Hypoglycaemia is associated with the absence of a decrease in diurnal macular thickness in patients with diabetic macular oedema

AIM

Spontaneous diurnal variations measured by optical coherence tomography (OCT) have been reported in diabetic macular oedema (DME) together with a daytime decrease in central macular thickness (CMT). For this reason, this study aimed to investigate the influence of acute glucose and blood pressure changes on daytime variations in CMT in patients with DME.

METHODS

In this prospective observational study of type 1 (n=4) and type 2 (n=18) diabetic patients with DME, OCT scans, capillary blood glucose, and systolic and diastolic blood pressure measurements were performed at 9 a.m., 12 a.m., 3 p.m., 6 p.m. and again at 9 a.m. the day after. At the same time, the study protocol included simultaneous ambulatory blood pressure and glucose monitoring over a 24-h period. Hypoglycaemic episodes, defined as glucose values<60mg/dL, were also recorded.

RESULTS

CMT decreased consistently between 9 a.m. and 6 p.m. in 10 patients (from 374±82μm to 337±72μm; P=0.01) and increased or remained steady in 12 others (from 383±136μm to 390±149μm; P=0.58), with a significant difference in CMT absolute change between the two groups (P<0.001). In the study population as a whole, the lower the mean diurnal blood glucose, the smaller the decrease in CMT during the day (P=0.027). Also, eight (67%) of the 12 patients with a flat CMT profile experienced a diurnal hypoglycaemic event whereas none of those with a CMT decrease had hypoglycaemia (P=0.002).

CONCLUSION

Hypoglycaemic events may explain the lack of diurnal CMT decrease in diabetic patients with DME. However, further studies need to be conducted to evaluate whether having no diurnal CMT decrease is associated with a poorer visual prognosis and whether it can be modified by better glucose control.

The clinical variability of maternally inherited diabetes and deafness is associated with the degree of heteroplasmy in blood leukocytes

CONTEXT

Maternally inherited diabetes and deafness (MIDD) is a rare form of diabetes with a matrilineal transmission, sensorineural hearing loss, and macular pattern dystrophy due to an A to G transition at position 3243 of mitochondrial DNA (mtDNA) (m.3243A>G). The phenotypic heterogeneity of MIDD may be the consequence of different levels of mutated mtDNA among mitochondria in a given tissue.

OBJECTIVE

The aim of the present study was thus to ascertain the correlation between the severity of the phenotype in patients with MIDD and the level of heteroplasmy in the blood leukocytes.

PARTICIPANTS

The GEDIAM prospective multicenter register was initiated in 1995. Eighty-nine Europid patients from this register, with MIDD and the mtDNA 3243A>G mutation, were included. Patients with MELAS (mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes) or with mitochondrial diabetes related to other mutations or to deletions of mtDNA were excluded.

RESULTS

A significant negative correlation was found between levels of heteroplasmy and age of the patients at the time of sampling for molecular analysis, age at the diagnosis of diabetes, and body mass index. After adjustment for age at sampling for molecular study and gender, the correlation between heteroplasmy levels and age at the diagnosis of diabetes was no more significant. The two other correlations remained significant. A significant positive correlation between levels of heteroplasmy and HbA(1c) was also found and remained significant after adjustment for age at molecular sampling and gender.

CONCLUSIONS

These results support the hypothesis that heteroplasmy levels are at least one of the determinants of the severity of the phenotype in MIDD.

Medullary thyroid carcinoma identified within the first year of life in children with hereditary multiple endocrine neoplasia type 2A (codon 634) and 2B

CONTEXT

Early prophylactic thyroidectomy in patients with multiple endocrine neoplasia (MEN) type 2 offers the best chance for a normal life expectancy.

OBJECTIVE

To analyze the results of thyroidectomy performed during the first year of life in six patients with MEN 2A (codon 634) or MEN 2B (codon 918) syndrome.

DESIGN AND SETTING

A university hospital-based prospective study from 2001 to 2008.

SUBJECTS AND METHODS

Six family members affected either by MEN 2A (n=3) or MEN 2B (n=3) syndrome were identified through neonatal genetic screening.

RESULTS

Total thyroidectomy was performed at a median age of 0.8 year in the six patients, with central lymph node dissection in five. Bilateral millimetric medullary thyroid carcinoma (MTC) was found in all patients, with a unilateral lymph node micrometastasis in two of the three MEN 2B patients. Before thyroidectomy, MEN 2B patients had much higher basal serum calcitonin levels than those with MEN 2A and controls. After thyroidectomy, with a median follow-up of 3.3 years, the six patients had no evidence of persistent MTC.

CONCLUSION

Bilateral millimetric MTC may be present during the first year of life in these patients, with lymph node metastases also occurring in MEN 2B patients. These results support a total thyroidectomy at the age of about one year in MEN 2A (codon 634) children with an abnormal serum calcitonin level, and a total thyroidectomy with central neck dissection within the first weeks of life in MEN 2B patients.

Switching fibrate to statin in type 2 diabetic patients: consequences on lipid profile

Interest of statins in terms of morbid-mortality reduction in primary and secondary prevention in type 2 diabetic patients has broadly been proven in recent studies, while evidence for fibrates preventive effect is considerably weaker. HMGCoA reductase inhibitors are known to decrease low density lipoprotein cholesterol (LDL C) in a greater extension than triglycerides (TG). In type 2 diabetic patients, the dyslipidemic profile is commonly associated with reduced high-density lipoproteins (HDL C), increased TG and normal or mildly elevated LDL C.

PATIENTS AND METHODS

Type 2 diabetic outpatients (n=45) treated with fibrate with or without history of cardiovascular disease were included. Mean age was 57.7+/-13.2 yr, sex ratio was 16/39 (F/M), and BMI was 29.3+/-4.4 kg/m(2). Non-inclusion criteria were TG>or=3.5 g/L and intolerance to statins or a combined lowering lipid therapy. Serum lipid profile, HbA(1c) and creatin kinase (CK) were assessed under treatment with fibrate, then after a 3-month wash-out period, and after a 6-month treatment with a low dose of atorvastatin (10 mg/day).

RESULTS

After a 3-month wash-out period, total cholesterol (TC) was 1.98+/-0.31 g/L (m+/-SD), TG 1.63+/-1.09 g/L, HDL C 0.46+/-0.12 g/L, and LDL C 1.22+/-0.31 g/L. Comparing lipid profile with atorvastatin vs fibrate, we observed a significant decrease in TC and LDL C (1.56 vs 1.79 g/L P=0.001, and 0.84 vs 1.09 g/L, P=0.001, respectively). No significant difference between treatments was observed for TG (1.35 vs 1.17 g/L, P=0.06), and HDL C (0.44 vs 0.48 g/L, P=0.15). When treated with atorvastatin, 90% of patients achieved a LDL C<1 g/L, compared to 51% when treated with fibrate (P=0.001). HbA(1c) remained about 7.6+/-1.5%, and CK in the normal range.

