This research involved 1040 pregnant women of age group 18–40. This finding indicate that insulin resistance is more prevalent in pregnant women of age group 31–40. Furthermore, maximum GDM mothers were found majorly in this age group. Analyzing the lipid profile of these same cases, it is observed that lipid parameters like TC, TG, VLDL are significantly raised in the GDM mothers and also insulin resistance is also significantly raised .
The connections between OGTT and insulin resistance have been examined in previous studies as suggested by (Ranganath Muniyappa et al. 2021).[13] This study involves assessing insulin sensitivity in humans and it showed that indices derived from OGTT are accurate in predicting insulin resistance. The correlation analysis revealed a significant medium positive relationship between OGTT and IR (r = 0.4659, p = 0.0024). This suggests that as OGTT level increases IR also tend to increase.
The correlation between TC and OGTT indicates that there is a non significant very small positive relationship between these two parameters (r = 0.0189, p = 0.9077) aligning with the previous studies (F A Rahnemaei et al. 2021)[14], (Zhang et al. 2022) [15]. It indicates that higher TC levels are linked to higher OGTT levels. The decreased concentration of TC, during OGTT, was related to an increased risk of postpartum abnormal glucose regulation in GDM women.
The concentration of LDL is increased in pregnancy along with TC and TG due to the elevation in maternal estrogen level. LDL cholesterol constitutes a significant portion of total cholesterol and high levels of TC often reflect elevated LDL levels. This strong correlation underlies the use of both TC and LDL as key markers in cardiovascular risk assessment and guides clinical decisions in lipid management. [16] Results of the correlation indicated that there is a significant large positive relationship between TC and LDL (r = 0.8699, p < 0.001) (Mikael Huhtala et al. 2023).[17] Impaired glucose tolerance, identified by OGTT, often leads to higher LDL cholesterol levels due to insulin resistance. This condition increases cardiovascular risk. Early detection through OGTT can guide interventions to improve insulin sensitivity and lower LDL cholesterol. [18] Results of the correlation indicated that there is a non significant very small negative relationship between OGTT and LDL. (r = -0.0037, p = 0.9814), indicating that as OGTT levels increases there might be a decrease in LDL level. Conversely the studies of F A Rahnemaei et al. 2021 [14] shows contradicting results.
The TG/HDL has been advocated as a simple clinical indicator of insulin resistance as studies done by Jui Kun Chiang et al 2011. [19] Insulin resistance is linked to higher total cholesterol, LDL cholesterol, and triglycerides, along with lower HDL cholesterol. Results of the correlation indicated that there is a non significant small positive relationship between TC and IR, (r = 0.2562, p = 0.1106) with increase in level of TC, the level of IR tend to increase slightly. Similar results are unveiled in the studies of F A Rahnemaei et al. 2021.[14] Moreover it has been found that as maternal age increases the risk of GDM also increases as also found by Yu-Jin Koo et al 2012 .[20] With insulin resistance, the body's cells don't respond normally to insulin. Glucose can't enter the cells as easily, so it builds up in the blood. This can eventually lead to Type II diabetes mellitus. Though, increased insulin resistance is seen during the course of a healthy pregnancy.[21] During the early stages of normal pregnancies, the pancreatic β-cells secrete more insulin, which slows the rise in plasma glucose levels. This regulation explains the abnormally modest increases in plasma glucose levels brought on by elevated insulin resistance. IR is a state in which normal concentrations of insulin cannot elicit a response of target cells, and the negative feedback urges the body to secrete excess insulin. When insulin secretion fails to compensate for IR, Gestational Diabetes Mellitus emerges. Physiological IR during pregnancy is beneficial to fetal growth and can effectively supply nutrients but the degree of IR if significantly higher than that of normal pregnancy, which will cause many adverse effects on mother and fetus, such as preterm delivery, cesarean, macrosomia.[22] Individuals with GDM are more likely to acquire chronic insulin resistance because of the superimposition of lower insulin production by the cells in that condition (GDM) (Irfat Ara et al. 2022). [23]