Detection of early sympathetic cardiovascular neuropathy by squatting test in NIDDM.
; ; et al
in Diabetes Care (1994), 17(2), 149-51
OBJECTIVE--To determine the role of the squatting test in the detection of early sympathetic neuropathy in patients with non-insulin-dependent diabetes mellitus (NIDDM). RESEARCH DESIGN AND METHODS--Three ... [more ▼]
OBJECTIVE--To determine the role of the squatting test in the detection of early sympathetic neuropathy in patients with non-insulin-dependent diabetes mellitus (NIDDM). RESEARCH DESIGN AND METHODS--Three groups of nonsmoking, nonobese subjects were studied: 10 healthy subjects, 10 NIDDM patients without autonomic neuropathy (AN), and 10 NIDDM patients with AN defined by the presence of a pathological deep-breathing value. All subjects were given three postural tests: lying-to-standing, sitting-to-standing, and squatting test. Heart rate (HR) and finger arterial pressure were recorded with a noninvasive technique. RESULTS--Blood pressure (BP) fall (expressed as decremental area) was not significantly different among the groups at standing up after sitting or lying. By contrast, a significantly greater BP drop occurred in NIDDM patients with AN (1,123 +/- 245 mm2) compared with NIDDM patients without AN (460 +/- 232 mm2) or normal subjects (429 +/- 138 mm2, P < 0.001). The HR increase after all the orthostatic maneuvers was smaller in diabetic patients with AN (P < 0.01) compared with that recorded in other groups. Significant correlations were observed between BP fall after squatting and either the expiration:inspiration ratio at deep breathing (r = -0.77, P < 0.001) or the duration of diabetes (r = 0.76, P < 0.001). CONCLUSIONS--The intrinsic orthostatic load of the squatting test, which is greater than conventional postural maneuvers, makes the squatting test an easy and useful test to detect early orthostatic dysregulation in NIDDM. [less ▲]Detailed reference viewed: 31 (2 ULg)
Pulsatile insulin delivery has greater metabolic effects than continuous hormone administration in man: importance of pulse frequency.
; Scheen, André ; et al
in Journal of Clinical Endocrinology and Metabolism (1991), 72(3), 607-15
The aim of this study was to see if the greater effect of insulin on hepatic glucose output when insulin is given using 13-min pulses in man remains when the same amount of insulin is delivered using 26 ... [more ▼]
The aim of this study was to see if the greater effect of insulin on hepatic glucose output when insulin is given using 13-min pulses in man remains when the same amount of insulin is delivered using 26-min pulses. The study was performed on nine male healthy volunteers submitted to a 325 min glucose-controlled glucose iv infusion using the Biostator. The endogenous secretion of pancreatic hormones was inhibited by somatostatin. Three experiments were performed in each subject on different days and in random order. In all cases glucagon was replaced (58 ng min-1). The amounts of insulin infused were identical in all instances and were 0.2 mU kg-1 min-1 (continuous), 1.3 mU kg-1 min-1, 2 min on and 11 min off (13-min pulses) or 2.6 mU kg-1 min-1, 2 min on and 24 min off (26-min pulses). Blood glucose levels and glucose infusion rate were monitored continuously by the Biostator, and classic methodology using D-[3-3H] glucose infusion allowed to study glucose turnover. When compared with continuous insulin, 13-min insulin pulses induced a significantly greater inhibition of endogenous glucose production. This effect disappeared when insulin was delivered in 26-min pulses. We conclude that, in man, an adequate pulse frequency is required to allow the appearance of the greater inhibition of pulsatile insulin on endogenous glucose production. [less ▲]Detailed reference viewed: 22 (1 ULg)
Impaired insulin-induced erythrocyte magnesium accumulation is correlated to impaired insulin-mediated glucose disposal in type 2 (non-insulin-dependent) diabetic patients.
; ; et al
in Diabetologia (1988), 31(12), 910-5
Plasma and erythrocyte magnesium levels were measured by atomic absorption spectrometry in 12 healthy subjects and 12 moderately obese patients with Type 2 (non-insulin-dependent) diabetes mellitus. Basal ... [more ▼]
Plasma and erythrocyte magnesium levels were measured by atomic absorption spectrometry in 12 healthy subjects and 12 moderately obese patients with Type 2 (non-insulin-dependent) diabetes mellitus. Basal plasma and erythrocyte magnesium levels were significantly lower in diabetic patients than in control subjects. In vitro incubation in the presence of 100 mU/l insulin significantly increased magnesium erythrocyte levels in both control subjects (p less than 0.001) and patients with diabetes (p less than 0.001). However, even in the presence of 100 mU/l insulin, the erythrocyte magnesium content of patients with Type 2 diabetes was lower than that of control subjects. The in vitro dose-response curve of the effect of insulin on magnesium erythrocyte accumulation was shifted to the right when red cells of diabetic patients were used, with a highly significant reduction of the maximal effect. Such reduction of the maximal effect of insulin suggests that the impairment of insulin-induced erythrocyte magnesium accumulation observed in Type 2 diabetic patients results essentially from a post-receptor defect.(ABSTRACT TRUNCATED AT 250 WORDS) [less ▲]Detailed reference viewed: 15 (0 ULg)
Prostaglandines, secretion d'insuline et diabete sucre.
