Influencing factors of QTc among the clinical characteristics in type 2 diabetes mellitus

The influence of different glucose tolerance on QTc interval: a population-based study

BACKGROUND

Corrected QT (QTc) interval has been reported to be associated with type 2 diabetes. This study aimed to explore the relationship between different glucose tolerance and QTc intervals among middle-aged and older Chinese individuals.

METHODS

We conducted a cross-sectional analysis that included 9898 subjects (3194 men and 6704 women) in a Chinese population. Glucose tolerance was studied during the oral glucose tolerance test (OGTT). Insulin, blood pressure, hemoglobin A1c (HbA1c), serum lipids, hepatic transaminases and waist-to-hip ratio were assessed. The QTc interval was derived from ECG recordings, and the subjects were stratified based on different glucose tolerance.

RESULTS

QTc interval levels were increased significantly in the subjects with abnormal glucose metabolism compared with the normal glucose regulation group. Multiple regression analyses showed that the QTc interval was significantly associated with fasting plasma glucose, 2-h OGTT plasma glucose and HbA1c. The odds ratio of prolonged QTc was 1.396 for impaired glucose regulation (IFG)/impaired fasting glucose (IGT) (95% CI 0.126-1.730), and 1.342 for type 2 diabetes (95% CI 0.142-1.577) after all potential confounders were adjusted.

CONCLUSIONS

Impaired glucose tolerance (IGR) and diabetes are associated with prolonged QTc intervals among middle-aged and older Chinese individuals. Abnormal glucose regulation can be used to monitor the QTc interval in the population.

Heart rate-corrected QT interval: A novel diagnostic biomarker for diabetic peripheral neuropathy

AIMS/INTRODUCTION

To explore the relationship between heart rate-corrected QT (QTc) interval and diabetic peripheral neuropathy (DPN), and whether QTc interval has diagnostic utility for DPN beyond nerve conduction velocity.

MATERIALS AND METHODS

A total of 965 patients with diabetes, including 473 patients with DPN and 492 patients without DPN, underwent standard 12-lead electrocardiography and detailed assessments of peripheral neuropathy.

RESULTS

Patients with DPN had longer QTc intervals than those without. Among participants, from the first to fourth quartile of QTc interval, the proportion of patients with DPN appreciably increased and the nerve conduction velocity obviously decreased (P for trend <0.001). The univariate and multivariate analyses showed that prolonged QTc interval was closely associated with increased risk of DPN (univariable odds ratio 1.112, 95% confidence interval 1.097-1.127, P < 0.001; multivariable odds ratio 1.118, 95% confidence interval 1.099-1.137, P < 0.001). Receiver operating characteristic analysis for the diagnosis of DPN showed a greater area under the curve for QTc interval of 0.894 than the median nerve motor conduction velocity of 0.691, median nerve sensory conduction velocity of 0.664 and peroneal nerve motor conduction velocity of 0.692. The optimal cut-off point of QTc interval for DPN was 428.5 ms with sensitivity of 0.715 and specificity of 0.920 (P < 0.001). The combination of QTc interval and nerve conduction testing increased the area under the curve for the diagnosis of DPN (from 0.736 to 0.916; P < 0.001).

CONCLUSIONS

QTc interval with 428.5 ms has more reliable diagnostic utility for DPN than nerve conduction velocity, and prolonged QTc interval is closely associated with an increased risk of DPN.

The relationship between adenosine deaminase and heart rate-corrected QT interval in type 2 diabetic patients

BACKGROUND

Prolonged heart rate-corrected QT (QTc) interval may reflect poor prognosis of patients with type 2 diabetes (T2D). Serum adenosine deaminase (ADA) levels are related to hyperglycemia, insulin resistance (IR) and inflammation, which may participate in diabetic complications. We investigated the association of serum ADA levels with prolonged QTc interval in a large-scale sample of patients with T2D.

METHODS

In this cross-sectional study, a total of 492 patients with T2D were recruited. Serum ADA levels were determined by venous blood during fasting. QTc interval was estimated from resting 12-lead ECGs, and prolonged QTc interval was defined as QTc > 440 ms.

