Influence of blood glucose on heart rate and cardiac autonomic function. The DESIR study.

OBJECTIVES: To evaluate in a general population, the relationships between dysglycaemia, insulin resistance and metabolic variables, and heart rate, heart raterecovery and heart rate variability. METHODS: Four hundred and forty-seven participants in the Data from an Epidemiological Study on the Insulin Resistance syndrome (DESIR) study were classified according to glycaemic status over the preceding 9 years. All were free of self-reported cardiac antecedents and were not taking drugs which alter heart rate. During five consecutive periods: rest, deep breathing, recovery, rest and lying to standing, heart rateand heart ratevarability were evaluated and compared by ANCOVA and trend tests across glycaemic classes. Spearman correlation coefficients quantified the relations between cardio-metabolic risk factors, heart rateand heart ratevarability. RESULTS: Heart ratediffered between glycaemic groups, except during deep breathing. Between rest and deep-breathing periods, patients with diabetes had a lower increase in heart ratethan others (P(trend) < 0.01); between deep breathing and recovery, the heart rateof patients with diabetes continued to increase, for others, heart ratedecreased (P(trend) < 0.009). Heart ratewas correlated with capillary glucose and triglycerides during the five test periods. Heart rate variabilitydiffered according to glycaemic status, especially during the recovery period. After age, sex and BMI adjustment, heart rate variabilitywas correlated with triglycerides at two test periods. Change in heart ratebetween recovery and deep breathing was negatively correlated with heart rate variabilityat rest, (r=-0.113, P < 0.05): lower resting heart rate variabilitywas associated with heart rateacceleration. CONCLUSIONS: Heart rate, but not heart rate variability, was associated with glycaemic status and capillary glucose. After deep breathing, heart raterecovery was altered in patients with known diabetes and was associated with reduced heart rate variability. Being overweight was a major correlate of heart rate variability.