CTRP9 a potential biomarker for cardiac autonomic neuropathy in T2DM

Levels of the C1q tumour necrosis factor-related protein 9 (CTRP9) adipokine correlate significantly and independently with cardiac autonomic neuropathy (CAN) in diabetics, a new study has shown.

A total of 262 patients (mean age, 55 years; 179 men) with type 2 diabetes mellitus (T2DM) participated in the study and underwent standard cardiovascular autonomic reflex tests (CARTs). Patients were divided into three according to the results: non-CAN, early CAN, and definite CAN. Enzyme-linked immunosorbent assays were used to measure serum CTRP9.

Early and definite CAN patients tended to be older and had higher levels of fasting plasma glucose (FPG) and glycated haemoglobin (HbA1c) than controls. Systolic and diastolic blood pressure values were elevated in those with early CAN, but reduced in the definite CAN subgroup, both relative to non-CAN controls.

Serum CTRP9 also differed significantly across the patient groups and showed significantly lower levels in early and definite CAN participants vs controls (p<0.05).

The researchers then categorized the patients into tertiles of CTRP9 levels. CARTs scores were significantly elevated in the first and second tertiles and were lowest in patients with the highest CTRP9 concentrations (5.0 vs 3.0 vs 1.0; p<0.001).

Multinomial logistic regression confirmed that CTRP9 was a significant, independent, and inverse predictor of definite CAN (prevalence ratio [PR], 0.730, 95 percent confidence interval [CI], 0.714–0.949; p=0.047). The model was adjusted completely for covariates, including sex and age, blood pressure, diabetes duration, FPG and HbA1c, liver function, and blood lipid profile.

No such interaction with early CAN was reported after all adjustments (PR, 0.966, 95 percent CI, 0.935–0.996; p=0.781).