Ambulatory Blood Pressure Monitoring and Circadian Rhythm of Blood Pressure in Diabetes Mellitus

Abstract

Systolic and diastolic blood pressures display a circadian rhythmicity that can be assessed by 24-hour ambulatory blood pressure monitoring and analysed using the cosinor procedure. Altered characteristics to the circadian rhythm of blood pressure, which may result in adverse health outcomes, have been observed in both prediabetes and diabetes. We have investigated the circadian variability of blood pressure in patients with type 1 and type 2 diabetes. Chronobiologically interpreted ambulatory blood pressure monitoring uncovered not only midline estimating statistic of rhythm (MESOR)-hypertension and circadian hyper-amplitude-tension, but also circadian ecphasia (an odd timing of the daily blood pressure swing). Diastolic blood pressure acrophases were found to be phase shifted to earlier along the time axis only in patients with diabetes, but not in those with essential hypertension. Several mechanisms, from changes in nutrient-dependent signalling pathways to diabetic autonomic neuropathy, can contribute to alterations of circadian time structures in diabetic people. The chronology of blood pressure changes in animal models of diabetes and hypertension suggests that a chronobiological approach to the diagnosis of blood pressure disorders could offer advantages, but longitudinal studies in humans are needed to determine its potential relevance in hypertension associated with diabetes.