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Biomedical subjects

A Mohn

Publications and source records attributed to A Mohn.

At least 19 recordsLinked to original sources

Macroangiopathy in adults and children with diabetes: from molecular mechanisms to vascular damage (part 1).

Type 2 diabetes mellitus (T2DM) is an increasing problem in childhood; however type 1 diabetes mellitus (T1DM) remains by far the most common type of diabetes in this age group. In this review we will focus on T1DM, because this will have the greatest implication for patients diagnosed in childhood. During the atherosclerotic process, several molecular, receptorial and cellular factors provide a continous mechanism of vascular damage. In diabetic children this state seems to be enhanced and facilitated so that accelerated atherosclerosis is associated with an increased risk of cardiovascular events in respect to the non diabetic population. Hyperglycemia PER SE and associated with diabetes is an important risk factor for atherosclerosis. At present a substantial part of children with diabetes do not reach satisfactory glycemic control. Other risk factors for the development and progression of atherosclerosis may be inherited or develop in the course of the disease: hypertension, dyslipidemia, insulin resistance, obesity, cigarette smoking, physical inactivity, disturbance of platelet function, coagulation and fibrinolysis. The development and progression of atherosclerosis should be blocked at an early age, if possible. Primary prevention to all risk factors for cardiovascular disease is important and intervention is indicated if necessary. At the moment the best therapeutic strategy is to maintain metabolic control at a physiologic level and perform screening and early intervention for vascular complications.

Adult↗

Macroangiopathy in adults and children with diabetes: risk factors (part 2).

Autoimmune or type 1 diabetes mellitus (T1DM), accounts for 90-95% of all cases of diabetes, while type 2 diabetes mellitus (T2DM), characterized by impaired insulin sensitivity and production, accounts for the other 5-10%. Atherosclerotic process starts during childhood and recognize several mechanisms that are activated in response to NOXIUS STIMULI and participate in a complex state which is accepted to be a chronic inflammatory state. T1DM patients, especially those with a non-optimal metabolic control, have a higher risk of developing all macrovascular complications such as myocardial infarction, stroke and silent ischemia. Macrovascular disease is mainly associated with hyperglycemia, dyslipidemia, obesity, hypertension, hypercoagulable state, cigarette smoking, lack of exercise, endothelial dysfunction, hyperhomocysteinemia and vascular wall abnormalities. In this paper we review the importance of traditional and non-traditional risk factors for macrovascular complications in children with T1DM and discuss their role in the pathogenesis of the excess cardiovascular mortality in these patients.

Adult↗

Physical exercise and diabetes during childhood.

Active life and physical fitness may represent the most effective strategies to prevent chronic diseases and to improve growth and development for children, including those with diabetes. Observational studies have demonstrated the association between life style and prevention of chronic diseases in the general population. These studies have been showed a reduction of morbidity for vascular diseases in trained subjects who present adequate cardiovascular fitness and practise regular exercise. The exercise-related protective effects may be mediated in part through components of the metabolic syndrome: improved insulin sensitivity, decreased weight and visceral fat accumulation, reduced low density lipoprotein (LDL) and triglycerides, increased high density lipoprotein (HDL), decreased blood pressure. These effects are more significant in patients with type 1 diabetes (T1DM), because hyperglycemia-related morbidity and mortality are associated with chronic complications. In particular, improved insulin sensitivity may determine a better glucose profile which in turn may positively influence the diabetes-related microvascular complications. Furthermore, improved blood pressure and normalization of lipid profile may also contribute to the prevention of vascular complications. Nonetheless, physical activity can improve psychological well-being by increasing self-esteem and enhancing quality of life. Although patients with T1DM may participate in all kind of sports and physical activities, there are several potential adverse events, including hypoglycemic and hyperglycemic episodes, that can occur. Thus, patients and health professionals have to know in details the physiological effect of physical exercise and its metabolic events in order sport to be healthy and enjoyable for all children, adolescents and young adults with T1DM.

