A reference interval study for common biochemical analytes in Eastern Turkey: a comparison of a reference population with laboratory data mining.
INTRODUCTION
The aim of this study was to define the reference intervals (RIs) in a Turkish population living in Northeast Turkey (Erzurum) for 34 analytes using direct and indirect methods. In the present study, the regional RIs obtained were compared with other RI studies, primarily the nationwide study performed in Turkey.


MATERIALS AND METHODS
For the direct method, 435 blood samples were collected from a healthy group of females (N = 218) and males (N = 217) aged between 18 and 65 years. The sera were analysed in Ataturk University hospital laboratory using Roche reagents and analysers for 34 analytes. The data from 1,366,948 records were used to calculate the indirect RIs using a modified Bhattacharya method.


RESULTS
Significant gender-related differences were observed for 17 analytes. There were also some apparent differences between RIs derived from indirect and direct methods particularly in some analytes (e.g. gamma-glutamyltransferase, creatine kinase, LDL-cholesterol and iron). The RIs derived with the direct method for some, but not all, of the analytes were generally comparable with the RIs reported in the nationwide study and other previous studies in Turkey.There were large differences between RIs derived by the direct method and the expected values shown in the kit insert (e.g. aspartate aminotransferase, total-cholesterol, HDL-cholesterol, and vitamin B12).


CONCLUSIONS
These data provide region-specific RIs for 34 analytes determined by the direct and indirect methods. The observed differences in RIs between previous studies could be related to nutritional status and environmental factors.
['Bakan|Ebubekir|E|', 'Polat|Harun|H|', 'Ozarda|Yesim|Y|', 'Ozturk|Nurinnisa|N|', 'Baygutalp|Nurcan Kilic|NK|', 'Umudum|Fatma Zuhal|FZ|', 'Bakan|Nuri|N|']
D000293:Adolescent D000328:Adult D000368:Aged D001219:Aspartate Aminotransferases D001774:Blood Chemical Analysis D008076:Cholesterol, HDL D057225:Data Mining D005260:Female D006801:Humans D007755:Laboratories, Hospital D008297:Male D008875:Middle Aged D012016:Reference Values D014421:Turkey
reference intervals indirect method direct method Bhattacharya method regional differences