RESULTS

In this study, the prevalence of prolonged QTc interval was 22.8%. Serum ADA levels were positively associated with QTc interval (r = 0.324, P < 0.0001). The proportion of participants with prolonged QTc interval increased significantly from 9.2% in the first tertile (T1) to 24.7% in the second tertile (T2) and 39.0% in the third tertile (T3) of ADA (P for trend < 0.001). After adjusting for other possible risk factors by multiple linear regression analysis, serum ADA level was still significantly associated with QTc interval (β = 0.217, t = 3.400, P < 0.01). Multivariate logistic regression analysis showed that female (OR 5.084, CI 2.379-10.864, P < 0.001), insulin-sensitizers treatment (OR 4.229, CI 1.290-13.860, P = 0.017) and ADA (OR 1.212, CI 1.094-1.343, P < 0.001) were independent contributors to prolonged QTc interval.

CONCLUSIONS

Serum ADA levels were independently associated with prolonged QTc interval in patients with T2D.

Assessment of Hypertension Using Clinical Electrocardiogram Features: A First-Ever Review

Hypertension affects an estimated 1.4 billion people and is a major cause of morbidity and mortality worldwide. Early diagnosis and intervention can potentially decrease cardiovascular events later in life. However, blood pressure (BP) measurements take time and require training for health care professionals. The measurements are also inconvenient for patients to access, numerous daily variables affect BP values, and only a few BP readings can be collected per session. This leads to an unmet need for an accurate, 24-h continuous, and portable BP measurement system. Electrocardiograms (ECGs) have been considered as an alternative way to measure BP and may meet this need. This review summarizes the literature published from January 1, 2010, to January 1, 2020, on the use of only ECG wave morphology to monitor BP or identify hypertension. From 35 articles analyzed (9 of those with no listed comorbidities and confounders), the P wave, QTc intervals and TpTe intervals may be promising for this purpose. Unfortunately, with the limited number of articles and the variety of participant populations, we are unable to make conclusions about the effectiveness of ECG-only BP monitoring. We provide 13 recommendations for future ECG-only BP monitoring studies and highlight the limited findings in pregnant and pediatric populations. With the advent of convenient and portable ECG signal recording in smart devices and wearables such as watches, understanding how to apply ECG-only findings to identify hypertension early is crucial to improving health outcomes worldwide.

Diabetic microvascular complications associated with myocardial repolarization heterogeneity evaluated by Tp-e interval and Tp-e/QTc ratio

INTRODUCTION

The heterogeneity in myocardial repolarization increases the risk of ventricular arrhythmias and sudden death in patients with diabetes mellitus (DM). The Tp-e interval and Tp-e/QTc ratio are found to be useful in the prediction of ventricular arrhythmias. In this study, we aimed to investigate the Tp-e interval and Tp-e/QTc ratio in diabetic patients with and without microvascular complications.

MATERIALS AND METHODS

This cross-sectional observational study included patients with type 2 DM who presented to the endocrinology outpatient clinic. Diabetic microvascular complications were evaluated. The Tp-e interval, Tp-e/QT ratio, and Tp-e/QTc ratio were also calculated.

RESULTS

A total of 240 patients with type 2 DM (148 patients had microvascular complications) were included in the study. Diabetic neuropathy rate was 30.4%, diabetic nephropathy rate was 38.4%, and diabetic retinopathy rate was 21.7%. Upon comparing patients according to Tp-e/QTc ratio, the median Tp-e/QTc interval of the group of patients with complications was 0.21 (0.19-0.23) and the median Tp-e/QTc ratio of the group of patients without complications was 0.19 (0.18-0.20) (p < 0.001). When patients were grouped according to the presence and severity of retinopathy, the Tp-e/QTc ratio was more prolonged in the proliferative retinopathy group [0.27 (0.23-0.30)] than the non-proliferative retinopathy group [0.20 (0.19-0.22), p < 0.001]. When patients were grouped according to the presence and severity of nephropathy, the Tp-e/QTc ratio was more prolonged in the macroalbuminuria and microalbuminuria group than the normoalbuminuric group [0.25 (0.21-0.30), 0.23 (0.19-0.24), and 0.19 (0.20-0.22), respectively, p = 0.002].

CONCLUSIONS

Our study is the first to demonstrate the association of the Tp-e interval and Tp-e/QTc ratio with the presence and severity of microvascular complications in patients with type 2 DM.

Effect of Vitamin D status on QTc interval in type 2 diabetes mellitus

OBJECTIVES

Diabetes mellitus (DM) is associated with autonomic neuropathy and metabolic abnormalities. These predispose the patients to prolongation of QTc and risk of arrhythmias and sudden cardiac death. Vitamin D may also cause QTc prolongation. We hypothesized that concomitant Vitamin D deficiency and Type 2 DM may act in synergy to prolong QTc interval.