CONCLUSION

In well-controlled type 2 diabetic patients previously treated with fibrate, short-term (6 months) treatment with low-dose atorvastatin (10 mg/day) improves TC and LDL C levels, without any alteration in TG and HDL C levels.

Retinal and renal complications in patients with a mutation of mitochondrial DNA at position 3,243 (maternally inherited diabetes and deafness). A case-control study

AIMS/HYPOTHESIS

We assessed the prevalence and determinants of retinal and renal complications in patients with maternally inherited diabetes and deafness (MIDD).

METHODS

This was a multicentre prospective study comparing the prevalence of retinopathy and renal disease in 74 patients with MIDD and 134 control patients matched for sex, age and clinical presentation at onset of diabetes, duration of diabetes and current treatment. Comparisons were adjusted for HbA(1c) and hypertension.

RESULTS

In MIDD patients, HbA(1c) (7.6 +/- 1.6 vs 8.5 +/- 2.0%, p < 0.002), systolic blood pressure (126.6 +/- 16.2 vs 133.1 +/- 17.3 mmHg, p < 0.007) and prevalence of hypertension (33.8 vs 64.2%, p < 0.0001) were lower than in control patients. Prevalence of diabetic retinopathy was 3.7-fold lower in MIDD patients (6/74, 8 vs 40/134, 29.6%, p < 0.0001). Differences between groups remained significant after adjustment for hypertension, systolic blood pressure and HbA(1c). In MIDD, urinary albumin excretion (314.8 vs 80.1 mg/24 h, p = 0.035) and creatinine plasma levels (103.5 vs 82.2 micromol/l, p = 0.0178) were higher and GFR was lower. Impaired renal function (GFR <60 ml/min) was four- to sixfold more frequent in MIDD. Differences between MIDD and control diabetic patients further increased when adjusted for HbA(1c) and systolic blood pressure (p < 0.0001). Adjustment for treatment with an ACE inhibitor or angiotensin II receptor antagonist did not modify the results.

CONCLUSIONS/INTERPRETATION

This study indicates that diabetic retinopathy is less prevalent in MIDD than in control diabetes. This suggests that retinal alterations due to mitochondrial disease may have a protective role. By contrast, nephropathy is far more frequent in MIDD, suggesting the presence of a specific renal disease independent of diabetic nephropathy.

Muscle infarction in a young woman with brittle type 1 diabetes

We present the first case of muscle infarction in a 30-year-old woman who had a 5-year history of type 1 diabetes mellitus that was not complicated by nephropathy, retinopathy or neuropathy. All common causes of muscle infarction were excluded, particularly microangiopathy and a hypercoagulable state. The differential diagnosis included infection (pyomyositis, necrotic fasciitis), focal inflammatory myositis, vascular events, trauma, tumor and diabetic amyotrophy, all of which were excluded. In spite of good glycaemic control, her diabetes remained brittle; alternating states of transient acute hypoglycaemia and hyperglycaemia may have been responsible for the infarction. Brittleness resumed after treatment with subcutaneous insulin infusion using a portable pump. No recurrence of muscle infarction was observed during a 18-month follow-up.

Occurrence of gestational diabetes mellitus, maternal and fetal outcomes beyond the 28th week of gestation in women at high risk of gestational diabetes. A prospective study

AIM

Among the numerous guidelines defining the diagnostic strategy of gestational diabetes mellitus (GDM), none of them suggest a follow-up in women with risk factors beyond the 28th week of gestation (WG). The primary objective of this study was to assess the incidence of GDM beyond 28 WG in a group of women at high risk. The secondary objectives were to evaluate maternal and fetal outcomes in early and late GDM (between 24-28 WG, and beyond 28 WG), as well as to compare them to a normal glucose tolerance (NGT) group.

METHODS

A prospective study conducted in 191 consecutive women. Between 24-28 WG, the diagnosis of GDM was performed in a two-step approach (50 then 75 g). Beyond the 28 WG, the diagnosis of GDM was based on self-monitoring blood glucose (SMBG). All women were educated about an individualized diabetic diet and to perform SMBG daily glucose profiles.

RESULTS

Seventy-two percent of the women at risk had developed GDM. Among these, 54% had developed early GDM, between 24-28 WG, and 18% had developed late GDM, beyond the 28th WG. Gestational age of late GDM was estimated 30 WG. In late GDM, onset of diabetes seems to be predicted by an increase in capillary glucose value determined at 22:00 hours, but this needs to be confirmed. Women who develop GDM2 have a significantly higher rate of macrosomia and more important pre-pregnancy overweight, underlining this impact in the occurrence of macrosomia. Finally maternal outcomes were not different in the 3 groups with intensive intervention.

Zygomycosis: an uncommon cause for peripheral facial palsy in diabetes

Mucormycosis is an emerging fungal infection with a high rate of mortality. Diabetic and immuno-compromised patients are the most frequent hosts. We report a case of rhino-orbito-cerebral mucormycosis revealed by facial palsy in a diabetic, immuno-compromised patient with difficult life conditions. He received intravenous antifungal treatment (amphotericin B) and early surgical debridement and completely recovered with no recurrence after 3 months of follow-up. Physicians should be aware of such atypical clinical presentations due to the need for early appropriate combined medical and surgical management to improve disease recovery and prognosis.

Acute lower limb ischemia is a frequent complication of severe diabetic hyperosmolarity

AIM

To describe the outcome of intensive care unit (ICU) patients admitted with a hyperglycaemic hyperosmolar non-ketotic syndrome (HHNS), with a specific analysis of precipitating conditions and complications including lower limb ischemia.

METHODS

Retrospective review of patients admitted in a university-hospital ICU for HHNS.

RESULTS

Seventeen consecutive patients (9F/8M, age: 75 years [57-81] (median [25-75% percentiles], Glasgow Coma score: 13 [12-14]) were admitted for HHNS over an 8-year period (1998-2005). On admission, the blood glucose level was 40.0 mmol/l [26.3-60.8], the corrected serum sodium concentration 167 mmol/l [158-174], and the calculated plasma osmolarity 384 mosmol/l [365-405]. All the patients presented with renal failure due to severe dehydration. An infection was identified as the precipitating factor in 8/17 cases. Three (18%) patients died in the ICU. Non-survivors were significantly older than survivors (P=0.02). Using univariate analysis, no other parameter measured on admission was related to mortality. Four patients (24%) presented with lower limb ischemia. They had a significantly more elevated blood urea nitrogen (P=0.03), creatinine phosphokinase level (P=0.04), and leukocyte count (P=0.02). The bilateral, symmetrical, and distal extremity involvement suggested diminished blood flow due to hyperviscosity, hypotension, vasoconstrictors, or cholesterol emboli rather than a proximal arterial obstruction as causative mechanisms. No patient was treated surgically. Ischemia reversed with fluid loading and resulted in toe dry digital necrosis.

