Prevalence, outcome and associated factors of deranged liver function tests in patients on home parenteral nutrition.

INTRODUCTION: The prevalence of deranged liver function tests (LFT) in patients on long-term home parenteral nutrition (HPN) is poorly documented. The aim of our study was to document the prevalence of this complication and possible associated factors.

METHOD: Retrospective analysis of case notes of 107 patients on HPN was performed. Deranged LFT was defined as any biochemical parameter of LFT that is 1.5 times above the reference range.

RESULTS: There were 39 males and the median age was 51 (range 20-73) years old. Median duration of HPN was 40 (range 6-252) months. Underlying diagnoses were Crohn's disease (40%), ischaemic bowel disease in 28.1% (arterial or venous), post-surgical intestinal adhesion and fistula (16.9%) and others (21.7%). The mean energy intake from HPN was 1003+/-544(SD) kcal/day with 845+/-474 kcal/day from glucose, 157+/-127 kcal/day from fat and mean nitrogen intake was 6.2+/-3.6 g/day. Raised alkaline phosphatase (mean 197+/-143(SD)U/L) was the most common abnormality (40 patients). Two patients had hyperbilirubinaemia; one patient had hereditary spherocytosis and in the other patient, the cause could be attributed to HPN with bilirubin of 54 micromol/l. Fifty-one patients (47.7%) had deranged LFT as judged from raised parameters on LFT. Abnormality in LFT was transient in nine patients. For the other 42 patients (39%), abnormalities in LFT remained stable for median duration of follow-up of 18.5 (range 3-180) months. No patients developed decompensated liver disease. On univariate analysis, length of small bowel of less than 100 cm, a higher total caloric intake from HPN (mean 1117+/-486 kcal against 907+/-576 kcal, P<0.05), and higher daily caloric intake from HPN in relation to calculated daily energy requirement (70+/-32% against 57+/-36%) were noted to be significantly associated with deranged LFT. However, on multivariate analysis, length of small bowel of less than 100 cm was the only significant variable for deranged LFT.

CONCLUSION: Our finding showed the prevalence of deranged LFT to be 39% and raised alkaline phosphatase was the most common abnormality. Length of small bowel of less than 100 cm was found to be a significant independent variable for deranged LFT and the reason for this observation could be due to higher parenteral caloric intake. In our experience, LFT abnormalities are associated with a good prognosis as none of the patients developed decompensated liver disease.