| Background: China has the largest number of patients with T2 DM in the world.The prevalence of diabetes is related to the aging of the population.More than 20% of the elderly suffer from diabetes(more than 95% of T2DM),and more than 45% of the elderly are in a pre-diabetic state.If not treated,some elderly people will eventually become Diabetes,and the prognosis is very poor.Aging and diabetes are two well-known risk factors for cardiovascular disease(CVD).With age,many people will experience asymptomatic hyperglycemia,aggravate metabolic disorders,cause occult microvascular and large blood vessel damage,and increase the risk of cardiovascular and cerebrovascular emergencies.Due to the lack of sensitive early diabetes predictors,some elderly patients with prediabetes or early diabetes will have irreversible vascular damage.At this time,it is difficult to effectively reduce the incidence of cardiovascular complications through treatment methods such as strict blood sugar control.Therefore,it is necessary to intervene as soon as possible to keep the plasma glucose steady state as close to normal as possible.In recent years,it has been found that the oral glucose tolerance test(OGTT)one hour plasma glucose(1h PG)has a good predictive effect on T2 DM,and some studies have found that its predictive effect is better than fasting plasma glucose(FPG)and OGTT 2 hour plasma glucose(2h PG);another study found that the triglyceride fasting plasma glucose index(Ty G index)is a good substitute for insulin resistance,and has a certain predictive effect on T2 DM.However,these studies are mostly concentrated in Western regions or the subjects are mainly middle-aged people,and there are few studies on the Chinese elderly.Objective: To understand the predictive effect of OGTT 1-hour plasma glucose on T2 DM and cardiovascular events,and the predictive effect of Ty G index on T2 DM in elderly male population.Methods: This study collected and compiled data of patients who underwent physical examination and treatment at the Second Medical Center of the Chinese People’s Liberation Army General Hospital from May 1998 to May 1999.A total of 1697 atients with undiagnosed diabetes and aged ≥ 60 years old were included.Multivariate COX regression analysis models were established to analyze the risk of OGTT 1-hour plasma glucose and T2 DM and CVD events.Receiver Operating Characteristic(ROC)curve analysis was used to analyze the effect of OGTT 1-hour plasma glucose on T2 DM.The predictive power of the models was evaluated using C-statistics.Establish multivariate COX regression analysis models to analyze the Ty G index,plasma glucose,blood lipid indicators and the risk of T2 DM.The predictive effects of Ty G index,blood glucose and lipid indexes on T2 DM were analyzed by ROC curve analysis,and the predictive ability of the models were evaluated by C-statistics.Results: A total of 862 subjects,all male and ≥60 years old,were enrolled and followed up for 20 years.With a median age of 74.0(68.0-79.0)years,544 patients(63.1%)developed T2 DM,with an overall incidence of 54.5 per 1000 person-years,and 215 patients(24.9%)developed CVD events.(1)Multivariate COX regression analysis showed that both 1h PG and 2h PG were positively correlated with T2 DM.When included as continuous variables,for every 1mmol/L increase in 1h PG,the HR value(95% CI)for T2 DM was 1.325(1.269-1.384);for every 1mmol/L increase in2 h PG,the HR value(95% CI)for T2 DM is 1.383(1.308-1.463).Although FPG is also a predictor of T2 DM,adding 1h PG and PFG or adding 2h PG and FPG to the model at the same time,FPG is no longer a risk factor for T2DM(P<0.05).When1 h PG and 2h PG were included as categorical variables,compared with the first 1h PG tertile group,the risk of progression to T2 DM in the 1h PG second tertile group and the third tertile group increased by 1.809(95% CI: 1.423-2.298)times and 4.153(95%CI: 3.275-5.267)times;compared with the first tertile of 2h PG,the risk of developing T2 DM in the second and third tertile of 2h PG increased by 1.449(95% CI:1.149-1.829)times and 3.292(95% CI: 2.632-4.117)times.The ROC curve shows that FPG,1h PG,and 2h PG all have predictive power for T2 DM.The area under the curve(AUC)of 1h PG is 0.766(95%CI: 0.734-0.797)greater than PFG [AUC(95%)CI): 0.587(0.548-0.625),P <0.001] and 2h PG [AUC(95% CI): 0.713(0.679-0.747),P = 0.005].FPG,1h PG and 2h PG were added into the traditional risk factor models,and the C-statistic of 1h PG was the highest,which was 0.795(95%CI: 0.765--0.825),compared with the model with FPG[AUC(95%CI): 0.684(0.648--0.720)] and 2h PG[AUC(95%CI): 0.746(0.713-0.778)].(2)Single factor COX regression analysis showed that both 1h PG and 2h PG were positively correlated with CVD events,and FPG was not a risk factor for CVD events.When continuous variables were included in the multivariate COX regression analysis,the HR value(95% CI)for CVD events was 1.097(1.027-1.172)for every 1mmol/L increase in 1h PG;while the 2h PG level had nothing to do with the occurrence of CVD events.When 1h PG and 2h PG were included as categorical variables,compared with the 1h PG first tertile group,the risk of CVD events in the 1h PG second tertile group and the third tertile group increased by 1.464(95% CI: 1.031-2.080)times and 1.538(95% CI: 1.092-2.166)times;while the univariate and multivariate analyses of the 2h PG tertiles were not related to the occurrence of CVD events.(3)Ty G index,1h PG and 2h PG were all independent risk factors for T2 DM when Ty G index,blood glucose and lipid indexes were included as continuous variables or categorical variables.The ROC curve showed that the AUC of 1h PG and 2h PG were both greater than Ty G index.When Ty G index,1h PG and2 h PG were added into the traditional risk factor model,the C-statistics were all greater than that of the model with Ty G index added.Conclusion:(1)Among the older male population,1h PG and 2h PG have obvious predictive effects on T2 DM,and the predictive effect of 1h PG is stronger than that of2 h PG.OGTT is usually used to diagnose T2 DM.1h PG can be implemented in the prevention plan,which is more time-saving than 2h PG.(2)Among the older male population,1h PG has certain predictive effect on CVD events,while FPG and 2h PG have nothing to do with CVD events.(3)Although previous studies have found that Ty G index is a good substitute for insulin resistance and has certain predictive effect on T2 DM,our research found that in elderly men,Ty G index is not as good as OGTT in predicting T2 DM.Ty G index may not be appropriate for screening high-risk populations for type 2 diabetes among elderly men. |
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