CONCLUSION

HHNS is a rare but life-threatening cause of ICU admission. There is a high incidence of lower limb ischemia in HHNS patients, which may be related to dehydration and blood hyperviscosity.

Elevation of CKP induced by ezetimibe in monotherapy

Few cases of myopathy have been reported in patients treated with ezetimibe as monotherapy or in association with a statin. We report on two cases of elevation of CKP that occurred upon monotherapy with ezetimibe, which were reversible after discontinuation of the drug. In both cases, patients previously experienced intolerance with other lipid-lowering agents. The pathogenesis of muscle toxicity associated with ezetimibe is not known yet. An interaction with statin or a toxicity mechanism common to several lipid-lowering drugs have been suggested. A potential role of induction of glucuronidation by numerous associated drugs can also be involved Although association of ezetimibe with myopathy seems to be uncommon, special attention should be given to patients treated with ezetimibe who had a previous intolerance to other lipid-lowering drugs and who received several drugs.

Kearns Sayre syndrome: an unusual form of mitochondrial diabetes

Kearns Sayre syndrome (KSS) is a mitochondrial disorder characterized by the emergence before age 20 of progressive external ophthalmoplegia, pigmentary retinopathy, together with other heterogeneous clinical manifestations, including cardiac conduction defects, muscle abnormalities and endocrinopathies. KSS is associated with large heteroplasmic deletions in mitochondrial DNA. We report the case of a 43-year-old woman, with diabetes mellitus as a first manifestation at age 19. Later, she exhibited bilateral ptosis and external ophthalmoplegia with progressive worsening. DNA analysis identified a large mitochondrial DNA (mtDNA) deletion, which confirmed the diagnosis of KSS. By reporting this case with diabetes mellitus as first manifestation, we aim at emphasizing problems of diagnosis in these subtypes of mitochondrial diabetes.

Diabète et cytopathies mitochondriales : données anatomo-pathologiques

Maternal diabetes associated with neural deafness is designated as MIDD (maternal inherited diabetes and deafness); it is linked to a A3243G tRNA leucine gene mutation. The disease course is progressive and involvement of other systems is frequent. In most cases, macular pattern dystrophy is present. Muscular lesions are characteristic of mitochondrial myopathies. Mitochondrial abnormalities have also been observed in pancreas, heart, kidney, smooth muscle of the digestive tract with variable heteroplasmy levels. MIDD may present as a single syndrome or is part of MELAS or Kearns-Sayre syndrome.

Screening for diabetic retinopathy: the first telemedical approach in a primary care setting in France

OBJECTIVES

Diabetic retinopathy (DR) remains a major cause of visual impairment in France, due to insufficient regular annual screening. Fundus photography is a sensitive alternative to ophthalmoscopy for DR screening. The aim of our study was to report the first telemedical approach to this screening in a primary care setting in France.

METHODS

A DR screening centre equipped with a nonmydriatic camera was opened in the 18th district of northern Paris and placed at the disposal of general practitioners (GPs) of the Réseau de Santé Paris Nord (North Paris Health Network). These GPs were invited to send their diabetic patients who had no known DR and had had no fundus examination for more than one year to this screening center. Retinal photographs were taken by an orthoptist without pupillary dilation and sent for grading through the Internet to the Lariboisière Hopital Ophthalmology Department.

RESULTS

During an 18-month period, 912 DR screening examinations were performed in 868 diabetic patients referred to the DR screening center by 240 GPs. Patients' mean +/- SD age was 59.9 +/- 11.1 years. Of these 868 patients, 260 (30%) said they never have had an ophthalmological examination. Diabetic retinopathy was detected in 197 patients (22.7%). The proportion of patients for whom fundus photographs of one or both eyes could not be assessed was 10.1%. 159 patients (18.3%) required referral to an ophthalmologist.

CONCLUSION

Nonmydriatic photography, combined with teletransmission to a reading centre, proved to be a feasible valid method for the detection of DR. This screening method allowed the identification of patients requiring prompt referral to an ophthalmologist for further complete eye examination.

Heterogeneity of diabetes phenotype in patients with 3243 bp mutation of mitochondrial DNA (Maternally Inherited Diabetes and Deafness or MIDD)

OBJECTIVE

In patients with maternally inherited diabetes and deafness (MIDD), due to 3 243 A > G mutation of mitochondrial DNA (mtDNA), diabetes may present with variable phenotypes.

OBJECTIVE

To ascertain the existence of two distinct phenotypes, MIDD1 and MIDD2, in a series of patients with MIDD.

DESIGN

Multicenter prospective study.

PATIENTS

77 patients with diabetes and the mtDNA 3243 mutation and 139 control patients with type 1 (T1D) or type 2 (T2D) diabetes, matched according to initial presentation of diabetes, age at onset, sex, and duration of diabetes (24 T1D and 115 T2D, including 55 treated with insulin).

MEASUREMENTS

Anthropometric characteristics (height, body weight, body mass index [BMI], sex), family history of diabetes, and characteristics of diabetes (age at onset, treatment, hemoglobin A1c [HbA1c]), extrapancreatic manifestations.

RESULTS

In 13 cases (17%, MIDD1), diabetes presented as insulin-dependent from the onset, with ketoacidosis in 6 cases. In 64 cases (83%, MIDD2), diabetes resembled T2D, and was treated with diet in 12 cases, oral hypoglycemic agents in 21 cases, or insulin in 31 cases. Compared with patients with MIDD2, patients with MIDD1 were characterized by lower age at onset of first manifestation of MIDD (25.4 +/- 9.6 vs 33.7 +/- 13.2 Years, P<0.0005), lower body weight (49.1 +/- 7.4 vs 56.3 +/- 10.9 kg, P<0.0025), lower BMI (18.2 +/- 2.3 vs 20.9 +/- 3.6 kg/m2, P<0.0005), and higher HbA1c levels (9.5 +/- 2.0 vs 7.5 +/- 1.6%, P<0.0005). Frequency of family history of diabetes and of extrapancreatic manifestations was the same in both MIDD subtypes. No difference was found within the MIDD2 subtype when comparing patients treated with or without insulin. Compared with matched controls, patients with MIDD had a lower BMI (MIDD1/T1D 18.2 +/- 2.3 vs 24.0 +/- 3.6 kg/m2 and MIDD2/T2D 20.9 +/- 3.6 vs 30.2 +/- 5.9 kg/m2, P<0.0025). Lastly, male patients with MIDD had a shorter height than controls (MIDD1/T1D: 166.1 +/- 3.2 vs 177.3 +/- 6.6 cm and MIDD2/T2D: 168.4 +/- 7.2 vs 173.6 +/- 6.6 cm P<0.025).

CONCLUSIONS

These results confirm the existence of two different phenotypes in MIDD, MIDD1 and MIDD2, which may be related to the severity of the mitochondrial disease. The role of other genetic and/or environmental factors in the variable phenotype of MIDD remains to be elucidated.

