Alterations of blood pressure in type 1 diabetic children and adolescents

Type 1 diabetes

Type 1 diabetes is a chronic disease caused by autoimmune destruction of pancreatic β cells. Individuals with type 1 diabetes are reliant on insulin for survival. Despite enhanced knowledge related to the pathophysiology of the disease, including interactions between genetic, immune, and environmental contributions, and major strides in treatment and management, disease burden remains high. Studies aimed at blocking the immune attack on β cells in people at risk or individuals with very early onset type 1 diabetes show promise in preserving endogenous insulin production. This Seminar will review the field of type 1 diabetes, highlighting recent progress within the past 5 years, challenges to clinical care, and future directions in research, including strategies to prevent, manage, and cure the disease.

Is there a characteristic pattern of ambulatory blood pressure profile in type 1 diabetic children and adolescents?

PURPOSE

To examine the characteristics of ambulatory blood pressure (ABP) including blood pressure variability (BPV) and its association with albuminuria in type 1 diabetic (T1D) children and to identify potential predictors of high-normal albuminuria and microalbuminuria.

METHODS

ABP monitoring was performed in 201 T1D children and adolescents (mean age, 14.7±3.8 years) with T1D duration over 1 year. The level of albuminuria was assessed as the albumin/creatinine ratio (ACR) and patients were further classified as low-normal, high-normal or microalbuminuria.

RESULTS

Fifteen T1D children (7.5%) were hypertensive using office blood pressure (BP) and 10 (5%) according to ABP. T1D subjects had elevated 24-hour systolic BP (SBP) and diastolic BP (DBP) (+0.2 and + 0.3 standard deviation score [SDS]) and nighttime SBP and DBP (+0.6 and +0.8 SDS) compared to reference values. Patients with microalbuminuria had significantly higher 24-hour, daytime and nighttime DBP compared to normoalbuminuric subjects. There was a high percentage of nondippers (74.1%). Nighttime diastolic BPV was significantly higher in subjects with high-normal compared to low-normal albuminuria (p=0.01). A weak correlation was found between ACR and daytime DBP SDS (r=0.29, p<0.001 and nighttime DBP SDS (r=0.21, p=0.003). Age and nighttime diastolic BPV were predictors of high-normal albuminuria while nighttime DBP was a strong predictor for microalbuminuria.

CONCLUSION

T1D children have impaired BP regulation although most of them do not fulfill the criteria for sustained hypertension. There is an association between diastolic ABP and diastolic BPV with rising levels of albuminuria pointing to a clear connection between BP and incipient diabetic nephropathy.

Technological Ecological Momentary Assessment Tools to Study Type 1 Diabetes in Youth: Viewpoint of Methodologies

Type 1 diabetes (T1D) is one of the most common chronic childhood diseases, and its prevalence is rapidly increasing. The management of glucose in T1D is challenging, as youth must consider a myriad of factors when making diabetes care decisions. This task often leads to significant hyperglycemia, hypoglycemia, and glucose variability throughout the day, which have been associated with short- and long-term medical complications. At present, most of what is known about each of these complications and the health behaviors that may lead to them have been uncovered in the clinical setting or in laboratory-based research. However, the tools often used in these settings are limited in their ability to capture the dynamic behaviors, feelings, and physiological changes associated with T1D that fluctuate from moment to moment throughout the day. A better understanding of T1D in daily life could potentially aid in the development of interventions to improve diabetes care and mitigate the negative medical consequences associated with it. Therefore, there is a need to measure repeated, real-time, and real-world features of this disease in youth. This approach is known as ecological momentary assessment (EMA), and it has considerable advantages to in-lab research. Thus, this viewpoint aims to describe EMA tools that have been used to collect data in the daily lives of youth with T1D and discuss studies that explored the nuances of T1D in daily life using these methods. This viewpoint focuses on the following EMA methods: continuous glucose monitoring, actigraphy, ambulatory blood pressure monitoring, personal digital assistants, smartphones, and phone-based systems. The viewpoint also discusses the benefits of using EMA methods to collect important data that might not otherwise be collected in the laboratory and the limitations of each tool, future directions of the field, and possible clinical implications for their use.

