[Plasma homocysteine levels in hyperinsulinemic patients]

In order to evaluate the clinical characteristics of metabolic syndrome, a screening procedure was performed and in a cohort of middle-aged (40-60 years) hyperinsulinaemic (fasting plasma insulin > 15 microU/ml) and/or postprandial [120 min after 75 g glucose load] insulin > 45 microU/ml) subjects (n = 91; men/women: 38/53; age mean +/- SD 47.6 +/- 4.3 years; body mass index: 34.6 +/- 4.9 kg/m2; waist-hip ratio: 0.92 +/- 0.07; actual blood pressure 146 +/- 16/87 +/- 9 mmHg; fasting insulin: 24.2 +/- 11.3 microU/ml; postprandial insulin 125.5 +/- 103.8 microU/ml; serum LDL-cholesterol: 3.73 +/- 1.09 mmol/l; HDL-cholesterol: 1.12 +/- 0.30 mmol/l; triglycerides: 2.97 +/- 2.38 mmol/l; uric acid 279 +/- 79 mumol/l) plasma fasting homocysteine, vitamin B12 and folic acid levels were simultaneously determined. The values were separately evaluated according to the stages of glucose tolerance (normal glucose tolerance [n = 47]; impaired glucose tolerance [n = 24] and diabetes mellitus [n = 20]). Laboratory normal values were determined in 47 healthy subjects (control group, age: 45.0 +/- 7.8 years, men/women: 19/28). There was no significant difference between hyperinsulinaemic and control subjects regarding plasma homocysteine (9.28 +/- 3.81 mumol/l vs. 9.63 +/- 2.70 mumol/l), folic acid (8.5 +/- 5.9 ng/ml vs. 7.5 +/- 2.1 ng/ml) and vitamin B12 levels (423 +/- 141 pg/ml vs. 356 +/- 121 pg/ml). Plasma homocysteine levels were significantly (p < 0.001) higher in hyperinsulinaemic men than women (11.34 +/- 4.72 mumol/l [n = 38] vs. 7.86 +/- 2.13 mumol/l [n = 53]). There was no significant difference between subgroups classified according to the stages of glucose tolerance in hyperinsulinaemic groups. Plasma homocysteine values exceeding the upper limit of normal range (> 12.45 mumol/l) were detected at a similar prevalence rate in control (4/47 = 8.5%) and in hyperinsulinaemic subjects (10/91 = 10.9%). A weak but statistically significant correlation was found between plasma homocysteine values and age of subjects (r = 0.222; p < 0.05) whereas a stronger correlation was documented between plasma homocysteine and serum creatinine values (r = 0.658; p < 0.001) in hyperinsulinaemic groups (n = 91). Plasma homocysteine values independently from the stages of glucose tolerance are not elevated in hyperinsulinaemic subjects. Hyperhomocysteinaemia is not a characteristic feature of hyperinsulinism suggesting that plasma homocysteine levels are of no considerable importance in the complex pathomechanism of atherosclerosis at early stages of metabolic syndrome.

[Metabolic syndrome-x at the turn of the millennium (Theoretical aspects with practical consequences)]

The authors give an overview on the hypothesis of the metabolic syndrome-x in accordance with insulin resistance and hyperinsulinism in triggering the development of type 2 diabetes mellitus with its clinical complexity. Dealing with the criticism of the original hypothesis, they touch the problem of protein-insufficient feeding in utero and consequences later in life. They discuss the recently emerging importance of postprandial hyperglycaemic condition, which might be even more responsible in leading to atherosclerotic lesions than the hyperinsulinism itself. Finally, they deal with the non-pharmacological intervention and drug therapy as well. A short overview of the results of the UKPDS (United Kingdom Prospective Diabetes Study) are also given, pointing out the clinical importance of correct antihyperglycaemic and antihypertensive treatment. The authors emphasise the utmost importance of early prevention in behalf of avoiding type 2 diabetes and cardiovascular complications as well.