METHODS

Newly diagnosed Type 2 DM patients were recruited from Department of Endocrinology. Lead II ECG was acquired for 5 min during supine rest using a digital data acquisition system. QTc interval extraction was performed using software. 25-hydroxy Vitamin D estimation was done using Chemiluminescence method. Patients were divided into two groups- Vitamin D deficient and insufficient (VDD/I) and optimal (VDO) as per standard criteria. QTc intervals were compared between the two groups.

RESULTS

Sixty-five patients participated in the study. Age was comparable between the groups (p=0.67, Unpaired t-test). There was no significant difference amongst QTc intervals between the groups (p=0.19, Mann Whitney test). Also, there was no significant correlation between Vitamin D levels and QTc intervals assessed using Spearman's correlation coefficient.

CONCLUSIONS

While it seems plausible, coexisting Vitamin D deficiency and Type 2 DM probably do not act in synergy to prolong QTc interval. These findings merit future research on larger cohorts to investigate the relationship between Vitamin D status and newly diagnosed Type 2 DM on QTc intervals.

Severity and multiplicity of microvascular complications are associated with QT interval prolongation in patients with type 2 diabetes

Aims/Introduction

A prolonged QT interval plays a causal role in life‐threatening arrhythmia, and becomes a risk factor for sudden cardiac death. Here, we assessed the association between microvascular complications and the QT interval in patients with type 2 diabetes.

Materials and Methods

Patients with type 2 diabetes (n = 219) admitted to Nippon Medical School Hospital (Tokyo, Japan) for glycemic control were enrolled. QT interval was measured manually in lead II on the electrocardiogram, and corrected for heart rate using Bazett's formula (QTc). Diabetic neuropathy, retinopathy and nephropathy were assessed by neuropathic symptoms or Achilles tendon reflex, ophthalmoscopy and urinary albumin excretion, respectively.

Results

In univariate analyses, female sex (P = 0.025), duration of type 2 diabetes (P = 0.041), body mass index (P = 0.0008), systolic blood pressure (P = 0.0011) and receiving insulin therapy (P < 0.0001) were positively associated with QTc. Patients with each of the three microvascular complications had longer QTc than those without: neuropathy (P = 0.0005), retinopathy (P = 0.0019) and nephropathy (P = 0.0001). As retinopathy or nephropathy progressed, QTc became longer (P < 0.001 and P < 0.001 for trend in retinopathy and nephropathy, respectively). Furthermore, QTc was prolonged with the multiplicity of the microvascular complications (P < 0.001 for trend). Multiple regression analyses showed that neuropathy, nephropathy and the multiplicity of the microvascular complications were independently associated with QTc.

Conclusions

Patients with type 2 diabetes with severe microvascular complications might be at high risk for life‐threatening arrhythmia associated with QT interval prolongation.

The association of long-term glycaemic variability versus sustained chronic hyperglycaemia with heart rate-corrected QT interval in patients with type 2 diabetes

Objectives

Prolonged heart rate-corrected QT(QTc) interval is related to ventricular arrhythmia and cardiovascular mortality, with considerably high prevalence of type 2 diabetes. Additionally, long-term glycaemic variability could be a significant risk factor for diabetic complications in addition to chronic hyperglycaemia. We compared the associations of long-term glycaemic variability versus sustained chronic hyperglycaemia with the QTc interval among type 2 diabetes patients.

Methods

In this cross-sectional study, 2904 type 2 diabetes patients were recruited who had undergone at least four fasting plasma glucose (FPG) and 2-hour postprandial plasma glucose (PPG) measurements (at least once for every 3 months, respectively) during the preceding year. Long-term glycaemic variabilities of FPG and 2-hour PPG were assessed by their standard deviations (SD-FPG and SD-PPG, respectively), and chronic fasting and postprandial hyperglycaemia were assessed by their means (M-FPG and M-PPG, respectively). HbA1c was also determined upon enrolment to assess current overall glycaemic control. QTc interval was estimated from resting 12-lead electrocardiograms, and more than 440 ms was considered abnormally prolonged.

