Complications of pediatric and adolescent type 1 diabetes mellitus

Left ventricular longitudinal systolic dysfunction in children with type 1 diabetes mellitus: A systematic review and meta-analysis

OBJECTIVE

Children with type one diabetes mellitus (T1DM) may have subclinical myocardial insults but large heterogeneity exists among the reports. This study aimed to compare myocardial strain values of the left ventricle (LV) in paediatric patients with T1DM without overt cardiac disease and healthy controls.

METHODS

Five databases (MEDLINE, Embase, Scopus, Web of Science and Cochrane central register of controlled trials) were searched from inception to March 30, 2020. The studies reporting two-dimensional speckle tracking echocardiography in asymptomatic T1DM paediatric patients and control groups were included. Pooled mean strain values in each group and mean difference (MD) between the two groups for LV global longitudinal strain (LVGLS) and LV global circumferential strain (LVGCS) were assessed using a random effects model.

RESULTS

Ten studies (755 T1DM and 610 control) with LVGLS were included with 6 studies having LVGCS (534 T1DM and 403 control). Patients with T1DM had overall 3 percentage points lower LVGLS than healthy subjects (18.4 %, 95 % confidence interval [17.1, 19.6] vs 21.5 % [20.3, 22.7], MD = -3.01 [-4.30, -1.71]). A similar result was seen in LVGCS (18.7 % [15.4, 22.0] vs. 21.4 % [18.1, 24.6], MD = -3.10[-6.47, 0.26]) but not statistically significant. Meta-regression identified those with higher Haemoglobin A1c (HbA1c) had worse GLS.

CONCLUSIONS

Subclinical LV dysfunction among patients with T1DM occurs as early as in their childhood, while even EF is preserved. The longitudinal cardiac function is altered, but not the circumferential. GLS can be used to detect subclinical LV systolic dysfunction in paediatric population.

Prevalence of Depression in Patients with Type 1 Diabetes between 10 and 17 Years of Age in Jordan

METHODS

The study was conducted by distributing the Center for Epidemiological Studies Depression Scale for Children (CES-DC) to adolescents with T1D seen at Jordan University Hospital between February 2019 and February 2020. Demographic, clinical, and socioeconomic data were collected using electronic clinical charts. Possible predictors of depression were assessed using logistic regression analysis.

RESULTS

A total of 108 children were enrolled in the study with mean age of 13.7 ± 2.3 years. Fifty-eight children (53.7%) had a CES depression score less than 15, and 50 children (46.3%) had a depression score of 15 or more. The number of diabetes-related hospital admissions and the frequency of self-monitoring of blood glucose (SMBG) were significantly different between the two groups. In the multivariable analysis, both gender and SMBG frequency were statistically significant. Girls were more likely to have a depression score ≥ 15 (OR = 3.41, p = 0.025) than boys. Patients who were rarely testing blood glucose levels were more likely to have a depression score ≥ 15 compared to those who were testing regularly (OR = 36.57, p = 0.002).

CONCLUSION

The prevalence of depressive symptoms is relatively high in adolescents with T1D, especially in those living in developing countries. Longer diabetes duration, higher glycated hemoglobin level, and less frequent blood glucose monitoring are associated with higher depression scores.

Effects of circadian blood pressure patterns on development of microvascular complications in pediatric patients with type 1 diabetes mellitus

PURPOSE

The effects of circadian blood pressure (BP) alterations on the development and progression of microvascular complications in type 1 diabetes mellitus (T1DM) patients are unknown. We evaluated the effects of circadian BP alterations with development of microvascular complications during follow-up with patients with childhood-onset T1DM.

METHODS

We investigated the medical records of 81 pediatric patients with T1DM who underwent 24-hour ambulatory BP monitoring (ABPM) between January 2009 and February 2010.

