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Biomedical subjects

C Sachon

Publications and source records attributed to C Sachon.

36 records · Page 2Linked to original sources
PubMed1994

Brain metabolism after recurrent insulin induced hypoglycaemic episodes: a PET study.

Neuropsychological testing was carried out and the rate of oxygen metabolism in the brain was measured by PET in 15 highly selected patients with type 1 diabetes. The aim was to investigate the impact on the brain of hypoglycaemic comas resulting from insulin treatment. No significant difference was found between nine patients with a history of more than 10 hypoglycaemic comas and six others who denied any history of such events. These data suggest that intensified insulin treatment, although increasing the frequency of hypoglycaemic coma, may not always be harmful for the brain. This may be explained by the limited duration of hypoglycaemic coma induced by conventional insulin treatment.

Adult↗
PubMed1994

[Diabetic pregnancy. Evaluation and prospects from the study of 212 diabetic pregnancies followed-up between 1985 and 1992].

A total of 212 diabetic pregnancies were studied prospectively over the period 1985 to 1986, included: 76 insulinodependent diabetics (IDD), 34 non insulinodependent diabetics (NIDD), and 102 gestational diabetes. The perinatal mortality rate for all diabetic pregnancies was 1.4% (n = 3); 3 congenital malformations were recorded (a therapeutic abortion was performed in 2 cases). These results are comparable with those of the non diabetic population. However, it is to be noticed that maternal as well as neonatal morbidity was important (hypoglycaemic comas: 18 in 9 IDD, preeclampsia: 7 IDD, 2 NIDD, 1 DG; caesarean delivery: 50% IDD, 50% NIDD, 25% DG; neonatal morbidity 20% of the new born. The main objectives must be targeted on the prevention of severe hypoglycaemia in IDD, the early diagnosis of DG and the development of pregnancy care in NIDD.

Adult↗
PubMed1992

Cognitive function, insulin-dependent diabetes and hypoglycaemia.

A series of seven psychometric tests, to evaluate mental concentration and the ability to retain selective attention, lexical fluency, wordlist memorizing and psychomotor speed, was performed on 25 non-diabetic control subjects and 55 insulin-dependent diabetes (IDD) patients of similar social background and professional status. When tested, none of the diabetics was hypoglycaemic and these patients were divided into two groups: Group I: 30 IDD patients unaware of hypoglycaemia, and experiencing frequent and severe episodes of hypoglycaemia. Group II: 25 IDD patients aware of hypoglycaemia. Groups I and II had experienced the disease for the same period of time (17 +/- 13 vs. 14 +/- 11 years, respectively) and they had similar HbA1c levels (7.14 +/- 1.25% vs. 8.6 +/- 1.88%, respectively) and degenerative complications. Compared with the scores of the controls, the Group I scores were lower in four tests: trail-making part A (psychomotor speed; P less than 0.001) and part B (retaining selective attention; P less than 0.01), lexical fluency (P less than 0.01) and Rey auditory-verbal learning test (wordlist learning; P less than 0.05). Group II scores were lower in two tests: trail-making part A (P less than 0.01) and part B (P less than 0.05). In word memorizing, the performance of Group I was inferior to that of Group II (P less than 0.05). In general, these psychometric tests showed that IDD scores were lower than those of the controls, with an average of 67% for Group II and 80% for Group I. Chronic hyperglycaemia and severe hypoglycaemia may have a deleterious effect on cognitive performance. In particular, several severe episodes of hypoglycaemia could be responsible for permanent memory impairment.

Adolescent↗
PubMed1990

Unawareness of hypoglycemia by insulin-dependent diabetics.

After several years of insulin therapy, about 20% of insulin-dependent diabetics have little or no perception of hypoglycaemia because of a loss of the adrenergic warning symptoms. This defect, poorly correlated with the presence of autonomic neuropathy, has been classically explained by a defect in the catecholamine secretion. We compared the hormonal counterregulation during hypoglycaemia induced by subcutaneous injection of insulin in 7 insulin-dependent diabetics with poor perception of hypoglycaemia and experiencing repeated episodes of severe hypoglycaemia (group A) and 7 insulin-treated diabetics with very good perception of hypoglycaemia and not experiencing severe hypoglycaemia (group B). Groups A and B were similar in terms of age, duration of diabetes, HbA1c level and degenerative complications. The glucagon levels were identical and non-reactive in the two groups. The basal levels and secretion peaks of adrenaline, noradrenaline, growth hormone and cortisol were similar between the two groups, but there was a significant delay in secretion in group A with a blood glucose threshold of adrenergic secretion of between 3.1 +/- 0.5 and 1.6 +/- 0.2 mmoles/l in group A and between 4.6 +/- 0.3 and 3.2 +/- 0.2 mmoles/l in group B (P less than 0.05). This delayed secretion could be explained by desensitisation of the hypothalamic glucostat and could be due to the frequency and/or severity of hypoglycaemic episodes.