Evaluation of a new non-mydriatic digital camera for detection of diabetic retinopathy

AIMS

To compare the results of fundus photography using a new non-mydriatic digital camera with the results of reference standard of Early Treatment Diabetic Retinopathy Study (ETDRS) retinal photographs, for the detection of diabetic retinopathy (DR).

METHODS

Fundus colour photographs were taken with a Topcon non-mydriatic camera of 147 eyes of 74 diabetic patients, without pupillary dilation (five overlapping fields of 45 degrees; posterior pole, nasal, temporal, superior and inferior). Three retinal specialists classified the photographs in a masked fashion, as showing no DR or mild non-proliferative DR (NPDR) not requiring referral, moderate or more severe NPDR and/or macular oedema, or as non-gradable image requiring referral. ETDRS 35-mm colour slides served as reference images for DR detection.

RESULTS

For moderately severe to severe DR, the sensitivities of detection reported by the three observers were 92, 100 and 92%, respectively, and the specificities, 87, 85, and 88%. For four levels of DR severity (none or mild NPDR, moderate NPDR, severe NPDR and proliferative DR), the percentages of exact agreement between the three observers on the retinopathy grades assigned to the non-mydriatic photographs and to the ETDRS reference slides were 94.6, 93 and 87.6%, respectively (kappa 0.60-0.80). Sixteen eyes of nine patients (11%) were judged ungradable by at least one observer. In a second series of 110 patients, evaluated in the setting of a screening procedure, fewer photographs were ungradable (< 6%).

CONCLUSION

These results suggest that fundus photographs taken by the Topcon TRC-NW6S non-mydriatic camera, without pupillary dilation, are suitable for DR screening.

[Diabetic retinopathy in children and adolescents]

Diabetic retinopathy rarely occurs before puberty and is never proliferative in prepubescent children. On the opposite, puberty and adolescence are high-risk periods for diabetic retinopathy progression, and call for strict ophthalmologic monitoring. The period between 16 and 18 years of age is particularly critical. Progression towards florid diabetic retinopathy is to be especially feared and should be prevented in the course of adolescence, as this form can be severe and can lead to blindness. Risk factors are probably many, including diabetes duration, difficulties in achieving glycemic control due to increase in insulin requirements, low compliance to treatment, and hormonal changes related to puberty (abnormalities of the growth hormone (GH)/insulin-like growth factor-I (IGF-1) axis). Systematical diabetic retinopathy screening should be performed in adolescents, notably by non-mydriatic fundus photographs. Furthermore, the anticipation of the switch from pediatric to adult structures, together with the careful information and education of parents and children may improve visual prognosis of young diabetic patients, whose life expectancy is high.

Influence of oral antidiabetic drugs compliance on metabolic control in type 2 diabetes. A survey in general practice

BACKGROUND

To address compliance with oral antidiabetic agents and its impact on metabolic control in type 2 diabetic patients treated in general practice.

METHODS

Prospective assessment of self-reported compliance with a standardized questionnaire in an homogeneous cohort of 11,896 type 2 diabetic patients treated by their general practitioner with one or two oral antidiabetic agents, and analysis of determinants of compliance with treatment (age, diabetes duration, educational level, severity of complications, frequency of antidiabetic oral agents daily dosing).

RESULTS

Optimal compliance (no omission) was reported in only 46% of cases. In multivariate analysis, HbA(1c) levels were positively correlated with age, daily dosing frequency of oral antidiabetic agents and low educational level, but not with diabetes duration. Low daily dosing was associated with a better metabolic control. HbA(1c) levels were associated with compliance with treatment, with a 1.4% mean difference between group with optimal and group with worst compliance.

CONCLUSIONS

These results suggest the interest of reducing daily dosing frequency of oral antidiabetic agents, in order to improve compliance with treatment and metabolic control.

N(carboxymethyl)lysine as a biomarker for microvascular complications in type 2 diabetic patients

AIMS

Hyperglycemia is linked to vascular dysfunction in patients with diabetes mellitus, either directly or through advanced glycation end product (AGE) formation. Experimental evidence has indicated the possible involvement of AGEs in the genesis of vascular complications. We investigated whether serum levels of AGEs and of the glycoxidation compound carboxymethyl-lysine (CML) were increased and correlated with vascular complications in type II diabetes mellitus.

METHODS

Serum levels of AGEs and CML-human serum protein (CML-HSP) were measured by a specific immunoassay in 51 men and 26 women aged 58 +/- 6.1 years (mean +/- SD) who had been treated for type II diabetes mellitus for 11 +/- 8 years, and in a non-diabetic control group consisting of 39 men and 21 women aged 55.5 +/- 7.5 years. Patients with macroalbuminuria or abnormal creatinine clearance were excluded from the study.

RESULTS

The serum levels of AGEs were significantly increased in patients with type II diabetes compared to controls (P<0.001). Blood levels of CML-HSP were significantly increased in diabetic patients compared to normal subjects [35.3 +/- 27.4 and 9.3 +/- 7.2 (mean +/- SD) pmol/mg of protein, respectively; P<0.0001]. In diabetic patients with retinopathy or microalbuminuria (urinary albumin excretion: UAE > 30 mg/24 h), CML-HSP levels were significantly higher (P<0.02), and even more elevated in patients with both complications.

CONCLUSION

In patients with type II diabetes, CML-HSP levels that are at variance with the HbA(1c) index for blood glucose may be a biomarker of glycoxidation, and related to the development of microvascular complications.

Advanced glycation end products, their receptors and diabetic angiopathy

The role of chronic hyperglycemia in the development of diabetic microvascular complications and in neuropathy has been clearly established by intervention studies. However, the biochemical or cellular links between elevated blood glucose levels, and the vascular lesions remain incompletely understood. This review focuses on the consequences of hyperglycemia on the formation of advanced glycation end-products (AGEs), and on the role of AGEs and of their specific receptors (RAGE) in the functional and anatomical alterations of the vascular wall. AGEs are formed during the Maillard reaction by the binding of aldoses on free NH(2) groups of proteins, which, after a cascade of molecular rearrangements, result in molecules of brown color and specific fluorescence. Experimental studies have indicated that the binding of AGEs to RAGE activates cells, particularly monocytes and endothelial cells. Activated endothelial cells produce cytokines, and express adhesion molecules and tissue factor. The role of AGEs in increased oxidative stress, and in the functional alterations in vascular tone control observed in diabetes, in part related to a reduction in nitric oxide, is also discussed. The microvascular retinal, glomerular and nerve lesions induced by experimental diabetes in animals are prevented by an inhibitor of AGEs formation, aminoguanidine. The administration in diabetic animals of recombinant RAGE, which hinders AGEs-RAGE interaction, prevents hyperpermeability and vascular lesions. These data suggest a central role of AGEs and RAGE in the development of chronic complications of diabetes.

