Multicentre Trial of a Programmable Implantable Insulin Pump in Type I Diabetes

Programmable implantable pumps permitting variable-rate intraperitoneal insulin infusion are currently investigated as a potential alternative to subcutaneous insulin therapy. An improved version of the Siemens implantable system has been evaluated in 6 European centres on 31 type I diabetic patients treated for 10–30 months. Contrary to other pump models there were no proven pump malfunctions and only one no-flow reduction unrelated to catheter obstruction. The latter resulted in 12 surgical catheter replacements. There were 2.0 incidents of programmer malfunctions per patient-year easily managed by reconfiguration or replacement. Insulin remained clear and active in the pump reservoir and glycaemic control remained in the near-normoglycaemic range. Thus, insulin therapy with the Siemens implantable pump is feasible and effective up to 2.5 years.

Review: Sulphonylureas and cardiovascular risk: facts and controversies

Cardiovascular complications are the principal cause of death in type 2 diabetes. The importance of glycaemic control in preventing cardiovascular complications has been demonstrated. However, some oral antidiabetic agents and especially some sulphonylureas (SU) have been accused of having a deleterious effect on cardiovascular risk. A retrospective analysis of the administrative database of Saskatchewan Health for 5,795 subjects, identified by their first-ever dispensation for an oral antidiabetic agent, suggests that a higher exposure to SUs was associated with increased mortality. Nevertheless, the effects of SUs on cardiac ATP-sensitive potassium channels in experimental studies vary between agents and studies, so that the clinical relevance of this phenomenon is unclear. Moreover, 11 years of follow-up of patients randomised to glibenclamide or chlorpropamide in the United Kingdom Prospective Diabetes Study demonstrated no adverse effects on a range of cardiovascular end points. Despite SU structural differences and differences in binding to cardiac SU receptors, the clinical evidence base does not support the selection of one sulphonylurea over another on the basis of ischaemic preconditioning, possibly because ischaemic preconditioning may be blunted or absent in diabetes. The main objective remains the prevention or delay of diabetic complications through improvement of glycaemic control together with other cardiovascular risk factors.

Glycaemic index methodology

The glycaemic index (GI) concept was originally introduced to classify different sources of carbohydrate (CHO)-rich foods, usually having an energy content of >80 % from CHO, to their effect on post-meal glycaemia. It was assumed to apply to foods that primarily deliver available CHO, causing hyperglycaemia. Low-GI foods were classified as being digested and absorbed slowly and high-GI foods as being rapidly digested and absorbed, resulting in different glycaemic responses. Low-GI foods were found to induce benefits on certain risk factors for CVD and diabetes. Accordingly it has been proposed that GI classification of foods and drinks could be useful to help consumers make 'healthy food choices' within specific food groups. Classification of foods according to their impact on blood glucose responses requires a standardised way of measuring such responses. The present review discusses the most relevant methodological considerations and highlights specific recommendations regarding number of subjects, sex, subject status, inclusion and exclusion criteria, pre-test conditions, CHO test dose, blood sampling procedures, sampling times, test randomisation and calculation of glycaemic response area under the curve. All together, these technical recommendations will help to implement or reinforce measurement of GI in laboratories and help to ensure quality of results. Since there is current international interest in alternative ways of expressing glycaemic responses to foods, some of these methods are discussed.

Ambulatory 24-hour fast using flexible insulin therapy in patients with type 1 diabetes

AIM

Prolonged fasting may be necessary in life for religious, medical and other reasons. For this reason, our study investigated the feasibility and safety of a 24-h fast conducted at home for patients with type 1 diabetes.

RESEARCH DESIGN AND METHODS

Thirty-four patients with type 1 diabetes performed a 24-h complete fast at home. Thirteen patients were treated with multiple insulin injections using either glargine (n=12) or NPH (n=1) as basal insulin. The remaining patients were treated with an insulin pump. All patients received their basal insulin only, which was adjusted to 40% of their total daily dose, and were monitored by either a Gold(®) or Guardian(®) continuous glucose monitoring (CGMS) device. Capillary glucose (SMBG) was targeted at 3.9-7.8 mmol/L, with a standardized protocol for correction of hyper- and hypoglycaemia. Interstitial glucose (IG) profiles were compared with the SMBG values; the IG profiles of patients using glargine or a pump and either of the two CGMS devices were also compared.

RESULTS

All of the patients completed the 24-h fast with no major incident. At the end of the fast, 80% of the IG values were on target. The route by which insulin was delivered made no difference, but there were more IG values on target in patients monitored by the Guardian(®) device. IG was below target in 104 occurrences and above-target in 34. After a mean intake of 10 g of sucrose, below-target IG was corrected within 30 min [range: 15-40]. The mean insulin dose to correct above-target episodes was 1 U.

CONCLUSION

Prolonged fasting is possible at home in patients with type 1 diabetes, provided the basal dose is adjusted. The use of CGMS is not necessary, but offers useful information on the patient's IG profile during the fast.

Peak-time determination of post-meal glucose excursions in insulin-treated diabetic patients

OBJECTIVE

This study aimed to determine the optimal time to measure peak blood glucose values to find the best approach for self-monitoring blood glucose after a meal.

DESIGN AND METHODS

For this retrospective analysis, 69 ambulatory continuous glucose-monitoring system (CGMS) profiles were obtained from 75 consecutive insulin-treated patients with diabetes. The parameters measured were the peak post-meal blood glucose values, peak time, and rates of increase and decrease to and from the zenith of the resulting curves.

