<b>Electrocardiographic Profile of a Group of Adolescents and Young Adults with Type 1 Diabetes at the Yaoundé Central Hospital</b>

Abstract

Objectives This study aimed to evaluate the electrocardiographic (ECG) profile of young Cameroonian subjects living with T1D. Methodology A descriptive and analytical cross-sectional study was conducted from December 2016 to May 2017. The study population included 89 patients with type 1 diabetes (T1D), recruited from the diabetes care unit of the Yaoundé Central Hospital and 89 gender-matched control subjects, and recruited from schools in the city of Yaoundé. Each participant underwent a full clinical evaluation (history, weight, height, and blood pressure) and a resting electrocardiogram. The outcome variables analysed were the existence of arrhythmias, conduction defects, ventricular hypertrophy, atrial enlargement, ischemic changes, and repolarisation defects. Data were analysed using Epi Info version 7 software. Continuous data are presented as mean ± standard deviation. ANOVA and Chi-squared tests were used to compare means and proportions, respectively. Electrical abnormalities were compared by calculating the Odds Ratio (OR). A p-value of <0.05 was considered statistically significant. Results Their mean age was 18.3 ±4.2 years for the cases (T1D), and 14.7 ± 2.2 years for the controls (p<0.001). Sex, weight, and systolic blood pressure (BP) were similar in both groups. In the DT group, the mean duration of diabetes was 4.7±3.5 years, the mean HbA1c was 8.7 ± 2.1%, and the mean daily insulin was 46.5 ± 17 UI. The Cases had significantly higher mean diastolic BP than controls (72.7±8.5 versus 64.1±7.4, p<0.001). The cases had significantly lower mean heart rate (74±11.9beats/min versus 80±13.6, p=0.002), longer P wave duration (104±10ms versus 84±10, p<0.00), longer QRS duration (86±10ms versus 71±20, p<0.001), shorter PR interval (149±20ms versus 156± 156±20, p=0.004). No pre-excitation, nor conduction defect was seen in the cases. The mean peripheral voltage criteria for ventricular hypertrophy (Cornell and Lewis indices) were similar between groups. The mean precordial (Sokolow index) criteria was significantly lower in the cases (22.1±5.6mm versus 24.7±7.2, p=0.009). Sinus arrhythmia (OR: 2.3, p=0.01), early repolarisation pattern (OR 16.4, p=0.001), left atrial enlargement (OR: 9.9, p=0.018), and Q waves in two concordant leads (OR: 4.3, p<0.001) were significantly more frequent in the cases. Moritz sign (predominantly negative biphasic P wave in V1) was significantly more frequent in controls (p=0.03). One case of Wolf-Parkinson-White pattern, one case of wandering pacemaker, were seen in the controls. The ECG changes in the cases were not associated with the dose of insulin, duration of diabetes, or HbA1c. Conclusion After approximately five years of T1D evolution, the ECG profile in adolescents and young adults shows significant changes compared to non-diabetics. These alterations notably include frequent sinus arrhythmia, left atrial enlargement, concordant Q waves, an early repolarisation pattern, and lower precordial voltage criteria (Sokolow index). They also had a significantly longer QRS and QTc duration, and a lower heart rate.