Association between impaired cold perception threshold and serum calcium in patients with type 2 diabetes mellitus

Objective To investigate the association between serum calcium levels and cold perception threshold (CPT) in patients with type 2 diabetes mellitus. Methods This retrospective study analyzed 334 type 2 diabetes mellitus patients from a tertiary hospital endocrinology department (March 2020–November 2024). Clinical, laboratory, and quantitative sensory testing (QST) data were collected. The correlations between serum calcium and cold/heat perception thresholds (CPT/HPT) were assessed using correlation analysis, multiple linear regression, and multivariable fractional polynomial (MFP) modeling. Results Among the 334 enrolled patients with type 2 diabetes mellitus (146 DM only; 188 with DPN), the DPN group was older and had longer diabetes duration (both P < 0.001). Patients with DPN demonstrated significantly impaired thermal sensation, with lower CPT and higher HPT than the DM group (both P < 0.001). Serum calcium positively correlated with mean CPT in both the total cohort ( r = 0.170, P = 0.001) and the DPN subgroup ( r = 0.160, P = 0.028), and negatively correlated with mean HPT in the total cohort ( r = −0.115, P = 0.031) and the DPN subgroup ( r = −0.175, P = 0.017), but not in the DM‐only group. A calcium‐CPT dose–response relationship was observed. Conclusion Serum calcium is an independent influencing factor for CPT in patients with type 2 diabetes mellitus, with a dose–response relationship observed. This finding suggested that in type 2 diabetes mellitus patients with low serum calcium levels, there should be heightened awareness of the risks of impaired cold perception and aggravated neuropathy, thereby enabling earlier risk stratification and personalized management.