RESULTS

The mean peak time after breakfast was 72+/-23 min, which was reached in less than 90 min in 80% of the patients. The apparent glucose rate of increase from pre-meal to the maximum postprandial value was 1.23+/-0.76 mg/dL/min, while the glucose rate of decrease was 0.82+/-0.70 mg/dL/min. Peak time correlated with the amplitude of postprandial excursions, but not with the peak glucose value. Also, peak times were similar after breakfast, lunch and dinner, and in type 1 and type 2 diabetic patients.

CONCLUSION

To best assess peak postprandial glucose levels, the optimal time for blood glucose monitoring is about 1h and 15 min after the start of the meal, albeit with wide interpatient variability. Nevertheless, 80% of post-meal blood glucose peaks were observed at less than 90 min after the start of the meal.

Prevalence and predictive factors of sleep apnoea syndrome in type 2 diabetic patients

AIM

This study aimed to assess the prevalence and characteristics of sleep apnoea syndrome (SAS) in patients hospitalized for poorly controlled type 2 diabetes.

METHODS

An overnight ventilatory polygraphic study was systematically performed in 303 consecutive patients.

RESULTS

Overall, 34% of these patients had mild SAS, as defined by a respiratory disturbance index (RDI) of 5-15; 19% had moderate SAS (RDI: 16-29) and 10% had severe SAS (RDI>or=30). The SAS was obstructive in 99% of the apnoeic patients. The percentage of patients with excessive daytime sleepiness (Epworth sleepiness scale>10), fatigue or nocturia did not significantly differ among patients with severe, moderate or mild SAS versus non-apnoeic patients. The percentage of patients who snored was significantly higher in patients with severe or moderate SAS versus non-apnoeic patients. HbA(1c), duration of diabetes and the prevalences of microalbuminuria, retinopathy and peripheral neuropathy did not significantly differ among patients with severe, moderate or mild SAS versus non-apnoeic patients. However, patients with severe or moderate SAS had significantly higher values for body mass index, waist circumference and neck circumference than non-apnoeic patients.

CONCLUSION

In type 2 diabetic patients with poor diabetic control, obstructive SAS is highly prevalent and related to abdominal obesity, and should be systematically screened for, as it cannot be predicted by the clinical data.

Treatment for 2 mo with n 3 polyunsaturated fatty acids reduces adiposity and some atherogenic factors but does not improve insulin sensitivity in women with type 2 diabetes: a randomized controlled study

BACKGROUND

Information is lacking on the potential effect of n-3 polyunsaturated fatty acids (PUFAs) on the adipose tissue of patients with type 2 diabetes.

OBJECTIVE

We evaluated whether n-3 PUFAs have additional effects on adiposity, insulin sensitivity, adipose tissue function (production of adipokines and inflammatory and atherogenic factors), and gene expression in type 2 diabetes.

DESIGN

Twenty-seven women with type 2 diabetes without hypertriglyceridemia were randomly allocated in a double-blind parallel design to 2 mo of 3 g/d of either fish oil (1.8 g n-3 PUFAs) or placebo (paraffin oil).

RESULTS

Although body weight and energy intake measured by use of a food diary were unchanged, total fat mass (P < 0.019) and subcutaneous adipocyte diameter (P < 0.0018) were lower in the fish oil group than in the placebo group. Insulin sensitivity was not significantly different between the 2 groups (measured by homeostasis model assessment in all patients and by euglycemic-hyperinsulinemic clamp in a subgroup of 5 patients per group). By contrast, atherogenic risk factors, including plasma triacylglycerol (P < 0.03), the ratio of triacylglycerol to HDL cholesterol (atherogenic index, P < 0.03), and plasma plasminogen activator inhibitor-1 (P < 0.01), were lower in the fish oil group than in the placebo group. In addition, a subset of inflammation-related genes was reduced in subcutaneous adipose tissue after the fish oil, but not the placebo, treatment.

CONCLUSIONS

A moderate dose of n-3 PUFAs for 2 mo reduced adiposity and atherogenic markers without deterioration of insulin sensitivity in subjects with type 2 diabetes. Some adipose tissue inflammation-related genes were also reduced. These beneficial effects could be linked to morphologic and inflammatory changes in adipose tissue. This trial was registered at clinicaltrials.gov as NCT0037.

A review of the metabolic syndrome

While the concept of this syndrome has been described more than 60 years ago, and more formally almost 20 years ago, the controversy continues as to its utility, which of the various syndrome definitions should be used and their ability to predict diabetes and/or cardiovascular disease. The metabolic syndrome, of cardiovascular risk factors, provides an early warning of at risk subjects and emphasises the need to treat more aggressively (by at least lifestyle modification) patients with multiple abnormalities even though the abnormalities might be slight. Further, the syndrome can be easily used in clinical practice and when it is assessed against the background of the patient's age, sex and smoking habits, it provides an evaluation of potential cardiovascular risk. Prospective intervention studies are the only means of definitively accepting or refuting the usefulness of the syndrome. The metabolic syndrome is an entity which merits attention from both the medical profession and public health authorities.

