Erythrocytosis and Performance of HbA1c in Detecting Diabetes on an Oxygen-Deficient Plateau: A Population-based Study.

Abstract

CONTEXT:

The hemoglobin A1c (HbA1c) test is a standard test for diabetes screening and diagnosis.

OBJECTIVE:

To evaluate A1c performance for diabetes screening in high-altitude polycythemia compared to a population with a high proportion of people living in an oxygen-deficient environment.

DESIGN:

A population-based epidemiological survey was conducted.

SETTING:

The cities Lhasa and Shigatse were selected. Volunteers were recruited through educational advertisements about diabetes.

PARTICIPANTS:

A total of 1401 Tibetan adults without known diabetes.

INTERVENTIONS:

Oral glucose tolerance test (OGTT), HbA1c, and complete blood cell count were performed. Hemoglobin A1c was evaluated using high-performance liquid chromatography, and serum glucose level, using the hexokinase method.

MAIN OUTCOME MEASURES:

World Health Organization criteria were used to define diabetes and prediabetes. Hemoglobin A1c test performance was evaluated using receiver operating characteristic analysis.

RESULTS:

The participants' mean age was 44.3 ± 15.0 years; 33.3% of the participants were men and 38.6% lived in urban areas. The prediabetes and diabetes prevalence rates were 7.5% and 3.6%, respectively. The optimal HbA1c cutoff for detecting diabetes was 46 mmol/mol (6.4%), with a sensitivity and specificity of 60.8% and 93.6%, respectively. The cutoff for detecting diabetes was 6.7% (50 mmol/mol) in subjects with high-altitude polycythemia (HAPC). The relationship between red blood cell (RBC) counts and HbA1c was significant (P < 0.001), while there was no correlation between hemoglobin (Hb) and HbA1c (P = 0.085). Multiple linear regression analysis showed that after adjusting for age and fasting serum glucose or 2-hour OGTT (OGTT2h) serum glucose, RBC count and not Hb level was an independent risk factor for HbA1c (β = 0.140, P < 0.001).

CONCLUSIONS:

The optimal HbA1c cutoff for detecting diabetes was 46 mmol/mol (6.4%) in Tibet. Red blood cell count was an independent risk factor for elevated HbA1c, and HAPC may affect the predictive ability of HbA1c.

• Authors: Qian Ren, Xuemei Lv, Lihui Yang, Jun Yue, Yingying Luo, Lingli Zhou, Shuyou Meng, Senlin Yang, Basang Puchi, Xianghai Zhou, Linong Ji
• Journal: The Journal of clinical endocrinology and metabolism (J Clin Endocrinol Metab) Vol. 105 Issue 4 (04 01 2020) ISSN: 1945-7197 [Electronic] United States
• PMID: 31904080 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © Endocrine Society 2020. All rights reserved. For permissions, please e-mail: [email protected].

Chemical References

• Biomarkers
• Blood Glucose
• Glycated Hemoglobin A
• hemoglobin A1c protein, human
• Oxygen

Topics

• Adult
• Biomarkers (blood)
• Blood Glucose (analysis)
• Case-Control Studies
• China (epidemiology)
• Diabetes Mellitus (blood, diagnosis, epidemiology)
• Female
• Follow-Up Studies
• Glucose Tolerance Test
• Glycated Hemoglobin (analysis)
• Humans
• Male
• Mass Screening (methods)
• Middle Aged
• Oxygen (metabolism)
• Polycythemia (physiopathology)
• Prediabetic State (blood, diagnosis, epidemiology)
• Prevalence
• Prognosis
• ROC Curve