Objective To explore the interaction between family history of diabetes and hyperlipidemia on the risk of diabetes in population with normotension.Methods A multistage stratified probability random sampling was conducted to select a representative sample of urban residents aged 20-74 years in Harbin.A total of 376 diabetes patients with normotension and 3 692 residents with normal blood pressure,normal fasting glucose,and normal 2 hours glucose from OGTT were surveyed.The interaction was evaluated by using crossover analysis and additive model.Results Multivariate logistic regression analysis indicated that there was a possible additive interaction between family history of diabetes and hyperlipidemia on the risk of diabetes.The relative excess risk due to the interaction,the attributable proportion due to the interaction,and the synergy index were 1.97 (95％CI:-0.32-4.26),0.30 (95％CI:0.03-0.57),and 1.54 (95％CI:0.96-2.47),respectively.There were significant combination effects between family history of diabetes and high both total cholesterol and triglyceride,isolated high total cholesterol,and isolated high triglyceride levels;the ORs were 10.55 (95％CI:5.62-19.80),7.81 (95％CI:3.65-16.71) and 5.13 (95％CI:3.22-8.16),respectively.Conclusion There might be synergistic effect between family history of diabetes and hyperlipidemia on the risk of diabetes in population with normotension.

Objective: To investigate the value of haemogobin A₁c(HbA₁c) for diagnosing various hyperglycemias in the Second Affiliated Hospital of Harbin Medical University. Methods: This study is based on the data randomly selected from patients without clinical intervention in the endocrinology department and admission office in the Second Affiliated Hospital of Harbin Medical University from January 1st of 2010 to December 31th of 2012. In this study, 2 853 patients aged 16-85 year were selected, who performed OGTT and HbA₁c on the same day. Their data of HbA₁c and OGTT were collected. Selection criteria: the OGTT and HbA₁c were performed simultaneously unless the patients had acidosis, and patients with past history of diabetes and oral hypoglycemic drugs or insulin treatment, or other basic combined diseases were included in this study. People in pregnancy were ruled out. Area under the receiver operating characteristics curve (ROC), sensitivity, and specificity were adopted to evaluate the diagnosis effect of HbA₁c using FPG and OGTT as golden standard for diabetes and pre-diabetes. Results: The area under the ROC were 0.902 (95% confidence interval 0.890-0.914) for HbA₁c alone and 0.915 (0.906-0.925) for FPG alone. The HbA₁c threshold of 6.5% showed the highest Youden index of 64.4% and significantly higher sensitivity 81.1% compared with FPG ≥ 7.0 mmol/L (69.8%, P < 0.01) in detecting diabetes. The optimal HbA₁c thresholds for diagnosing pre-diabetes was 5.6% (the area under the ROC: 0.725; sensitivity: 74.1%; specificity: 60.3%). Conclusions These findings suggest that HbA₁c 6.5% and 5.6% can be used as the diagnosing criterions for diabetes and pre-diabetes among the population who visit department of endocrinology.