[Apollinaire Bouchardat and diabetes]

Apollinaire Bouchardat (1806-1886) begins its hospital formation by the pharmacy internship and then starts his medical studies. He becomes chief pharmacist of the Hôtel-Dieu in 1835 and during 20 years, he devotes his life to the study of diabetes. Through observations and experiments, he builds new concepts allowing to establish the bases of clinical diabetology due to a solid competence in fundamental sciences and his intelligence in semiologic observations. He studied urine glucose as a reflect of the clinical state of the patients and, in order to carry out its exact measurement, he recommended the use of the polarimeter. He engaged himself in many studies concerning well as the patients diet as to their way of life. Thus he recommended a large decrease in starchy foods and sugars, he encouraged physical exercise and considered that, since the assumption of responsibility of the diabetic was serious, it could foresee the remission of disease. Due to encouraging results, he developed self-monitoring by the patients by the means of simple chemical reagents, convinced that making patients responsible, despite difficulties of the diet, could modify their attitude. Precursor of the modern diabetology, one can consider that he founded it as a true medical discipline. Its major work: De la Glycosurie ou diabète sucré, son traitement hygénigue is pro-bably the first textbook on diabetes, associating clinical observations, experimental steps and proposals for a treatment based on the patients' way of life: mainly diet and exercise: still preached steps, a hundred and fifty years later.

Motivational effects of 12-week moderately restrictive diets with or without special attention to the Glycaemic Index of foods

Low glycaemic index (GI) diets may facilitate weight loss via behavioural and/or endocrine mechanisms. This study investigated whether the outcomes of the Weight Watchers POINTS Weight-Loss System could be improved by encouraging dieters to select low GI, high-carbohydrate foods. Ninety-six women (age 20-72 years; BMI 25-40 kg/m2) were recruited as they started the Weight Watchers POINTS programme for 12 weeks. Weekly classes were randomized so that seven (forty-five women) followed the regular programme while seven others (fifty-one women) followed a revised programme encouraging the selection of low GI foods. Anthropometric and biochemical parameters were measured before and after the 12-week diets. Participants rated hunger and desire to eat using visual analogue scales on 1 d per week, several times per d. Attrition was the same in both groups (32 v. 30 %), as well as many benefits (5 % weight loss, decreases in insulinaemia and blood lipids, waist and hip circumferences, blood pressure). Hunger and desire to eat were rated consistently lower in the low GI group over the 12-week diet. Group differences in subjective sensations were especially large in the afternoon. The 12-week weight management yielded many significant anthropometric and biochemical benefits that were not improved by encouraging dieters to select low GI foods. The subjective benefits (lower hunger and desire to eat) of the low GI diet may be a worthwhile contribution to the motivation of dieters that might affect adherence to the diet over the long term.

Low glycemic index foods should play a role in improving overall glycemic control in type-1 and type-2 diabetic patients and, more specifically, in correcting excessive postprandial hyperglycemia

There is a large bulk of evidence that using low glycemic index (GI) foods has a very significant impact on the amelioration of metabolic disturbances observed in diabetic and/or hyperlipidemic patients and in subjects affected by the metabolic syndrome. Studies bringing convincing evidence against this concept are very rare if any. Improvement is observed not only in postprandial blood glucose and insulin variations but also in circulating plasma lipid levels and the morphology and function of adipocytes. Using the concept of low GI foods in diet counseling of diabetic patients is not exclusive of other measures to improve postprandial and overall blood glucose control. On the contrary, the use of low GI foods should be considered as one of other means and tools available to improve diabetes control (such as other dietary modifications, use of specific and nonspecific drug therapy altering postprandial blood glucose). Among these therapies, the most promising ones are alpha-glucosidase inhibitors, glynides, rapid insulin analogues and in the near future the GLP1 analogue. Again, all these classes of drugs could be associated with one another in order to obtain a postprandial delta excursion target of not below 20 and not above 40-50 mg/dl blood glucose.

Effect of baking process on postprandial metabolic consequences: randomized trials in normal and type 2 diabetic subjects

OBJECTIVE

To determine the impact of the form, fibre content, baking and processing on the glycaemic, insulinaemic and lipidaemic responses of different French breads.

DESIGN AND SUBJECTS

First study: Nine healthy subjects were randomized to consume in a crossover design one of six kinds of French bread (each containing 50 g available carbohydrate): classic baguette, traditional baguette, loaf of wholemeal bread (WM-B), loaf of bread fermented with yeast or with leaven, a sandwich and a glucose challenge as reference.

RESULTS

The glycaemic index (GI) values ranged from 57+/-9% (mean+/-s.e.m.), for the traditional baguette, to 85+/-27% for the WM-B. No significant difference was found among the different tested bread. The insulinaemic index (II), however, of the traditional baguette and of the bread fermented with leaven were lower than the other breads (analysis of variance: P<0.01). Postprandial plasma triglycerides showed similar profiles. The traditional baguette tended to decrease postprandial free fatty acids compared to levels after the classic baguette.

RESULTS

The GI of the traditional baguette was lower than that of the classic baguette (n=8, venous blood: 70+/-4 vs 75+/-4, P=0.002; capillary blood: 69+/-5 vs 83+/-6, P=0.028, respectively).

CONCLUSIONS

Some varieties of French bread (the TB) have lower II, in healthy subjects, and lower GI, in type 2 diabetic subjects, than that of the other varieties. These results might be due to bread processing difference rather than fibre content.

SPONSORSHIPS

Supported by grants from the National French Milling Association.