Whole-body (201)Tl scintigraphy can detect exercise lower limb perfusion abnormalities in asymptomatic diabetic patients with normal Doppler pressure indices

Significant lower limb arterial obstruction is usually detected by Doppler ankle-brachial pressure index (ABPI) measurement. However, ABPI is non-contributory in cases of diabetic medial sclerosis or calcifications and is unsuitable for the detection of small vessel involvement. Thallium-201, a perfusion agent, is frequently used for the investigation of coronary artery disease, and whole-body (201)Tl scintigraphy (WBS) has also been reported to be useful in the assessment of peripheral artery disease (PAD). Thus, we evaluated the clinical feasibility of simultaneous myocardial and lower limb perfusion assessment. WBS was performed after treadmill exercise and myocardial scintigraphy, and again 4 h later. Calf (201)Tl fractional activities (percentage of whole-body (201)Tl uptake) were calculated. We determined a threshold value of normal post-exercise calf (201)Tl uptake (mean of the (201)Tl fractional uptakes minus 2 SD) in a control group of nine healthy volunteers. We checked its accuracy in a pilot group of 25 diabetic patients with proven PAD. This method permitted the detection of lower limb perfusion abnormalities in 38% of 47 asymptomatic diabetic patients with no evidence of PAD. In conclusion, for asymptomatic diabetic patients, whole-body (201)Tl scintigraphy after a treadmill test seems an efficient method of showing lower limb perfusion abnormalities not detected by ABPI measurement. It allows the evaluation of vascular status with no additional inconvenience for patients when performed after myocardial scintigraphy.

Increased levels of soluble Fas in serum from diabetic patients with neuropathy

OBJECTIVE

The aim of this study was to investigate circulating soluble Fas (sFas) and Fas ligand (sFasL), two transmembrane glycoproteins involved in apoptosis, in the serum of diabetic patients.

MATERIAL AND METHODS

We assessed sFas and sFasL serum levels in normal controls (n=15), and in both 42 diabetic patients without complications, or with predominant retinopathy or neuropathy, using sFas and sFasL specific ELISA method.

RESULTS

sFasL serum levels were less than 0.1 ng/ml in normal controls and in each group of diabetic patients. In diabetic patients with a predominant neuropathy, sFas serum levels were significantly increased not only when compared with normal controls (13.5 +/- 3.6 ng/ml vs 7.1 +/- 1.1 ng/ml, p<0.001), but also when compared with patients without complications (vs 9.1 +/- 1.8 ng/ml, p<0.001) or with a predominant retinopathy (vs 8.7 +/- 1.9 ng/ml, p<0.001).

CONCLUSIONS

These preliminary data suggest that a dysregulation of the Fas system in peripheral neuronal cells may be involved in the increase of sFas observed in diabetic patients with neuropathy.

Maternally inherited diabetes and deafness: a multicenter study

BACKGROUND

Maternally inherited diabetes and deafness (MIDD), which is seen in 0.5% to 2.8% of patients with type 2 diabetes mellitus, is related to a point mutation at position 3243 of mitochondrial (mt) DNA. Its clinical description is incomplete.

OBJECTIVE

To study the clinical presentation and complications of diabetes in patients with MIDD and to identify clinical characteristics that may help select diabetic patients for mtDNA mutation screening.

DESIGN

Multicenter prospective descriptive study.

SETTING

16 French departments of internal medicine, diabetes and metabolic diseases, or both.

PATIENTS

54 patients with type 2 diabetes mellitus and the mtDNA 3243 mutation.

MEASUREMENTS

Characteristics of diabetes, metabolic control (glycosylated hemoglobin level), complications of diabetes, and involvement of other organs.

RESULTS

On average, patients with MIDD were young at diabetes onset and presented with a normal or low body mass index. None were obese. Seventy-three percent of probands had a maternal family history of diabetes. Diabetes was non-insulin-dependent at onset in 87% of patients; however, 46% of patients had non-insulin-dependent disease at onset but progressed to insulin therapy after a mean duration of approximately 10 years. Neurosensory hearing loss was present in almost all patients. Eighty-six percent of patients who received an ophthalmologic examination had macular pattern dystrophy (a specific retinal lesion). Forty-three percent of patients had myopathy, 15% had cardiomyopathy, and 18% (9 of 51) had neuropsychiatric symptoms. Although the prevalence of diabetic retinopathy was 8% among patients who received an ophthalmologic examination, lower than expected after a mean 12-year duration of diabetes, prevalence of kidney disease was 28%. This suggests that a specific renal involvement was the result of mitochondrial disease.

CONCLUSIONS

Maternally inherited diabetes and deafness has a specific clinical profile that may help identify diabetic patients for mtDNA testing.

24-hour glycemic profile in type 2 diabetic patients treated with gliclazide modified release once daily

OBJECTIVES

In type 2 diabetes, the primary and secondary prevention of long-term micro- and macrovascular complications requires a control of blood glucose levels 24 hours a day. The present study was undertaken to assess the effect of a new formulation of gliclazide administered once daily, gliclazide modified release, on plasma glucose levels over 24 hours.

MATERIAL AND METHODS

In 21 type 2 diabetic patients previously treated by diet alone or oral antidiabetic agents, glycemic profile (8 am, 10 am, 12 am, 2 pm, 5 pm, 8 pm, 10 pm, 3 am and 8 am), overall glycemic control, acceptability, and compliance with treatment were assessed before and after a 10-week treatment with gliclazide modified release, (30-60 mg), given once daily at breakfast.

RESULTS

The results indicate a significant decrease in plasma glucose levels at all points of the cycle. Mean plasma glucose levels over 24 hours and mean plasma glucose levels during the fasting and the postprandial periods were significantly improved after treatment. In previous drug-naive patients, decrease in HbA1C was observed (1.0 +/- 1.1%, P=0.022). The acceptability was good, with no hypoglycemic events, and a high compliance with treatment was also observed.

CONCLUSION

We can therefore conclude that gliclazide modified release, given once daily at breakfast, is effective over 24 hours in reducing plasma glucose levels in type 2 diabetes. This once-daily administration should lead to an optimal patient compliance with treatment.

[High carcinoembryonic antigen level following cancer surgery: another way to detect thyroid medullary carcinoma]

INTRODUCTION

Thyroid medullary carcinoma is usually detected in the presence of an isolated thyroid nodule or in the context of a family disease: familial thyroid medullary carcinoma or multiple endocrine neoplasia type 2A.

EXEGESIS

Here we report a third means of detection: an unexplained rise in carcinoembryonic antigen levels after cancer surgery. In each case, the carcinoembryonic antigen increase led to the assessment of the caicitonin plasma level and to a thyroid echography being performed. Thyroid medullary carcinoma was confirmed in every case after surgery.

CONCLUSION

Even though the association of thyroid follicular carcinoma with familial adenomatous polyposis is common, the association of thyroid medullary carcinoma with breast or colonic carcinoma remains exceptional and probably accidental. Due to the seriousness of the thyroid medullary carcinoma, it is mandatory to look for it in the event of an unexplained rise in the carcinoembryonic antigen level, by assessing the calcitonin plasma level.

