(p(Homa-IR<2.5 vs. Homa-IR≥2.5)=0,035,
p(Homa-IR<2.5 vs. control)=0,238, p(Homa-IR≥2.5 vs.
control)=0,002).
Although the diastolic early filling time (E wave duration) was lower in
the patient group than the control group, this difference was not
statistically significant (p=0.052) . However, the E wave duration
with insulin resistance was statistically more down in the group than
the control group (68.60±19.24 (Homa-IR≥2.5), 83.50±16.35
(Control)); p=0.020) . It was revealed that the main reason for the
significant differences in E/A and E/e’ ratios was the difference in E
wave duration, also with the considerable effect of insulin resistance.
Studies conducted with insulin resistance have shown that insulin
resistance may lead to subclinical myocardial and vascular
irregularities, such as decreased global longitudinal strain values
and arterial stiffness in individuals without significant coronary
artery disease. Insulin resistance, directly and indirectly, causes
adverse effects in the vascular area. Endothelial dysfunction and
disruption of the vasomotor response to the pro-inflammatory,
pro-coagulant endothelium can be listed among these effects (33). In
another study, insulin resistance has been shown to increase the
likelihood of ischemia-related cardiac dysfunction (34). It can be
thought that the stated effects of insulin resistance may be among the
reasons for the differences in diastolic parameters we found in our
study.
Prediabetic patients without previous coronary artery disease have been
shown to have higher mpi scores than healthy populations, which has been
associated with possible subclinical systolic and diastolic dysfunction
(35). In our study, the septal mpi score (Tei index) was found to be
significantly higher in patients with hypoglycemia, and no significant
difference was found in the lateral mpi score (p=0.045 and
p=0.474; respectively)
Similar effects of recurrent hypoglycemia have been demonstrated in
animal experiments with mice, as demonstrated as increased carotid
intima-media thickness due to hyperglycemia in persons with metabolic
syndrome (19,36). Interestingly, an increase in the circulating
catecholamine levels causes a decrease in the peripheral arterial
resistance through β-2 receptor-mediated vasodilation. In the acute
phase of hypoglycemia in healthy people, vascular elasticity increases.
Additionally, increased catecholamine levels cause a decrease in
peripheral arterial resistance with beta-2 receptor-associated
vasodilation. However, hypoglycemia episodes (especially in diabetic
patients) have been reported in previous studies to cause arterial
stiffness. It has been shown that hematological and hemodynamic changes
during hypoglycemia may play a role in this situation (12,14,37).
In our study, the patient group observed that the carotid intima-media
thickness was more remarkable, and the brachial flow-mediated dilatation
value was smaller, which is an indicator of endothelial dysfunction. It
was revealed that findings related to carotid intima-media thickness was
marked by insulin resistance (p(Homa-IR<2.5 vs.
control)=0.027, p(Homa-IR≥2.5 vs. control)<0.001) . Still, in
terms of brachial flow-mediated dilatation, when the groups with and
without insulin resistance were compared with the control group, the
significance levels were found to be similar(p(Homa-IR<2.5 vs. control)=0.027, p(Homa-IR≥2.5 vs.
control)=0.028) . We can state that these findings are compatible with
the pathophysiological process in related studies (12,14,21,34,37).
Considering the study population’s age group, the findings determined
predominantly in terms of diastolic functions (also with endothelial
functions) may be predictive for other cardiac pathologies. It was also
revealed that the increase in insulin resistance might affect the
distinction in diastolic function, septal isovolumetric relaxation time,
and carotid intima-media thickness parameters found among the study
groups.
We can state that our study will contribute to the literature in the
light of echocardiographic findings and peripheral examinations after
further evaluations of patients admitted to the emergency department
with hypoglycemia. These findings may guide possible future studies that
will be conducted with many patients’ participation and in which cardiac
involvement can be demonstrated in more detail (such as strain
echocardiography, 3D echocardiography).