Connection Observed Between Intrahepatic Cholestasis of Pregnancy and NAFLD
A STUDY has demonstrated a potential link between intrahepatic cholestasis of pregnancy (ICP) and non-alcoholic fatty liver disease (NAFLD). In a unique, retrospective, single-centre study, patients with ICP were matched with controls to investigate the link between the two conditions as well as associated metabolic risk factors, such as obesity, dyslipidaemia, hypertension, and diabetes.
The research team from the Icahn School of Medicine at Mount Sinai, New York City, New York, USA sourced electronic medical records between January and December 2017 from a healthcare database in New York City of 149 patients of ICP and matched them with 200 patients who were pregnant without a diagnosis of ICP. Patients had a median age of 30 years, and the mean body mass index of the participants was 27.5 kg/m2. There was a higher proportion of Hispanic women in the ICP group, compared with the control group (75% versus 62%, respectively). Patients in both subgroups had a comparable median age (odds ratio [OR]: 1.02; 95% confidence interval [CI]: 0.99–1.06), nulliparity (OR: 0.79; 95% CI: 0.48–1.30), and prevalence of hepatitis C (OR: 1.35; 95% CI: 0.08–21.67). Certain metabolic risk factors were also similar across the two subgroups, including rates of obesity (OR: 1.01; 95% CI: 0.62–1.61), hypertension (OR: 0.69; 95% CI: 0.31–1.52), HbA1c >5.5% (OR: 0.80; 95% CI: 0.34–1.9), and total cholesterol >200 mg/dL (OR: 4.15; 95% CI: 0.83–20.84).
The methodology of the study comprised a Pearson’s chi-square or Fisher’s exact test, and Wilcoxon rank-sum tests. These were used to evaluate the association of ICP with categorical variables and continuous variables, respectively, and unadjusted odds ratios to compare the ICP and control groups for clinically significant outcomes.
Results showed that the patients in the ICP group had higher median levels of alanine aminotransferase (ALT) (32 versus 16 U/L; p<0.0001), and in this group the ALT levels were more likely to be >50 U/L (two times the upper limit of normal; OR: 3.22; 95% CI: 1.48–7.03). The ICP subgroup had higher median alkaline phosphatase (181 versus 128 U/L; p<0.0001), and total bilirubin (0.5 versus 0.35 mg/dL; p<0.0001) compared to the control group, and they were also more likely to have a history of biliary disease (OR: 3.29; 95% CI: 1.39–7.80), and to have evidence of steatosis on liver imaging (OR: 4.69; 95% CI: 1.68–13.12). Hispanic women were nearly twice as likely to be diagnosed with ICP than non-Hispanic women (OR: 1.90; 95% CI: 1.87–3.03). ICP patients were also significantly more likely to have a diagnosis of NAFLD than controls (OR: 5.7; 95% CI: 2.08–15.65).
Dr Kushner, Division of Liver Diseases at the Icahn School of Medicine at Mount Sinai, commented: “We recommend additional research to look at differences in NAFLD progression in women who had NAFLD and were later diagnosed with ICP, compared to women with NAFLD who did not go on to develop ICP, because that may be a reflection of the role that bile acid metabolism plays in these particular patients.” Tatyana Kushner, Mount Sinai Doctors Faculty Practice, added “This could have implications for future management of fatty liver disease. Additionally, these findings suggest that ICP patients should be seen by a liver specialist because they may go on to develop chronic liver disease or may already have already existing underlying liver disease.”