RESULTS

Mean age at diagnosis and ABPM evaluation was 8.0±3.9 and 15.6±2.4 years, respectively. Hypertension (daytime, nighttime, and 24-hour mean hypertension) data were available in 42 patients. During the 8 years of follow-up after ABPM, microvascular complications occurred in 8 patients (diabetic retinopathy [DR] alone in 5, microalbuminuria alone in 2, and both in 1), of whom 7 had nondipper BP. Nighttime diastolic BP, nighttime mean arterial pressure, and glycated hemoglobin A (HbA1c) level were higher in patients with DR than in those without DR (P<0.05 for all). Daytime or nighttime BP and presence of dipper BP were not related to microvascular complications, but diabetic microvascular complications were more likely to occur in patients with an older age at diagnosis and higher HbA1c level. The proportion of patients with DR was higher in those with nondipper hypertension (83.3%) compared with dipper and nondipper normotension (0% and 16.7%, respectively; P=0.021).

CONCLUSION

As a predictor of microvascular complications, nondipper hypertension was not significant. Glycemic control rather than nondipper hypertension is the predominant factor determining DR in T1DM patients.

Homozygosity of the Z-2 polymorphic variant in the aldose reductase gene promoter confers increased risk for neuropathy in children and adolescents with Type 1 diabetes

BACKGROUND

Diabetic neuropathy (DN) is the least recognized complication of diabetes mellitus and may start early in the course of the disease. Aldose reductase (AKR1B1) gene promoter Z-2/Z-2 polymorphism increases the expression of AKR1B1 enzyme and may contribute to DN.

SUBJECTS

We evaluated 108 Type 1 diabetes (T1D) children and adolescents (mean ± SD age: 13.5 ± 3.46 years, disease duration: 5.3 ± 3.4 years) and 150 healthy controls (age: 11.9 ± 2.7 years).

METHODS

In both groups, pupillary dilation (PD) in darkness, postural blood pressure test (PBPT), and vibration sensation thresholds (VST) in upper and lower limbs were estimated as indices of autonomic and peripheral neuropathy, respectively. Nerve conduction studies (NCS) were performed in patients as peripheral neuropathy index. The polymorphisms of AKR1B1 gene were evaluated using microsatellite (AC)n sequence Z.

RESULTS

PBPT, PD, and VST impairments were more frequent in patient group compared with controls, while 38.6% of patients exhibited NCS abnormality. Gender, age, pubertal status, height, body mass index, diabetes duration, HbA1c, and anti-GAD titers were associated with neuropathy indices in patients. There was a strong correlation between PD and NCS in patients, while homozygous patients for Z-2 AKR1B1 gene polymorphism had higher prevalence of abnormal NCS (83.3% vs. 34.6%), PD (62.5% vs. 31.5%), and PBPT values compared with heterozygous or negative patients. Homozygous AKR1B1 status predicted PD, NCS, and PBPT variance, while PD, VST, NCS, and PBPT parameters accurately discriminated homozygous AKR1B1 patients.

CONCLUSIONS

Impaired indices of peripheral and autonomic DN were present in a significant proportion of young T1D patients. PD, VST, NCS, and PBPT parameters were simultaneously associated with homozygous state of AKR1B1 Z-2 gene polymorphism, implicating polyol metabolism with both autonomic and peripheral neuropathies.

The Diabetes-Specific Risk-Taking Inventory: Piloting a New Measure for Adolescents With Type 1 Diabetes

OBJECTIVE

We sought to develop and pilot a new measure, the Diabetes-Specific Risk-Taking Inventory (DSRI), to assess unhealthy risk-taking behaviors among adolescents with type 1 diabetes.

METHODS

Thirteen diabetes health care providers, 30 adolescents with type 1 diabetes (aged 15-19 years, 60% female, mean A1C 8.7% [72 mmol/mol], and 33% on insulin pumps), and the adolescents' caregivers rated the perceived riskiness of each item on the DSRI. Adolescents completed the DSRI, for which they reported how often they engaged in 34 behaviors that could place them at risk for acute complications of type 1 diabetes or out-of-range blood glucose levels. Adolescents also completed the risk-taking subscale from the Risk-Taking and Self-Harm Inventory for Adolescents, and parents completed the parent-proxy Diabetes Management Questionnaire. Mean A1C during the previous year was obtained via medical chart review.

