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Biomedical subjects

P Valensi

Publications and source records attributed to P Valensi.

At least 73 records · Page 4Linked to original sources
PubMed1998

[Diabetic autonomic neuropathy: what are the risks?].

This paper considers the risks related to each of the complications of diabetic autonomic neuropathy. Gastroparesia induces its own functional disorders in the digestive tract but is also probably involved in an undetermined proportion of unstable diabetes. Neural bladder, in its aspect of hypoactive, hypocontractile and hypoaesthesic bladder, makes patients prone to urinary chronic retention and repeated urinary infections or even kidney disease. In patients with hypoglycaemia unawareness, the responsibility of autonomic neuropathy may be suspected in those with severe cardiac autonomic neuropathy (CAN) or selective autonomic neuropathy characterised only by a defect in adrenergic contraregulation of hypoglycaemia. CAN is the best-known and most frequent complication of dysautonomia. Several longitudinal studies have clearly shown that CAN is associated with excessive mortality. Various functional disorders may account for the increased frequency of cardiovascular events. In particular, a reduction of left ventricle ejection fraction, inadaptability of haemodynamic response to exercise, alterations of the nycthemeral pattern of blood pressure variations, ventricle repolarisation and ventilatory function have been associated with CAN. Though the relationship between CAN and silent myocardial ischaemia is not clearly established, CAN seems to increase the frequency of major cardiac events, particularly in patients with silent myocardial ischaemia. Vascular neuropathy, by altering peripheral vasomotricity, may contribute to foot ulcer. The statistical association between CAN and retinopathy and kidney disease suggests that CAN might contribute to worsening microangiopathic complications or at least be considered as a marker of these complications. Finally, several arguments suggest an association between CAN and insulin resistance. Thus CAN might be involved in the poor prognosis of kidney disease or insulin resistance. From a practical point of view, the risks related to diabetic dysautonomia, which range from simple discomfort to severe complications, should lead to systematic detection of dysautonomia. In any event, detection by standardised tests analysing heart rate variations should be widely performed, and the presence of CAN should lead to a specific cardiovascular assessment.

Cardiovascular System↗
PubMed1997

[What degree of glycemic control can be obtained in diabetics?].

In diabetic patients, blood glucose should be controlled to a level which prevents acute metabolic complications, forestalls the development of micro and macroangiopathic complications and remains compatible with good quality of life. Recent interventional trials in both insulin-dependent and non-insulin-dependent patients have helped identify this target glucose level. Maintaining HbA1c between 7 and 7.5% appears to be a realistic objective with minimum risk of severe hypoglycemia. This goal, which may be difficult to reach in certain patients, can only be achieved through the co-ordinated efforts of patients and health care providers. The ideal system includes patient education, renewed training for general practitioners who care for most of the non-insulin-dependent as well as a large number of insulin-dependent diabetic patients in France, close follow-up with regular consultations (calling upon specialists when therapeutic adaptations are required) and an organized system of nursing care by specially trained caregivers. The extra cost of this combined organization is to be balanced against expenditures for complications of diabetes.

Blood Glucose Self-Monitoring↗
PubMed1997

Adrenocorticotropin-producing pituitary carcinoma with liver metastasis.

We report here the extremely rare case of a twenty-eight year-old woman with a metastatic ACTH-secreting pituitary carcinoma. This is the thirteenth case to be described in the literature. Ten years ago Cushing's disease was diagnosed. After pituitary surgery, then bilateral adrenalectomy, a Nelson's syndrome appeared. The particularly extensive pituitary secondary development led to several pituitary surgical procedures, radiotherapy, and octreotide treatment. Eight years after Cushing's disease was diagnosed, liver tumors were discovered. Pathological examination and ACTH immunostaining demonstrated the secretory nature of these metastases. The lack of ectopic tumor, the LPH/ACTH equimolar ratio and a study of the plasma proopiomelanocortin derivatives by HPLC showed that the ACTH secretion originated in pituitary tissues (in situ and liver metastases). The processing of POMC seems thus to be normal in this kind of tumor and metastases. Intact POMC levels were very high, indicating an aggressive tumor, and ACTH/LPH production was paradoxically stimulated by octreotide. This case is also exceptional because of the slow development of the disease, which may be due to the complementary hepatic chemoembolization treatment.