Hypoglycemia in adults

Hypoglycemia is a clinical and biological syndrome, caused by an abnormal decrease in plasma glucose levels to below 0.55 g/l (3.0 mmol/l). Hypoglycemia is responsible for non-specific signs and symptoms which should be noted in a particular pathological context, and for secretion of counterregulatory hormones (mainly glucagon and catecholamines). Difficulty in identifying the etiology is variable, based upon history and physical examination, and hormonal investigations or imaging procedures, according to the results. Drug-related hypoglycemia is the most frequent observed cause (mainly in insulin-treated diabetic patients, but many drugs may be involved), followed par toxicity (alcohol mainly). Tumor-induced hypoglycemia is secondary to inappropriate insulin secretion by a beta-cell pancreatic tumor (insulinoma), and, rarely to an extrapancreatic mesenchymal large tumor secreting IGF-II. Hypoglycemia is present in other diseases, such as hormonal deficiencies, hepatic, or renal failure, or acute cardiac insufficiency. Multifactorial hypoglycemia seems to be underdiagnosed, mainly in hospitalized, underfed older patients with severe disease or sepsis. Autoimmune hypoglycemia is rare, due to insulin or insulin-receptor autoantibodies. Reactive hypoglycemia is observed after gastrectomy, but true primitive hypoglycemia appears to be rare, with false excess diagnosis in the majority of the cases.

Insulin autoimmune syndrome: a rare cause of hypoglycaemia not to be overlooked

We report the case of a Caucasian patient with insulin autoimmune syndrome (IAS), defined as the association of hypoglycaemic attacks with insulin autoantibodies in individuals not previously treated with exogenous insulin. This rare syndrome (more than 200 published cases) has been reported mainly in Japan. Most affected patients present with other autoimmune disorders, most often Graves' disease. In most cases, insulin autoantibodies appear a few weeks after the beginning of treatment with a drug containing a sulphyldryl group. A significant increase in insulin and C-peptide plasma concentrations and the presence of other antiorgan antibodies are observed. The susceptibility haplotype is present in the Japanese population, which may account for the high frequency of IAS. Spontaneous remission is observed in 80% of cases, with cessation of hypoglycaemic attacks and disappearance of insulin autoantibodies some months after withdrawal of the drug. This rare cause of hypoglycaemia in Caucasian subjects should be considered in aetiologic investigation of spontaneous hypoglycaemia.

Prevalence of macular pattern dystrophy in maternally inherited diabetes and deafness. GEDIAM Group

OBJECTIVE

To evaluate the prevalence of macular pattern dystrophy (MPD) in maternally inherited diabetes and deafness (MIDD), a new subtype of diabetes mellitus that cosegregates with a mutation of mitochondrial DNA (i.e., the substitution of guanine for adenine at position 3243 of leucine transfer RNA) and to report the clinical characteristics of MPD.

DESIGN

Prospective cohort study.

PARTICIPANTS

Forty-six patients from 29 families with an adenine-to-guanine mutation of mitochondrial DNA were recruited from a French collaborative multicenter study. Thirty-five patients had MIDD, 8 were asymptomatic children of MIDD patients, and 3 had MELAS syndrome (mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes). The 33 MIDD patients with diabetes were matched for diabetes duration and gender with 33 patients with "common" type-2 diabetes to compare the prevalence of diabetic retinopathy (DR) in both series.

METHODS

All patients had a full ophthalmologic examination and fundus photographs.

MAIN OUTCOME MEASURES

The presence and severity of MPD and DR were assessed in each patient.

RESULTS

Thirty MIDD patients (85.7%) of 35 exhibited bilateral MPD characterized by linear pigmentation surrounding the macula and optic disc. In 24 of these 30 patients, visual acuity was 20/25 or more in both eyes. The prevalence of DR was 6% in MIDD patients with diabetes versus 15% for patients with common type-2 diabetes (a difference that was not significant, P = 0.23). The fundus of each of the eight asymptomatic children was normal. MPD was present in one of the three cases of MELAS.

CONCLUSION

The prevalence of MPD in MIDD is high. Its detection may be helpful for the diagnosis of this new subtype of diabetes, for which specific treatments may be proposed.

Somatostatin receptor scintigraphy in pituitary adenomas: a somatostatin receptor density index can predict hormonal and tumoral efficacy of octreotide in vivo

Previous studies have failed to predict somatostatin analog response with somatostatin receptor scintigraphy in pituitary adenomas. In vitro studies have shown that the density of somatostatin receptors in pituitary tumors might be critical for octreotide response.

METHODS

The density of somatostatin receptors was calculated in vivo combining the uptake index obtained from somatostatin receptor scintigraphy and the tumor volume obtained by MRI. The ratio of these two values, called density index (DI), was established in 32 of 37 consecutive patients with pituitary adenomas (11 had growth hormone-secreting adenomas, 4 thyroid-stimulating hormone-secreting and 17 nonfunctioning). It was compared with hormonal response, assessed in 15 secreting adenomas on growth hormone or thyroid stimulating hormone suppression (which was considered significant when it reached at least 50% of basal level), and with tumor shrinkage (which was considered significant when > or =20% of pretherapeutic value) in 12 secreting and 14 nonfunctioning adenomas.

RESULTS

In agreement with previous reports, uptake index is not predictive of octreotide response. In contrast, DI predicts both hormonal suppression and tumor shrinkage (P = 0.009 and P = 0.0002, respectively) obtained with octreotide therapy. DI sensitivity, specificity and accuracy were 92% each, and a positive correlation was found between DI and the percentage of tumor shrinkage (r = 0.54, P = 0.004).

CONCLUSION

The combination of scintigraphic and MRI data allows the computation of a DI for somatostatin receptors that points out patients who can profit from somatostatin analog treatment.

Learning vector quantizer in the investigation of thyroid lesions

OBJECTIVE

To investigate the capability of the learning vector quantizer (LVQ) in the discrimination of benign from malignant thyroid lesions.

STUDY DESIGN

The study was performed on May-Grünwald-Giemsa-stained smears taken by fine needle aspiration (FNA). Using a custom image analysis system, 25 features that describe the size, shape and texture of approximately 100 nuclei were measured from each case. Statistical features were extracted from each case, and a linear regression analysis was performed to detect the statistically significant features. The cases were distributed by category, as follows: 100 cases of goiter and follicular adenomas, 11 cases of follicular carcinoma, 35 cases of papillary carcinoma, 24 cases of oncocytic adenoma, 8 cases of oncocytic carcinoma and 20 cases of Hashimoto thyroiditis. About 30% of the cases from each class were used for training two LVQ classifiers. The remaining 139 cases, out of a total of 198, were used as the test set. A classifier was used to discriminate into four classes and a second into two classes.

RESULTS

The application of LVQ neural networks allows good discrimination between benign and malignant lesions (O.A. = 97.8). However, reliable discrimination of the cytologic types of the lesions was not obtained.

