Glycated haemoglobin threshold for dysglycaemia screening, and application to metabolic syndrome diagnosis in HIV-infected Africans

PLoS One. 2019 Jan 31;14(1):e0211483. doi: 10.1371/journal.pone.0211483. eCollection 2019.

Abstract

Background: Glycated haemoglobin (HbA1c) test has been increasingly promoted as an alternative to fasting plasma glucose (FPG) or oral glucose tolerance test (OGTT) to diagnose dysglycaemia but its performance in HIV-infected Africans has yet to be established. This study aimed to assess the diagnostic accuracy of HbA1c for dysglycaemia including FPG-defined and OGTT-defined dysglycaemia, and OGTT-defined diabetes in HIV-infected Africans, and the effect of HbA1c-predicted dysglycaemia on Joint Interim Statement (JIS)-based prevalent metabolic syndrome (MS).

Methods: A cross-sectional study included HIV-positive patients recruited across public healthcare facilities in the Western Cape. The recommended HbA1c cut-points were tested alongside the optimal cut-points obtained from receiver operating characteristic curve analyses, while the agreement between the MS criteria were assessed using kappa statistic.

Results: 748 participants (157 men), median age 38 years, 93% on anti-retroviral drugs were included. The optimal HbA1c cut-points of 5.75% (39.3 mmol/mol) showed 54% sensitivity, 84% specificity for FPG-defined dysglycaemia, and 52% sensitivity, 85% specificity for OGTT-defined dysglycaemia. The HbA1c value of 5.85% (40.4 mmol/mol) (63% sensitivity, 99% specificity) was optimal for diabetes. The internationally advocated cut-point of 6.5% (48 mmol/mol) had 37% sensitivity and 99% specificity for diabetes, while HbA1c ≥5.7% (≥39 mmol/mol) yielded similar performance with the study-specific cut-point for any dysglycaemia. MS prevalence by the JIS criteria (28.2%) increased to 29.7% when using HbA1c ≥5.75% (≥39.3 mmol/mol) and to 32.9% with HbA1c ≥5.7% (≥39 mmol/mol); agreement between the original and modified criteria was generally good.

Conclusions: This study agrees with the internationally recommended HbA1c cut-point for detecting dysglycaemia, but not for diabetes in HIV-infected Africans. In line with previous studies in general African populations, our findings suggest that similar factors interfere with HbA1c values regardless of HIV infection status. Replacing FPG-based with HbA1c-predicted dysglycaemia in the JIS criteria to diagnose MS is feasible in HIV-infected Africans.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Africa / epidemiology
  • Biomarkers / blood*
  • Cross-Sectional Studies
  • Diabetes Mellitus / physiopathology*
  • Female
  • Glucose Intolerance / blood
  • Glucose Intolerance / diagnosis*
  • Glucose Intolerance / etiology
  • Glucose Tolerance Test
  • Glycated Hemoglobin / analysis*
  • HIV / isolation & purification
  • HIV Infections / complications*
  • HIV Infections / virology
  • Humans
  • Male
  • Mass Screening / methods*
  • Metabolic Syndrome / blood
  • Metabolic Syndrome / diagnosis*
  • Metabolic Syndrome / etiology
  • Middle Aged
  • Prevalence
  • ROC Curve

Substances

  • Biomarkers
  • Glycated Hemoglobin A
  • hemoglobin A1c protein, human

Grants and funding

Grand Challenge Canada, through the Global Alliance on Chronic Diseases initiative funded this study. NRF Innovation Doctoral Research Scholarship, Doctoral Scholarship and Yeoman Bequest Bursary through the University of Cape Town supported KAN. These funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Global Evaluation Science provided support in the form of salary for EJM but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific role of this author is articulated in the ‘author contribution’ section.