Adolescent↗

Type 2 diabetes mellitus in children and adolescents.

Over the last decade, there has been an alarming increase of Type 2 diabetes mellitus (T2DM) in youths, concomitant with the rise of obesity in this age group. T2DM is a progressive disease with a gradual increase in insulin resistance associated later with a decline in insulin secretion with fasting hyperglycemia. Prevalence of T2DM in children is mostly linked to some risk factors: obesity and sedentary lifestyle, puberty, membership of ethnic minorities, features of insulin resistance, family history of T2DM, female gender and perinatal factors. Prevention is essential and can be considered a public health approach directed to the general population. Treatment of T2DM in youth is complex and based on different strategies: diet, exercise and pharmacotherapy. An appropriated intervention program must be started early, in order to prevent or retard the progression of the disease and associated comorbidities.

Acanthosis Nigricans↗

Autosomal malignant osteopetrosis. From diagnosis to therapy.

Osteopetrosis is a heterogeneous family of rare human genetic disorders due to markedly decreased bone resorption. It is one among disorders causing osteosclerosis of the trabecular bone and/or hyperostosis of the cortical bone. Four types of human osteopetrosis have been clearly defined, but patients with atypical symptoms are frequent, suggesting that there are additional forms. The most severe expression of this condition in its malignant form is inherited as an autosomal recessive disorder and it is usually fatal before school age. It presents with failure to thrive, severe hepatosplenomegaly, pancytopenia and nerve compression leading to blindness and deafness during infancy. The case of a 2-month-old female child with severe hepatosplenomegaly, failure to thrive, nystagmus, pancytopenia, gengival hyperplasia, optic atrophy, absent evoked visual potential and increased bone density within the total skeleton, is reported. Diagnosis of autosomal recessive malignant osteopetrosis was established by transiliac bone biopsy. She underwent bone marrow transplantation, but died soon afterwards. This rare and mortal disorder of bone formation requires early diagnosis and immediate pharmacological treatment, consisting in administration of vitamin D, in order to enhance bone resorption and of prednisone to improve hematological indexes and, if possible, bone marrow transplantation in order to ameliorate quality of life and survival.

Anti-Infective Agents↗

Kidney involvement and disease in patients with diabetes.

Diabetic nephropathy is the leading cause of end-stage renal disease in western or westernised countries and the largest contributor to the total cost of diabetes care around the world. In addition to the development of diabetic nephropathy and end-stage renal failure, diabetic patients with evidence of albuminuria have a much higher risk of developing myocardial infarctions, cerebrovascular accidents, severe progressive retinopathy, and peripheral and autonomic neuropathy. A cumulative incidence of diabetic nephropathy has been documented after duration of diabetes of at least 25 years in both type 1 and type 2 diabetic patients, although more recent studies have demonstrated a substantial reduction of its incidence. Before the onset of overt proteinuria, there are several renal functional changes, including renal hyperfiltration, hyperperfusion, and increasing capillary permeability to macromolecules. Basement-membrane thickening and mesangial expansion have long been recognized as pathological hallmark of diabetic nephropathy. It has been postulated that diabetic nephropathy occurs as a result of the interplay of metabolic and haemodynamic factors in the renal microcirculation. Hyperglycaemia plays a pivotal role in the pathogenesis of diabetic renal disease, but genetic factors are also of crucial importance. The accumulation of advanced glycosilation end products (AGEPs), the activation of isoforms of protein kinase C (PKC) and the acceleration of the aldose reductase pathway may explain how hyperglycaemia damages vessels. Growth factors (i.e. TGF-b, IGF-1, VEGF) may also play an important role in the pathogenesis. There is a familial clustering of diabetic kidney disease: a number of gene loci have been investigated to try to explain the genetic susceptibility to this complication. The two main treatment strategies for prevention of diabetic nephropathy are improved glycaemic control and blood pressure lowering, particularly using drugs such angiotensin-converting enzyme inhibitors and angiotensin II receptor antagonists. Many potential treatment modalities in preventing and treating diabetic nephropathy are presently being evaluated; some of them will possibly be available in the near future in order to try to modify the natural course of kidney involvement and disease in patients with diabetes.

