Diabete & metabolisme最新文献

Quinine and its isomer quinidine are well-known causes of iatrogenic hypoglycaemia, due to excessive insulin secretion. The situation is less clear regarding other anti-malarial quinine analogues. In particular, this adverse effect has never been described with mefloquine (Lariam). We report a case of hypoglycaemia after mefloquine therapy (1,500 mg over two days) for severe gastrointestinal cryptosporidiasis in a cachectic AIDS patient with protracted diarrhoea. Blood glucose levels, which were normal before treatment, dropped to 2.3 mmol/l within a few hours and were corrected by i.v. glucose infusion. Hypoglycaemia did not recur despite continued treatment. Rat islets of Langerhans exposed to mefloquine in vitro (10(-8) mol/l to 10(-3) mol/l) secreted significantly more insulin than control islets (up to 980 +/- 180 microU/ml/5 islets incubated with mefloquine 10(-3) mol/l, vs 20 +/- 4 microU/ml/5 untreated islets). Mechanisms and triggering factors of hypoglycaemia induced by mefloquine and some other anti-malarial quinine analogues are discussed. Clinicians who manage cachectic patients, particularly those with protracted diarrhoea and/or receiving anti-malarial drugs including mefloquine, should be aware of the risk of severe hypoglycaemia.

We compared the morphology of platelets obtained from diabetic patients in various stages of retinopathy and nephropathy with those of control patients. The platelets were collected on to polyethylene films, processed and observed under scanning electron microscopy. Different platelet morphologies were observed within the diabetic group, correlating with the severity of complications, whereas platelets appeared normal in the control group. After more extensive follow-up and comparative studies, these preliminary observations could provide another diagnostic tool for detecting and evaluating severe complications associated with diabetes.

We performed a case-control study to investigate the determinants of macular oedema in patients with diabetes mellitus. Patients with macular oedema (n = 20) were selected for study, together with a random sample of subjects without macular oedema (controls, n = 21). Both groups were similar for sex, type of diabetes, treatment and glycaemic control. Patients with maculopathy had higher systolic and diastolic blood pressure than controls (P < 0.006 and P < 0.03, respectively). Impaired renal function was proportionally higher in patients with maculopathy than in controls (60% vs 47%). Vibratory perception was more impaired in the maculopathy group than the control group (P < 0.02), and maculopathy was associated with the presence of cardiovascular autonomic neuropathy. R-R variation and the brake index were significantly lower in patients than control subjects (P < 0.01 for both). Moreover, the group with maculopathy had a greater fall in systolic blood pressure after standing than did the control group (P < 0.0001). Autonomic neuropathy may be associated with the development of maculopathy and retinopathy, although additional evidence is required to confirm this association. Conditions associated with high blood pressure may accelerate progression and aggravate maculopathy.

This series of three articles reviews the designs of studies which can be used to identify risk factors of a disease, here: diabetes or complications of diabetes. In the present issue of Diabete & Metabolisme, the first article of the series, we give the definition of a risk factor, along with measures of its force--relative risk and odds ratio, followed by the epidemiological definitions of the diseases: diabetes, coronary heart disease and hypertension. Risk factors are further discussed and we complete the discussion by some observations on the bias which can arise from a study or from its analysis, which can lead the researcher to the wrong conclusion. The three types of epidemiological studies which are used to determine whether factors are associated with a disease: observational or cross-sectional studies, cohort studies and case-cohort studies will be described in the second of the series in the next issue of the journal. Examples will be provided of each of these study types; their advantages and disadvantages will be discussed. In a third issue, the final paper will provide some examples of the study types and the identification of risk factors. The first examples involve diabetes and pancreatic cancer, the second birth weight and non-insulin dependent diabetes. Having found an association between a risk factor and diabetes, then we will discuss whether it can be considered to be a risk factor and if so and whether it is likely to be a cause of the disease.