Postprandial glycaemia: a plea for the frequent use of delta postprandial glycaemia in the treatment of diabetic patients

Postprandial hyperglycaemia is a phenomenon often neglected by patients as well as doctors. While patients only voluntarily measure morning and preprandial capillary glycaemia, physicians do not encourage the measurement of anything further. The specific role of postprandial hyperglycaemia in the determination of late diabetes complications, such as micro- and macroangiopathy, remains controversial. It is however undeniable that the postprandial glycaemic excursion plays an important role in total hyperglycaemia reflected by an increase in glycated haemoglobin. The postprandial glycaemia measurement or, more appropriately, the postprandial glycaemic excursion (the difference between postprandial and preprandial glycaemia, also called the postprandial delta glycaemia), is important to measure and there are specific tools to correct it when abnormal. Postprandial delta glycaemia should lie between 30 and 50 mg/dl. It is thus suggested to measure it not necessarily on a daily basis, but when it is expected that the glycaemic couple, or "pre-postprandial couple", is high. The specific tools for treatment of postprandial hyperglycaemia can be dietetic (carbohydrate quantity reduction or ingestion of fiber-rich and/or low glycaemic index foods) or medicinal. Among the specific medicinal treatments are the alpha-glucosidase-inhibitors (which can be used for both type 1 and type 2 diabetic patients), glinides and fast-acting insulins. Rather than first treating fasting and interprandial hyperglycaemia, as has been commonly done by physicians, the authors recommend the simultaneous treatment of pre-, inter- and postprandial hyperglycaemia. The optimal time at which to evaluate postprandial glycaemia is approximately 1 h and 15 minutes for type 1 and type 2 diabetic patients.

The T-786C and C774T endothelial nitric oxide synthase gene polymorphisms independently affect the onset pattern of severe diabetic retinopathy

Genetic factors could be implicated in the pathogenesis of severe diabetic retinopathy (DR). Recently, we reported a strong association between the eNOS4b/a endothelial nitric oxide synthase (eNOS) polymorphism and severe DR. To examine whether T-786C and C774T eNOS polymorphisms are involved in severe DR, 254 Caucasians with longstanding C-peptide-negative type 1 diabetes, 128 patients with absent/mild DR (control group), and 126 patients with preproliferative/proliferative DR (study group) were genotyped. The distribution of T-786C and C774T eNOS polymorphisms was in Hardy-Weinberg equilibrium and did not differ between the study and control groups. However, in case patients (n=126), T-786C and C774T polymorphisms influenced the onset pattern of severe DR (P=0.0169 and P=0.0257, respectively). The C-786C genotype was associated with early-onset severe DR (duration of diabetes: 15.2+/-5.9 vs. 19.4+/-6.3 years, P=0.0105), and the homozygous T774T genotype was associated with late-onset severe DR (24.3+/-7.0 vs. 18.4+/-6.2 years, P=0.0067). In the case of patients with high glycosylated hemoglobin levels (HbA1c >8%, n=88), the association between the T-786C polymorphism and early-onset severe DR was stronger (P=0.0068). Case patients carrying the C-786C genotype had higher HbA1c values (9.61+/-1.89%) than those carrying the T-786T genotype (8.93+/-1.47%, P=0.0173). Multivariate analysis showed that T-786C polymorphism was the best independent factor for onset pattern of severe DR (P<0.001). These findings, supported by previous associations between eNOS4b/a polymorphism and DR, suggest that T-786C and C774T eNOS polymorphisms affect the onset pattern of severe DR.

Dietary fish oil positively regulates plasma leptin and adiponectin levels in sucrose-fed, insulin-resistant rats

Insulin resistance and adiposity induced by a long-term sucrose-rich diet (SRD) in rats could be reversed by fish oil (FO). Regulation of plasma leptin and adiponectin levels, as well as their gene expression, by FO might be implicated in these findings. This study was designed to evaluate the long-term regulation of leptin and adiponectin by dietary FO in a dietary model of insulin resistance induced by long-term SRD in rats and to determine their impact on adiposity and insulin sensitivity. Rats were randomized to consume a control diet (CD; n = 25) or an SRD (n = 50) for 7 mo. Subsequently, the SRD-fed rats were randomized to consume SRD+FO or to continue on SRD for an additional 2 mo. Long-term SRD induced overweight and decreased both plasma leptin and adiponectin levels without change in gene expression. Dyslipidemia, adiposity, and insulin resistance accompanied these modifications. Shifting the source of fat to FO for 2 mo increased plasma levels of both adipokines, reversed insulin resistance and dyslipidemia, and improved adiposity. These results were not associated with modifications in gene expression. These results suggest that increasing both adipokines by dietary FO might play an essential role in the normalization of insulin resistance and adiposity in dietary-induced, insulin-resistant models.

Association between a protein polymorphism in the start codon of the vitamin D receptor gene and severe diabetic retinopathy in C-peptide-negative type 1 diabetes

CONTEXT

The vitamin D (VD) receptor (VDR) is extensively expressed in retina. The plasma concentration of 1,25-dihydroxyvitamin D3 has been inversely correlated with the severity of diabetic retinopathy (DR), which raises the possibility that VD, through its antiinflammatory, antioxidant, antiproliferative, and antiangiogenic properties, may protect diabetic retina. The TaqI VDR polymorphism has been associated with severe DR. The FokI VDR polymorphism is a T-to-C substitution in the first codon (f allele), abolishing the first translation initiation site and resulting in a peptide lacking three amino acids (F allele), which increases the transcriptional activity of VDR.

OBJECTIVE AND DESIGN

To examine whether FokI polymorphism is involved in severe DR, 254 Caucasians with longstanding C-peptide-negative type 1 diabetes, 128 patients with absent/mild DR (control group), and 126 patients with preproliferative/proliferative DR (study group) were genotyped using PCR-restriction fragment length polymorphism analysis.

RESULTS

The genotype distribution was in Hardy-Weinberg equilibrium and was different between groups (P = 0.046). The frequency of F allele was significantly higher in the control (66.4%) than in the study group (56%, odds ratio = 0.64, 95% confidence interval 0.44-0.92, P = 0.016). In subjects with fewer than 25 yr of diabetes duration (median value, n = 134), this association was strongly increased (P = 0.0008).

