Heart Rate Variability: Short‐Term Studies are as Useful as Holter to Differentiate Diabetic Patients from Healthy Subjects

Background: The definitive incorporation of heart rate variability (HRV) as a clinical tool depends on the development of more confident techniques of measurement. The length of the studies is a critical issue. Whereas Holter studies allow the monitorization at different hours and activities, short‐term recordings allow the control of environmental conditions. Recording length is also strongly related to the procedure of analysis; for instance, some time‐domain indexes are strongly affected by the duration of the study. Meanwhile, spectral analyses require stationary conditions, only achieved in short‐term studies. Our main goal was to determine if HRV indexes obtained from short‐term analyses were as useful as those from Holter monitoring for diagnosis of reduced HRV in diabetes. Methods: We studied two groups: one with impaired HRV (15 diabetic patients) and another with normal HRV (15 healthy subjects). HRV indexes obtained from 24‐hour Holter recordings (SDNN, rMSSD, and the power of LF and HF bands), were correlated with analog indexes obtained from 10‐minute digital acquired studies within each group. Besides, we compared the diabetic and control groups using the indexes obtained with both methodologies. Results: The correlation was high (0.70≤ r ≤ 0.85, P ≤ 0.0032 ) in the diabetic group, but was poor in the control group. HRV values were significantly lower in the diabetic group either for 24‐hour or short‐term studies (P ≤ 0.0113) . Conclusion: We conclude that short‐term studies are at least as powerful as Holter to differentiate the diabetic group (impaired HRV) from the control group.