Masked hypertension and its associations with glycemic variability metrics in children and adolescents with type 1 diabetes

BACKGROUND

Masked hypertension defined as having normal office blood pressure (BP) but hypertension detected by continuous BP monitoring has been observed in children and adolescents with type 1 diabetes (T1D). However, no study has evaluated whether masked hypertension is associated with glycemic variability (GV) in these patients. We hypothesized that masked hypertension might be associated with high GV in patients with T1D.

METHODS

This cross-sectional study performed continuous glucose monitoring (CGM) in parallel with ambulatory blood pressure monitoring (ABPM) in T1D patients aged 6-21 years. Patients who had known hypertension were excluded. CGM data from the same day as ABPM was calculated for GV including standard deviation (SD), coefficient of variation (CV) of glucose levels, and unstable glycemia which was defined as having a CV of glucose levels ≥ 36%.

RESULTS

Thirty-three patients had complete ABPM and CGM data. Mean (SD) age was 13.8 (3.8) years and mean (SD) duration of T1D was 5.4 (3.6) years. All patients had normal office BP, but ABPM showed masked hypertension in 9 patients (27%). In comparison with normotensive patients, patients with masked hypertension had longer duration of T1D (7.4 vs. 4.6 years, p = 0.049), higher insulin requirement (1.2 vs. 0.9 units/kg/day, p = 0.049), and higher SD of glucose (70.3 vs. 47.9 mg/dl, p = 0.038). Masked hypertension group had a greater number of patients (71% vs. 19%, p = 0.02) with unstable glycemia. Multivariate analysis revealed that unstable glycemia was associated with masked hypertension.

CONCLUSIONS

The presence of unstable glycemia in children and adolescents with T1D is associated with masked hypertension. Graphical abstract.

Peripheral and Autonomic Neuropathy Status of Young Patients With Type 1 Diabetes Mellitus at the Time of Transition From Pediatric Care to Adult-Oriented Diabetes Care

INTRODUCTION

The prevalence of neuropathic lesions in young patients with type 1 diabetes mellitus (T1DM) at the time of transition from pediatric care to adult-oriented diabetes care is poorly studied. A comparative study with healthy volunteers to assess the possible neuropathic condition of this special population and to identify the potential early screening needs has not been performed yet. The results may provide important feedback to pediatric diabetes care and a remarkable baseline reference point for further follow up in adult diabetes care.

PATIENTS AND METHODS

Twenty-nine young patients with T1DM [age: 22.4 ± 2.9 years; HbA1c: 8.5 ± 2.1%, diabetes duration: 12.2 ± 5.8 years; (mean ± SD)] and 30 healthy volunteers (age: 21.5 ± 1.6 years; HbA1c: 5.3 ± 0.3%) were involved in the study. Autonomic function was assessed by standard cardiovascular reflex tests. Complex peripheral neuropathic testing was performed by Neurometer^®, Neuropad^®-test, Tiptherm^®, Monofilament^®, and Rydel-Seiffer tuning fork tests.

RESULTS

T1DM patients had significantly higher diastolic blood pressure than controls (80 ± 9 vs. 74 ± 8 mmHg, p < 0.01), but there was no significant difference in systolic blood pressure (127 ± 26 vs. 121 ± 13 mmHg). Cardiovascular reflex tests had not revealed any significant differences between the T1DM patients and controls. No significant differences with Neurometer^®, Neuropad^®-test, and Monofilament^® were detected between the two groups. The vibrational sensing on the radius on both sides was significantly impaired in the T1DM group compared to the controls with Rydel-Seiffer tuning fork test (right: 7.5 ± 1.0 vs. 7.9 ± 0.3; left: 7.5 ± 0.9 vs. 7.9 ± 0.3, p < 0.05). The Tiptherm^®-test also identified a significant impairment in T1DM patients (11 sensing failures vs. 1, p < 0.001). In addition, the neuropathic complaints were significantly more frequently present in the T1DM patient group than in the controls (9 vs. 0, p < 0.01).