CONCLUSION

These results indicate that the use of neural networks combined with image morphometry may offer useful information on the potential for malignancy of thyroid lesions and may improve the diagnostic accuracy of FNA of the thyroid gland, especially in cases of follicular neoplasms classified as suspicious for malignancy and in cases of oncocytic tumors.

Mutations in the cationic trypsinogen gene and evidence for genetic heterogeneity in hereditary pancreatitis

Hereditary pancreatitis (HP) is a rare inherited disorder, characterised by recurrent episodes of pancreatitis often beginning in early childhood. The mode of inheritance suggests an autosomal dominant trait with incomplete penetrance. The gene, or at least one of the genes, responsible for hereditary pancreatitis has been mapped to the long arm of chromosome 7 and a missense mutation, an arginine to histidine substitution at residue 117 in the trypsinogen cationic gene (try4) has been shown to segregate with the HP phenotype. The aim of this work was to investigate the molecular basis of hereditary pancreatitis. This study was performed on 14 HP families. The five exons of the trypsinogen cationic gene were studied using a specific gene amplification assay combined with denaturing gradient gel electrophoresis (DGGE). The present paper describes three novel mutations, namely K23R and N29I and a deletion -28delTCC in the promoter region. We also found a polymorphism in exon 4, D162D. In eight of these families we found a mutation which segregates with the disease. A segregation analysis using microsatellite markers carried out on the other families suggests genetic heterogeneity in at least one of them. Our findings confirm the implication of the cationic trypsinogen gene in HP and highlight allelic diversity associated with this phenotype. We also show that the pattern of inheritance of HP is probably complex and that other genes may be involved in this genetic disease.

Chronic diarrhoea and diabetes mellitus: prevalence of small intestinal bacterial overgrowth

The mechanisms of chronic diarrhoea, a frequent symptom in diabetes mellitus, are multifactorial and complex, although small intestinal bacterial overgrowth and autonomic neuropathy seem to play a major role. This study evaluated the prevalence of small intestinal bacterial overgrowth and the effects of antibiotic treatment in a population of diabetic patients with chronic diarrhoea (defined as > 3 stools/24 h, weight > 200 g/24 h, duration > 3 weeks). Small intestinal bacterial overgrowth syndrome was diagnosed by glucose-hydrogen breath testing (sensitivity: 78%, specificity: 89%). The characteristics of diarrhoea (duration, number of stools per day, and gastrointestinal symptoms) were noted. Autonomic neuropathy was assessed by cardiac parasympathetic tests. A total of 35 patients were included, 15 with small intestinal bacterial overgrowth syndrome (43%, group 1) and 20 with no bacterial overgrowth (group 2). Age (52.9 +/- 13.5 vs. 53.9 +/- 11.8 years, NS), duration of diabetes (13.8 +/- 9.1 vs. 10.6 +/- 7.8 years, NS), and HbA1c level (10 +/- 2.9 vs. 10.9 +/- 2.4%, NS) were not different between the two groups. In group 1, duration of diarrhoea was longer (18.1 +/- 18.5 vs. 7.75 +/- 4.02 months, P = 0.05), the number of stools higher (7.1 +/- 5.7 vs. 4.6 +/- 2.6/24 h, P < 0.05), and gastrointestinal symptoms more frequent (13 vs. 10, P < 0.05). The prevalence of small intestinal bacterial overgrowth syndrome and gastrointestinal symptoms was not different in patients with and without autonomic neuropathy (9 vs. 8 and 12 vs. 11 respectively, NS). Eight patients with bacterial overgrowth received antibiotics (amoxicillin-clavulanic acid, 1.5 g/24 h for 10 days). Dramatic clinical improvement was observed in 6 out of 8 of these patients. It is concluded that small intestinal bacterial overgrowth should be considered in case of chronic diabetic diarrhoea because of its frequency (43%), facility of diagnosis, and often successful treatment with antibiotics.

Altered gap and tight junctions in human thyroid oncocytic tumors: a study of 8 cases by freeze-fracture

Human oncocytic tumors of the thyroid gland may be either adenomas or carcinomas. The morphology and the ultrastructure of these oncocytes are well-known. Numerous studies have demonstrated the role of gap and tight junctions in experimental and human carcinogenesis; however, the junctional complexes of the oncocytic tumors have never been studied. The aim of this study is to analyze gap and tight junctions in the oncocytic tumors of the thyroid. Because they are morphologically similar, whether benign or malignant, they offer an attractive model for studying the junctional complexes in both benign and malignant lesions. Eight oncocytic human thyroid tumors were collected and studied by freeze-fracture. Four of these cases were benign and four were malignant. Four cases of normal gland were also studied to represent the control group. Normal tight and gap junctions were described for the control group. No gap junctions could be found for the oncocytic tumors. Furthermore, alterations of the tight junctions were described; especially focal tights in the oncocytic adenomas and well organized and labyrinthic tight junctions in the oncocytic carcinomas. The lack of gap junction in the benign as well as in the malignant oncocytomas may suggest that the absence of gap junction is not sufficient for malignancy. The alterations of the tight junctions found in the oncocytic tumors of the thyroid are similar to those observed in poorly differentiated tissues or tumors, and may suggest a cellular regression rather than a tumorogenic factor.

Diabetes, advanced glycation endproducts and vascular disease

The high incidence of vascular complications in patients with diabetes mellitus remains incompletely understood. Several metabolic or endocrine abnormalities have been postulated as possible triggers for micro and macroangiopathies. This review article focuses on the consequences of hyperglycemia, leading to the formation of advanced glycation endproducts (AGE), on vascular function. Advanced glycation endproducts are the product of the binding of aldoses onto free amino groups of proteins or lipoproteins, which, after molecular rearrangement, result in a class of molecules of a brown color and specific fluorescence. Different cell membrane proteins have been shown to bind AGE and the best characterized receptor for AGE has been named RAGE. The AGE receptor is present on different cell types including endothelial cells, smooth muscle cells, lymphocytes and monocytes. Experimental studies have revealed that the binding of AGE to RAGE produces an activation of monocytes and endothelial cells. Activated endothelial cells produce interleukin and express vascular cell adhesion molecule and tissue factor. Advanced glycation endproducts, when infused into animals, induce an increase in vascular permeability. The blockade of RAGE by specific antibodies corrects the hypermeability observed in diabetic animals. The prevention of AGE formation by aminoguanidine treatment improves the microvascular lesions found in diabetic animals either in the retina or the glomerus. The infusion of recombinant RAGE in diabetic animals corrects hyperpermeability. The colocalization of RAGE and AGE at the microvascular site of the injury suggests that their interaction may play a significant role in the pathogenesis of diabetic vascular lesions.