RESULTS

Results indicated good content validity and feasibility for using the DSRI in a research context, as 100% of adolescents who consented to the study completed the measure. The DSRI was positively correlated with general risk-taking and negatively correlated with diabetes management, indicating preliminary evidence of convergent validity. The DSRI also correlated with A1C.

CONCLUSION

This pilot study extends our previous work in developing a conceptual model for illness-specific risk-taking. The DSRI is a promising new measure to assess illness-specific risk-taking, including unhealthy risk-taking behaviors, for adolescents with type 1 diabetes.

Impact of Socioeconomic Characteristics on Metabolic Control in Children with Type 1 Diabetes in a Developing Country

OBJECTIVE

Adequate glycemic control in children with type 1 diabetes reduces the risk of future complications. Identifying factors affecting haemoglobin A1c (HbA1c) is crucial to management of metabolic control. We aimed to identify possible socioeconomic predictors of poor metabolic control this patient group in Jordan, a developing country with limited resources.

METHODS

Medical charts of children with type 1 diabetes attending the pediatric endocrine clinics in two major diabetes centers were reviewed. HbA1c ≥7.5% (58 mmol/mol) was considered to reflect poor metabolic control. Logistic regression analysis was performed to identify predictors of poor glycemic control. The association between socioeconomic characteristics and metabolic control was evaluated using multiple correspondence analysis (MCA).

RESULTS

Two hundred and fifty-nine children were enrolled in the study. One fifth of the patients (20.5%) achieved HbA1c <7.5%. Patients with dietary non-compliance [odds ratio (OR): 3.533, confidence interval (CI): 1.803 - 6.926; p<0.001], and those who were overweight (OR: 3.869, CI: 1.218 - 12.294; p=0.022) were more likely to have poor metabolic control. Children whose mothers had a bachelor’s degree or higher were less likely to have poor metabolic control compared to children whose mothers had only elementary education (OR: 0.241, CI: 0.079 - 0.734; p=0.012). MCA revealed an association between low socioeconomic status and poor metabolic control. Children with deceased mothers had significantly higher HbA1c of 10.6±1.86% compared to an average of 8.7±1.45% for the rest of participants (p=0.005).

CONCLUSION

Low socioeconomic status, lower levels of maternal education and maternal death were associated with poor metabolic control. Identifying children with these risk factors might play an important role in optimizing metabolic control and provide better diabetes care.

Left ventricular functions in pediatric patients with ten years or more type 1 diabetes mellitus: Conventional echocardiography, tissue Doppler, and two-dimensional speckle tracking study

BACKGROUND

Cardiac dysfunction is a complication of type 1 diabetes mellitus (T1DM) with primary concern in adults. However, studies have evaluated left ventricle (LV) myocardial changes in pediatrics but not the long-term effect of T1DM in such vulnerable age. Therefore, we assessed LV functions in pediatric patients with long-duration T1DM using different echocardiographic modalities.

METHODS

Between July 2015 and March 2016, 48 T1DM patients were prospectively compared to 35 healthy controls. Pediatric patients with T1DM for 10 years or more were included in the study. Patients were subjected to history taking, clinical examination, glycated hemoglobin (HbA1c), and microalbuminuria measurements. Moreover, conventional echocardiography, tissue Doppler, and 2D speckle tracking were performed to analyze LV functions.

