesterol returning to liver. Thus, modification of lipoproteins (VLDL, LDL, and HDL) in terms of relative distribution as well as absolute mass appeared to have an important bearing on lithogenesis (19). However, information on lipoprotein and apolipoprotein dynamics in gallbladder disease subjects is scarce (20). Apolipoproteins were suggested as better indicators of cholesterol metabolism than lipoproteins. They were more stable than their respective lipoproteins (21) during acute changes and also played an active role in lipoprotein metabolism (17). Further, plasma and biliary lipids were related to a common metabolic pathway 5., 7., 8., 9., 10., 11., 12., 13., 14., 15., 16., 17., 18., 19., 20.. We propose to evaluate the relationship between serum concentration of apolipoproteins Apo A-I and Apo B with gallbladder disease.