CONCLUSIONS

In conclusion, we observed, in a cohort of Caucasians with C-peptide-negative type 1 diabetes, a novel association between the functional FokI VDR polymorphism and severe DR, especially among subjects with fewer than 25 yr of diabetes duration.

Non food-related environmental stimuli induce increased meal intake in healthy women: comparison of television viewing versus listening to a recorded story in laboratory settings

The objective of the present study, performed under laboratory conditions, was to assess the impact of two non food-related environmental stimuli (television and auditory stimulus) on meal intake. Normal weight women (N = 48) ate lunch in the laboratory once a week for four weeks. All lunches were identical and included popular traditional foods, of which participants could eat ad libitum. The first and last lunches were eaten in the absence of the environmental stimuli (control conditions); in the other two tests, presented in random order, subjects ate while either watching television or listening to a recorded story. Energy intakes were determined for each meal, as were ratings of hunger, satiety and meal palatability. Subjects filled out the Three Factor Eating Questionnaire at the end of the meal series. Meal size was significantly larger in the presence of both environmental stimuli than in both control conditions (+11.6%, 280 kJ, p < 0.01). Television viewing induced a significant stimulation of intake, equal to, but not greater than the effect of the auditory stimulus. Ratings of hunger, satiety, and palatability were not significantly different between conditions, despite the differences in intake. These results suggest that environmental, non food-related stimuli could stimulate intake regardless of hunger-satiety or palatability conditions. Environmental stimulation of eating should be tested in other populations, eg subjects with weight control problems, and other conditions, e.g. free-living.

Effects of dipeptide administration on hypoglycaemic counterregulation in type 1 diabetes

OBJECTIVES

To investigate if a dipeptide made of glutamine and alanine is able to contribute to the recovery from insulin-induced hypoglycaemia in type 1 diabetes.

RESEARCH DESIGN AND METHODS

Fifteen adult type 1 patients were randomly assigned to study group (n=7): intravenous infusion of 20 g Dipeptiven in normal saline (i.e., 8 g alanine and 13 g glutamine), or control group (n=8): same infusion, normal saline only. A 150 min gradual hypoglycaemic hyperinsulinemic clamp was administered after 2 h of infusion. Counterregularory hormones, symptoms, and cognitive function (4 choice reaction test) were regularly measured during the study.

RESULTS

Blood glucose and glucose infusion rates were similar in the 2 groups. Circulating levels of alanine and glutamine peaked at 90 min and remained elevated throughout the test. This was associated with significant differences in: glucagonemia 107 +/- 20 vs 58 +/- 8 pg/ml, and neuroglycopenic symptoms scores: 7 +/- 3 vs 18 +/- 13, at t 150 min, in study and control group, p<0.05. Dysautonomic symptoms, cognitive tests as well as epinephrine, norepinephrine, cortisol and growth hormone were similar between groups.

CONCLUSION

Intravenous infusion of a dipeptide made of alanine and glutamine is capable to reactivate glucagon secretion during insulin-induced hypoglycaemia and to reduce hypoglycaemic symptoms.

The potential of metformin for diabetes prevention

Well designed intervention trials, such as the Diabetes Prevention Program (DPP), have demonstrated the potential of lifestyle interventions or pharmacologic treatments for the prevention or delay of type 2 diabetes in subjects with impaired glucose tolerance (IGT). Lifestyle interventions are likely to form the cornerstone of the management of IGT in the future, as they do in the management of type 2 diabetes today. However, it remains to be seen whether the intensive lifestyle interventions employed in trials such as the DPP can be transferred successfully from the highly structured environment of a randomised trial to routine, day-to-day management within the primary care sector. Thus, pharmacologic treatment may provide an important additional option where subjects are unwilling or unable to improve their diet and levels of physical activity. Treatment with metformin significantly reduced the incidence of diabetes in subjects with IGT and high-normal fasting plasma glucose in the DPP. Moreover, metformin was well tolerated, and health economic analyses suggest that metformin treatment is cost-effective in the US and Europe. The DPP investigators found that the protective effect of metformin persisted beyond the end of the study, and estimated that only one quarter of the protection arose from a short-lived pharmacological effect. The results of the DPP identify metformin as an effective option for the prevention of diabetes in subjects with IGT and impaired fasting glucose.

Dietary fish oil increases lipid mobilization but does not decrease lipid storage-related enzyme activities in adipose tissue of insulin-resistant, sucrose-fed rats

Fish oil feeding has been shown to limit visceral fat accumulation in insulin-resistant rats. Our goal was to determine whether this finding is due to increased fat mobilization or decreased lipid storage. Adipocytes were isolated from rats fed for 3 wk a diet containing 57.5 g/100 g sucrose and 14 g/100 g lipids as either fish oil (SF) or a mixture of standard oils (SC); there was also a reference group (R). Substituting fish oil for standard oils protected rats from visceral fat hypertrophy, hypertriglyceridemia and hyperglycemia. The stimulation of lipolysis was greater in adipocytes isolated from SF-fed rats than in those from SC-fed rats. Fatty acid synthase (FAS) activity was markedly lower in the liver but not in the adipose tissues of rats fed SF. Lipoprotein lipase (LPL) activity was 2.2-fold higher in the adipose tissues but not in the muscle in rats fed the SF diet than in those fed the SC diet. The decrease in visceral fat in rats fed fish oil could be attributed to decreased plasma triacylglycerol concentration and/or increased lipid mobilization rather than to reduced lipid storage.