Adrenocorticotropic Hormone↗
PubMed1997

Peripheral vasoconstrictor responses to sympathetic activation in diabetic patients: relationship with rheological disorders.

The sympathetic nervous system regulates peripheral blood flow. This study investigated sympathetic vascular control in diabetic patients by measuring cutaneous blood flow (CBF) with a laser Doppler device at rest and during three sympathetic activation tests: deep-breathing, changing positions from sitting to standing, and using the Valsalva maneuver. The influence of various factors, particularly rheological changes, was also assessed. Forty-two type II diabetes mellitus (non-insulin-dependent [NIDDM]) patients and 14 control subjects were studied. The mean value and standard deviation (SD) of basal CBF at rest were not significantly different in the two groups. In 12 NIDDM patients, the SD was less than the lowest limit found in the controls. During the three tests, the reduction in CBF and its downward slope were lower in NIDDM patients than in controls, with the greatest difference occurring during the deep-breathing test. During this test, the downward slope of CBF was less than the lowest control level in 14 NIDDM patients. The log SD of basal CBF correlated with the decrease in CBF during the sitting-to-standing and Valsalva tests in control subjects and during all three tests in NIDDM patients. In NIDDM patients, log mean basal CBF correlated negatively with the log erythrocyte filtration index ([FI] an index of rigidity) and positively with hemoglobin A1c (HbA1c). The log downward slope of CBF during the deep-breathing test correlated negatively with log erythrocyte Fl. The log downward slope of CBF during the sitting-to-standing and Valsalva tests correlated positively with total cholesterol and triglycerides, respectively. Basal CBF and the CBF response to these tests did not correlate with retinopathy, nephropathy, peripheral neuropathy, or heart rate variations during these tests. This study suggests that CBF assessment by laser Doppler flowmetry affords an attractive noninvasive way to investigate sympathetic nervous function in diabetic patients. The amplitude of changes in basal CBF and the decrease in CBF during the deep-breathing test show that this is a simple and sensitive procedure for detecting sympathetic nerve dysfunction. Moreover, theological blood properties and metabolic factors seem to strongly influence resting CBF and vasomotor reflexes.

Adult↗
PubMed1997

Hyperinsulinemia and hypofibrinolysis: effects of short-term optimized glycemic control with continuous insulin infusion in type II diabetic patients.

A defect in the fibrinolytic system results from an increase in type 1 plasminogen activator inhibitor (PAI-1) in diabetes. It can be considered an independent risk factor for the development of cardiovascular disease. In obese and type II diabetic patients, plasma PAI-1 level correlates with fasting insulinemia. However, during the euglycemic clamp, acute hyperinsulinemia does not increase PAI-1 production. The present study was undertaken to investigate the effect of optimized glycemic control by continuous subcutaneous insulin infusion (CSII) on the hypofibrinolytic state for 14 days in 16 type II diabetic patients with poor metabolic control despite maximal oral antidiabetic treatment. Plasma PAI-1 activity levels decreased from 13.38 +/- 2.85 IU/mL to 6.77 +/- 1.81 IU/mL (P = .002) during CSII, along with a concurrent improvement in insulin sensitivity (index obtained by basal glycemia-nadir glycemia/basal glycemia) during the insulin sensitivity test (0.121 +/- 0.03 v 0.057 +/- 0.02, P = .02). These results suggest that insulin resistance rather than hyperinsulinism may be involved in the hypofibrinolytic state in type II diabetic patients. The positive correlation between the changes in triglycerides and in PAI-1 activity (r = .589, P = .026) strongly suggests a role for triglycerides in the impairment of fibrinolysis, which could be a link between insulin resistance and hypofibrinolysis.