Results

Patients with prolonged QTc interval (≥440 ms) had greater M-FPG, M-PPG, SD-PPG and HbA1c than those with normal QTc interval but comparable SD-FPG. QTc interval was correlated with M-FPG, M-PPG, SD-PPG and HbA1c (r = 0.133, 0.153, 0.245 and 0.207, respectively, p = 0.000) but not with SD-FPG (r = 0.024, p = 0.189). After adjusting for metabolic risk factors via multiple linear regression analysis, SD-PPG, M-PPG and HbA1c (t = 12.16, 2.69 and 10.16, respectively, p = 0.000) were the major independent contributors to the increased QTc interval. The proportion of prolonged QTc interval increased significantly from 10.9% to 14.2% to 26.6% for the first (T1) to second (T2) to third (T3) tertiles of SD-PPG. After adjusting via multiple logistic regression analysis, the odd ratios of prolonged QTc interval of the T2 and T3 versus the T1 of SD-PPG were 1.15 (95% CI, 0.82–1.60) and 2.62 (1.92–3.57), respectively.

Conclusions

Increased long-term variability of PPG is a strong independent risk factor for prolonged QTc interval in type 2 diabetes patients, in addition to long-term postprandial hyperglycaemia and current HbA1c.

Prevalence of QT prolongation and associated LVEF changes in diabetic patients over a four-year retrospective time period

Aim: To evaluate the prevalence and longitudinal changes of prolonged QTc in DM patients admitted to our community hospital, and to determine, if any, its correlation with changes of left ventricular ejection fraction (LVEF). Methods: A retrospective chart review of patients with Type 1 (T1DM) and Type 2 (T2DM) with at least two admissions during a four-year period was performed to identify QTc interval, and LVEF, as measured on transthoracic echocardiogram. Changes in QTc and LVEF between patient hospital admissions were compared. Results: A prolonged QTc interval was found in 66.7% (n = 24) of type 1 and 51.3% (n = 154) type 2 diabetic patients. The QTc interval is progressively increased in both type 1 and type 2 diabetes during follow-up, although it did not reach statistical significance. A total of 62% patients (23 out 37 patients) had a reduction of LVEF during follow-up. Conclusion and Discussion: High prevalence of QTc prolongation was confirmed in hospitalized patients with in both T1DM and T2DM. Significant reduction of LVEF correlated with QTc prolongation over a mean of 17.3 months in T2DM patients, and may have implications for interventions.

Abbreviations CHF: Congestive heart failure LVEF: Left ventricular ejection fraction

QTc interval in young Gujarati hypertensives: Effect of disease, antihypertensive monotherapy, and coexisting risk factors

OBJECTIVES

To study the effect of disease duration, treatment and risk factors on QTc interval among young hypertensives.

MATERIALS AND METHODS

A case-control study was conducted on 142 hypertensives (60 males, 82 females) taking calcium channel blocker (CCB) or angiotensin-converting enzyme inhibitor (ACEI) as monotherapy. After blood pressure measurement, we recorded lead II electrocardiograph with minimum ten waveforms. QTc was derived from average of ten values using Bazett's formula. QTc interval >0.43 s in male and >0.45 s in female was considered abnormal.

RESULTS

Cases had mean duration of hypertension 5 years, mean age of 40 years, and poor blood pressure control (systolic blood pressure >140 and diastolic blood pressure >90 mm of Hg). Newly diagnosed hypertensives had significantly higher QTc values than the matched known cases (0.44 vs. 0.42 s, P < 0.05). Known hypertensives did not differ significantly in QTc values by the duration of disease. CCB users showed small, insignificant disadvantage for abnormally prolonged QTc values than ACEI users. With coexisting diabetes, smoking, and positive family history of hypertension, there was odds risk of 7.69, 2.75, and 2.54, respectively for prolonged QTc.

CONCLUSION

Our study showed prolonged QTc in hypertensives more so in newly diagnosed, unaffected by duration or use of ACEI, or CCB but associated with modifiable risk factors. This underscores high risk of repolarization abnormality-induced future events, suggesting early screening of hypertension, strict blood pressure control, optimum use of QTc measurement, and preventive pharmacotherapy to reduce this aftermath.

The relationship between insulin sensitivity and heart rate-corrected QT interval in patients with type 2 diabetes

BACKGROUND

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.

METHODS

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. The insulin sensitivity index (Matsuda index, ISI_Matsuda) derived from 75-g OGTT and other metabolic risk factors were examined in all patients. The QTc interval was estimated using a resting 12-lead electrocardiogram, and an interval longer than 440 ms was considered abnormally prolonged.

