Kannan Subramanian, Jaipalreddy Chinthala, Annapandian Vellaichamy Muthupandi, Murali Mohan Bangalore Venkatraman, Damodar Sharat, Khadilkar Kranti Shreesh, Shivaprasad Kumbenahalli Siddegowda
Department of Endocrinology, Diabetes and Metabolism, Mazumdar Shaw Medical Center, Narayana Health City, Bangalore, Karnataka, India.
Department of Internal Medicine and Pulmonary Medicine, Mazumdar Shaw Medical Center, Narayana Health City, Bangalore, Karnataka, India.
Indian J Endocrinol Metab. 2019 Jan-Feb;23(1):91-96. doi: 10.4103/ijem.IJEM_190_18.
It is well known that anemia and red cell turn over affects the HbA1c value. Iron deficiency anemia increases the HbA1c and haemolytic anemia lowers it. However, the cut-off of haemoglobin (Hb) or red-cell indices when the HbA1c value becomes unreliable is not known.
We sought to find out values of HbA1c and red-cell indices where there is considerable discordance between HbA1c and plasma glucose (PG) values in the diagnosis of diabetes (DM) and pre-diabetes (Pre-DM) making HbA1c values unreliable.
A cross-sectional study of 237 non-diabetic subjects who attended our out-patient division of preventive health check-up clinics, between November 2016 and December 2017. Data was collected only from relatively healthy subjects who had voluntarily opted for undergoing a preventative health check-up (including a diabetes screening). Patients were classified as concordant (fasting and 2-hr post meal glucose values are in agreement with HbA1c) and discordant (values are not in agreement with HbA1c).
A total of 237 patients (73% males) with mean age was 47.2±9.7 years (range 25-75) were included in the study. The HbA1c definition group had more diagnosis of DM (153 vs 96) and but lesser numbers of pre-DM (66 vs 102) compared to the PG group. Out of 237 patients, 133 (56%) showed concordance and 104 (44%) were discordant. The FPG, 2h-PPBG and HbA1c are significantly higher in the concordant group. The Hb value and MCV were significantly higher (p<0.05) in concordant group whereas, RDW and platelets are significantly higher (p<0.05) in discordant group. The highest rate of discordance was noted in the HbA1c strata of 6.5-7% (72%) followed by HbA1c of 5-6.4% (42%) and least in the HbA1c strata >7% (20%). While no single Hb or MCV value could predict discordance, a RDW value >17 was consistently associated with discordance across all the HbA1c strata.
A HbA1c below 7% is significantly influenced by red-cell turn over indices and clinicians need to perform additional testing using plasma glucose levels to confirm the presence of diabetes or pre-diabetes. In patients whose RDW >17, HbA1c should be replaced by 75gm OGTT as a test of choice for diagnosis of diabetes or pre-diabetes.
众所周知，贫血和红细胞周转会影响糖化血红蛋白（HbA1c）值。缺铁性贫血会使HbA1c升高，而溶血性贫血则会使其降低。然而，尚不清楚当HbA1c值变得不可靠时血红蛋白（Hb）或红细胞指数的临界值。
我们试图找出在糖尿病（DM）和糖尿病前期（Pre-DM）诊断中，HbA1c与血浆葡萄糖（PG）值之间存在显著差异，从而使HbA1c值不可靠时的HbA1c和红细胞指数值。
对2016年11月至2017年12月期间在我院预防性健康检查门诊就诊的237名非糖尿病患者进行横断面研究。数据仅收集自自愿选择接受预防性健康检查（包括糖尿病筛查）的相对健康的受试者。患者分为一致组（空腹和餐后2小时血糖值与HbA1c一致）和不一致组（值与HbA1c不一致）。
本研究共纳入237例患者（73%为男性），平均年龄为47.2±9.7岁（范围25-75岁）。与PG组相比，HbA1c定义组的DM诊断更多（153例对96例），但糖尿病前期患者数量较少（66例对102例）。在237例患者中，133例（56%）表现为一致，104例（44%）表现为不一致。一致组的空腹血糖（FPG）、餐后2小时血糖（2h-PPBG）和HbA1c显著更高。一致组的Hb值和平均红细胞体积（MCV）显著更高（p<0.05），而不一致组的红细胞分布宽度（RDW）和血小板显著更高（p<0.05）。在HbA1c为6.5-7%的分层中不一致率最高（72%），其次是HbA1c为5-6.4%的分层（42%），而在HbA1c>7%的分层中最低（20%）。虽然没有单一的Hb或MCV值可以预测不一致，但RDW值>17在所有HbA1c分层中都与不一致始终相关。
HbA1c低于7%受红细胞周转指数的显著影响，临床医生需要使用血浆葡萄糖水平进行额外检测以确认糖尿病或糖尿病前期的存在。对于RDW>17的患者，应将HbA1c替换为75克口服葡萄糖耐量试验（OGTT）作为诊断糖尿病或糖尿病前期的首选检测方法。
