The homocysteine distribution: (Mis)judging the burden

The nonfasting plasma total homocysteine (P-tHcy) concentration was measure d in a random sample of 3025 Dutch adults aged 20-65 years (main study). Th e positively skewed distribution had a geometric mean of 13.9 mu mol/L in m en and 12.6 mu mol/L in women. Blood of the main study was not cooled or ce ntrifuged immediately after drawing. A stability study (n = 26) indicated t hat this could have resulted in a small (0.4 mu mol/L) overestimation of th e means. A comparative study (n = 88), and a reproduction of these results in an entirely different population (n = 213), showed a systematic differen ce in P-tHcy concentration of -2.4 mu mol/L between our laboratory (Nijmege n, the Netherlands) and that in Bergen, Norway. With the information of the additional studies we provided precise and valid data of the Dutch P-tHcy distribution, from which we conclude the status in the Netherlands is worse than in other European countries. Furthermore, we showed that comparison o f P-tHcy data is complicated unless the interlaboratory differences are kno wn. (C) 2001 Elsevier Science Inc. All rights reserved.