; ; Scheen, André et al
in Diabète & Métabolisme (1988), 14(6), 721-7
The islets of Langerhans have the enzymatic equipment permitting the synthesis of the metabolites of arachidonic acid: cyclo-oxygenase and lipo-oxygenase. Numerous studies have shown that cyclo-oxygenase ... [more ▼]
The islets of Langerhans have the enzymatic equipment permitting the synthesis of the metabolites of arachidonic acid: cyclo-oxygenase and lipo-oxygenase. Numerous studies have shown that cyclo-oxygenase derivatives, mainly PGE2, reduce the insulin response to glucose whereas lipo-oxygenase derivatives, mainly 15-HPETE, stimulate insulin secretion. So, for instance, drugs that increase prostaglandins synthesis as colchicine or furosemide inhibit insulin secretion while non steroid anti-inflammator drugs, mainly salicylates, which inhibit cyclo-oxygenase, enhance the insulin response to various stimuli. In type-2 (non insulin-dependent) diabetes, an increased sensitivity to endogenous prostaglandins has been proposed as a possible cause for the insulin secretion defect which characterizes this disease. Play in favor of this hypothesis the fact that the administration of PGE inhibits the insulin response to arginine in type-2 diabetics but not in normal subject and the fact that the administration of salicylates could improve the insulin response to glucose in some of these patients. [less ▲]Detailed reference viewed: 111 (0 ULg)
Primary role of glucagon release in the effect of beta-endorphin on glucose homeostasis in normal man.
; ; Scheen, André et al
in Acta Endocrinologica (1987), 115(2), 161-9
The present study aimed at evaluating the effect of human beta-endorphin on pancreatic hormone levels and on glucose metabolism in normal subjects. Infusion of 143 nmol/h beta-endorphin in 7 subjects ... [more ▼]
The present study aimed at evaluating the effect of human beta-endorphin on pancreatic hormone levels and on glucose metabolism in normal subjects. Infusion of 143 nmol/h beta-endorphin in 7 subjects caused a significant rise in plasma glucose concentrations (+ 1.7 +/- 0.3 mmol/l) which was preceded by a significant increase in peripheral plasma glucagon levels (+ 44 +/- 13 ng/l). No changes occurred in the plasma concentrations of insulin and catecholamines (adrenaline and noradrenaline). The influence of beta-endorphin per se on glucose homeostasis was studied in 7 other subjects using the euglycaemic clamp technique in which the endocrine pancreatic function was fixed at its basal level with somatostatin together with replacement of basal insulin and glucagon by the exogenous infusion of these hormones. In this new metabolic conditions, beta-endorphin failed to have significant influences on the various parameters of tracer-estimated glucose metabolism (production, utilization, and clearance) and on the plasma levels of the gluconeogenic precursors (glycerol and alanine). Moreover, the levels of pancreatic and counterregulatory hormones (cortisol and catecholamines) were not different between beta-endorphin and control studies. We conclude that the naturally occurring opioid peptide beta-endorphin produced an hyperglycaemic effect in man which appears to be mediated by glucagon. The opioid seems to have no direct effect on glucose metabolism. These results suggest that the metabolic effects of beta-endorphin in normal man are secondary to its impact on pancreatic hormone secretion and not a consequence of a direct modulation of glucose metabolism. [less ▲]Detailed reference viewed: 40 (0 ULg)
Insulin induces opposite changes in plasma and erythrocyte magnesium concentrations in normal man.
; ; et al
in Diabetologia (1986), 29(9), 644-7
Plasma and erythrocyte magnesium levels were measured by atomic absorption spectrophotometry in 10 healthy volunteers during an oral glucose tolerance test and during an euglycaemic hyperinsulinaemic ... [more ▼]
Plasma and erythrocyte magnesium levels were measured by atomic absorption spectrophotometry in 10 healthy volunteers during an oral glucose tolerance test and during an euglycaemic hyperinsulinaemic glucose clamp. At min 180 and 210 of the oral glucose tolerance test, a significant decline in plasma magnesium levels (p less than 0.01 and p less than 0.05 respectively) and a significant increase in erythrocyte magnesium levels (p less than 0.01 and p less than 0.05 respectively) were observed. Similar changes were seen during the second hour of the glucose clamp, during which euglycaemia (4.1 +/- 0.4 mmol/l) was maintained despite hyperinsulinaemia (110-130 mU/l). During in vitro incubations, glucose (5 mmol/l) did not modify erythrocyte magnesium levels. In contrast, erythrocyte magnesium levels were significantly increased (p less than 0.01) by insulin (100 mU/l), an effect entirely abolished by ouabain (5 X 10(-4) mol/l). These results suggest that insulin induces a shift of magnesium from the plasma to the erythrocytes both in vivo and in vitro. These data may help to interprete the abnormalities in magnesium circulating levels frequently reported in diabetic patients. [less ▲]Detailed reference viewed: 41 (0 ULg)