RESULTS

The QTc interval was significantly and negatively correlated with the ISI_Matsuda (r = -0.296, p < 0.001), and 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 ISI_Matsuda (β = -0.23, t = -12.63, p < 0.001). The proportion of patients with prolonged QTc interval significantly increased from 12.1% to 17.9%, 25.6% and 37.9% from the fourth to third, second and first quartile of the ISI_Matsuda, respectively. After adjusting for anthropometric parameters by multiple logistic regression analysis, the corresponding odd ratios (ORs) for prolonged QTc interval of the first, second and third quartiles versus the fourth quartile of ISI_Matsuda were 3.11 (95% CI 2.23-4.34), 2.09 (1.51-2.88) and 1.53 (1.09-2.14), respectively, and p for trend was <0.001.

CONCLUSIONS

Reduced insulin sensitivity is associated with an increase in the QTc interval in patients with type 2 diabetes.

Prevalence and risk factors for prolonged QT interval and QT dispersion in patients with type 2 diabetes

AIMS

Prolonged QT interval is associated with cardiac arrhythmias and sudden death. The present study determined the prevalence of prolonged QT interval and QT dispersion and defined their clinical and metabolic predictors in patients with type 2 diabetes.

METHODS

Cross-sectional study included 501 patients with type 2 diabetes. A standard 12-lead electrocardiogram was recorded. QT corrected for heart rate (QTc) >440 ms and QT dispersion (QTd) >80 ms were considered abnormally prolonged. QTc ≥ 500 ms was considered a high-risk QTc prolongation. Demographic, clinical and laboratory data were collected. Independent risk factors for prolonged QTc and QTd were assessed using logistic regression analysis.

RESULTS

Prevalence of QTc > 440 ms and QTd > 80 ms were 44.1 and 3.6 %, respectively. Prevalence of high-risk QTc (≥500 ms) was 2 % only. Independent risk factors for QTc prolongation >440 ms were mean blood glucose (β = 2.192, p < 0.001), treatment with sulphonylurea (β = 5.198, p = 0.027), female gender (β = 8.844, p < 0.001), and coronary heart disease (β = 8.636, p = 0.001). Independent risk factors for QTc ≥ 500 ms were coronary heart disease (β = 4.134, p < 0.001) and mean blood glucose level (β = 1.735, p < 0.001). The independent risk factor for prolonged QTd was only coronary heart disease (β = 5.354, p < 0.001).

CONCLUSIONS

Although the prevalence of prolonged QTc > 440 ms is significant, the prevalence of high-risk QTc (≥500 ms) and QTd > 80 ms is very low in patients with type 2 diabetes. Hyperglycaemia and coronary heart disease are strong predictors of high-risk QTc.

QT Indexes in Cirrhotic Patients: Relationship with Clinical Variables and Potential Diagnostic Predictive Value

BACKGROUND AND AIMS

A wide spectrum of cardiovascular changes characterizes cirrhosis, ranging from subclinical alterations to hyperkinetic syndrome. We looked for ECG markers of ventricular repolarization in a population of patients with cirrhosis in comparison to patients without cirrhosis and we investigated the relationship between these and other clinical and laboratory variables.

METHODS

In 149 patients with cirrhosis and 152 controls, we measured QT maximum interval (QTmax), QT corrected interval (QTc), QT minimum interval (QTmin), QT dispersion (QTdisp), QT peak and T peak-to-end (TpTe).

RESULTS

In subjects with cirrhosis, in comparison with controls, we observed a higher mean QTmax, mean QTc, mean QTmin, mean QTdisp and mean TpTe. At Cox regression analysis, diastolic blood pressure and beta-blocker treatment were significantly associated with mean QTmax, hypertension with mean QTmin and mean QTc, diastolic blood pressure, beta-blockers and ACE-inhibitors/ARBs with QT disp, and beta-blockers with TpTe. Analysis of ROC curves showed a significant area under curve towards cirrhosis diagnosis, respectively, for a cut-off value of > 400 msec of QTmax, > 360 msec of QTmin, > 450 msec of QTc, > 105 msec of TpTe and > 55 msec of QTdisp.

CONCLUSIONS

Our study shows that QT indexes are altered in cirrhotic patients and have a potential diagnostic predictive value.

Poor glycaemic control and arrhythmias

OBJECTIVE

To evaluate number, type, and complexity of arrhythmias in diabetics compared with controls and, among diabetics, comparing good glycaemic control (GGC) and poor glycaemic control (PGC) patients.

