Non-Communicable Diseases Research Unit, South African Medical Research Council, Cape Town, South Africa.
Department of Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.
PLoS One. 2019 Jan 31;14(1):e0211483. doi: 10.1371/journal.pone.0211483. eCollection 2019.
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).
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.
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.
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.
糖化血红蛋白（HbA1c）检测作为替代空腹血糖（FPG）或口服葡萄糖耐量试验（OGTT）来诊断糖代谢异常的方法，已得到越来越多的推广，但在感染 HIV 的非洲人群中的应用效能仍有待确定。本研究旨在评估 HbA1c 检测对糖代谢异常（包括 FPG 定义和 OGTT 定义的糖代谢异常）以及 HIV 感染者 OGTT 定义的糖尿病的诊断准确性，并评估 HbA1c 预测的糖代谢异常对基于联合临时声明（JIS）的常见代谢综合征（MS）的影响。
本横断面研究纳入了在西开普省公共医疗设施中招募的 HIV 阳性患者。检测了推荐的 HbA1c 切点以及通过受试者工作特征曲线分析获得的最佳切点，同时使用kappa 统计评估了 MS 标准之间的一致性。
共纳入 748 名参与者（157 名男性），中位年龄 38 岁，93%接受抗逆转录病毒药物治疗。最佳 HbA1c 切点为 5.75%（39.3mmol/mol），对 FPG 定义的糖代谢异常的敏感性为 54%，特异性为 84%，对 OGTT 定义的糖代谢异常的敏感性为 52%，特异性为 85%。HbA1c 值为 5.85%（40.4mmol/mol）（63%的敏感性，99%的特异性）时对糖尿病的诊断最佳。国际上推荐的 6.5%（48mmol/mol）切点对糖尿病的敏感性为 37%，特异性为 99%，而 HbA1c≥5.7%（≥39mmol/mol）切点与本研究的特定切点对任何糖代谢异常的检测性能相似。使用 JIS 标准时，MS 的患病率（28.2%）升高至 HbA1c≥5.75%（≥39.3mmol/mol）时的 29.7%，HbA1c≥5.7%（≥39mmol/mol）时升高至 32.9%；原始标准和修改标准之间的一致性通常较好。
本研究与国际上推荐的用于检测糖代谢异常的 HbA1c 切点一致，但对 HIV 感染者的糖尿病诊断切点不一致。与一般非洲人群中的先前研究一致，我们的研究结果表明，无论 HIV 感染状态如何，相似的因素都会干扰 HbA1c 值。在 HIV 感染者中，用 HbA1c 预测的糖代谢异常替代基于 FPG 的 JIS 标准来诊断 MS 是可行的。