[To observe, or to observe and to act?]

The UKPDS Study has clearly shown that diagnosis and therapeutic management of type 2 diabetes and its complications occur lately in the course of the disease, and that diabetes control deteriorates and micro- and macrovascular complications risk increase with the duration of the disease. Recent data from the STENO-2 study demonstrate the cardiovascular benefit of an intensified multifactorial management of diabetes and associated cardiovascular risk factors in type 2 diabetic patients at high cardiovascular risk. This paper advocates for an early intensive management of type 2 diabetes from the diagnosis in order to maintain glycaemia and glycosylated haemoglobin at the lowest possible level (even less than the current recommended levels) and for an early aggressive management of all known risk factors (including overweight and obesity, elevated arterial blood pressure, dyslipidaemias, etc.). This implies the early use of multiple therapy at adequate doses and a dramatic change in conventional medical habits, from a late and delayed management of diabetes and its complications to their early prevention using all therapeutic resources.

Accuracy of the continuous glucose monitoring system in inpatient and outpatient conditions

OBJECTIVE

To evaluate in inpatient and outpatient conditions, using only non-calibration data, the accuracy of the Continuous Glucose Monitoring System (CG-MS).

RESEARCH DESIGN AND METHODS

Twelve, 21 and 20 type 1 diabetic patients participated in 3- day inhospital, 6-day ambulatory (i.e., 2 sensors worn consecutively) and 3-day ambulatory studies. Capillary glucose tests (7-8/day) served as comparisons. Pairs of data (excluding the 4 daily pairs used automatically by the CGMS for calibrations) were analyzed using correlation coefficient, error -grid analysis, and mean of absolute differences.

RESULTS

Two third and half of the sensing days were qualified as "optimal", i.e., interpretable by the CGMS program in the inpatient and outpatient studies, respectively. Correlation coefficient was 0.92, 0.81 and 0.73 in the inpatient, 6 day outpatient and 3-day outpatient studies. 98%, 93% and 96% of the data fell in the A or B error-grid "clinically acceptable" zones. Mean absolute differences between sensor and glucometer values were 25 +/- 2, 34 +/- 5 and 32 +/- 5 mg/dl.

CONCLUSION

CGMS may be used for assessment of glycemic trends, though accuracy is more in the range of glucometers than of laboratory tests. Inhospital utilisation improved accuracy and 6-day rather than 3-day sessions may be more appropriate to evaluate day to day reproducibility of glucose profile.

[Metabolic syndrome: to observe or to act?]

Type 2 diabetes is characterized by a very high cardiovascular risk. This risk has usually been present for a very long time when diabetes is diagnosed. The combination of several metabolic abnormalities known as metabolic syndrome seems to be responsible for this increased risk. Insulin resistance is a major component of metabolic syndrome, which also includes clinical abnormalities such as increased waist circumference, hypertriglyceridemia, high blood pressure. It is very important to screen subjects with metabolic syndrome because of their high risk. Furthermore, some pharmaceutical agents could be effective in reducing the risk related to insulin resistance. Metformin effectiveness has been shown for the reduction of diabetes related complications and mortality, mainly in the cardiovascular field. Its place among the other potentially active agents remains to be determined as well as how it should be used in combination to lifestyle changes and how effective it is on a long-term basis.

Health benefits of low glycaemic index foods, such as pulses, in diabetic patients and healthy individuals

The present paper covers the health benefits of low glycaemic index foods, such as pulses. Nutritional factors potentially play a crucial role in health and disease. A low-fat, high-carbohydrate diet is often recommended as a part of a healthy life-style. Historical works have shown that carbohydrate foods differ in their ability to affect post-ingestive glycaemia. The glycaemic index concept allows a ranking of carbohydrate-rich foods in terms of their blood glucose raising potential. Pulses are foods with very low glycaemic index values. Numerous studies have documented the health benefits that can be obtained by selecting foods of low glycaemic index. These benefits are of crucial importance in the dietary treatment of diabetes mellitus: glycaemic control is improved as well as several metabolic parameters, such as blood lipids. The results of human studies have been confirmed by animal experiments in the field of diabetes. Diets with low glycaemic index value improve the prevention of coronary heart disease in diabetic and healthy subjects. In obese or overweight individuals, low-glycaemic index meals increase satiety and facilitate the control of food intake. Selecting low glycaemic index foods has also demonstrated benefits for healthy persons in terms of post-prandial glucose and lipid metabolism. Several public health organizations have recently integrated consideration of the glycaemic index in their nutritional recommendations for patients with metabolic diseases and for the general population.

Glycaemic and insulinaemic responses to a new hydrogenated starch hydrolysate in healthy and type 2 diabetic subjects

BACKGROUND

Industrialists are searching for a sugar replacement in confectioneries such as hard candies, gum and chocolate. Lycasin HBC is a suitable candidate. Nevertheless, no information on its plasma glucose and insulin responses exists. Therefore, we aimed to evaluate the glycaemic and insulinaemic indices of Lycasin HBC in healthy subjects and in subjects with type 2 diabetes mellitus.

METHODS

Six healthy and six type 2 diabetic men participated in the study. Each subject absorbed, after an overnight fast, a challenge of either 50 g of glucose or 50 g of Lycasin HBC using a randomised double-blind crossover design. Blood samples for measuring plasma glucose and insulin concentrations were collected during a 3 hour period.

