Bone-specific alkaline phosphatase and metabolic dyslipidaemia in type 2 diabetes mellitus

Background and objectives Previous studies have attempted to associate elevated liver enzymes with the onset of diabetes. However, clinically relevant data on total and bone-specific alkaline phosphatase (ALP and B-ALP) in Indians who have a higher predisposition to metabolic syndrome (MetS) and cardiovascular disease remain limited. Since type 2 diabetes mellitus (T2DM) and MetS share common risk factors, including dyslipidaemia, this study aimed to evaluate total ALP and B-ALP levels and examine their association with metabolic dyslipidaemia in T2DM. Methods A case-control study was conducted with 80 participants (40 T2DM cases and 40 healthy controls). Fasting samples were analysed for plasma glucose, serum lipid profile, HbA1c, insulin, and B-ALP. B-ALP was quantified using a commercial ELISA kit (Fine Test, China). Group differences were evaluated using Mann-Whitney U-test, and associations were examined using Spearman’s rank correlation. Results Serum total ALP and B-ALP levels were significantly higher in patients with T2DM than in controls [ALP: 95 (80.5–116) U/L vs. 84.5 (68 -104.5) U/L, P =0.03; B-ALP: 22.32 (12.54–32.81) ng/mL vs. 13.55 (6.66–26.12) ng/mL, P =0.03]. In T2DM patients, B-ALP showed a significant negative correlation with total cholesterol (TC) (rho=-0.3788, P =0.02) and low-density lipoprotein cholesterol (LDL-C) (rho=-0.3881, P =0.01). Subgroup analysis indicated a positive association between B-ALP and anthropometric indices in patients with T2DM without MetS. Interpretation and conclusions Total ALP and B-ALP were elevated in T2DM, and B-ALP showed inverse associations with total cholesterol and low-density lipoprotein cholesterol (LDL-C) in this cohort from western Rajasthan.