Risk and penetrance of primary hyperparathyroidism in multiple endocrine neoplasia type 2A families with mutations at codon 634 of the RET proto-oncogene. Groupe D'etude des Tumeurs à Calcitonine

Germline mutations of the RET proto-oncogene are responsible for multiple endocrine neoplasia type 2, including multiple endocrine type 2A (MEN 2A), type 2B (MEN 2B), and familial medullary thyroid carcinoma. The relationship between specific mutations and syndromic features has been established. In particular, the risk for pheochromocytoma and hyperparathyroidism (HPT) in MEN 2A patients is clearly associated with the presence of the RET mutation at a specific position, i.e. at codon 634. Also, a correlation between a specific mutation, C634R, and the development of HPT has been suggested but is still controversial. To further investigate the relationship between specific mutations of codon 634 and the development of HPT, we studied a population of 188 individuals, carrying mutations at codon 634, namely C634R (65 patients belonging to 10 families), C634Y (80 patients belonging to 11 families), or the less frequent codon 634 mutations [i.e. C634S, C634F, C634G, or C634W (43 patients belonging to 9 families)]. In this series of patients, we defined an overall HPT prevalence of 19.1% and found that this prevalence did not vary significantly, with respect to the nature of the mutation. However, irrespective of the particular mutation, the prevalence of HPT showed a high interfamilial variability. The statistical model that best fitted with the observed data was in favor of the heterogeneity of the risk for HPT, with 40% of the families showing an HPT risk of 34% and 60% of the families showing an HPT risk of 9%. In addition, our study clearly demonstrated that HPT could be an early component of the disease and provided the first estimate of age-specific and mutation-specific HPT penetrance in individuals with mutations of codon 634 of the RET proto-oncogene.

Glycaemic control and development of retinopathy in type 2 diabetes mellitus: a longitudinal study

Relationships between glycaemic control, hypertension, and development of microangiopathy have been well documented in Type 1 (insulin-dependent) but not in Type 2 (non-insulin-dependent) diabetes mellitus. Therefore, we have investigated these relationships in a cohort of 64 Type 2 patients free of retinopathy (by angiofluorography), who were regularly followed until development of retinopathy or for at least 7 years as outpatients. Glycaemic control was assessed by 1 to 4 HbA1 determinations per year. Retinal status was monitored by annual angiofluorography. Nonproliferative retinopathy developed in 14 patients (cumulative incidence at 13 years: 29.8%) after a mean diabetes duration of 14.3+/-8.9 years (range 2-27). In multivariate analysis (Cox model), mean HbA1 during follow-up (p < 0.001), and hypertension at first examination (p = 0.09) were associated with the development of retinopathy, but age, sex, BMI, diabetes duration, smoking, and fasting blood glucose were not. The relative risk for developing retinopathy (RR) was 7.2 (IC 95%: 1.61-32.4) in patients with a mean HbA1 during follow-up above the median value of the cohort (8.3%) compared with patients with HbA1 during follow-up below this value. RR was 2.5 (IC 0.8-8) in patients with HbA1 at first examination above compared to below the median value (8.4%). RR was 3.0 (IC 0.9-10) in patients treated for hypertension at baseline compared to those without treatment. A sixfold increase in retinopathy prevalence was observed between patients with mean HbA1 in the highest or lowest quartile of mean HbA1 distribution during follow-up. This longitudinal study indicates a strong association between long-term glycaemic control and the development of diabetic retinopathy in Type 2 diabetes.

Monitoring of metabolic control in patients with non-insulin-dependent diabetes mellitus on oral hypoglycaemic agents: value of evening blood glucose determination

Monitoring of metabolic control in patients with non-insulin-dependent (Type 2) diabetes (NIDDM) is usually based upon blood glucose assay in the morning (after an overnight fast) and in the postprandial state (breakfast or lunch). However, this schedule does not seek low blood glucose values, especially in the evening. We have conducted a prospective study of laboratory blood glucose profiles (8 am, 9.30 am after a 35 g carbohydrate breakfast and in the evening between 5 and 7 pm). We have included 58 consecutive NIDDM patients regularly followed in our clinic (39 men, age 60 +/- 11.5 years, diabetes duration 8.6 +/- 6.5 years, BMI 25.5 +/- 3 kg m-2), treated with the sulphonylurea gliclazide, alone (40-320 mg 24 h-1, mean 170 +/- 110 mg) (group 1, n = 32) or in combination with metformin (1000-3000 mg 24 h-1, 2400 +/- 620 mg) (group 2, n = 26). All patients were stable, with no change in dosage for at least 3 months. Mean glycaemic control was good (group 1 HbA1c: 6.5 +/- 1.1%, group 2: 6.9 +/- 0.7%). Evening blood glucose values were the lowest of the day in 26 patients of group 1 (81.3%) and in 22 of group 2 (84.6%). Mean evening blood glucose levels were lower (p = 0.001) than 8 am values (group 1: 5.8 +/- 1.4 vs 6.1 +/- 1.6 mmol l-1, group 2: 6.5 +/- 1.8 vs 6.9 +/- 1.9) and than 9.30 am values (group 1: 7.6 +/- 1.5, group 2: 12.3 +/- 2.8). No blood glucose values in the hypoglycaemic range were observed. HbA1c was strongly correlated (p = 0.002 to 0.0001) in the whole group with 8 am (r = 0.39), 9.30 am (r = 0.56), and evening blood glucose values (r = 0.42). These results indicate that, in patients treated with the sulphonylurea gliclazide, alone or in combination with metformin, the lowest blood glucose values occur in the evening more frequently (4/5) than in the morning. Therefore, evening blood glucose determination should be performed systematically in the course of the metabolic evaluation of NIDDM patients on oral hypoglycaemic agents.

Diabetes: from phenotypes to genotypes

Diabetes mellitus comprises a heterogeneous group of diseases which have chronic hyperglycaemia in common as well as the resulting microvascular, macrovascular and neurological complications of this condition. Familial studies have provided strong evidence for the existence of genetic determinants in the different types of diabetes. In particular, monozygotic twin studies have indicated a higher rate of concordance in non-insulin-dependent (NIDDM) than in insulin-dependent diabetes mellitus (IDDM). In IDDM, 8 susceptibility loci have been identified, notably the HLA complex and insulin promotor gene. Rigorous family studies have identified monogenic subtypes representing 10-15% of all NIDDM: MODY2 related to glucokinase gene mutations, MODY1 and MODY3 secondary to mutation of hepatic nuclear factors, and diabetes resulting from deletion or mutation of mitochondrial DNA. Most NIDDM result from polygenic heredity, and susceptibility genes conducive to increased receptivity to deleterious environmental influences are now under investigation, such as beta 3 adrenergic receptor, FABP2 and OB. Precise analysis of phenotypes in the remaining families or systematic screening of the genome could allow the genes of each subtype to be identified. Finally, susceptibility genes for the increased severity and frequency of vascular complications have been identified, such as angiotensin converting enzyme, aldose reductase and aldehyde dehydrogenase genes. This progress has been facilitated by developments in molecular biology.