RESULTS

The calculated glycaemic index of Lycasin HBC was 47 +/- 10% in healthy subjects and 25 +/- 6% in patients with type 2 diabetes mellitus. The insulinaemic index of Lycasin HBC was 23 +/- 4% and 39 +/- 14%, respectively. As glucose levels oscillate in a very limited range in normal healthy subjects, the insulinaemic index must be considered here. On the other hand, it is the glycaemic rather than the insulinaemic index that must be assessed in diabetic subjects due to impairment of insulin secretion.

CONCLUSIONS

The tested Lycasin HBC showed a low insulinaemic index in healthy subjects (23 +/- 4%) and a low glycaemic index (25 +/- 6%) in type 2 diabetic patients. Thus, it might be considered as an interesting sucrose substitute in confectionery for individuals with or without diabetes.

Dietary (n-3) polyunsaturated fatty acids up-regulate plasma leptin in insulin-resistant rats

The study was designed to evaluate the chronic regulation of plasma leptin by dietary (n-3) polyunsaturated fatty acids (PUFA) in insulin-resistant, sucrose-fed rats. Male Sprague-Dawley rats were randomly assigned to consume for 3 or 6 wk a diet containing 57.5% (g/100 g) sucrose and 14% lipids as either fish oil (SF) or control oils (SC). After 3 and 6 wk of consuming the SF diet, plasma leptin was 70% (P < 0.001) and 75% (P < 0.05) greater, respectively, than in rats fed the SC diet. The same result was found when plasma leptin was adjusted by total fat mass, as measured by dual-energy X-ray absorptiometry. Despite high leptin levels, food intake of rats fed the SF diet was greater than in SC-fed rats without any difference in body weight or total fat mass. After 3 wk, accumulated leptin in epididymal and retroperitoneal adipose tissue was higher in the SF-fed rats than in the SC-fed rats. However, after 6 wk, tissue leptin in the SF-fed rats did not differ from that of the SC-fed rats. The SF diet increased adipose tissue glucose transporter-4 protein quantity and prevented the sucrose-induced elevations in plasma triglycerides and free fatty acids. When all SC- and SF-fed rats (both diets and feeding durations) were considered, plasma leptin levels were positively correlated with body weight (r = 0.5, P < 0.0001) and with total fat mass (r = 0.5, P < 0.0005). These results suggest that plasma leptin at a given time could be inappropriately high for a given fat mass in insulin-sensitive rats fed (n-3) PUFA.

Regulation of glucose transport and transporter 4 (GLUT-4) in muscle and adipocytes of sucrose-fed rats: effects of N-3 poly- and monounsaturated fatty acids

The goal of this study was to compare the short-term effects of dietary n-3 polyunsaturated (fish oil) and monounsaturated (olive oil) fatty acids on glucose transport, plasma glucose and lipid controls in a dietary insulin resistance model using sucrose-fed rats. The underlying cellular and molecular mechanisms were also determined in the muscle and adipose tissue. Male Sprague-Dawley rats (5 weeks old) were randomized for diets containing 57.5 % (w/w) sucrose and 14 % lipids as either fish oil (SF), olive oil (SO) or a mixture of standard oils (SC) for 3 weeks. A fourth control group (C) was fed a diet containing 57.5 % starch and 14 % standard oils. After three weeks on the diet, body weight was comparable in the four groups. The sucrose-fed rats were hyperglycemic and hyperinsulinemic in response to glucose load. The presence of fish oil in the sucrose diet prevented sucrose-induced hyperinsulinemia and hypertriglyceridemia, but had no effect on plasma glucose levels. Insulin-stimulated glucose transport in adipocytes increased after feeding with fish oil (p < 0.005). These modifications were associated with increased Glut-4 protein (p < 0.05) and mRNA levels in adipocytes. In the muscle, no effect was found on Glut-4 protein levels. Olive oil, however, could not bring about any improvement in plasma insulin, plasma lipids or Glut-4 protein levels. We therefore conclude that the presence of fish oil, in contrast to olive oil, prevents insulin resistance and hypertriglyceridemia in rats on a sucrose diet, and restores Glut-4 protein quantity in adipocytes but not in muscle at basal levels. Dietary regulation of Glut-4 proteins appears to be tissue specific and might depend on insulin stimulation and/or duration of dietary interventions.

Five-week, low-glycemic index diet decreases total fat mass and improves plasma lipid profile in moderately overweight nondiabetic men

OBJECTIVE

To evaluate whether a 5-week low-glycemic index (LGI) diet versus a high-glycemic index (HGI) diet can modify glucose and lipid metabolism as well as total fat mass in nondiabetic men.

RESEARCH DESIGN AND METHODS

In this study, 11 healthy men were randomly allocated to 5 weeks of an LGI or HGI diet separated by a 5-week washout interval in a crossover design.

RESULTS

The LGI diet resulted in lower postprandial plasma glucose and insulin profiles and areas under the curve (AUCs) than the HGI diet. A 5-week period of the LGI diet lowered plasma triacylglycerol excursion after lunch (AUC, P < 0.05 LGI vs. HGI). These modifications were associated with a decrease in the total fat mass by approximately 700 g (P < 0.05) and a tendency to increase lean body mass (P < 0.07) without any change in body weight. This decrease in fat mass was accompanied by a decrease in leptin, lipoprotein lipase, and hormone-sensitive lipase RNAm quantities in the subcutaneous abdominal adipose tissue (P < 0.05).