Diabetic Nephropathies↗

Serum angiogenin concentrations in young patients with diabetes mellitus.

BACKGROUND: Angiogenin serum levels were measured in a large group of type 1 diabetic young patients, looking at whether increased Angiogenin concentrations are associated with long-term glycemic control and microvascular complications. MATERIALS AND METHODS: Four groups of patients were compared to 223 age- and sex- matched healthy controls: 196 type 1 diabetic patients (age range 3-24 years, onset of diabetes before the age of 12 years; duration of disease longer than 2 years), without microvascular complications were divided into three groups on the basis of age (group 1, n = 37, age < 6 years; group 2, n = 71, age 6-12 years; group 3, n = 88, age > 12 years); 53 adolescents and young adults (age 16.1-29.7 years) with diabetic microvascular complications (background, preproliferative or proliferative retinopathy, albumin excretion rate 20-200 microg min-1) (group 4). RESULTS: Angiogenin serum levels were significantly increased in diabetic pre-school and pre-pubertal children, and particularly elevated in pubertal subjects compared with age- and sex-matched controls. Adolescents and young adults with microvascular complications had very high angiogenin concentrations. One-year mean HbA1c values were correlated with angiogenin levels (r = 0.389; p < 0.01). In poorly controlled diabetics (HbA1c > 10%), long-term (2 years) improvement of glycemic control determined a significant reduction of angiogenin concentrations in both pre-school and pre-pubertal children as well as in pubertal youngsters. CONCLUSIONS: Angiogenin serum concentrations are increased in diabetic children even before puberty. Severity of microvascular complications is associated with markedly increased angiogenin serum levels. Long-term tight glycemic control determines a consistent reduction of angiogenin concentrations.

Adolescent↗

The effect of subclinical hypothyroidism on metabolic control in children and adolescents with Type 1 diabetes mellitus.

AIMS: Associated autoimmune phenomena might influence metabolic control in children and adolescents with Type 1 diabetes mellitus. A retrospective case control study was performed in order to explore the effect of subclinical hypothyroidism on metabolic control in Type 1 diabetes mellitus. PATIENTS AND METHODS: For this purpose each patient with Type 1 diabetes and subclinical hypothyroidism (cases) was matched for age, duration of disease and, if possible, for sex, with two to three diabetic patients without hypothyroidism (controls). Parameters of metabolic control such as HbA1c, total insulin requirement and frequency of symptomatic hypoglycaemia were retrieved for 12, 6 and 3 months before and after diagnosis of hypothyroidism. RESULTS: Thirteen patients (two male/11 female) patients were diagnosed with subclinical hypothyroidism and were matched with 31 controls (nine male/22 female). There was no difference (mean and range) in terms of age (11.9 years (4.4-18.1) vs. 11.7 years (3.5-18.1), P = 0.9) and duration of disease (5.1 years (1.2-10.5) vs. 4.38 years (0.9-10.8), P = 0.6) between the two groups. There was no difference in HbA1c and total insulin requirement between the two groups at any time point of assessment (anova P = 0.8 and P = 0.1, respectively). Patients with hypothyroidism had significantly more symptomatic hypoglycaemic episodes during the 12 months before diagnosis (anova P = 0.05), increasing progressively during this time period and reaching a peak at time 0 (5.5+/-0.4 vs. 1.6+/-0.1 episodes/month, P = 0.01). No difference could be detected within 6 months of starting substitution therapy (2.4+/-0.2 vs. 1.6+/-0.1 episodes/week, P = 0.8). CONCLUSIONS: These data suggest that subclinical hypothyroidism is associated with an increased risk of symptomatic hypoglycaemia. The prompt introduction of substitution therapy is recommended as it reduces its frequency.