Microalbuminuria is a risk marker for cardiovascular morbidity and mortality in Type 2 diabetes. We studied microalbuminuria among French Type 2 diabetic patients in general practice, because we set-up a trial using cardiovascular events as end-points. Two thousand twenty four volunteer patients were studied for Urinary Albumin Concentration (UAC) during outpatient visit to general practitioners. The UAC was measured on first samples. If UAC was positive (> or = 20 mg/l), a second sample was requested. If UAC was positive two times, persistently elevated UAC was identified (micro or macroalbuminuria). Clinical characteristic, cardiovascular antecedents and risk factors were studied. One hundred five first samples were excluded due to urinary infection; 1,217 others displayed normal UAC (< 20 mg/l); 63.4%; group N), 557 microalbuminuria (20-200 mg/l; 29.0%, group mu), and 145 others macroalbuminuria (> 200 mg/l; 7.6%; group M). Among subjects with positive first sample, 26.5% had persistent albuminuria. There was no intergroup difference for age, but males were more frequent in groups mu or M than N (p < 10(-4)). Blood pressure and body mass index varied between groups. Smokers and alcoholic subjects were more frequent in groups mu and M than N (p = 0.037 and p = 0.0003 respectively), as were cases with myocardial infarction (p = 0.0026), lower limb arteritis (p < 10(-4)), and laser-treated diabetic retinopathy (p = 0.0002). Antihypertensive treatments were taken by 61% of the subjects. Elevated UAC (micro or macroalbuminuria) is frequent among french Type 2 diabetic patients cared by their general practitioners, and is associated with a high cardiovascular risk profile.(ABSTRACT TRUNCATED AT 250 WORDS)

Nutri-Expert is a system for self-monitoring and dietetic education, accessible through Minitel. A preliminary randomised evaluation of one hundred diabetic patients in the Midi-Pyrénées region showed that Nutri-Expert improved dietetic knowledge, dietary habits and metabolic balance. The aim of the present study was to show that the system can be successfully prescribed to patients by physicians outside the center which originated it, indicating the benefit of a wider use of Nutri-Expert, among the diabetic population. One hundred and fifty-five patients, recruited by six French centres of diabetology, used Nutri-Expert from their homes for six months. Clinical examination, tests of dietetic knowledge and biological tests, including lipid fractions, were carried out before and after six months of use. After six months, there was a significant improvement in the patients' dietetic knowledge and in some biological parameters. Nutri-Expert is thus useful even when prescribed by a centre other than the hospital which devised the system. It is an additional beneficial tool in the ambulatory management of diabetic patients.

Amylin is a 37 amino-acid peptide mainly produced by the islet beta-cell. Aggregation of amylin is partly responsible for amyloid formation. Amyloid deposits occur both extracellularly and intracellularly and may contribute to beta-cell degeneration. Amylin is packed in beta-cell granules and cosecreted with insulin in response to the same stimuli but, unlike other beta-cell products, it is produced from specific a gene on chromosome 12. Basal, plasma amylin concentrations are around 5 pM, and increase fourfold after meals or glucose. Higher levels are found in cases of insulin resistance, obesity, gestational diabetes and in some patients with NIDDM. Low or absent levels are found in insulin-dependent diabetic patients. There are similarities between amylin and non beta-cell peptides such as calcitonin gene related peptides (CGRP). They may bind to the same receptor, determine similar post-receptor phenomena and qualitatively similar actions but with different degree of potency. The actions of amylin are multiple and mostly exerted in the regulation of fuel metabolism. In muscle, amylin opposes glycogen synthesis, activates glycogenolysis and glycolysis (increasing lactate production). Consequently, amylin increases lactate output by muscle and increases the plasma lactate concentration. In fasting conditions, this lactate may serve as a gluconeogenic substrate for the liver, contributing to replenish depleted glycogen stores and to increase glucose production. In non-fasting conditions, lactate can be transformed by liver in triglycerides. It is not clear at present whether amylin actions on the liver are direct or mediated by changes in circulating metabolites. A probably indirect effect of amylin in muscle is to decrease insulin- (or glucose)-induced glucose uptake, which may contribute to insulin resistance. Other actions include inhibition of glucose-stimulated insulin secretion and, in general, actions mimicking CGRP effects. Some of these actions are seen at supraphysiological concentrations. The physiopathological consequences of amylin deficiency, or excess are under active by investigated.