RESULTS

Mean age of patients was 15.5 ± 2 years, and mean T1DM duration was 11.7 ± 1.8 years. LV dimensions, EF and FS, and mass index did not statistically differ between groups, but E/E' ratio was significantly higher in the diabetic group. Global longitudinal strain (GLS) and global circumferential strain (GCS) were significantly lower in diabetic patients compared with controls (P = 0.038; P = 0.001, respectively). Mean HbA1c was found to be a significant predictor of decreased GLS in the diabetic population (95% CI, 0.096-0.244; P = 0.001) but not predicting GCS. Microalbuminuria had no significance in predicting strain.

CONCLUSIONS

Despite the long-duration of affection with T1DM during childhood in our patients, alterations on LV myocardial function could not be detected either clinically or by conventional echocardiography. Tissue Doppler and speckle tracking could be used in the follow up of myocardial status in pediatric diabetic patients.

Diabetes technology: improving care, improving patient-reported outcomes and preventing complications in young people with Type 1 diabetes

With the evolution of diabetes technology, those living with Type 1 diabetes are given a wider arsenal of tools with which to achieve glycaemic control and improve patient-reported outcomes. Furthermore, the use of these technologies may help reduce the risk of acute complications, such as severe hypoglycaemia and diabetic ketoacidosis, as well as long-term macro- and microvascular complications. In addition, diabetes technology can have a beneficial impact on psychosocial health by reducing the burden of diabetes. Unfortunately, diabetes goals are often unmet and people with Type 1 diabetes too frequently experience acute and long-term complications of this condition, in addition to often having less than ideal psychosocial outcomes. Increasing realization of the importance of patient-reported outcomes is leading to diabetes care delivery becoming more patient-centred. Diabetes technology in the form of medical devices, digital health and big data analytics have the potential to improve clinical care and psychosocial support, resulting in lower rates of acute and chronic complications, decreased burden of diabetes care, and improved quality of life.

Early onset symptomatic neuropathy in a child with Type 1 Diabetes mellitus

Diabetic neuropathy (DN) is a major complication of Type 1 Diabetes Mellitus (T1DM). It is usually subclinical in childhood, but can cause significant impairment with its progression through to adulthood. Current guidelines vary in their recommendation regarding screening for DN in children with T1DM, with some advocating starting screening 5 years after the diagnosis of T1DM. Clinical assessment comprising of history and neurological examination is the most commonly used method for screening, though Nerve Conduction Studies (NCS) provide better sensitivity in picking up early subclinical diabetic neuropathy. We describe an adolescent female with poorly controlled T1DM, presenting with symptomatic diabetic neuropathy within 2 years of disease onset and as the initial long term complication. Thus, guidelines regarding screening for DN may need revision, to start screening earlier than presently recommended, and NCS could play a prominent role in screening children with significant risk factors for developing DN.

Teenagers with poor metabolic control already have a higher risk of microvascular complications as young adults

AIMS

To evaluate how HbA1c in adolescents with type 1 diabetes affects microvascular complications in young adults.

METHODS

All individuals registered in the Swedish paediatric diabetes quality registry (SWEDIABKIDS) 13-18 years of age, and as adults registered in the Swedish National Diabetes Registry (NDR) in both the years 2011 and 2012 were included, in total 4250 individuals.

RESULTS

Of the individuals with mean HbA1c >78 mmol/mol in SWEDIABKIDS 83.4% had retinopathy, 15.8% had microalbuminuria and 4.9% had macroalbuminuria in NDR. The logistic regression analysis showed that the OR to develop macroalbuminuria as a young adult was significantly higher in the group with mean HbA1c >78 mmol/mol in SWEDIABKIDS (p<0.05). Among the patients with mean HbA1c above 78 mmol/mol in both registries there was a significantly higher proportion that had retinopathy, microalbuminuria (p<0.001) and/or macroalbuminuria (p<0.01) compared to the group with HbA1c below 57 mmol/mol in both registries. Only 6.5% of the persons in this study were over 30 years of age.

CONCLUSIONS

Paediatric diabetes teams working with teenagers must be aware of the impact of good metabolic control during adolescence, and should intensify the care during this vulnerable period of life to reduce the risk of microvascular complications in young adults.