Adolescent↗

Screening for vascular complications in children and adolescents with type 1 diabetes mellitus.

Type 1 diabetes mellitus poses a significant health burden, particularly as a result of its microvascular complications. Clinically evident diabetes-related microvascular complications are extremely rare in childhood and adolescence. However, early functional and structural abnormalities may be present a few years after the onset of the disease. Therefore, regular screening for diabetic microvascular disease, particularly retinopathy and nephropathy, are of foremost importance in paediatric diabetes care. Early detection of diabetic microangiopathy and timely treatment of early signs of these complications have a pivotal role in prevention of blindness and end-stage renal failure in children and adolescents with diabetes.

Diabetes Mellitus, Type 1↗

Angiopathy in children with diabetes.

Diabetic angiopathy includes those complications associated with chronic hyperglycaemia. The major long-term complications of diabetes can be categorized into two classes: macrovascular (i.e., cardiovascular complications) and microvascular (i.e., nephropathy, retinopathy, and neuropathy). Clinically evident diabetic vascular disease is rare in children and adolescents with type 1 diabetes mellitus: however, the permanent threat of severe vascular organ disease within one or two decades, of early invalidity and limited life expectancy following long-term poor metabolic regulation (which is known to the health professional but only incompletely sensed by the young patient), forces the paediatrician to try to reach from the start the aim of normoglycaemia instead of merely somewhat reduced hyperglycaemia, normal lipid and amino acid patterns and near normal fluctuations of all metabolic parameters. With our present means of intervention, this goal is achieved only temporarily, if at all, necessitating immense permanent efforts by the patient and his or her family, including a greater responsibility (compared to that of his/her peers) for his/her everyday lifestyle. In this review natural history, risk factors and screening of diabetic microvascular and macrovascular complications will be described, with particular emphasis to the aspects of these complications in childhood and adolescence. Pediatric diabetologists, other health professionals and families of children must be aware of the risk of diabetic angiopathy (a Damocle's sword on the head of patients with diabetes) and try to do their best for preventing these complications.

Adolescent↗

Daytime liver glycogen accumulation, measured by 13C magnetic resonance spectroscopy, in young children with Type 1 diabetes mellitus.

AIM: To examine daytime liver glycogen accumulation in prepubertal children with Type 1 diabetes mellitus (Type 1 DM) compared with non-diabetic controls. METHODS: Liver glycogen content was ascertained in the fasting (morning) and fed (afternoon) state using 13C magnetic resonance (MR) spectroscopy. Data were analysed from six children with Type 1 DM (median (range) age 8.7 (6.3-12.2) years), who were all on conventional insulin regimens, and six healthy controls (age 8.9 (7-10.2) years). RESULTS: Children with diabetes tended to have lower fasting glycogen values than controls but this did not reach statistical significance (median (range) 154 (70-177) vs. 178 (120-203) mM glycosyl units, Type 1 DM vs. controls respectively; P = 0.06). Glycogen increased in all children with diabetes during the day and concentrations were similar to those in controls by the afternoon (175 (157-299) vs. 172 (136-238) mM glycosyl units; P = 0.7). CONCLUSIONS: The ability of young children with Type 1 DM to replace liver glycogen depleted after an overnight fast was at least as good as that in control subjects, suggesting that impaired glycogen storage is not a contributory factor in nocturnal hypoglycaemia.

Activity Cycles↗

Celiac disease in children and adolescents with type I diabetes: importance of hypoglycemia.