Blood Glucose↗
PubMed1997

Impairment of antidiuretic hormone and atrial natriuretic peptide regulation in the obese woman with a swelling syndrome and an increase in capillary permeability to albumin.

OBJECTIVE: To study the regulation of antidiuretic hormone (ADH) and atrial natriuretic peptide (ANP) in obese and lean women with a swelling syndrome. PATIENTS: Thirty-four obese women and 12 lean women with a swelling syndrome and an abnormal isotopic test of capillary permeability to albumin were investigated. MEASUREMENTS: After 10 nocturnal hours of fluid restriction, subjects were asked at 8am to ingest a tap water load of 20 ml/kg within 10 min and to remain strictly recumbent until twelve noon on the first day, and to remain standing and to walk around until twelve noon on the second day. Free water clearance and the cGMP/creatinine and albumin/creatinine ratios were determined hourly in the morning. RESULTS: The total 4 h-urinary volume/ingested water volume ratio was significantly lower on the second day both in the lean and the obese patients, the differences being slightly larger in the obese patients. The increase in free water clearance was significantly less on the second day in the obese patients. The increase in cGMP/creatinine ratio was also significantly lower on the second day in the obese patients. The maximum level of the urinary albumin/creatinine ratio was significantly higher on the second day in the obese patients. CONCLUSION: In obese women with a swelling syndrome: (1) The higher increase in the urinary albumin excretion rate after water loading followed by a sustained upright position suggests a widespread alteration in capillary function, which is also indicated by the isotopic test of capillary permeability to albumin. (2) The water load-induced inhibition of ADH secretion and stimulation of ANP secretion or ANP activity, more defective in the upright position than in the recumbent one, is probably another major contributing factor to orthostatic oedema.

Adult↗
PubMed1997

Insulinaemia and slight overweight: the case of Vietnamese hypertensives.

OBJECTIVE: To examine the relationship between hypertension, overweight and indices of insulin resistance in Vietnamese subjects. PATIENTS: One hundred and eight hypertensive subjects (51 men and 57 women) over 40 y of age were compared with 36 control subjects over 40 y of age. METHODS: Blood glucose and plasma insulin were measured at fasting and 2 h after 75 g glucose taken orally. RESULTS: Hypertensive subjects had significantly higher body mass index (BMI), triceps skinfold, waist and hip circumferences and waist/hip ratio. Glycaemia at fasting and after glucose were similar in the two groups. Insulinaemia at fasting and after glucose were significantly higher in the hypertensive subjects. In the whole series of hypertensive subjects, plasma insulin and insulin/glucose ratio at fasting and after glucose correlated significantly with BMI, triceps skinfold and waist and hip cicumferences. After exclusion of the subjects with BMI > 22 kg/m2, compared with the controls, plasma insulin and insulin/glucose ratio were significantly higher in the whole hypertensive group and separately in hypertensive men and women. The logistic regression analyses have shown that plasma insulin and insulin/glucose ratio at fasting and after glucose were significantly associated with hypertension, independently of gender, BMI and waist circumference. CONCLUSION: This study shows that in Vietnamese people, essential hypertension is associated with a significant increase in BMI, which however remains far lower than the definition threshold of occidental obesity and with a state of insulin resistance found despite very slight or no excess weight.

Aged↗
PubMed1997

Simultaneous effects of aneuploidy and oncogenic human papillomavirus on histological grade of cervical intraepithelial neoplasia.