Knowledge of carbohydrate counting and insulin dose calculations among hospital staff in a regional general paediatrics unit

The aim of this study was to assess the carbohydrate and insulin knowledge of the staff at Children's Ark at the University Hospital, Limerick. Carbohydrate counting and insulin dose calculations based on carbohydrates and blood sugars are integral to intensive insulin management of type 1 diabetes mellitus (T1DM). The PedCarbQuiz, a validated questionnaire, was modified, and applied to the staff on our general paediatrics ward. 48/70 eligible staff responded (rate 68 %). Overall knowledge was good: 75.5 % was the average score for correctly identifying foods containing carbohydrate. However, poor scores were obtained for calculating multiple items and meal values (average score 29 %), and exact values of insulin required (average score 38 %). These results highlight the need for re-education among staff on a general paediatrics ward, to empower ward staff to contribute effectively to the education and management of patients with T1DM.

Technology Use for Diabetes Problem Solving in Adolescents with Type 1 Diabetes: Relationship to Glycemic Control

BACKGROUND

This study examines technology use for problem solving in diabetes and its relationship to hemoglobin A1C (A1C).

SUBJECTS AND METHODS

A sample of 112 adolescents with type 1 diabetes completed measures assessing use of technologies for diabetes problem solving, including mobile applications, social technologies, and glucose software. Hierarchical regression was performed to identify the contribution of a new nine-item Technology Use for Problem Solving in Type 1 Diabetes (TUPS) scale to A1C, considering known clinical contributors to A1C.

RESULTS

Mean age for the sample was 14.5 (SD 1.7) years, mean A1C was 8.9% (SD 1.8%), 50% were female, and diabetes duration was 5.5 (SD 3.5) years. Cronbach's α reliability for TUPS was 0.78. In regression analyses, variables significantly associated with A1C were the socioeconomic status (β = -0.26, P < 0.01), Diabetes Adolescent Problem Solving Questionnaire (β = -0.26, P = 0.01), and TUPS (β = 0.26, P = 0.01). Aside from the Diabetes Self-Care Inventory--Revised, each block added significantly to the model R(2). The final model R(2) was 0.22 for modeling A1C (P < 0.001).

CONCLUSIONS

Results indicate a counterintuitive relationship between higher use of technologies for problem solving and higher A1C. Adolescents with poorer glycemic control may use technology in a reactive, as opposed to preventive, manner. Better understanding of the nature of technology use for self-management over time is needed to guide the development of technology-mediated problem solving tools for youth with type 1 diabetes.

Low-dose otelixizumab anti-CD3 monoclonal antibody DEFEND-1 study: results of the randomized phase III study in recent-onset human type 1 diabetes

OBJECTIVE

Previous studies demonstrated that the anti-CD3 monoclonal antibody otelixizumab, administered at a total dose of 48-64 mg, can slow the loss of C-peptide in recent-onset type 1 diabetes patients, with frequent reactivation of Epstein Barr virus (EBV). The DEFEND-1 (Durable Response Therapy Evaluation for Early or New-Onset Type 1 Diabetes) trial was designed to test whether a lower dose of otelixizumab could preserve C-peptide secretion in new-onset type 1 diabetes patients.

RESEARCH DESIGN AND METHODS

A multicenter, randomized, placebo-controlled trial was performed in sites in the U.S., Canada, and Europe. Two hundred eighty-one patients were randomized to treatment with 3.1 mg otelixizumab administered over 8 days or placebo. The primary end point of the study was the change in C-peptide area under the curve (AUC) from a 2-h mixed-meal tolerance test at month 12.