BACKGROUND: Symptomatic hypoglycemia is an unavoidable problem in the treatment of type I diabetes. Celiac disease is associated with malabsorption and may therefore represent an important risk factor. METHODS: The frequency of symptomatic hypoglycemia in patients with type I diabetes and celiac disease (cases) was compared with those of patients who had diabetes without celiac disease (controls). For this purpose, each case was matched for age, sex, and duration of disease with one to two control patients. Indices of metabolic control (hemoglobin [Hb]A1c, frequency of hypoglycemia, and total insulin requirement) were retrieved for the 18 months before and after diagnosis of celiac disease. RESULTS: Eighteen patients (6 males and 12 females) had diagnosed celiac disease and were matched with 26 control patients (10 males and 16 females). There was no difference in age (11.0 years; range, 1.8-21.9 vs. 13.1 years; range, 2.3-22; P = 0.3) and duration of disease (8.4 years; range, 1.2-19.3 vs. 8.3 years; range, 1.1-18.7; P = 0.3) between the two groups. During the 6 months before and after diagnosis of celiac disease the cases had significantly more hypoglycemic episodes than the controls (means +/- SD; 4.5+/-4 vs. 2.0+/-2.2 episodes/months, P = 0.01). This was reflected by a progressive reduction in insulin requirement over the 12 months before diagnosis reaching a nadir at time 0 (0.6+/-0.2 vs. 0.9+/-0.3, P = 0.05). CONCLUSION: These data suggest that underlying celiac disease is associated with an increased risk of symptomatic hypoglycemia and that the introduction of a gluten-free diet with normalization of the intestinal mucosa may reduce its frequency.

Adolescent↗

Increased vascular endothelial growth factor serum concentrations may help to identify patients with onset of type 1 diabetes during childhood at risk for developing persistent microalbuminuria.

This study was designed to evaluate whether vascular endothelial growth factor serum concentrations may identify adolescents with onset of type 1 diabetes during childhood at greater risk to develop persistent microalbuminuria and incipient diabetic nephropathy. In January 1989, vascular endothelial growth factor serum levels were measured in 101 normoalbuminuric diabetic children and adolescents (aged 7-14.9 yr; onset of diabetes before age 18 yr; duration of diabetes >7 yr). Participants were clinically examined at baseline and annually thereafter. Vascular endothelial growth factor serum concentrations were measured every year during the 8-yr follow-up period. Over 8 yr, 11 of 101 patients (10.9%) developed persistent microalbuminuria; no patient developed overt nephropathy. The risk of developing microalbuminuria was higher in children with increased vascular endothelial growth factor serum levels (using 160 pg/ml as the arbitrary cut-off point; group 1) compared with those with normal vascular endothelial growth factor serum levels at the beginning of the study (group 2; 19.2 vs. 2.0%; P < 0.01; sensitivity, 90.9%; specificity, 53.3%). The odds ratio for the occurrence of microalbuminuria after adjustment for confounding variables (albumin excretion rate, sex, hemoglobin A(1c), mean blood pressure, cholesterol, and triglycerides) in type 1 diabetic adolescents with elevated vascular endothelial growth factor serum levels was 4.1 (95% confidence interval, 2.0-10.9). These results suggest that vascular endothelial growth factor serum concentrations may be one of the predictors and risk factors for microalbuminuria and incipient diabetic nephropathy in adolescents and young adults with onset of diabetes during childhood. Persistently increased vascular endothelial growth factor serum levels may help to identify normotensive, normoalbuminuric patients with type 1 diabetes who are predisposed to develop persistent microalbuminuria later in life.

Adolescent↗

The potential role of insulin analogues in the treatment of children and adolescents with Type 1 diabetes mellitus.

