Apolipoprotein E genotype and the risk of gallbladder disease in pregnancy

The E4 allele of apolipoprotein E (apoE4) has previously been associated wi th symptomatic gallstone disease. The aim of this study was to determine if apoE4 is associated with the development of gallbladder sludge and/or ston es during pregnancy. We conducted a nested case-control study based on an o ngoing cohort study of gallbladder disease in pregnancy. Women in this stud y receive gallbladder ultrasounds in each trimester of pregnancy. Cases (n = 52) were defined as women with incident gallbladder sludge or stones diag nosed at the third trimester ultrasound. Controls (n = 104) were defined as women without gallbladder sludge or stones on any of 3 study ultrasounds. ApoE genotyping was performed from stored white blood cell pellets. Data we re analyzed by stratified analysis and Multivariate logistic regression. Ca ses and controls were similar in baseline characteristics. Forty-two women had sludge, 6 had gallstones, and 4 had both sludge and stones. After adjus ting for risk factors such as age, parity, and body mass index, the odds ra tio (OR) for the association between heterozygosity or homozygosity for the apoE4 allele and incident gallbladder sludge or stones was 0.91 (95% confi dence interval [CI], 0.41-2.02). Further adjustment for family medical hist ory and serum lipid levels did not substantially change these results (OR, 0.73; 95% CI, 0.29-1.82). In conclusion, apoE4 appears to have little or no overall association with the development of new gallbladder sludge or ston es in pregnancy. However, an effect could not be ruled out in certain subgr oups, such as blacks or women who are homozygous for apoE4.