The Relationship Between Insulin Sensitivity And Heart Rate-corrected QT Interval In Patients With Type 2 Diabetes

Objective Reduced insulin sensitivity not only contributes to the pathogenesis of type 2 diabetes but is also linked to multiple metabolic risk factors and cardiovascular diseases(CVD).A prolonged heart rate-corrected QT interval(QTc interval)is related to ventricular arrhythmias and CVD mortality and exhibits a high prevalence among type 2 diabetes patients.The aim of the study was to investigate the relationship between insulin sensitivity and the QTc interval in patients with type 2 diabetes.Methods1.This cross-sectional observational study recruited 2927 patients with type 2 diabetes who visited the Affiliated Haian Hospital and Second Affiliated Hospital of Nantong University from January 2011 to December 2015.2.All participants received a 75-g oral glucose tolerance test(75-g OGTT)after enrolment.And blood samples were collected at basal(0 min),and 30,60,120,and 180 min after glucose ingestion for the determinations of plasma glucose and insulin levels.Systemic insulin sensitivity was assessed using the 5 values of plasma glucose and insulin proposed by Matsudax(ISIMatsuda).3.The QTc interval was estimated using a resting 12-lead electrocardiogram,and an interval longer than 440 ms was considered abnormally prolonged.4.The other metabolic risk factors,including age,sex,blood pressure,body mass index(BMI),drug medication,health behaviours,medical history,lipid profiles,serum uric acid(UA)and Hb A1 c,were also collected.Results1.The distributions of the QTc interval and log-transformed systemic insulin sensitivity(log ISIMatsuda)were approximately normal.2.Pearson's correlation test showed the QTc interval was significantly and negatively correlated with the ISIMatsuda(r= – 0.296,p < 0.001).3.When the multiple linear regression analysis was adjusted for anthropometric parameters,metabolic risk factors,and current antidiabetic treatments,the QTc interval remained significantly correlated with the ISIMatsuda(? = –0.23,t = –12.63,p < 0.001).4.Meanwhile,feamale(? = 0.22,p < 0.001),age(? = 0.13,p < 0.001),hypertension(? = 0.078,p < 0.001),insulin treatments(? = 0.062,p = 0.001)and serum uric acid(? = 0.059,p = 0.002)were also the independent risk factors for increased QTc interval.5.The proportion of patients with prolonged QTc interval significantly increased from 12.1% to 17.9% to 25.6% to 37.9% from the fourth(Q4)to the first(Q1)quartile of the ISIMatsuda,respectively,and p for trend < 0.001.6.After adjusting for anthropometric parameters by multiple logistic regression analysis,the corresponding odd ratios(ORs)for prolonged QTc interval of the third,second and first quartiles versus the fouth quartile of ISIMatsuda were 1.53(95% CI,1.09–2.14),2.09(1.51–2.88)and 3.11(2.23–4.34),respectively,and p for trend was <0.001.Conclusions1.Reduced systemic insulin sensitivity assessed by ISIMatsuda is associated with an increase in the QTc interval in patients with type 2 diabetes.2.In addition to nonmodifiable risk factors including female and age,modifiable risk factors,such as hypertension,insulin treatments and serum uric acid,also are independent risks for prolonged QTc interval in patients with type 2 diabetes.