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

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 squat test (1-min standing, 1-min squatting, 1-min standing) was used with continuous monitoring of HR and BP, using a Finapres((R)) 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.Peer reviewe

Haemodynamic changes during a squat test, pulsatile stress and indices of cardiovascular autonomic neuropathy in patients with long-duration type 1 diabetes.

AIM: Cardiovascular autonomic neuropathy (CAN) and pulsatile stress are considered to be independent cardiovascular risk factors. This study compared haemodynamic changes during an active orthostatic test in adult patients with type 1 diabetes (T1DM), using low versus high RR E/I ratios as a marker of CAN. METHODS: A total of 20 T1DM patients with low RR E/I ratios were compared with 20 T1DM patients with normal RR E/I ratios, matched for gender (1/1 ratio), age (mean: 46years) and diabetes duration (22-26years); 40 matched healthy subjects served as controls. All subjects were evaluated by continuous monitoring of arterial blood pressure (Finapres((R))) and heart rate using a standardized posture test (1-min standing, 1-min squatting, 1-min standing), thus allowing calculation of baroreflex gain. RESULTS: Compared with controls, T1DM patients showed lower RR E/I ratios, reduced baroreflex gains, higher pulsatile stress (pulse pressurexheart rate), greater squatting-induced pulse pressure rises, orthostatic hypotension and reduced reflex tachycardia. Compared with T1DM patients with preserved RR E/I ratios, T1DM patients with low RR E/I ratios showed reduced post-standing reflex tachycardia and baroreflex gain, and delayed blood pressure recovery, but no markers of increased pulsatile stress. Interestingly, decreased baroreflex gain was significantly associated with both pulsatile stress and microalbuminuria. CONCLUSION: The use of RR E/I ratios to separate T1DM patients allows the detection of other CAN markers during an orthostatic posture test, but with no significant differences in pulsatile stress or microalbuminuria. In this context, squatting-derived baroreflex gain appears to be more informative.Peer reviewe

Metabolically obese normal-weight subjects. Part two: prognosis and management

Metabolically obese normal-weight (MONW) individuals are frequently not detected because of a falsely reassuring body weight. However, they have most of the metabolic syndrome markers known to be associated with a higher risk of type 2 diabetes, cardiovascular disease and mortality. The present review paper aims to describe the clinical consequences to which MONW people are exposed and the main principles of managing this syndromeLes personnes non obèses « métaboliquement anormales » (MONW) sont rarement dépistées en raison d’un poids corporel faussement rassurant. Elles présentent pourtant bon nombre de marqueurs du syndrome métabolique, connus pour être associés à un risque accru de diabète de type 2, de maladies cardiovasculaires et de mortalité. Cet article vise à évaluer les conséquences cliniques auxquelles sont exposées les personnes MONW et à décrire les grands principes de la prise en charge thérapeutique de ce syndrome

Abnormal glucose metabolism in patients treated with antipsychotics.

Second-generation (atypical) antipsychotic medications are of great benefit to a wide variety of people with psychiatric disorders, especially patients with schizophrenia. However, one constellation of adverse effects is an increased risk of obesity, diabetes, and metabolic syndrome. Increasing numbers of reports concerning impaired glucose tolerance, diabetes, and ketoacidosis have raised concerns about a possible association between abnormal glucose metabolism and treatment with atypical antipsychotics, although the question is still debated because of the presence of many confounding factors. A close relationship between drug-induced weight gain and risk of diabetes has been reported, emphasizing the role of insulin resistance. However, some cases of diabetes developed independently of weight gain, rather rapidly and possibly progressing to ketoacidosis, thus arguing for a severe impairment of insulin secretion. Another debated question is whether diabetes risk is a class action or a differential action. Although not fully scientifically proven yet, available evidence suggests that clozapine and olanzapine have a higher propensity to induce diabetes and metabolic syndrome compared with other atypical antipsychotic drugs, risperidone and quetiapine. Despite more limited available data, amisulpride, aripiprazole and ziprazidone showed less likelihood of precipitating diabetes. Interestingly, reversibility of drug-related diabetes has been reported with aripiprazole. The choice of atypical antipsychotic medication for a specific patient depends on many factors, but the likelihood of developing diabetes should become an important consideration. When prescribing an atypical antipsychotic, a commitment to careful baseline screening and follow-up monitoring is essential in order to mitigate the risk of developing diabetes and associated complications