Emerging evidence highlights cardiovascular autonomic neuropathy is an independent predictor of rapid kidney function decline in type 2 diabetes mellitus (T2DM). Altered heart rate variability (HRV) was associated with microvascular complications, including diabetic nephropathy. The aim of this study was to determine whether HRV components independently predict estimated glomerular filtration rate (eGFR), in addition to conventional clinical and laboratory factors, in patients with T2DM.

A cross-sectional study was conducted with 58 patients diagnosed with T2DM. Clinical features, along with hematological and urine test results, were obtained. Statistical analyses compared the prevalence and levels of HRV indices between T2DM patients with CKD and those without CKD. A short-term (5-minute) HRV analysis by chest strap ECG was used to measure variables of time-domain (SDNN: Standard deviation of all NN intervals (ms) and RMSSD: Root mean square of successive NN differences (ms)) and frequency-domain (HFpow: High-frequency power (ms²) and LFpow: Low-frequency power (ms²). Stepwise linear regression adjusted for sex, age and BMI was used to estimate the relationship between independent variables and eGFR.

There were 66 patients (59.1% male) with mean age 63.03 ± 9.31 years. Age-, sex-and BMI-adjusted linear regression using backwards data entry showed a significant model explained 78.2% of the variance of eGFR (F(8,26) = 16.285, p < 0.001, adjusted R2 = 0.782). The results showed that SDNN (β = 1.198, t = 3.141, p = 0.004), triglyceride (β = 0.016, t = 2.284, p = 0.031), albumin (β = –13.892, t = –2.133, p = 0.043) and HbA1c (β = –4.193, t = –2.205, p = 0.037), homocysteine (β = –2.340, t = –5.250, p < 0.001) and LFpow (β = –0.011, t = –3.313, p = 0.003) were predictors of eGFR.

HRV components independently predict eGFR, in addition to conventional clinical and laboratory factors, in patients with type 2 diabetes mellitus. These findings highlight the potential value of HRV assessment for detection of cardiac autonomic neuropathy in T2DM, particularly among those at risk for or with established CKD.