MRC/Wits Rural Public Health and Health Transitions Research Unit, School of Public Health, University of the Witwatersrand, Johannesburg, South Africa
Department of Chemical Pathology, University of the Witwatersrand, Johannesburg, South Africa.
BMJ Open. 2021 Jun 17;11(6):e046060. doi: 10.1136/bmjopen-2020-046060.
We investigated concordance between haemoglobin A1c (HbAc)-defined diabetes and fasting plasma glucose (FPG)-defined diabetes in a black South African population with a high prevalence of obesity.
Cross-sectional study.
Rural South African population-based cohort.
765 black individuals aged 40-70 years and with no history of diabetes.
The primary outcome measure was concordance between HbA-defined diabetes and FPG-defined diabetes. Secondary outcome measures were differences in anthropometric characteristics, fat distribution and insulin resistance (measured using Homoeostatic Model Assessment of Insulin Resistance (HOMA-IR)) between those with concordant and discordant HbA/FPG classifications and predictors of HbA variance.
The prevalence of HbA-defined diabetes was four times the prevalence of FPG-defined diabetes (17.5% vs 4.2%). Classification was discordant in 15.7% of participants, with 111 individuals (14.5%) having HbA-only diabetes (kappa 0.23; 95% CI 0.14 to 0.31). Median body mass index, waist and hip circumference, waist-to-hip ratio, subcutaneous adipose tissue and HOMA-IR in participants with HbA-only diabetes were similar to those in participants who were normoglycaemic by both biomarkers and significantly lower than in participants with diabetes by both biomarkers (p<0.05). HOMA-IR and fat distribution explained additional HbA variance beyond glucose and age only in women.
Concordance was poor between HbA and FPG in diagnosis of diabetes in black South Africans, and participants with HbA-only diabetes phenotypically resembled normoglycaemic participants. Further work is necessary to determine which of these parameters better predicts diabetes-related morbidities in this population and whether a population-specific HbA threshold is necessary.
我们研究了在南非一个肥胖患病率高的黑人人群中，血红蛋白 A1c（HbA1c）定义的糖尿病与空腹血浆葡萄糖（FPG）定义的糖尿病之间的一致性。
横断面研究。
南非农村人群为基础的队列。
765 名年龄在 40-70 岁之间、无糖尿病病史的黑人个体。
主要观察指标是 HbA 定义的糖尿病与 FPG 定义的糖尿病之间的一致性。次要观察指标是在 HbA/FPG 分类一致和不一致的个体之间，在人体测量特征、脂肪分布和胰岛素抵抗（使用稳态模型评估胰岛素抵抗（HOMA-IR）进行测量）方面的差异，以及 HbA 变异的预测因素。
HbA 定义的糖尿病患病率是 FPG 定义的糖尿病患病率的四倍（17.5% vs 4.2%）。在 15.7%的参与者中分类不一致，有 111 名个体（14.5%）仅有 HbA 糖尿病（kappa 值为 0.23；95%CI 为 0.14 至 0.31）。仅有 HbA 糖尿病的参与者的体重指数中位数、腰围和臀围、腰臀比、皮下脂肪组织和 HOMA-IR 与两种生物标志物均正常的参与者相似，明显低于两种生物标志物均有糖尿病的参与者（p<0.05）。只有在女性中，HOMA-IR 和脂肪分布才能解释血糖和年龄以外的 HbA 变异。
在南非黑人中，HbA 和 FPG 在诊断糖尿病方面的一致性较差，仅有 HbA 糖尿病的参与者表型上与血糖正常的参与者相似。需要进一步研究确定这些参数中的哪一个能更好地预测该人群中与糖尿病相关的发病率，以及是否需要一个特定于人群的 HbA 阈值。
