Association of salivary alpha 2‐macroglobulin levels and clinical characteristics in type 2 diabetes

Abstract

Aims/IntroductionStudies suggest that salivary proteins can be used as potential non‐invasive markers for clinical diagnosis and screening for diabetes. Previous reports showed that plasma alpha 2‐macroglobulin (A2MG) levels were higher in diabetic patients, especially with diabetic complications. We investigated the relationship between salivary A2MG values and clinical characteristics in patients with type 2 diabetes.Materials and MethodsA total of 91 adults were recruited from our outpatient clinics. The study the patients' collected general and biochemical data, and blood glucose (fasting glucose, glycated hemoglobin [HbA1c]) data. Plasma and salivary A2MG levels were examined by enzyme‐linked immunosorbent assay.ResultsThe salivary A2MG levels were significantly positively correlated with plasma A2MG levels, fasting glucose HbA1c and periodontitis status. After 3 months of follow up, the net change of salivary A2MG values positively correlated with the net change of fasting glucose, HbA1c and triglyceride levels, but negatively correlated with high‐density lipoprotein cholesterol changes. Furthermore, the correlations between salivary A2MG and fasting glucose HbA1c were better than plasma A2MG, respectively.ConclusionsOur data show that salivary A2MG levels have better correlation with fasting glucose HbA1c and periodontitis status than plasma A2MG in diabetic patients. Salivary A2MG concentration might serve as a non‐invasive marker for clinical diabetic control.

Relationship between Salivary Alpha-2 Macroglobulin and HbA1c among Patients with Type-2 Diabetes Mellitus: A Cross-sectional Study

“…These results indicate that A2MG can be used as a diagnostic method for diabetes with high specificity. Our results are in line with other studies, which detected higher concentrations of A2MG in blood and saliva of prediabetic state subjects compared to healthy controls;[11121314] however, we have taken only DM2 patients, who already on treatment.…”

“…In nephropathy, the biomarkers as serum creatinine are known to be raised, correlating with severity of kidney damage. Studies have indicated that A2MG is elevated in the blood of patients with type 1 and DM2, particularly in those with other complications due to diabetes, such as chronic renal failure or nephrotic syndrome,[1112] though in our study we have excluded stages IV–V patients of CKD. Serum creatinine, fasting plasma glucose, and postprandial plasma glucose are biomarkers of diabetes mellitus.…”

Molecular form and concentration of serum α2-macroglobulin in diabetes

“…We also found significantly high serum levels of α 2 -macroglobulin in DM patients compared with healthy volunteers. Several studies have reported a positive correlation between the HbA 1c level and α 2 -macroglobulin level in serum 20–22 , but we did not. To negate the possibility that blood glucose levels in DM affect serum concentrations of α 2 -macroglobulin, we obtained the exact glycemic profiles of 57 individuals through 48-h CGM.…”

“…Inter-assay and intra-assay CVs were small, and the results were stably reproducible. α 2 -macroglobulin levels in human serum have ranged by six orders of magnitude, and reported to be 0.5–2.5 µg/dL when measured using commercial ELISA kits 22,23,25 . Albumin and Ig molecules make up the greatest proportion of plasma proteins, but α 2 -macroglobulin is regarded to be one of top-12 abundant proteins.…”

“…Increased levels in DM patients were later ascribed mostly to associated conditions, such as microvascular complications 17 , or worsened glycemic control 18–21 . However, those classical studies employed several assay methods using limited numbers of samples, whereas recent studies using commercial enzyme-linked immunosorbent assay (ELISA) kits have reported serum levels of α 2 -macroglobulin to be low 8,11,12,22–25 . The concentrations reported thus far have been very inconsistent, ranging widely over six orders of magnitude 15–23,25–27 .…”