Adult↗
PubMedDate not supplied

Relevance of measuring red blood cell disaggregability in insulin-dependent diabetic patients.

A viscometric study of blood from insulin-treated diabetic patients is carried out. Patients are divided into three major groups--group I: without or with minimal retinopathy and recent diabetes (n = 37), group II: without or with minimal retinopathy and at least 20 years of diabetes duration (n = 35), group III: with severe retinopathy (n = 27). Each group is also subdivided according to the glycosylated hemoglobin (HbA1c) level, used to assess long-term glycemic control. Finally, the rheological parameters of six groups are compared: three of which have a HbA1c level less than 7.5% [I1 (n = 15), II1 (n = 9), III1 (n = 9)] and three others have a HbA1c level more than 7.5% [I2 (n = 22), II2 (n = 26), III2 (n = 18)]. The most important result concerns the thixotropy index xi t, which reflects the dynamic property of red blood cell (RBC) disaggregability under shear. Strong correlations between this parameter and HbA1c level are found for groups I (r = -0.53, p < 0.001) and III (r = -0.68, p < 0.001), providing evidence of a RBC disaggregability disorder for a poor glycemic control of diabetes. In contrast, such a correlation is not pointed out for the group II. As the value for xi t is not statistically different for groups II1 and II2 and is close to the normal value in both groups, the existence of a rheological protection against the retinopathy could be involved.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

[Intolerance to carbohydrates: the seven questions].

The borderline between diabetes and intolerance to carbohydrates has been drawn on the basis of prospective studies which determined a glycaemic threshold marking the risk for microangiopathy. On the other hand, the borderline between intolerance to carbohydrates and normal glucose tolerance remains arbitrary: 25% for subjects who are intolerant to carbohydrates return to normal glucose tolerance within 10 years. This is due to the fact that intolerance to carbohydrates is a heterogeneous entity which should be dismembered according to the severity of insulin deficiency and to the degree of insulin resistance. Alteration of insulin secretion is perhaps the most specific marker of susceptibility to non insulin dependent diabetes, but insulin resistance is certainly the principal factor exhausting insulin secretion and leading to non insulin dependent diabetes. Insulin resistance and the hyperinsulinism it creates seem to facilitate atherogenesis, even when glucose tolerance is still normal, so that the oral glucose tolerance test is not only poorly reproducible but loses a great deal of its value in the early detection of vascular risk. Measurements of fasting and post-prandial glucose levels and of A1C haemoglobin, cholesterol, triglyceride, and HDL cholesterol levels usually make it possible to classify subjects into one of the three following categories: (1) no risk of macro- or microangiopathy; (2) diabetes with a risk of macro- or microangiopathy; (3) intolerance to glucose with risk of atherogenesis but no risk of microangiopathy. The oral glucose tolerance test probably remains useful within a small set of values that are either very slightly above normal or dissociated. Measuring blood insulin levels might be a better way of assessing the risk of atherogenesis, but the clinical use of this test requires evaluation.

Arteriosclerosis↗
PubMedDate not supplied

Hypoglycemic symptoms and decreased beta-adrenergic sensitivity in insulin-dependent diabetic patients.

Thirty-seven insulin-dependent diabetic patients were tested for symptoms of hypoglycemia, cardiac autonomic neuropathy (i.e., heart rate variation during deep breathing, Valsalva maneuver, immediate heart rate response to standing), and isoproterenol sensitivity (defined as the dose of isoproterenol required to increase heart rate by 25 beats/min: I25). Tests of cardiac autonomic neuropathy showed no relation to hypoglycemic symptoms. On the contrary, a clear relationship could be established between isoproterenol sensitivity and adrenergic symptoms of hypoglycemia. Diabetic patients with decreased response to isoproterenol had fewer adrenergic symptoms, perceived hypoglycemia at a lower blood glucose level, and had more hypoglycemic accidents. Symptoms most related to isoproterenol sensitivity were tremor, sweaty palms, and hunger. With the isoproterenol-sensitivity test a distinction could be made between the groups at high (I25 greater than 3 micrograms) and low (I25 less than 3 micrograms) risk for hypoglycemic accidents. We suggest that the isoproterenol-sensitivity test could be used to identify diabetic patients at increased risk for hypoglycemia.

Adult↗