OBJECTIVE: To investigate whether ploidy and oncogenic human papillomavirus types can be correlated with the histological grade of cervical intraepithelial neoplasia (CIN) in the same tissue sections. DESIGN: Histological data were obtained from 292 dysplastic lesions of the cervix and classified according to the CIN and the Bethesda terminologies. The samples were analysed using Feulgen-stained image analysis cytometry for ploidy and Human papillomaviruses DNA typing by in situ hybridisation, respectively. SETTING: Colposcopy Clinic at Alfred Fournier Institute, Paris. POPULATION: Three hundred and forty women referred for an abnormal cervical smear. RESULTS: The ploidy data strongly segregate high grade from low grade squamous intraepithelial lesions (aneuploidy 78% versus 21%; P < 0.0001). There was a significant association between aneuploidy and the severity of the lesions (94% for CIN 3, 55% for CIN 2 and 14% for CIN 1; P < 0.0001). Both classifications showed a significant association of histological grade with oncogenic human papillomavirus types (HPV 16-18-33; 20% in low grade and 78% in high grade squamous intraepithelial lesions, 31% and 75% in CIN 1 and CIN 3, respectively; P < 0.0001). The simultaneous effects of these viruses and ploidy demonstrate an association in aneuploid cells between the presence of oncogenic human papillomavirus types and histological grade (76% and 18% in high and low grade squamous intraepithelial lesions, respectively; P < 0.0001). Such an association was not observed in diploid cells (20% in both low and high grade squamous intraepithelial lesions). CONCLUSIONS: High risk human papillomavirus types do not exert and an independent effect on the histological grade of cervical intraepithelial neoplasia.

Aneuploidy↗
PubMed1997

Short-term effects of continuous subcutaneous insulin infusion treatment on insulin secretion in non-insulin-dependent overweight patients with poor glycaemic control despite maximal oral anti-diabetic treatment.

It is difficult to treat obese non-insulin-dependent diabetic patients (NIDDs) whose glycaemic control remains poor despite maximal oral antidiabetic therapy. We studied the effect of a continuous subcutaneous insulin infusion (CSII) associated with a low-calorie diet and metformin 1,700 mg/day on glycaemic control and basal and stimulated insulin secretion in a series of 82 overweight NIDD before (T1), during CSII (T2), and after CSII withdrawal (T3). Patients were treated for 8 to 23 days with a mean amount of 0.50 +/- 0.02 IU/kg/day. Glycaemic control was very good after 3-5 days of CSII and remained good at T3. At T2, fasting and postprandial plasma C peptide levels decreased significantly. At T3, fasting C peptide was very similar to T1, and postprandial C peptide was significantly higher than at T1. The molar fasting and postprandial plasma C peptide/glycaemia ratios increased significantly at T3. After glucagon injection, the molar delta C peptide/glycaemia ratio was significantly increased at T2 and even higher at T3. At T2, as at T1 and T3, there were significant correlations between fasting and postprandial C peptide levels and between the glucagon-induced C peptide peak and fasting and postprandial C peptide levels. Between T1 and T3 weight changes correlated significantly with the molar fasting C peptide/glycaemia ratio at T1. Twenty-nine of the 30 patients for whom this ratio was > 6.6 x 10(-8) lost weight. The length of CSII treatment did not correlate with weight changes or other biological parameters. This study shows that CSII with moderate amounts of insulin associated with a low-calorie diet and metformin provided rapid glycaemic control, led to weight loss, maintained regulation of insulin secretion and seemed to improve insulin secretion and sensitivity. These results were obtained in only 8 to 10 days.

Administration, Cutaneous↗
PubMed1997

[Response of the coronary arteries to cold test and flow velocity increase is improved by deferoxamine but not by L-arginine in diabetic patients].

