Carotenemia. Its Influence on the Validity of the Icteric Index

Abstract

In a paper with Hess 1 one of us called attention to the occurrence of carotenemia. At the time it was pointed out that this might in certain cases cause confusion with icterus. Later it was observed that the carotenemia might be very intense in diabetic patients on the high vegetable diet of the time.

It is obvious that carotene must exert some influence on the icteric index of the blood, a fact which has been appreciated by most of the workers in this field. Fiessinger, Walker and Thierry 2 from their work felt that the effect was negligible, Boeck and Yater 3 found that carotene accounted for from 10 to 55% of the icteric index, while White 4 concluded that the influence was negligible except in marked cases of xanthemia accompanying diabetes.

The subject has been reinvestigated on 161 patients, 75 of whom were suffering from diabetes mellitus, the carotene being determined in terms of the icteric index (lipochrome index) and in mg. per 100 cc. of serum. In 43 diabetic cases on which icteric indices were determined carotenemia was found to account for an average of 45% of the corresponding icteric indices, the extremes being 19.3 and 70.5%. The average icteric index was 7.1. The average lipochrome index for the 75 diabetic patients was 3.4, corresponding to an average carotene content of 0.25 mg. per 100 cc. of blood.

The average lipochrome index for the 86 non-diabetic patients was 1.7 with an average of 0.11 mg. carotene per 100 cc. of blood. In 10 of these cases with icteric indices below 10, carotenemia was responsible for an average of 20.6% of the corresponding icteric indices, while in 21 cases with icteric indices between 10 and 100 it averaged 8.6% and in 6 cases with icteric indices above 100 the lipochrome indices averaged only 1.2% of the corresponding icteric indices.

From the above findings it would not appear that carotenemia alters the validity of the icteric index except in cases of marked carotenemia such as may be found in some diabetic patients, and then only if the icteric index is quite low.