The main therapeutic challenge in the treatment of Type 1 diabetes is maintenance of near-normoglycaemia in order to prevent long-term complications and avoid hypoglycaemia. This goal is relevant from the onset of the disease and is feasible if physiological models of insulin replacement are used and patients are educated in the strategy of intensive insulin therapy. Although the use of available insulins within a multiple injection regimen has improved, metabolic control it is still far from being optimal. The recent introduction of insulin analogues with a short- and long-acting profile seems promising in improving metabolic control and quality of care. Insulin lispro and insulin aspart, the short-acting insulin analogues offer a better post-prandial profile, while insulin glargine the new long-acting insulin analogue might provide better overnight control. In fact, the theoretical combination of an acute prandial insulin peak with a flat interprandial and overnight plasma profile would closely mimic the 24-hr insulin profile of non-diabetic individuals. This would possibly lead to lower post-prandial blood glucose excursion and better fasting blood glucose associated with minimal risk of hypoglycaemia. The possible reduction of hypoglycaemia is especially important in children as recurrent episodes might represent a potential risk for cognitive impairment. However, recent clinical research on the short-acting insulin analogues demonstrates the difficulties of translating these theoretical benefits into clinical relevant advantages. This might happen to other insulin analogues and requires further and larger studies in order to fully exploit the theoretical advantages of insulin analogues in the paediatric population. Safety issues should also be carefully monitored when introducting analogues in long-term therapy.

Adolescent↗

Survey of unlicensed and off label drug use in paediatric wards in European countries. European Network for Drug Investigation in Children.

OBJECTIVE: To determine the extent of use of unlicensed and off label drugs in children in hospital in five European countries. DESIGN: Prospective study of drugs administered to children in general paediatric medical wards over four weeks. SETTING: Children's wards in five hospitals (one each in the United Kingdom, Sweden, Germany, Italy, and the Netherlands). SUBJECTS: Children aged 4 days to 16 years admitted to general paediatric medical wards. MAIN OUTCOME MEASURE: Proportion of drugs that were used in an unlicensed or off label manner. RESULTS: 2262 drug prescriptions were administered to 624 children in the five hospitals. Almost half of all drug prescriptions (1036; 46%) were either unlicensed or off label. Of these 1036, 872 were off label and 164 were unlicensed. Over half of the patients (421; 67%) received an unlicensed or off label drug prescription. CONCLUSIONS: Use of off label or unlicensed drugs to treat children is widespread. This problem is likely to affect children throughout Europe and requires European action.

Adolescent↗

Homocysteine levels during fasting and after methionine loading in adolescents with diabetic retinopathy and nephropathy.

OBJECTIVE: To assess plasma homocysteine levels in adolescents and young adults with type 1 (insulin-dependent) diabetes with and without microvascular complications. STUDY DESIGN: Homocysteine levels were measured during fasting and after methionine loading in plasma of 61 patients with onset of diabetes before the age of 12 years and duration of disease longer than 7 years. They had an albumin excretion rate (AER) between 20 and 200 microg/min in 2 of 3 overnight urine collections in a period of 6 months and/or retinopathy. Patients with persistent microalbuminuria were divided into 2 groups: subjects with AER of 20 to 70 microg/min and patients with AER of 70 to 200 microg/min. Adolescents (n = 54) without signs of diabetic retinopathy or nephropathy and matched control subjects (n = 63) were also studied. RESULTS: Homocysteine concentrations before and after methionine load were higher in adolescents with diabetic complications than in healthy subjects (fasting values: 12. 4 +/- 7.9 micromol/L vs 7.8 +/- 4.2 micromol/L; P <.01; after methionine load: 28.1 +/- 13.2 micromol/L vs 16.6 +/- 7.3 micromol/L; P <.005). Values of 11.9 micromol/L or higher were considered to constitute fasting hyperhomocysteinemia. The increase of homocysteine concentrations was particularly evident in young diabetic patients with AER >70 microg/min (fasting values: 14.7 +/- 5.6 micromol/L; after methionine load: 34.2 +/- 12.6 micromol/L) and in patients with proliferative retinopathy (fasting values: 15.1 +/- 5.0 micromol/L; after methionine load: 36.8 +/- 12.5 micromol/L). CONCLUSIONS: Increased plasma homocysteine concentrations may contribute to increased morbidity and death from cardiovascular disease in adolescents and young adults with diabetic retinopathy and nephropathy.

Adolescent↗