CONCLUSION

In this young T1DM population, cardiovascular autonomic neuropathy and cardiac morphological alterations could not be found. However, Rydel-Seiffer tuning fork and Tiptherm^®-tests revealed peripheral sensory neurological impairments in young T1DM patients at the time of their transition to adult diabetes care.

Blood pressure regulation determined by ambulatory blood pressure profiles in children and adolescents with type 1 diabetes mellitus: Impact on diabetic complications

BACKGROUND

The combination of high blood pressure and hyperglycemia contributes to the development of diabetic complications. Ambulatory monitoring of blood pressure (ABPM) is seen as standard to assess blood pressure (BP) regulation.

OBJECTIVE

We evaluated 24-hour BP regulation in 3529 children with type 1 diabetes, representing 5.6% of the patients <20 years of age documented in the DPV registry, and studied the influence of BP parameters including pulse pressure (PP) and blood pressure variability (BPV) on microalbuminuria (MA) and diabetic retinopathy (DR).

RESULTS

BP was increased in this selected cohort of children with diabetes compared to healthy German controls (standard deviation score (SDS) day: systolic BP (SBP) +0.06, mean arterial pressure (MAP) +0.08, PP +0.3; night: SBP +0.6, diastolic BP +0.6, MAP +0.8), while daytime diastolic BP (SDS -0.2) and dipping of SBP and MAP were reduced (SBP -1.1 SDS, MAP 12.4% vs 19.4%), PP showed reverse dipping (-0.7 SDS). Children with microvascular complications had by +0.1 to +0.75 SDS higher BP parameters, except of nocturnal PP in MA and diurnal and nocturnal PP in DR. Reverse dipping of PP was more pronounced in the children with MA (-5.1% vs -0.8%) and DR (-2.6% vs -1.0%). BP alteration was stronger in girls and increased with age.

CONCLUSION

There is an early and close link between 24-hour blood pressure regulation and the development of diabetic complications not only for systolic, diastolic, and mean arterial BP but also for the derived BP parameter PP and BPV in our selected patients.

Clinical Practice Guideline for Screening and Management of High Blood Pressure in Children and Adolescents

These pediatric hypertension guidelines are an update to the 2004 "Fourth Report on the Diagnosis, Evaluation, and Treatment of High Blood Pressure in Children and Adolescents." Significant changes in these guidelines include (1) the replacement of the term "prehypertension" with the term "elevated blood pressure," (2) new normative pediatric blood pressure (BP) tables based on normal-weight children, (3) a simplified screening table for identifying BPs needing further evaluation, (4) a simplified BP classification in adolescents ≥13 years of age that aligns with the forthcoming American Heart Association and American College of Cardiology adult BP guidelines, (5) a more limited recommendation to perform screening BP measurements only at preventive care visits, (6) streamlined recommendations on the initial evaluation and management of abnormal BPs, (7) an expanded role for ambulatory BP monitoring in the diagnosis and management of pediatric hypertension, and (8) revised recommendations on when to perform echocardiography in the evaluation of newly diagnosed hypertensive pediatric patients (generally only before medication initiation), along with a revised definition of left ventricular hypertrophy. These guidelines include 30 Key Action Statements and 27 additional recommendations derived from a comprehensive review of almost 15 000 published articles between January 2004 and July 2016. Each Key Action Statement includes level of evidence, benefit-harm relationship, and strength of recommendation. This clinical practice guideline, endorsed by the American Heart Association, is intended to foster a patient- and family-centered approach to care, reduce unnecessary and costly medical interventions, improve patient diagnoses and outcomes, support implementation, and provide direction for future research.

Nocturnal blood pressure is associated with the progression of microvascular complications and hypertension in patients with type 1 diabetes mellitus

AIMS

To evaluate relationships between early alterations in blood pressure and the progression of microvascular complications of diabetes in clinically-normotensive patients with type 1 diabetes (T1DM).

METHODS

In a prospective observational study of 85 normotensive T1DM patients without microalbuminuria, blood pressure (BP) was monitored over 24h using the ambulatory blood pressure monitoring (ABPM) system at baseline and 7years later. Development or progression of microalbuminuria, retinopathy and hypertension was evaluated.

