Department of Internal Medicine, University of Tsukuba Institute of Clinical Medicine, Ibaraki, Japan.
Lancet. 2011 Jul 9;378(9786):147-55. doi: 10.1016/S0140-6736(11)60472-8. Epub 2011 Jun 24.
The clinical relevance of the diagnostic criteria for prediabetes to prediction of progression to diabetes has been little studied. We aimed to compare the prevalence of prediabetes when assessed by the new glycated haemoglobin A(1c) (HbA(1c)) 5·7-6·4% criterion or by impaired fasting glucose, and assessed differences in progression rate to diabetes between these two criteria for prediabetes in a Japanese population.
Our longitudinal cohort study included 4670 men and 1571 women aged 24-82 years without diabetes at baseline (diabetes was defined as fasting plasma glucose ≥7·0 mmol/L, self-reported clinician-diagnosed diabetes, or HbA(1c) ≥6·5%) who attended Toranomon Hospital (Tokyo, Japan) for a routine health check between 1997 and 2003. Participants with a baseline diagnosis of prediabetes according to impaired fasting glucose (fasting plasma glucose 5·6-6·9 mmol/L) or HbA(1c) 5·7-6·4%, or both, were divided into four groups on the basis of baseline diagnosis of prediabetes. Rate of progression to diabetes was assessed annually.
Mean follow-up was 4·7 (SD 0·7) years. 412 (7%) of 6241 participants were diagnosed with prediabetes on the basis of the HbA(1c) 5·7-6·4% criterion. Screening by HbA(1c) alone missed 1270 (61%) of the 2092 prediabetic individuals diagnosed by a combination of impaired fasting glucose and HbA(1c) 5·7-6·4%. Overall cumulative probability of progression to diabetes did not differ significantly between participants with prediabetes discordantly diagnosed by either HbA(1c) or impaired fasting glucose alone (incidence was 7% for HbA(1c) alone [n=412 individuals and 30 incident cases] and 9% for impaired fasting glucose alone [n=1270, 108 cases]; log-rank test, p=0·3317). Multivariate-adjusted hazard ratios for incident diabetes were 6·16 (95% CI 4·33-8·77) for those diagnosed with prediabetes by impaired fasting glucose alone and 6·00 (3·76-9·56) for diagnosis by HbA(1c) alone, and were substantially increased to 31·9 (22·6-45·0) for diagnosis by both impaired fasting glucose and HbA(1c) compared with normoglycaemic individuals.
Diagnosis of prediabetes by both the new HbA(1c) criterion and impaired fasting glucose identified individuals with an increased risk of progression to diabetes. Although the new HbA(1c) criterion identified fewer individuals at high risk than did impaired fasting glucose, the predictive value for progression to diabetes assessed by HbA(1c) 5·7-6·4% was similar to that assessed by impaired fasting glucose alone. The two tests used together could efficiently target people who are most likely to develop diabetes and allow for early intervention.
Japan Society for the Promotion of Science; Ministry of Health Labor and Welfare, Japan.
用于预测糖尿病进展的糖尿病前期诊断标准的临床相关性研究较少。我们旨在比较新的糖化血红蛋白 A1c（HbA1c）5·7-6·4%标准或空腹血糖受损（impaired fasting glucose，IFG）评估的糖尿病前期的患病率，并在日本人群中评估这两种糖尿病前期标准之间的糖尿病进展率的差异。
我们的纵向队列研究包括 4670 名男性和 1571 名女性，年龄 24-82 岁，基线时无糖尿病（糖尿病定义为空腹血糖≥7·0mmol/L、自我报告的临床医生诊断的糖尿病或 HbA1c≥6·5%），他们在 1997 年至 2003 年间在 Toranomon 医院（日本东京）接受常规健康检查。根据 IFG（空腹血糖 5·6-6·9mmol/L）或 HbA1c 5·7-6·4%或两者的基线诊断患有糖尿病前期的参与者，根据基线诊断患有糖尿病前期，分为四组。每年评估糖尿病进展率。
平均随访时间为 4.7（SD 0.7）年。在 6241 名参与者中，412 名（7%）根据 HbA1c 5·7-6·4%标准被诊断为糖尿病前期。单独用 HbA1c 筛查漏诊了 1270 名（61%）同时患有 IFG 和 HbA1c 5·7-6·4%的糖尿病前期患者。单独使用 HbA1c 或 IFG 诊断的糖尿病前期患者的总体累积糖尿病进展概率无显著差异（HbA1c 单独的发生率为 7%[412 人，30 例发病]，IFG 单独的发生率为 9%[1270 人，108 例发病]；对数秩检验，p=0·3317）。单独使用 IFG 诊断的糖尿病前期患者的糖尿病发病的多变量调整后的危险比为 6.16（95%CI 4.33-8.77），单独使用 HbA1c 诊断的糖尿病前期患者的危险比为 6.00（3.76-9.56），而同时使用 IFG 和 HbA1c 诊断的患者的危险比显著增加到 31.9（22.6-45.0）与血糖正常的个体相比。
新的 HbA1c 标准和 IFG 联合诊断糖尿病前期可识别出糖尿病进展风险增加的个体。虽然新的 HbA1c 标准比 IFG 识别出更多处于高风险的个体，但 HbA1c 5·7-6·4%评估的糖尿病进展预测值与 IFG 单独评估的预测值相似。这两种测试联合使用可以有效地针对最有可能发展为糖尿病的人群，并允许早期干预。
日本科学促进会；日本厚生劳动省。