[Human insulin-induced lipoatrophy]

The medical history of a 14-year-old diabetic adolescent female patient is presented. The patient has been exclusively treated by human insulin since the manifestation of diabetes at age of 11. As a clinical curiosity lipoatrophy developed at different sites of insulin injections (upper arm, thigh, abdominal wall, buttock). The insulin administration technique by pen-devices was correct. The patient proved to be non-atopic without signs of insulin allergy on intracutan tests. On histological examination, "lipoblastoma-like" alterations without signs of local immune mechanisms and no inflammatory cell infiltrates were found at the site of lipoatrophy. The histological findings suggested dedifferentiation of adipose tissue mediated probably by elevated local tumor necrosis factor-alpha. Immunological consequences of previous human insulin treatment were documented by high insulin-specific IgG and IgE antibody titer, however, no clinical signs of immunogenic insulin resistance were found. Switching to insulin analogue (insulin lispro) before main meals no further lipoatrophic areas were observed despite of using human NPH-insulin for basal insulin supplementation. Insulin analogue (insulin lispro) may be useful for treating diabetic patients with lipoatrophy secondary to previous human insulin treatment.

Endothelial nitric oxide in diabetes mellitus: too much or not enough?

Vascular complications are the leading cause of increased mortality in patients with diabetes mellitus. Endothelial dysfunction, characterised by impaired endothelium-dependent vasoreactivity, is the first sign of blood vessel damage that precedes morphological changes of the vessel wall. With other factors altered bioavailability of nitric oxide, the most potent endothelium-derived vasodilator, contributes to the changes in vascular tone and integrity. In addition to the impairment of vascular reactivity and permeability, other anti-atherosclerotic functions of nitric oxide are also diminished, which may result in activated monocyte, leukocyte and platelet adhesion to the endothelium, increased platelet aggregation, lipoprotein influx to the subendothelial space and smooth muscle proliferation. Hyperglycaemia-induced increased oxidative stress and impairment of antioxidant defence are suggested to play a role in the pathomechanism of vascular damage, partly by influencing nitric oxide. Both in experimental and clinical Type 1 and Type 2 diabetes mellitus the apparently conflicting data of increased, unaltered or diminished nitric oxide action suggests a complex, time and localisation-dependent alteration of vascular function. The understanding of the mechanisms that lead to diabetic endothelial dysfunction and its early detection are necessary to establish appropriate intervention to prevent irreversible atherosclerotic vessel damage in patients with diabetes mellitus.

[A new method of molecular testing in the differential diagnosis of hereditary hemochromatosis]

Hereditary hemochromatosis is an autosomal, recessive disorder of the iron metabolism. The hemochromatosis gene (HFE) was previously located on chromosome 6 and recently identified by positional cloning. A point mutation, C282Y, was found to be present in the HFE gene in homozygous form in 64 to 100% of patients with established hemochromatosis. The relationship of a second polymorphic variant of the HFE gene, H63D to the formation of iron overload is debated. Although hemochromatosis is one of the most common inherited disorders among Caucasians, in the absence of specific signs it is rarely diagnosed. In order to obtain comparable epidemiological data for Hungary, we tested 1271 and 277 randomly selected, unrelated, healthy subjects for C282Y and H63D respectively. In addition C282Y testing was carried out in 58 patients suffering from liver cirrhosis, and in 191 individuals with suspected hemochromatosis. For C282Y and H63D mutation analyses polymerase chain reaction technique followed by Rsa I and Bcl I restriction enzyme digestion was used. We developed an alternative method for the detection of C282Y based on an amplification-generated Kpn I restriction site. The allele frequencies were 3.8% and 12.3% for C282Y and H63D respectively in the normal Hungarian population. There was no significant difference in C282Y allele frequencies between liver disease patients (1.7%) and the normal population. We identified 15 homozygous and 25 heterozygous individuals among 191 individuals with suspected hemochromatosis. The C282Y and the H63D allele frequencies in the normal Hungarian population were found to be similar to the allele frequencies observed in other European populations, indicating that there is a large number of individuals susceptible for iron overload in Hungary (1:700). Mutation analysis is a novel, non-invasive method in the diagnostics of hereditary hemochromatosis, which increasingly becomes part of the routine clinical work.