RESULTS

The change in 2-h C-peptide AUC was not different between placebo-treated patients and otelixizumab-treated patients (-0.20 vs. -0.22 nmol/L, P = 0.81). Secondary end points, including HbA1c, glucose variability, and insulin dose, were also not statistically different between the two groups. More patients in the otelixizumab group than in the placebo group experienced adverse events, mostly grade 1 or grade 2. There was no EBV reactivation (viral load >10,000 copies/10(6) peripheral blood mononuclear cells) in the otelixizumab group, in contrast with previously published studies at higher doses of otelixizumab.

CONCLUSIONS

Otelixizumab was well tolerated in patients with recent-onset type 1 diabetes at a total dose of 3.1 mg, but did not achieve preservation of levels of C-peptide or other markers of metabolic control.

Autonomic neuropathy in young people with type 1 diabetes: a systematic review

Autonomic neuropathy is an under-recognized complication of diabetes, although it affects multiple organ systems and has widespread clinical manifestations including orthostatic hypotension, exercise intolerance, gastroparesis, diarrhea, constipation, and urinary incontinence. The most severe consequences include hypoglycemia unawareness and cardiovascular dysfunction. Autonomic neuropathy is also implicated in sudden unexplained deaths in otherwise healthy young people--the ‘dead in bed syndrome’. In adults, cardiovascular autonomic neuropathy is an independent predictor of mortality, predominantly due to cardiovascular disease, nephropathy, and hypoglycemia. While overt autonomic neuropathy is rare in childhood and adolescence, subclinical signs of autonomic dysfunction are common, and can be found soon after diabetes diagnosis. Risk factors for autonomic neuropathy in young people include diabetes duration, poor glycemic control, and presence of aldose reductase gene (AKR1B1) polymorphisms, specifically the Z-2/Z-2 genotype. Autonomic dysfunction is accelerated by puberty.

Smoking and metabolic control in adolescents with type 1 diabetes

OBJECTIVE

To relate self-reported smoking frequency to metabolic control and other cardiovascular risk factors in adolescents with type 1 diabetes.

STUDY DESIGN

In the multicenter Diabetes Patienten Verlaufsdokumentationssystem database from Germany and Austria, anonymized records on 27 561 patients < 20 years of age with documented smoking status were available for analysis.

RESULTS

Self-reported smoking was negligible in patients younger than 11 years (0.1%), increasing to 5% in 11- to 15-year-old patients, and 28.4% in the 15- to 20-year-old age group. Multivariate analysis with adjustment for age, diabetes duration, sex, insulin therapy, and center differences, revealed that smokers had higher HbA1c-levels compared with non-smokers (9.1% vs 8.0%, P < .0001). Diastolic blood pressure was higher (68.2 vs 67.6 mm Hg, P < .0001), and the lipid profile was unfavorable in patients who smoke: Triglycerides and total cholesterol were higher and high-density lipoprotein-cholesterol was lower (all P < .0001).

CONCLUSIONS

Smokers display significantly worse metabolic control and a higher cardiovascular risk profile. Although not attested in trials, we state that education about smoking, smoking prevention, and psychological help for smoking cessation should be an integral part of comprehensive pediatric care for adolescent patients with type 1 diabetes.

Diabetic nephropathy in children and adolescents

Type 1 diabetes mellitus (T1DM) commonly occurs in childhood or adolescence, although the rising prevalence of type 2 diabetes mellitus (T2DM) in these age groups is now being seen worldwide. Diabetic nephropathy (DN) develops in 15-20% of subjects with T1DM and in similar or higher percentage of T2DM patients, causing increased morbidity and premature mortality. Although overt DN or kidney failure caused by either type of diabetes are very uncommon during childhood or adolescence, diabetic kidney disease in susceptible patients almost certainly begins soon after disease onset and may accelerate during adolescence, leading to microalbuminuria or incipient DN. Therefore, all diabetics warrant ongoing assessment of kidney function and screening for the earliest manifestations of renal injury. Pediatric health care professionals ought to understand about risk factors, strategy for prevention, method for screening, and treatment of early DN. This review considers each form of diabetes separately, including natural history, risk factors for development, screening for early manifestations, and strategy recommended for prevention and treatment of DN in children and adolescents.