RESULTS

Initially, 20 patients (24%) were diagnosed with masked hypertension and 31 (37%) with non-dipper pattern as the only pathological findings. At 7years: 1) twenty-seven patients (32%) had progression of retinopathy related to the nocturnal diastolic blood pressure (BPD) (OR:1.122; p=0.034) and final non-dipper pattern (OR:5.857; p=0.005); 2) seven patients (10%) developed microalbuminuria for which nocturnal systolic blood pressure (BPS) was a risk factor (OR:1.129; p=0.007); 3) five of the normotensive patients (9%) progressed to hypertension; historic HbA1c (OR:2.767; p=0.046) and nocturnal BPD (OR:1.243; p=0.046) being the related risk factors. BPD level ≥65mmHg was associated with an increase in progression of retinopathy and hypertension.

CONCLUSIONS

In T1DM patients there is an elevated prevalence of BP alterations, detected using ABPM. Alterations in nocturnal BP predispose to development/progression of microvascular complications and overt hypertension.

Prehypertension in adolescents with cardiovascular risk: a comparison between type 1 diabetic patients and overweight subjects

BACKGROUND

Adolescents with type 1 diabetes and obesity present higher cardiovascular risk and ambulatory blood pressure measurements (ABPM) has been shown to predict vascular events, especially by identifying the nondipper status. The aim of our observational cross-sectional study conducted in adolescents with type 1 diabetes, overweight subjects and healthy controls was to assess mean blood pressure parameters to identify subclinical cardiovascular risk.

METHODS

The study included adolescents patients with type 1 diabetes followed in our Pediatric Department in University of Catania between January 2011 and 2013. A total of 60 patients were enrolled, and 48 (32 male and 16 female) completed the study. For each subject we performed systolic and diastolic Ambulatory Blood Pressure Measurements (ABPM) during wakefulness and sleep recording blood pressure every 30 min for 24 h with the Tonoport V/2 GE CardioSoft V6.51 device. We compared the data of patients with those of overweight subjects and healthy controls.

RESULTS

ABPM revealed no significant difference between type 1 diabetic patients and overweight subjects in 24 h Systolic, 24 h Diastolic, Day-time Systolic, Night-time systolic and Day-time Diastolic blood pressure values but significantly different values in Night-time Diastolic blood pressure values (p < 0.001). We found significant differences between type 1 diabetic patients and healthy controls in all 24 h Systolic (p < 0.001), 24 h Diastolic (p < 0.01), Day-time Systolic (p < 0.01), Night-time Systolic (p < 0.001), Day-time Diastolic (p < 0.05) and Night-time Diastolic (p < 0.001) blood pressure values. We detected hypertension in 12/48 (25%) type 1 diabetic patients and in 10/48 overweight subjects (p = 0.62; OR 1.2; CI 0.48-3.29), whereas no-one of healthy controls presented hypertension (p < 0.001). We observed nondipper pattern in 40/48 (83.3%) type 1 diabetic patients, in 33/48 (68.8%) overweight subjects (p = 0.094; OR 2.27; CI 0.85-6.01), and in 16/48 (33.3%) of healthy controls (p < 0.001; OR 10; CI 3.79-26.3).

CONCLUSIONS

ABPM studies might help to define a subset of patients at increased risk for the development of hypertension. In evaluating blood pressure in type 1 diabetes and overweight subjects, ABPM should be used since a reduced dipping can indicate incipient hypertension.

Can ambulatory blood pressure monitoring detect early diastolic dysfunction in children with type 1 diabetes mellitus: correlations with B-type natriuretic peptide and tissue Doppler findings

AIM

To evaluate the relationship between 24-h blood pressure (BP) measurements and diastolic heart function evaluated by Doppler tissue imaging and B-type natriuretic peptide (BNP) levels in children with type 1 diabetes mellitus (DM).

PATIENTS AND METHODS

A total of 32 diabetic and 18 healthy children were enrolled. Spectral Doppler analysis and tissue Doppler measurements were performed by conventional echocardiography. The 24-h ambulatory BP and serum BNP levels were measured.