[Rapid hemoglobin A1c determination (a new possibility in diabetes care)]

To assess the long-term metabolic control, immunochemical method was used for hemoglobin A1c (HbA1c) determinations in diabetic patients. The use of DCA 2000 device (Bayer) resulted in immediate (< 6 min) HbA1c values. The reproducibility of this method was acceptable (within-run coefficients of variations were 3.48% and 4.80%). A close, linear correlation (r = 0.974; p < 0.001; n = 106) between HbA1c-values measured simultaneously by DCA 2000 and DIAMAT (Bio-Rad, method: high pressure liquid chromatography) was observed in diabetic patients. The new immunochemical method proved to be simple and reliable. The immediate (within 6 min) result makes the therapeutic decision easier during the care of diabetic patients.

[Delayed sulfonylurea resistance in non-insulin-dependent diabetes mellitus]

Non-insulin-dependent diabetes mellitus is one of the most common non-infectious diseases in Hungary. Oral hypoglycaemic agents, especially sulfonylurea drugs are basic therapeutic tools in the treatment of the disease. The cellular effects of sulfonylurea drugs are continuously investigated as their mode of hypoglycaemic action remains controversial despite the large number of experimental trials. According to the immediate or progressive nature of its insufficient blood glucose lowering effect, early (primary) and late (secondary) sulfonylurea failure can be distinguished. There are no exact criteria for the secondary sulfonylurea failure state. Having excluded causes other than drug failure, blood glucose profiles, and, if possible, serum or urinary C-peptide measurements should be carried out. Once sulfonylurea failure has been established other classes of antihyperglycaemic drugs in combination with insulin therapy or insulin therapy alone are to be introduced, respectively.

[Screening for microalbuminuria in diabetic patients in the primary health care system]

In order to detect the prevalence of microalbuminuria, a screening procedure was carried out in 1016 adult (age > 14 years) diabetic patients registered in primary health care system at the 17st district of the capital. The clinical characteristics of patients were investigated and microalbuminuria was measured by immunoturbidimetric method using first void morning urinary samples. In this way, the urinary albumin/creatinine ratio was calculated (abnormal value in men > or = 2.5 mg/mmol, in women > or = 3.5 mg/mmol). Moreover, serum creatinine, blood glucose, serum cholesterol and triglycerides were measured in fasting blood samples. After applying exclusion criteria data of 933 diabetic patients [129 insulin-dependent (IDDM) and 804 non-insulin-dependent (NIDDM) patients; 424 men, 509 women] were analysed. Abnormal urinary albumin/creatinine ratio was found in 315 (33.8%) patients. Microalbuminuria was detected in 32 (24.8%) IDDM and in 201 (25.0%) NIDDM patients. Macroalbuminuria was found in 13 (10.1%) IDDM and in 69 (8.6%) NIDDM patients. Abnormal urinary albumin/creatinine ratio was more often found in men than in women (IDDM men 41.3%, IDDM women 28.8%; NIDDM men 38.0%, NIDDM women 30.0%). Significant difference was found between diabetic patients with (n = 315) and without (n = 618) abnormal urinary albumin/creatinine ratio regarding age (64.3 +/- 0.7 years vs. 61.4 +/- 0.5 years; p < 0.001), duration of diabetes (10.3 +/- 0.5 years vs 7.9 +/- 0.3 years; p < 0.001) systolic blood pressure (151 +/- 1 mmHg vs 146 +/- 1 mmHg; p < 0.01), serum creatinine (99 +/- 2 mumol/l vs 88 +/- 1 mumol/l; p < 0.001) and blood glucose (10.4 +/- 0.2 mmol/l vs 9.4 +/- 0.1 mmol/l; p < 0.001). One third (33.8%) of diabetic patients in primary health care setting exhibited signs or were at risk of renal involvement of diabetes. Diabetic patients with micro- or macroalbuminuria should be carefully controlled in order to prevent or to decrease deterioration of renal function due to diabetic nephropathy.