UNLABELLED: Acetylcholine produces coronary artery (CA) constriction in diabetic patients suggesting an impairment of endothelium-dependent dilation. To examine the mechanism of this abnormal response. 2 physiological tests, i.e. cold pressor test (CPT) and coronary flow-increase induced by 10 mg papaverine (PAP) injection in the distal left anterior descending CA (dLAD), were performed before (1) and after (2) either i.v. L-arginine (L-arg, 625 mg/min x 10 min) or i.v. desferrioxamine (DFX, 50 mg/min x 10 min) in 15 normotensive nonsmoker diabetic patients with angiographically normal CA and normal cholesterol. Dimensions of the proximal LAD (pLAD) were measured by quantitative angiography. [table: see text] Before administration of L-arg or DFX, CPT induced a decrease of pLAD diameter, and PAP injection in dLAD dit not modify pLAD diameter. In the 7 diabetic patients receiving L-arg, responses to CPT and PAP were not modified. Conversely in the 10 patients receiving DFX, pLAD dilated in response to the 2 tests. Intracoronary isosorbide dinitrate, an endothelium-independent dilator, produced similar dilation in the 2 groups (+20 +/- 8% and +16 +/- 6%, respectively). CONCLUSIONS: 1) responses of angiography normal CA to CPT and to flow increase are impaired in diabetic patients; 2) abnormal responses are not improved by L-arg suggesting that a deficit in substrate for NO synthesis is not involved; 3) DFX restores a vasodilator response to the 2 tests suggesting that inactivation of NO by superoxide radicals might be partly responsible of the impairment of CA dilatation in diabetic patients.

Arginine↗
PubMed1997

[Insulin resistance and essential hypertension in Vietnamese subjects].

Several epidemiological and experimental studies suggest that essential arterial hypertension is associated with hyperinsulinism and insulin resistance in obese subjects and also in subjects with normal body weight. Undernutrition remains frequent in adult Vietnamese people and mean body mass index is around 18.5 kg/m2 in Vietnam. The aim of this study was to look for insulin resistance in hypertensive Vietnamese subjects, despite a markedly lower BMI in Vietnam than in occidental countries. One hundred and eight hypertensive patients (51 men and 57 women) over 40 years (mean = 65.4 years) were compared with 36 healthy subjects (23 men and 13 women) over 40 years (mean = 63.8 years). Hypertensive patients had significantly higher BMI (20.5 +/- 0.3 (SEM) kg/m2 vs 18.4 +/- 0.4 kg/m2; p < 0.01), thicker triceps skinfold (1.26 +/- 0.07 cm vs 0.71 +/- 0.07 cm; p < 0.001) and not significantly different waist/hip ratio (0.88 +/- 0.01 vs 0.85 +/- 0.01). Blood glucose at fasting and 2 hours after 75 g glucose taken orally were similar in hypertensive and normotensive subjects. Plasma insulin at fasting and 2 hours after glucose were significantly higher in hypertensive patients (44.4 +/- 5.1 pmol/L vs 21.6 +/- 3.2 pmol/L; p < 0.05 and 271.1 +/- 21.6 pmol/L vs 139.1 +/- 15.2 pmol/L; p < 0.001). Thus, despite under-nutrition, hypertensive Vietnamese patients have a moderate but significant increase in BMI and fat mass without predominant abdominal localization, and a state of insulin-resistance, compared with normotensive healthy subjects.

Adult↗
PubMed1997

[Alteration of cardiovascular vagosympathetic control evaluated by spectral analysis of variations of heart rate and blood pressure in obesity].

Several studies suggest alterations of parasympathetic and sympathetic control in obesity. We have already shown that more than 40% of non diabetic obese subjects have alterations of parasympathetic control of heart rate (HR) variations. The present study aimed to investigate parasympathetic and sympathetic cardiovascular control by using spectral analysis. Sixty-two non diabetic obese subjects were compared to 38 sex-matched healthy controls. Spectral analysis was performed by Anapres system and identified two particular peaks: the one of high frequency (0.20-0.25 Hz) for heart rate variations during controlled breathing which depends on parasympathetic activity, the other of low frequency (around 0.10 Hz) for systolic BP variations in the standing position which mainly depend on sympathetic activity. In control subjects the amplitude of the high frequency peak (r = -0.556, p < 0.0001) but not the amplitude of the low frequency peak correlated negatively with age. In the obese subjects both the high and low frequency peaks correlated negatively with age (r = -0.249; p = 0.05 and r = -0.289, p = 0.036 respectively) and did not correlate with body mass index. The high frequency peak was significantly lower than in controls (4.80 +/- 3.37 (SD) vs 8.38 +/- 4.14; p < 0.0001). In the 25 obese subjects over 40 years the low frequency peak was also significantly lower than in controls (10.00 +/- 3.10 vs 11.95 +/- 4.25; p < 0.05). This study suggests that 1) age must be taken into account when interpreting the cardiovascular parameters under vagosympathetic control; 2) in non diabetic obese subjects vagal activity is decreased and in those over 40 years sympathetic activity is also decreased.

