Assessment of vascular reactivity in young diabetics by cold pressor test and heart rate variability

Abstract

Background: Diabetes mellitus (DM) is one of the common causes for autonomic dysfunction. Increased duration of the disease further increases the risk of neuropathy. The cold pressor test (CPT) and heart rate variability (HRV) are two noninvasive tests which are used to study the vascular reactivity. Aim: This study aimed to assess the vascular reactivity in young diabetics with the help of CPT and HRV. Materials and Methods: This study included sixty young adolescents aged 16.71 ± 2.85 years. Thirty adolescents who were diagnosed with type 1 DM (T1DM) were recruited from the outpatient department of endocrinology, and their results were compared with age- and sex-matched thirty controls. Vascular reactivity was assessed with the help of CPT and HRV. Results: The change in systolic (23 ± 10.77 mmHg; P < 0.0001) and diastolic blood pressure (24.87 ± 8.63 mmHg; P < 0.0001) at the end of 1 min of CPT was significantly higher in the diabetic group than controls. Fasting blood glucose was significantly higher in the diabetic group (P < 0.0001) as compared to controls. It was also observed that sympathetic activity was significantly higher in the diabetic group (P = 0.003) whereas parasympathetic activity was significantly reduced in the diabetic group (P = 0.03). Conclusion: Adolescents with T1DM have increased vascular reactivity characterized by increased sympathetic and decreased parasympathetic activity. Thus, it may be concluded that young people with T1DM should be screened for increased vascular reactivity which may serve as a predictor of future hypertension in them.

Keywords

• Adolescents
• cold pressor test
• heart rate variability
• hyperreactors
• type 1 diabetes mellitus