Day-night blood pressure variation in normotensive and hypertensive NIDDM patients with asymptomatic autonomic neuropathy

In order to assess the characteristics of day-night blood pressure (BP) variation in normotensive and hypertensive non-insulin-dependent diabetic (NIDDM) patients with asymptomatic autonomic neuropathy, 54 NIDDM patients and 13 healthy control subjects were studied by casual BP measurements and 24-h ambulatory blood pressure monitoring. Signs but not symptoms of autonomic neuropathy were documented by results of standard cardiovascular function tests in each patient. Daytime (06:00-22:00) and nighttime (22:00-06:00) BP values were separately analyzed and delta day-night BP values and diurnal index were determined. Patients were classified as being normotensive or having hypertension according to the casual BP values and medical history. In normotensive NIDDM patients (n = 30), nighttime systolic BP was significantly higher, whereas delta day-night systolic and delta day night diastolic BP values as well as diurnal index were considerably lower than those in control subjects (n = 13). In hypertensive NIDDM patients (n = 24), similar alterations were found at higher BP levels. No significant difference was found in BP values if normoalbuminuric and microalbuminuric NIDDM patients were compared. 'Non-dipper' phenomenon could be found in normotensive and hypertensive NIDDM patients with asymptomatic autonomic neuropathy, suggesting that relative sympathetic overdrive due to incipient and predominantly parasympathetic impairment of cardiovascular innervation might play a role in early alterations of circadian BP variation.

Hypoglycemia factitia: Munchhausen syndrome in diabetes mellitus

The medical history of a 43-year-old non-insulin-dependent diabetic patient with severe and repetitive hypoglycemic episodes is reported. The exact diagnosis proved to be difficult. Finally, surreptitious insulin administration was documented by high serum insulin and low C-peptide values with an elevated molar ratio of insulin to C-peptide in peripheral venous blood during hypoglycemia. Confronting the patient with evidences of surreptitious insulin administration, hypoglycemic episodes abruptly stopped. Hypoglycemia factitia was assessed as a manifestation of Munchhausen syndrome in diabetes mellitus.

[Experience with microbiological studies of the diabetic foot]

In order to determine the microbiological characteristics of diabetic foot infection, 60 diabetic patients (21 women, 39 men; age between 43 and 89 years with a duration of diabetes from 0.5 to 37 years) were investigated. Immediately after the hospitalisation specimens from infected foot lesions were taken using Port-A-Cul special transport medium. Aerobic cultures were done in all cases according to conventional methods while anaerobic cultures were carried out when clinical signs indicated to perform it. Out of 60 lesions only 2 proved to be sterile. In the remaining 58 patients a total of 138 isolates were found resulting in an average of 2.3 organisms per lesions. Only aerobic isolates were identified in 45 patients whereas anaerobic species were also found in 12 patients. Only Candida was found in 1 patient while Candida in combination with bacterial strains was observed in 3 patients. In antimicrobial susceptibility testing beta-lactamase-stable antibiotics with broad spectrum, covering enterococcus and anaerobic organisms proved to be most effective. Diabetic foot infections have a polymicrobial nature. Antibiotic treatment of infections should be based on the results of microbiological investigation of diabetic foot.

[Factitious hypoglycemia--Munchausen syndrome in diabetes mellitus]

The medical history of a 43-year-old non-insulin-dependent diabetic patient is presented. The exact diagnosis of the cause of repetitive and severe hypoglycaemic episodes proved to be difficult. Finally, high serum insulin and low C-peptide values were found in peripheral venous blood during hypoglycaemia resulting in an elevated (> 1.0) molar ratio of insulin to C-peptide. The laboratory findings were assessed as consequences of surreptitious insulin administration. Factitious hypoglycaemia could be considered as a clinical manifestation of Munchhausen syndrome. Confronting the patient with evidences of surreptitious insulin injections, hypoglycaemic episodes abruptly discontinued to occur.