CONCLUSIONS

We concluded that 5 weeks of an LGI diet ameliorates some plasma lipid parameters, decreases total fat mass, and tends to increase lean body mass without changing body weight. These changes were accompanied by a decrease in the expression of some genes implicated in lipid metabolism. Such a diet could be of benefit to healthy, slightly overweight subjects and might play a role in the prevention of metabolic diseases and their cardiovascular complications.

eNOS4 polymorphism of the endothelial nitric oxide synthase predicts risk for severe diabetic retinopathy

BACKGROUND

Genetic factors may be involved in the development, and particularly in the severity, of diabetic retinopathy (DR), in addition to chronic hyperglycaemia. Increased nitric oxide generation has been suggested to play a significant role in the pathogenesis of DR.

AIMS AND METHODS

To examine whether the eNOS4 is involved in the risk of severe DR, 200 unrelated Caucasian Type 1 diabetic patients of long duration were randomly selected (M/F 103/97, age 44.4 +/- 12.4 years, diabetes duration 27.7 +/- 10.0 years, body mass index 24.3 +/- 3.4 kg/m2, HbA1c 8.6 +/- 1.3%). The eNOS4 polymorphism was analysed by polymerase chain reaction, and DR by retinal angiography and classified as presence (n = 101) or absence (n = 99) of severe (proliferative or pre-proliferative) DR.

RESULTS

The genotype distribution of eNOS4b/b (wild-type), eNOS4b/a (heterozygous) and eNOS4a/a (homozygous) was 72%, 24.5% and 3.5%, respectively. Frequency of eNOS4a/a was significantly lower in patients with severe DR (n = 0) when compared with controls (n = 7, odds ratio (OR) = 0 (95% confidence interval (CI) = 0.5-0.74), P = 0.02). eNOS4b/b was more frequent in patients with severe DR (n = 80) when compared with controls (n = 64, OR = 2.1 (95% CI = 1.1-4.12), P = 0.032). Frequency of eNOS4b/a was not different between the study (n = 21) and control groups (n = 28, ns). The allelic frequencies between the study and control groups were different (4b: n = 181 vs. n = 156, respectively, OR = 2.3 (95% CI = 1.27-4.25), P = 0.005; 4a: n = 21 vs. n = 42, respectively, OR = 0.4 (95% CI = 0.24-0.79), P = 0.005).

CONCLUSIONS

We demonstrate in Caucasians with Type 1 diabetes that (i) eNOS4a/a is associated with absent or non-severe DR, and (ii) eNOS4b/b is associated with severe DR.

Taq I polymorphism of the vitamin D receptor and risk of severe diabetic retinopathy

AIMS/HYPOTHESIS

Vitamin D, a molecule with antiproliferative, antiangiogenic, antioxidant and immunosuppressive effects, could play a role in the pathogenesis of severe diabetic retinopathy. We examined whether Taq I polymorphism of the vitamin D receptor is involved in the development of severe diabetic retinopathy.

METHODS

200 unrelated C-peptide-negative French Type I diabetic patients were randomly selected (male:female, 103:97, age 44.4 +/- 12.4 years, diabetes duration: 27.7 +/- 10.0 years, BMI: 24.3 +/- 3.4 kg/m(2), HbA(1c): 8.6 +/- 1.3 %). The Taq I site was analysed by PCR followed by digestion with Taq I enzyme. Diabetic retinopathy was assessed by retinal angiography and classified as presence (n = 101) or absence (n = 99) of severe (preproliferative or proliferative) diabetic retinopathy.

RESULTS

Frequency of wild-type genotype TT was lower in patients with severe diabetic retinopathy (n = 27) when compared with control subjects (n = 42, OR = 0.5, p = 0.028). Allele frequencies were not different between patients (T: n = 112 and t: n = 90) and control subjects (T: n = 128, and t: n = 70, p = 0.075). Global chi(2) (df = 2): p = 0.064. In subjects with diabetes duration of more than 25 years, TT was lower in severe diabetic retinopathy (n = 14) than control subjects (n = 18, OR = 0.3, p = 0.01). Allele frequencies were different between patients (T: n = 68 and t: n = 66) and control subjects (T: n = 52, OR = 0.5, and t: n = 26, OR = 1.9, p = 0.034). Global chi(2) (df = 2): p = 0.024. In subjects with HbA(1c) over 9 %, Tt was higher in patients (n = 28) than control subjects (n = 15, OR = 3.1, p = 0.019). Allele frequencies were not different between patients (T: n = 52 and t: n = 38) and control subjects (T: n = 57, and t: n = 29, p = 0.31). Global chi(2) (df = 2): p = 0.035.

CONCLUSION/INTERPRETATION

In French Type I (insulin-dependent) diabetic patients, we demonstrate an association between TT form (VDR) and low risk for severe diabetic retinopathy, especially in patients with long duration, and between Tt variant and high risk for severe diabetic retinopathy in subjects with poor glycaemic control.

[The diabetic at the table: pariah or model?]

Diet has long been part of the treatment. In fact modern dieting in diabetes comes only back 130 years ago with the description given by Apollinaire Bouchardat. He described how excessive glycosuria was observed in the postprandial periods and recommended a low carbohydrate diet. Along with the exclusion of simple sugars introduced 50 years later, the diabetic diet became a very restrictive one partly excluding the patients from normal social life event at home. Recent findings that carbohydrates should better represent 45 to 60% of the total daily caloric intake, that not all refined sugar are that "quick" nor particularly hyperglycaemic, along with the right use of mono-, poly- and saturated fat are now making the diabetic diet more flexible, more attractive, more eclectic. Nowadays we can say that the diet of a diabetic person (type 1 or 2) should follow is very comparable to that a non-diabetic person of the same age, sex, body weight and activity should also follow.