Spectrum and prevalence of atherogenic risk factors in 27,358 children, adolescents, and young adults with type 1 diabetes: cross-sectional data from the German diabetes documentation and quality management system (DPV)

OBJECTIVE

The aim of this data analysis was to ascertain the type and prevalence rate as well as age and sex distribution of cardiovascular risk factors in type 1 diabetic patients up to 26 years of age.

RESEARCH DESIGN AND METHODS

Cardiovascular risk factors such as obesity, hypertension, dyslipidemia, poor glycemic control, and smoking were analyzed in 27,358 patients who were divided into three groups (prepubertal, pubertal, and adult) using specifically designed diabetes software for prospective disease documentation.

RESULTS

More than half of the patients per age-group had at least one cardiovascular risk factor. Two risk factors were age dependently found in 6.2-21.7% and three or four risk factors in 0.5-4.7%. Elevated values of HbA(1c), total cholesterol, and BMI were found most frequently. Hypertension, smoking, and HDL cholesterol were observed more frequently in males, and elevated BMI, total cholesterol, and LDL cholesterol more often in females. Although 28.6% of the patients had dyslipidemia, merely 0.4% of them received medical treatment, and of the 8.1% of the patients with hypertension, only 2.1% of them were given antihypertensive medication.

CONCLUSIONS

With increasing age, a greater number of patients with cardiovascular risk factors were observed. Significant sex differences were seen in the majority of risk factors. Despite the high prevalence of risk factors, only a small minority of patients received antihypertensive or lipid-lowering treatment. Early identification, prevention, and treatment of additional risk factors seem to be necessary, particularly in light of the high incidence of future cardiovascular disease.

Complications of diabetes mellitus in childhood

Complications of diabetes include retinopathy, nephropathy, neuropathy, macrovascular disease, and associated autoimmune diseases. Clinical manifestations of complications uncommonly present in childhood and adolescence. Screening during the early years can identify subclinical disease and it offers an opportunity for early intervention. The Diabetes and Complications Control Trial has provided evidence for the long-term benefits of good glycemic control in preventing and delaying the onset of microvascular complications. Complications begin to manifest during adolescence, during which time all efforts should be made to educate and support young persons in achieving optimal diabetes control.

Rewarming index of the lower leg assessed by infrared thermography in adolescents with type 1 diabetes mellitus

The aim of this study was to determine whether infrared thermography before and after challenge of the lower leg in cold water may be a useful tool to detect abnormalities in skin blood flow in adolescent asymptomatic patients with type 1 diabetes mellitus (DM1) and to assess the optimal setting of skin temperature measurements. Twenty-five adolescents (10 female, 15 male, mean age 21.2 +/- 6.2 years, body mass index [BMI] 23.0 +/- 2.1 kg/m2) with a duration of DMI of 13.8 +/- 5.4 years and mean HbA1c levels 8.5 +/- 1.3% were compared to age- and sex-matched controls (BMI 22.9 +/- 2.2 kg/m2). Seven defined sites of the lower leg were assessed by infrared thermography before and for 10 min after exposure of the leg to 14 degrees C cold water. As skin temperature before exposure to cold water differs from individual to individual and basal temperature was significantly warmer in patients at the tip of the first (p < 0.05) and fifth (p < 0.05) toe, the rewarming index was calculated in order to compare data. Rewarming indexes of skin temperature during the whole measurement procedure (0-10 min) were significantly lower at the tip of the first (p < 0.05) and fifth (p < 0.01) toes and from minute 2-10 also at the inner ankle (p < 0.05) in patients compared to healthy controls. Rewarming indexes of the other four sites were not significantly different between patients and controls. Infrared thermography of the lower leg after cold water exposure is an easily applicable method and a useful tool to detect abnormalities of skin blood flow in adolescents with DM1 especially at the tips of the first and fifth toes and the inner ankle.