RESULTS

Analysis of ambulatory blood pressure monitoring (ABPM) recordings showed that median daytime diastolic BP load were significantly higher in diabetic patients compared to controls [12.35 (4.23-27.23) vs. 2.5 (0-8.7), p = 0.007]. Patients with elevated daytime systolic and diastolic BP loads had significantly higher BNP values compared to patients with normal BP load (31.4 ± 24.36 vs. 11.84 ± 11.25 pg/mL, p = 0.03 and 23.21 ± 15.12 vs. 12.12 ± 14.65 pg/mL, p = 0.03, respectively). Isovolemic contraction time (47.43 ± 7.84 vs. 42.27 ± 7.47, p = 0.045), isovolemic relaxation time (68.84 ± 10.43 vs. 58.77 ± 10.02, p = 0.02), and myocardial performance index (0.45 ± 0.10 vs. 0.37 ± 0.09, p = 0.02) as determined by tissue Doppler echocardiography were significantly high in diabetic patients compared to that of control cases. Ratio of mitral peak early diastolic flow velocity (E) to peak early diastolic myocardial velocities by tissue Doppler echocardiography (E') was also higher in patients with elevated daytime systolic BP load (E/E', 6.71 ± 1.97 vs. 4.91 ± 1.02, p = 0.04).

CONCLUSION

Elevated BP loads detected by 24-h ambulatory BP measurements in children with type 1 diabetes are associated with increased BNP levels and abnormal tissue Doppler echocardiography indices, indicating early stage cardiac dysfunction.

Non-dipping and arterial hypertension depend on clinical factors rather than on genetic variability of ACE and RGS2 genes in patients with type 1 diabetes

The aim of our study was to characterize the association of clinical and genetic risk factors such as: ACE genotype (rs17997552, rs1800764, rs4459609) and RGS2 (rs2746071) with the development of hypertension (HT) and non-dipping phenomenon in patients with type 1 diabetes mellitus (T1DM). A total of 238 adolescents and young adults with T1DM-103 females and 135 males, aged 8-30 years (mean 17.35 ± 5.2) with diabetes duration 1-26 years (mean 7.72 ± 6.2), with mean HbA1c (IFCC) 58 ± 15 mmol/mmol-were subjected to 24-h ambulatory blood pressure measurements (ABPM). The results of the ABPM were analyzed in association with the polymorphisms of ACE and RGS2 genes and clinical data of patients. HT was recognized in 65 (27 %) and non-dipping in 111 (46.63 %) patients. In the multivariate analysis of factors predisposing to HT, the variables that remained significant were the following: male sex (OR 1.62; 95 % CI 1.171-2.250), non-dipping (OR 1.40; 95 % CI 1.03-1.90) and total cholesterol level (OR 1.01; 95 % CI 1.005-1.021). The only factor influencing non-dipping was the duration of diabetes-OR 1.09 (95 % CI 1.04-1.14). The patients displaying non-dipping have a twice increased risk of development of HT (OR 2.17; 95 % CI 1.21-3.89). There was no association between disturbances of blood pressure (BP) and genotypes of ACE: rs17997552, rs1800764, rs4459609 and RGS2: rs2746071. Clinical rather than genetic risk factors seem to be connected with BP disturbances in young patients with T1DM. Although we have identified representative groups of HT versus non-HT and dipping versus non-dipping subjects, the effect of genetic predisposition to the development of higher BP is too weak to be statistically significant.

The late effects of anticancer therapy after childhood Wilm's tumor: the role of diastolic function and ambulatory blood pressure monitoring

OBJECTIVE

Wilms' tumor, or nephroblastoma, is the most common primary malignant renal tumor of childhood. The excellent outcome now expected for most children with this tumor is attributed to the combination of effective adjuvant chemotherapy, improved surgical and anesthetic techniques and also the radiosensitivity of the tumor. The numerous organ systems are subject to the late effects of anticancer therapy. The aim of this study was to investigate the blood pressure profile and ambulatory blood pressure monitoring, and also cardiac diastolic functions and pulmonary venous flow in 25 children with unilateral Wilms' tumor in remission.

METHODS

The patient group consists of 25 patients who successfully completed anticancer treatment for unilateral Wilms' tumor. Thirty-three age-, weight- and height-matched healthy children were considered as a control group for an echocardiographic study. Also, 20 age-, weight- and height-matched healthy children were considered as a control group for the ambulatory blood pressure monitoring study.

