TyG index may predict cardiac autonomic neuropathy in type 2 diabetes patients

The researchers found hyperglycemia, abdominal obesity, and hypertriglyceridemia are the risk factors for CAN development in T2DM patients.

Cardiac autonomic neuropathy is a major complication seen in type 2 diabetes patients. Risk factors for the development of CAN with T2DM are hypertriglyceridemia and hyperglycaemia. TyG index is calculated using both fasting triglyceride levels (FTG) and fasting blood glucose (FBG). There is a lack of data on the direct relationship between the TyG index and CAN in type 2 diabetes patients of the South Indian population.

To fill this knowledge gap, Angeline Jeyaseeli, Sri Venkateswaraa Medical College Hospital and Research Centre, Puducherry, India, and colleagues aimed to assess the TyG index levels in T2DM with and without CAN.

For this purpose, the researchers performed a cross-sectional study involving ten type 2 diabetes patients (58 males and 42 females) ages 30 to 60 years, who attended medicine OPD Sri Venkateswaraa Medical College, Hospital and Research Centre (SVMCH & RC) during the study period.

Measurement of diastolic blood pressure (DBP), systolic blood pressure (SBP), body mass index (BMI), hip circumference (HC), waist circumference (WC), weight, height, duration of illness, and age was done. From the patients' recent medical records, HbA1C (glycated haemoglobin) and lipid profile values were taken.

Ewing autonomic function tests were used for CAN diagnosis, which included heart rate response to deep breathing, heart rate response to standing, blood pressure response to standing and blood pressure response to isometric handgrip, and heart rate response to Valsalva manoeuvre. Fasting triglyceride levels and fasting blood glucose were measured and the TyG index was calculated from these parameters.

The study led to the following findings:

• Out of 100 T2DM patients, 42 patients were diagnosed with CAN.
• The mean levels of TyG Index, HbA1C, FBG, FTG, BMI and WC were significantly higher in T2DM patients with CAN when compared to T2DM without CAN.
• No significant difference was found in age, duration of illness, blood pressure and lipid profile parameters between the groups.

"We found that abdominal obesity measured by BMI and WC, hyperglycemia measured by FBG and HbA1C, and hypertriglyceridemia measured by FTG are the risk factors for developing cardiac autonomic neuropathy in patients with type 2 diabetes," the researchers wrote. "Our study results also showed that the TyG index can be used for CAN prediction in T2DM patients."

The limitations of the study included its cross-sectional nature implying that a direct causal relationship could not be established based on the results. Also, patients were recruited from a particular location over a time period and not from the general population of T2DM.

"Therefore, there is a need for prospective cohort studies to assess the TyG index as a marker for predicting CAN in patients with T2DM," Dr. Jeyaseeli and the team concluded.

Reference:

Jeyaseeli A, R G, Mathivanan D, et al. (July 27, 2023) Assessment of Triglyceride Glucose Index in Type 2 Diabetes Mellitus Patients With and Without Cardiac Autonomic Neuropathy. Cureus 15(7): e42541. doi:10.7759/cureus.42541