Bone mineral density in patients on home parenteral nutrition: a follow-up study

Background & aims: The variations of bone mineral density (BMD) during home parenteral nutrition (HPN) and their relationship with general, life style, primary disease and HPN risk factors were investigated by a follow-up study. Design: Patients who had BMD assessment in a previous cross-sectional survey underwent a 2nd BMD at femoral neck (FN) and lumbar spine (LS). Data about risk factors were collected by a structured questionnaire. BMD Z-score (number of standard deviations from normal values corrected for sex and age) and the annualized percent BMD change were analysed. Results: Sixty-five adult patients were enrolled (follow-up: 18.1±5.5 months). The mean BMD Z-score significantly increased at the LS (P=0.040) and remained unchanged at FN. In multiple regression analysis, the variations of the LS Z-score during HPN negatively correlated with the female sex (P=0.021) and the age at starting HPN (P=0.022). The analysis of the annualized percent BMD change confirmed the results obtained by the analysis of the Z-score. No factor was associated with BMD variation at FN. Conclusions: HPN was not associated with a decrease of BMD in most of the patients; LS BMD Z-score variations were related to general risk factors rather than to HPN factors, showing a negative association with age and female sex.