METHODS

We compared Ambulatory Electrocardiogram recordings of 92 diabetics and 100 controls. The glycaemic profile of 50 diabetics, taken the same day as the Ambulatory ECG recording, was subdivided into GGC (gluco-stick mean values between 100 and 140 mg/dL) or PGC (gluco-stick values ≤99 mg/dL in 3-of-4 daily determination or gluco-stick values ≥140 mg/dL in 3-of-4 daily determination).

RESULTS

Diabetics show a higher prevalence of either ventricular ectopic beats (VEBs) (93.47% vs. 82% controls, p < 0.05) and heart rate (both in sinus rhythm and in atrial fibrillation) (98.35 ± 10 beats/min in diabetics vs. 78.10 ± 8.1 in controls, p < 0.001). Moreover, diabetics with PGC show either a higher prevalence of VEBs (96.42% vs 77.27% in GGC, p < 0.05) and of supraventricular ectopic beats (SVEBs) (96.42% vs. 68.18 in GGC, p < 0.05); furthermore, diabetics with PGC show more severe and complex atrial and ventricular arrhythmias (SVEBs 32.14% vs 0%, p < 0.05; VEBs 39.28% vs 9.09%, p < 0.05).

CONCLUSIONS

The analysis of our sample shows that the arrhythmogenic condition is not only provided from diabetic condition per se but it is enhanced in PGC. Infact PGC patients showed higher number of VEBs, often polymorphic, expression of more severe arrhythmic and cardiovascular outcome. This could be partially explained by hyperactivation of autonomic nervous system during metabolic stress (which increases mean heart rate). Moreover more severe diabetic patients may present coronary microangiopathy that can further explain their arrhythmogenic tendency.

Prevalence and risk factors of prolonged QTc interval among Chinese patients with type 2 diabetes

Objectives. The aim of this study was to evaluate the prevalence and the risk factors of prolonged QTc interval among Chinese patients with type 2 diabetes. Methods. The retrospective study included 3156 outpatients from the Diabetes Centre, the 306th Hospital of PLA, during the period from September 2003 to June 2010. QT interval was measured manually in the 12-lead conventional electrocardiogram. The QT interval corrected for heart rate (QTc) was calculated using Bazett's formula. Additional demographic and laboratory data were also collected. Potential risk factors of prolonged QTc interval were assessed using multivariable regression. Results. The prevalence of prolonged QTc interval among Chinese patients with type 2 diabetes was 30.1%. Height (OR 0.156, 95% CI 0.032~0.748), waist circumference (OR 1.025, 95% CI 1.010~1.040), diastolic blood pressure (OR 1.016, 95% CI 1.007~1.026), postprandial glucose (OR 1.040, 95% CI 1.022~1.059), fasting insulin (OR 1.014, 95% CI 1.003~1.025), and presence of microalbuminuria (OR 1.266, 95% CI 1.033~1.551) were significant risk factors. Conclusions. The prevalence of prolonged QTc interval among Chinese patients with type 2 diabetes is high. Risk factors for prolongation of QTc interval were low height, high waist circumference, increasing diastolic blood pressure levels, high postprandial glucose levels, high fasting insulin levels, and presence of microalbuminuria.

Deterioration of cardiac autonomic function over a period of one year in relation to cardiovascular and somatic neuropathy complications in type 2 diabetes mellitus

AIMS

Progression of cardiac autonomic dysfunction (CADF) in relation to severity of diabetic autonomic neuropathy is well documented. But its progression while coexisting with somatic neuropathy (PNP) and cardiovascular disease (CVD) is less described. We monitored CADF over a period of one year in relation to PNP and CVD in patients with type 2 diabetes mellitus.

METHODS

Cardiac autonomic function was assessed in 104 type 2 diabetics. Based on complications study subjects were divided into four subgroups: Group A (No complications); Group B (with CVD); Group C (with PNP); Group D (with CVD and PNP). The parameters measured were: Expiratory:Inspiratory ratio (E:I ratio) and standard deviation of all the N-N intervals (SDNN). These parameters were measured at the baseline and at follow-up. Data analysis was done by employing suitable statistical tests.

RESULTS

In Group B: SDNN declined (p<0.001); E:I ratio did not change. In Group C: E:I ratio declined (p<0.01); SDNN did not change. In Group D: SDNN and E:I ratio declined significantly (p<0.001).

CONCLUSION

CADF coexisting with PNP and CVD deteriorates with time. E:I ratio and SDNN are suitable markers in monitoring CADF coexisting with PNP and CVD respectively in type 2 diabetes mellitus.