Squatting Amplifies Pulse Pressure Increase With Disease Duration in Patients With Type 1 Diabetes

Marchand

2011

Diabetes & Metabolism

Cardiovascular autonomic neuropathy (CAN) is a frequent complication of diabetes mellitus, which is associated with increased morbidity and mortality. It involves both the parasympathetic and sympathetic nervous systems, and may be diagnosed by classical dynamic tests with measurements of heart rate (HR) and/or arterial blood pressure (BP). An original squattest (1-min standing, 1-min squatting, 1-min standing) was used with continuous monitoring of HR and BP, using a Finapres ® device. This active test imposes greater postural stress than the passive head-up tilt test, and provokes large changes in BP and HR that can be analyzed to derive indices of CAN. In healthy subjects, squatting is associated with BP increases and HR decreases (abolished by atropine: SqTv index), whereas the squat-stand transition is accompanied by a deep but transient drop in BP associated with sympathetic-driven tachycardia (abolished by propranolol: SqTs index). In diabetic patients with CAN, BP increases are accentuated during squatting whereas reflex bradycardia is reduced. When standing from squatting position, the fall in BP tends to be more pronounced and orthostatic hypotension more prolonged, while reflex tachycardia is markedly dampened. The baroreflex gain, similar to that calculated during pharmacological testing with vasodilator/vasopressor agents, can be derived by plotting pulse intervals (R-R) against systolic BP levels during the biphasic response following the squat-stand transition. The slope, which represents baroreflex sensitivity, is significantly reduced in patients with CAN. This discriminatory index allows study of the natural history of CAN in a large cohort of diabetic patients.Keywords: Baroreflex sensitivity; Cardiovascular autonomic neuropathy; Finapres ; Squatting; Diabetes; Heart rate; Orthostatic hypotension; Posture test; Review RésuméTest postural d' accroupissement pour étudier la neuropathie autonome cardiovasculaire diabétique.La neuropathie autonome cardiaque (NAC) est une complication fréquente du diabète qui est associée à une augmentation de la morbidité et de la mortalité. Elle concerne à la fois les systèmes parasympathique et sympathique et peut être diagnostiquée classiquement par des tests dynamiques avec mesure des variations de la frequence cardiaque (FC) et de la pression artérielle (PA). Notre groupe a utilise un test postural original (1-min debout-1 -min accroupi ou « squatting »-1 -min debout) avec un monitorage continu de FC et PA avec un appareil Finapres ® . Ce test de redressement actif impose un stress postural plus prononcé que le test d'inclinaison passif sur une table basculante et provoque des variations amp les de PA et FC qui peuvent être analysées pour dériver des indices de NAC. Chez des sujets sains, le «squatting» entraîne une augmentation de PA et une diminution de FC (abolie par l'atropine : indice SqTv) alors que la transition accroupi-debout induit une chute importante mais transitoire de PA accompagnée d'une tachycardie d'origine sympathique (abolie par le ...

Section: Blood Pressure Changesmentioning

confidence: 82%

Squatting, a posture test for studying cardiovascular autonomic neuropathy in diabetes

Marchand

2011

Diabetes & Metabolism

“…1). Interestingly, this increase was amplified in patients with long-lasting type 1 diabetes, a finding attributed to increased arterial stiffness [17].…”

Section: Changes From Standing To Squattingmentioning

confidence: 94%

Squatting test: a dynamic postural manoeuvre to study baroreflex sensitivity

2011

Clin Auton Res

Self Cite

“…Careful analysis of BP and HR changes during both transition states, from standing to squatting and from squatting to standing, respectively, provides interesting information as far as performance of baroreflexes and haemodynamic homeostasis are concerned (Rossberg & Penaz, 1988). For instance, the analysis of HR and BP changes occurring during a squatting test has been used by our group to assess orthostatic hypotension (Scheen et al, 1990), cardiovascular autonomic neuropathy (CAN) (Philips et al, 2009) and pulsatile stress (Philips et al, 2008); Philips et al, 2010a; Philips et al, 2010b) in patients with type 1 diabetes mellitus. Furthermore, squatting position is a long recognized therapeutic manoeuvre that can improve haemodynamics in patients with some congenital cardiac diseases (tetralogy of Fallot) (Lurie, 1953;Guntheroth et al, 1968).…”

Section: Non-invasive Continuous Monitoring Of Systolic and Diastolicmentioning

confidence: 99%

Squatting test: A posture to study and counteract cardiovascular abnormalities associated with autonomic dysfunction

2011

Autonomic Neuroscience

Self Cite

word count = 225 words SUMMARYThe squatting test is an active posture manoeuvre that imposes one of the most potent orthostatic stresses. In normal subjects, the changes in blood pressure and heart rate are transient because of appropriate baroreflex homeostasis and do not provoke symptoms.However, in various pathological conditions, both the increase in blood pressure during squatting and the decrease in blood pressure during standing may be more important and sustained, potentially leading to complaints and adverse events. Squatting has been used to evaluate patients with tetralogy of Fallot, heart transplant, dysautonomia, including diabetic cardiovascular autonomic neuropathy, and individuals prone to vasovagal syncope. Careful analysis of changes in blood pressure and heart rate during the transition from standing to squatting and from squatting to standing allows the early detection of altered vagal and/or sympathetic function. Of note squatting position has been proposed as a therapeutic mean to counteract the fall in blood pressure in patients suffering from dizziness due to dysautonomia and orthostatic hypotension or presenting pre-syncope symptoms, such as soon after exercise.The aims of the present review are to analyse the haemodynamic pattern during a squatting test in various pathological situations and to describe what may be the negative and positive haemodynamic changes associated with this posture. We were especially interested in using the squatting test for the assessment of cardiovascular autonomic neuropathy associated with diabetes mellitus.