Adolescent↗
PubMed1997

Silent myocardial ischaemia and left ventricle hypertrophy in diabetic patients.

The purpose of this study was to evaluate the ability of three noninvasive techniques to detect silent myocardial ischaemia and analyse the factors associated with this condition, particularly left ventricular hypertrophy, in diabetic patients. An ECG stress test, a thallium-201 myocardial scintigraphy with dipyridamole intravenous infusion, ambulatory 48 h ECG monitoring and an echocardiographic study were performed in 92 diabetic patients without cardiac symptoms but with > or = 2 additional cardiovascular risk factors. At least one of these tests was positive in 28 patients (30.4%), suggesting silent myocardial ischaemia. Twenty-four of these patients had a coronary angiography which showed significant coronary stenosis in only 9 cases. An accurate echocardiographic tracing was obtained in 79 patients, particularly in 7 of the 9 with coronary stenosis. Left ventricular hypertrophy was detected in 34 patients, 6 of whom had coronary stenosis. In patients with left ventricular hypertrophy, the positive predictive values of myocardial scintigraphy and the ECG stress test were respectively 50% and 100%, as compared to only 33% and 11% in those without hypertrophy. In summary, coronary stenoses were found in < 10% of asymptomatic diabetic patients with > or = 2 cardiovascular risk factors, but more frequently in individuals with left ventricular hypertrophy. Thus, silent myocardial ischaemia should be searched for first in diabetic patients with hypertrophy, for which the stress test was the most accurate detection method in this study.

Adult↗
PubMed1997

[The "short Achilles tendon" syndrome: a new entity of the diabetic foot].

The "short Achilles tendon" syndrome, characterised by limited dorsiflexion of the tibiotarsal joint, is not well-known but could be a disposing factor for trophic disorders and plantar ulcer related to hypersupport in the diabetic subject. We report two cases of multicomplicated diabetic patients treated during several months for plantar ulcer superinfected with underlying osteoarthrits, whose course became rapidly favourable after tenotomy of the Achilles tendon. This simple surgical act can be performed in ambulatory conditions under local anaesthesia. Functional disability is negligible. The benefit of this treatment as part of the curative or preventive therapeutic arsenal for care of the diabetic foot remains to be evaluated.

Achilles Tendon↗
PubMed1996

TSH and prolactin responses to thyrotropin releasing hormone (TRH) and domperidone in patients with empty sella syndrome.

The aim of this study was to investigate TSH and PRL response to TRH and domperidone, an antidopaminergic drug which does not cross the blood-brain barrier, in 16 patients with primary empty sella (PES) and either normal or elevated plasma PRL level and to compare it with the response observed in 8 patients with prolactinoma. In the patients with PES and hyperprolactinemia, the PRL response to TRH was significantly lower than in the controls and the patients with PES and normal PRL, which suggests there is impaired PRL synthesis and release in cases of PES with hyperprolactinemia. The TSH response to domperidone was significantly elevated in patients with PES and either normal or elevated PRL, as in patients with prolactinoma. The PRL response to domperidone was significantly reduced in patients with PES and hyperprolactinemia as in patients with prolactionoma. These results suggestthat in PES with prolactinoma the inhibiting dopaminergic tone is increased on the thyrotropic cells and reduced on the lactotropic cells in PES with elevated PRL and that some patients with PES might bear a microprolactinoma in the bottom of the sella which remained undetected by the CT scan.

Adult↗