Serum Levels of Activin A: Predictor of Insulin Resistance and Atherosclerosis in Prediabetics

Abstract

Pathological effects of dysglycemia and insulin resistance on atherosclerosis and cardiac remodeling starts as early as in the prediabetic state before the onset of overt diabetes. Activin A is a molecule with multiple functions, including an important part in glucose homeostatic mechanisms as well as inflammatory processes and is therefore being researched as a useful novel biomarker for prompt recognition of the risk of cardiovascular disease (CVD) in prediabetic individuals, thereby helping in disease prognostication and early institution of therapeutic measuresObjective: The study aimed to measure serum levels of activin A in prediabetic patients and evaluate them in comparison to normoglycemic controls. The association of activin A with carotid intima media thickness (CIMT), left ventricular diastolic dysfunction (LVDD), and homeostatic assessment of insulin resistance (HOMA-IR) was also studiedMaterials and methods: A total of 60 prediabetic cases and 60 normoglycemic control subjects [matched as per age, gender, and body mass index (BMI)] were recruited. Measurement of serum glucose levels (fasting and postprandial) and fasting insulin levels and glycated hemoglobin (HbA1c) levels were done in all the subjects. The values of HOMA-IR were computed using established formulae. Enzyme-linked immunosorbent assay (ELISA) kits were used for the evaluation of serum levels of activin A in both groups. Parameters for the two groups were compared. In the cases, CIMT (using B-mode ultrasound) and LVDD (using two-dimensional (2D) echocardiography) were measured and correlated with activin A levelsResults: Serum fasting insulin (mIU/L) was considerably higher in cases than in the controls (p < 0.001). HOMA-IR median [interquartile range (IQR)] was 4 (3.25-4.93) in some cases, and that in the control group was 1.2 (0.88-1.5) (p < 0.001). Serum activin A levels in the cases group had a median (IQR) of 263.55 (227.1-279.5) ng/mL, which was substantially greater as compared to the control group 159.9 (150.7-178.7) ng/mL (p < 0.001). A significant positive association of serum activin A levels with HOMA-IR (ρ = 0.75, p < 0.001) and CIMT (ρ = 0.50, p < 0.001) was found. In LVDD grade I and II groups, the serum levels of activin A were 257.86 (219.3-271.2) ng/mL and 269 (244.19-291.5) ng/mL, respectively (p = 0.12)Conclusion: A substantial proportion of morbidity and mortality related to dysglycemic states can be attributed to cardiovascular complications. Elevated levels of activin A in prediabetes can act as an indicator of subclinical CVD leading to early diagnosis and intervention.