Diabetes is one of the predisposing agents for dyslipidemia and atherosclerosis, and there are evidences which show atherosclerosis even begins at childhood [9]. Moreover, the risk of coronary artery disease (CAD) is 2–4 times in diabetic individuals more than normal people [16]. Early diagnosis of raising blood cholesterol levels in asymptomatic individuals enables the recognition of an essential modifiable risk factor for CAD and who may get benefit from more serious dietary interventions [12].
Our study represents retrospective data from a single large diabetes care center in which we found a high prevalence of dyslipidemia (70.47%) in children and adolescents with T1DM. This high prevalence has been also reported in many studies [17,18,19,20]. However, this relatively higher than a study done in Bangladesh reporting a prevalence of 64% [10] and a previous Egyptian study that reported a prevalence of 65% that was done on 60 children and adolescents [21]. This high prevalence in our study was much higher than that reported by other studies who found a prevalence ranged from 26.2 to 48.5% [11, 22, 23]. This high prevalence of dyslipidemia among our patients could be attributed to the poor glycemic control as the number and percent of diabetic patients with poor glycemic control was higher than their equivalents of good glycemic control in dyslipidemia patients compared to normo-lipidemic patients but this did not reach statistical significance. Furthermore, the prevalence of dyslipidemias in the general Egyptian population including children and adolescents is high and underdiagnosed (37% of the Egyptian population) [24].
As regards the pattern of dyslipidemia, high LDL and low HDL were the most frequent abnormalities in the study group. This is in line with many previous studies [17, 21, 25, 26]. One study documented that increased TC and LDL were the main abnormalities [15]. However, some studies found that hypertriglyceridemia was the main disorder [10, 23, 27]. The wide range of prevalence and patterns of dyslipidemia in different studies may be due to multiple genetic factors in different ethnicities.
There were no significant differences in the prevalence of dyslipidemia between males and females. This is in concordance with a study conducted in Iran in 2017 [12]. On the other hand, Homma et al. [17] reported that females had significantly higher dyslipidemia prevalence.
There were no statistically significant differences between patients with and without dyslipidemia regarding age, sex, diabetes duration, age of diabetes onset, HbA1c, and glycemic control. This agreed with Zabeen et al. [10], and Rahbar and Hajian [12]. Nevertheless, another study reported that age, BMI, HbA1c, and poor metabolic control were significantly higher in cases with dyslipidemia [11].
Patients with poor glycemic control represent (HbA1c > 7.5%) 73.45% and they had significantly older, with longer diabetes duration, and higher TC, TG, and LDL compared to patients with good glycemic control. In addition, a significant association between HbA1c and the serum lipids was found in this study. This is in concordance with the results reported by other studies [10, 20, 28]. Serum lipids were higher in patients with poor metabolic control, but there was not significant relation between HbA1c, and diabetes duration as reported by one study [23]. However, other authors found no correlation between poor GC and HDL, LDL, TC, or the TG which is different from our results [17]. These results provide evidence that poor glycemic control can be considered a potential modifiable risk factor for dyslipidemia in this patient group.
There were significant positive correlations between HbA1c, TG, TC, and LDL with the age and diabetes duration. Verma et al. [29] found a significant relation between diabetes duration and HbA1c, which had conformity with this study. Another study reported a significant relationship between HbA1c and TG levels but its relationship with disease duration was not significant [12].
The strengths of this study include the large sample size. However, possible confounding variables that may account for the association between poor glycemic control and dyslipidemia were not considered. Patients with poor glycemic control and poor treatment compliance may be the ones who also do not undertake preventive measures as exercise, healthy diet, and strict follow-up. Data of pubertal assessment were not included in the study as this retrospective study depended mainly on data obtained from patients’ records which showed deficiency in this aspect and this limited the power to examine the well-known association between the different pubertal stages and dyslipidemia.