Lipid metabolism in kwashiorkor - abstract

ABSTRACT

The pathogenic mechanisms of fatty infiltration of the liver have been grouped into two categories those causing a reduction in the synthesis of lipoprotein responsible for the removal of liver triglycerides, and those leading to an increase in the synthesis of triglycerides in the liver beyond its normal capacity to dispose of them. A relative inability of the liver to synthesize low density lipoprotein has been poistulated to explain the fatty liver so often found in kwashiorkor. Consistent with this hypothesis is the finding in untreated kwashiorkor of very low levels of serum lipids, especially triglycerides. These levels rise early in recovery to above normal values and later return to normal levels. During the rise in serum lipids, there is a marked reduction in liver fat. In this study of Jamaican children with kwashiorkor a markedly different pattern was observed. On admission of the patients, a very wide range of serum triglycerides was found including some very high levels. During recovery different patterns were observed - the general tendency being toward a decrease from the initial values. The average value of serum lipids after recovery was lower than that on admission. One possible explanation for this difference is that liver fat in these children is not mainly triglyceride, as has been described in kwashiorkor, therefore changes in this metabolite would not reflect changes in liver fat. Measurements of triglyceride and total fat in liver biopsies showed this not to be the case - triglycerides did account for virtually all the excess liver fat. A second possibility is that there is an abnormality in the serum lipoprotein patterns and that the triglycerides are in a fraction not normally associated with their transport from the liver. Measurement of triglyceride in d<1.019 lipoprotein showed that the proportion of the total triglyceride in this fraction was the same in patients on admission and after recovery. Moreover, there is no evidence for chylomicronaemia or abnormal composition of the very low density lipoprotein d<1.006. It was found that the amounts of triglyceride in this fraction correlate well with other components (protein cholesterol and phospholipid) of this complex in malnourished and recovery patients. On the whole, the accumulated evidence does not support the hypothesis of reduced synthesis of low density lipoprotein as the main or only major cause of fatty infiltration of the liver in kwashiorkor (AU)