PMID- 37572984 OWN - NLM STAT- MEDLINE DCOM- 20230912 LR - 20230912 IS - 1873-2933 (Electronic) IS - 0009-9120 (Linking) VI - 119 DP - 2023 Sep TI - Establishment of a reference interval for total carbon dioxide using indirect methods in Chinese populations living in high-altitude areas: A retrospective real-world analysis. PG - 110631 LID - S0009-9120(23)00159-5 [pii] LID - 10.1016/j.clinbiochem.2023.110631 [doi] AB - BACKGROUND: Hypoxia leads to different concentrations of the bicarbonate buffer system in Tibetan people. Indirect methods were used to establish the reference interval (RI) for total carbon dioxide (tCO2) based on big data from the adult population of Tibet, a high-altitude area in Western China. METHODS: Anonymous tCO2 test data (n = 442,714) were collected from the People's Hospital of the Tibet Autonomous Region from January 2018, to December 2021. Multiple linear regression and variance component analyses were performed to assess the effects of sex, age, and race on tCO2 levels. Indirect methods, including Hoffmann, Bhattacharya, expectation maximization (EM), kosmic and refineR, were used to calculate the total RI and ethnicity-partitioned RI. RESULTS: A total of 230,821 real-world tCO2 test results were eligible. Sex, age, and race were significantly associated with the tCO2 levels. The total and ethnically-partitioned RIs estimated using the five indirect methods were comparable. The total RI of tCO2 was 14-24 mmol/L (calculated using Hoffmann and refineR) and 15-24 mmol/L (Bhattacharya, EM and kosmic). For Han nationality, the RIs were 14-25 mmol/L (calculated using Hoffmann and Bhattacharya), 16-23 mmol/L (EM), 15-24 mmol/L (kosmic), and 14.2-24.5 mmol/L (refineR). For the Tibetan population, the RIs were 14-24 mmol/L (calculated using Hoffmann and refineR), 15-24 mmol/L (Bhattacharya and kosmic), and 15-23 mmol/L (EM). The established RIs were significantly lower than those living at lower altitudes area (22-29 mmol/L) that was provided by the manufacturer. CONCLUSION: The tCO2 RI of the populations living on the Tibetan Plateau was significantly lower than those at the lower altitudes. The RIs established using indirect methods are suitable for clinical applications in Tibet. CI - Copyright (c) 2023 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved. FAU - Li, Shensong AU - Li S AD - Department of Clinical Laboratory, People's Hospital of Tibet Autonomous Region, Lhasa, China. FAU - Mu, Danni AU - Mu D AD - Department of Laboratory Medicine, Peking Union Medical College Hospital, Peking Union Medical College & Chinese Academy of Medical Science, Beijing, China. FAU - Ma, Chaochao AU - Ma C AD - Department of Laboratory Medicine, Peking Union Medical College Hospital, Peking Union Medical College & Chinese Academy of Medical Science, Beijing, China. FAU - Yixicuomu AU - Yixicuomu AD - Department of Clinical Laboratory, People's Hospital of Tibet Autonomous Region, Lhasa, China. FAU - Zhaxiyangzong AU - Zhaxiyangzong AD - Department of Clinical Laboratory, People's Hospital of Tibet Autonomous Region, Lhasa, China. FAU - Pang, Jinrong AU - Pang J AD - Department of Clinical Laboratory, People's Hospital of Tibet Autonomous Region, Lhasa, China. FAU - Zhan, Mingjun AU - Zhan M AD - Department of Clinical Laboratory, People's Hospital of Tibet Autonomous Region, Lhasa, China. FAU - Liu, Zhijuan AU - Liu Z AD - Department of Clinical Laboratory, People's Hospital of Tibet Autonomous Region, Lhasa, China. Electronic address: freefirl@163.com. FAU - Dan, Qu AU - Dan Q AD - Department of Clinical Laboratory, People's Hospital of Tibet Autonomous Region, Lhasa, China. Electronic address: daneilwind@126.com. FAU - Cheng, Xinqi AU - Cheng X AD - Department of Laboratory Medicine, Peking Union Medical College Hospital, Peking Union Medical College & Chinese Academy of Medical Science, Beijing, China. Electronic address: chengxq@pumch.cn. LA - eng PT - Comparative Study PT - Journal Article DEP - 20230811 PL - United States TA - Clin Biochem JT - Clinical biochemistry JID - 0133660 RN - 142M471B3J (Carbon Dioxide) RN - Tibetan people SB - IM MH - Adult MH - Humans MH - *Altitude MH - Altitude Sickness/blood/diagnosis/ethnology MH - *Carbon Dioxide/blood MH - *East Asian People/ethnology MH - *Hypoxia/blood/diagnosis/ethnology MH - Retrospective Studies MH - Tibet OTO - NOTNLM OT - Big data OT - Indirect method OT - Reference interval OT - Tibet OT - Total carbon dioxide COIS- Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. EDAT- 2023/08/13 00:43 MHDA- 2023/08/28 06:42 CRDT- 2023/08/12 19:28 PHST- 2023/05/10 00:00 [received] PHST- 2023/08/03 00:00 [revised] PHST- 2023/08/09 00:00 [accepted] PHST- 2023/08/28 06:42 [medline] PHST- 2023/08/13 00:43 [pubmed] PHST- 2023/08/12 19:28 [entrez] AID - S0009-9120(23)00159-5 [pii] AID - 10.1016/j.clinbiochem.2023.110631 [doi] PST - ppublish SO - Clin Biochem. 2023 Sep;119:110631. doi: 10.1016/j.clinbiochem.2023.110631. Epub 2023 Aug 11.