Heart rate variability in patients with diabetes mellitus type 2 depending from level glycemic control
AbstractObjective – to evaluate the features of HRV (as a predictor of sudden increase in cardiovascular mortality from arrhythmia) due to hypoglycemia mild to moderate severity.
Methods. It was conducted joint monitoring of blood glucose (CGMS) and Holter monitoring, 60 patients diagnosed with type 2 diabetes: mean age 63±7, disease duration from 1 up to 15 years.
Results. In patients with type 2 diabetes showed a reduction in heart rate variability (LF 321,8±346,7 vs 602,3 ± 528,2 ms2 (p=0,05), HF 108±105,1 vs 370±450, p=0,01). On the background of hyperglycemia observed significant decrease significantly low-frequency component of HRV (250,2±154,2 vs 426,2 ± 154,2 ms2, p=0,03). On the background of hypoglycemia, a decrease of high-frequency component of HRV in patients with a history of hypoglycemia 120,7±71,9 ms2 on the background of hypoglycemia vs 254,48±170,4 ms2 on background normoglycemia, p=0,09. In patients without hypoglycemia more pronounced decrease HRV HF 89±94 vs 329±263 ms2, p=0,03). Patients with diabetes were identified 2 type lowering blood pressure circadian index SI GARDEN 3,43±0,7 vs 15,5±0,8 in healthy SI DBP 4,3±0,9 vs 13,14±1,3 healthy. Blood pressure variability is significantly increased in patients with diabetes GARDEN ST (day) 17,1±0,5 vs 8,2 ±0,5 (p<0,05), ST DBP (day) 13,4±1,3 vs 9,3±0,4 (p<0,05), ST SAD (night) 15,0±0,5 versus 7,2±0,8 (p=0,05), ST DBP (night) 13,1±0,4 vs 8,6±0,7 (p<0,01). 79,5% of the studied patients had distorted the circadian rhythm of blood pressure.
Conclusions. For patients with diabetes mellitus type 2 in combination with coronary artery disease and hypertension characterized by reduced heart rate variability and disturbance circadian blood pressure profile, all of which increase the risk of acute cardiovascular events. Hyperglycemia further increases these risks, as indicated by the decrease in HRV. In patients with diabetes mellitus type 2 with no prior history of hypoglycemia, recorded a sharp decline in heart rate variability in response to the supposed onset symptomatic hypoglycemia, which is dangerous for the development of life-threatening arrhythmias, but preventable medication. In patients with diabetes mellitus type 2 and frequent hypoglycemia in history have not been reported changes in heart rate variability in response to the supposed onset hypoglycemia, due to lower sympathoadrenal response, which is extremely dangerous against the forecast due to the asymptomatic and high risk of severe hypoglycemia.
Keywords:diabetes mellitus, hyperglycemia, hypoglycemia, cardiac rhythm variability, blood pressure variability