Serum Prolactin, Glycemic Control, and Insuline Resistance in Type 2 Diabetes in Iraq: A Sex-Stratified Cross-Sectional Comparative Studay

Abstract

Type 2 diabetes mellitus (T2DM) represents an increasing health burden in Iraq. Prolactin (PRL) is involved in the regulation of glucose metabolism since high PRL serum levels are associated with low incidence of T2DM. This study evaluated the relationship between serum prolactin levels and key indicators of glycemic control and insulin resistance in T2DM patients, with a dedicated sex disaggregated analysis. A comparative cross-sectional study was conducted in Salahaddin Governorate, Iraq. The study included 60 participants: 30 patients with T2DM and 30 healthy individuals of the same age group (15 males and 15 females) aged between 20 and 60 years. All participants underwent baseline assessment (age and Body mass index (BMI)) and five vital signs (Fasting blood glucose (FBG), fasting insulin, glycated hemoglobin, insulin resistance index, and prolactin). All statistical analyses were performed using IBM SPSS Statistics software for Windows. The level of statistical significance was set at p < 0.05. Body mass index did not differ between the groups (P > 0.05). However, the patients were significantly older than the control group overall (p = 0.002 and p = 0.006, respectively). The patient group recorded higher fasting blood glucose and glycated hemoglobin (HbA1c) values compared to the control group in the overall sample (P < 0.05). At the correlation level, prolactin was associated with fasting blood glucose (r = 0.31, P = 0.013) and HbA1c (r = 0.35, P = 0.005) in the overall sample; while a non-statistically significant correlation was observed with the insulin resistance index (r = 0.24, P = 0.059), and no statistically significant correlation was found with fasting insulin. None of the sex-specific subgroup correlations were statistically significant. Prolactin shows a statistically significant positive association with palm-expressed FBG and HbA1c at the aggregate level when controlling for age difference between groups. Importantly, however, this association did not reach significance in the sex stratified subanalyses. Although this observation is a preliminary one, it should be confirmed in larger, broader powered studies specifically designed to explore sex dependent metabolic effects.