The relationship between serum levels of CA242, sialic acid and Lewis blood-group substance in type 2 diabetes mellitus patients

Abstract

Objective To investigate the relationship between levels CA242 , sialic acid and Lewis blood-group substance in type 2 diabetes mellitus (T2DM) patients. Methods Lewis blood group, serum CA242, siaiic acid (SA) and HbAlc levels were separately detected by agglutination test, ABC-ELISA assay, enzymatic method and immunoturbidimetric assay and the correlations between them were analyzed in 2000 T2DM patients and 500 healthy controls. Results The mean level and positive ratio of serum CA242 in T2DM patients were (20 470 ± 14 860) U/L and 6. 0% (121/2 000) , which were obviously higher than those of controls[(10 950 ±8 490) U/L,0.4% (2/500)]. There were significantly statistical differences (t′ = 18. 87,P<0.01,χ~2 =26. 1,P <0.01). The SA level of T2DM patients was(51.5 ± 18.6) μg/L, which was obviously lower than that of controls[ (56.3 ±13. 8) μxg/L] (t′ = 6. 45, P <0. 01). The CA242 levels were negatively correlated with SA ( r = - 0. 693 , P < 0. 01) but positively correlated with HbAl c ( r = 0. 547, P < 0. 01) in CA242-positive T2DM patients.The Lewis blood group in 98. 3% (119/121) CA242 positive T2DM patients belong to type-I chain substrate. After treatment, the CA242 levels were decreased in CA242-positive T2DM patients whereas SA levels were increased obviously. The CA242 and SA levels of pre- and post-therapy were 30 570 (27 040-42 630), (22 350 ± 13 400) U/L and (44. 5 ± 13. 5), (55. 5 ± 17. 2) μg/L, respectively. There were significantly statistical differences ( U = 5. 32, P < 0. 01, t′ =5.53,P<0.01). Conclusions The elevation of serum CA242 levels in T2DM patients is probably due to reaction between type-1 chain substrate and SA by non-enzymatic mode. It is not the consequence ofmalignancy. In T2DM patients, CA242 level can be effectively controlled by regulating blood sugar levels. Key words: Diabetes mellitus; type 2; Antigens; tumor-associated; carbohydrate; Sialic acids; Lewis blood-group system; Hemoglobin A; glycosylated