RESULTS

In our study, 24 h, daytime and night-time systolic blood pressure and night-time diastolic blood pressure measurements were found to be significantly increased in the patient group compared with healthy children. We detected diastolic filling pattern abnormalities. We also found increase in pulmonary venous flow (systolic and diastolic) in Wilms' tumor group.

CONCLUSIONS

We suggest the regular follow-up of survivors of Wilms' tumor for care and prevention of cardiovascular diseases.

Should mean arterial pressure be included in the definition of ambulatory hypertension in children?

BACKGROUND

The diagnosis of hypertension (HTN)/normotension (NT) on ambulatory blood pressure monitoring (ABPM) is usually based on systolic (SBP) or diastolic blood pressure (DBP). The goal of this study was to analyze whether inclusion of mean arterial pressure (MAP) improves the detection of HTN on ABPM.

METHODS

We retrospectively studied ABPM records in 229 children (116 boys, median age = 15.3 years) who were referred for evaluation of HTN. A diagnosis of HTN was made if: (A) MAP or SBP or DBP was ≥ 1.65 SDS (95th percentile); (B) SBP or DBP was ≥ 1.65 SDS (95th percentile), during 24-h or daytime or night-time in both definitions.

RESULTS

Using definition A, 46/229 patients had HTN compared to definition B by which only 37/229 patients had HTN (p = 0.001). The level of agreement between the two definitions was very good (kappa = 0.86 ± 0.04), however nine patients (19.5 %) were missed by not using MAP in the definition of HTN. These nine patients had only mild HTN with a median Z score of 1.69.

CONCLUSIONS

The inclusion of MAP in the definition of ambulatory HTN significantly increased the number of hypertensive patients. MAP may be very helpful in detecting mild HTN in patients with normal/borderline SBP and DBP.

[Renal function and blood pressure in type 1 diabetes mellitus]

INTRODUCTION

Persistent microalbuminuria is the accepted marker for early detection of a high risk of developing diabetic nephropathy in patients diagnosed with Type I Diabetes mellitus. The Ambulatory Blood Pressure Monitoring (ABPM) evaluates the circadian variations of blood pressure while awake and asleep.

OBJECTIVE

To show the renal function characteristics and the data provided by ABPM in a cohort of insulin dependent diabetic children referred to our hospital.

MATERIAL AND METHODS

A total of 61 patients with an age range between 6 and 17 years were studied. In each child blood pressure monitoring was arranged, the glomerular filtration rate in 24 hour urine was estimated, and glycosylated haemoglobin (HbA1c), total cholesterol, triglycerides, HDL cholesterol, LDL cholesterol, was measured.

RESULTS

None of the cases showed persistent microalbuminuria. The renal function showed an increase in the glomerular filtration rate (146.6 ±22 ml/minute/1.73 m(2)). In 39% of the cases there was no drop in systolic blood pressure during the night, whereas 11% of the patients in our series had a decrease in diastolic pressure. The cases were analysed depending on whether or not there had been a physiological arterial or diastolic pressure drop during the night: there were no significant differences in anthropometric data, glycosylated haemoglobin (HbA1c) levels, total cholesterol, triglycerides, HDL cholesterol, LDL cholesterol, glomerular filtration rate (GFR), proteinuria and microalbuminuria between both groups.

CONCLUSION

In Type I Diabetes Mellitus a decrease in the physiological blood pressure during the night is a frequent finding. There is also an increase in the glomerular filtration rate.

Pediatric ambulatory blood pressure monitoring: indications and interpretations

The prevalence of hypertension in children and adolescents is increasing, especially in obese and ethnic children. The adverse long-term effects of hypertension beginning in youth are known; therefore, it is important to identify young patients who need intervention. Unfortunately, measuring blood pressure (BP) is difficult due to the variety of techniques available and innate biologic variation in BP levels. Ambulatory BP monitoring may overcome some of the challenges clinicians face when attempting to categorize a young patient's BP levels. In this article, the authors review the use of ambulatory BP monitoring in pediatrics, discuss interpretation of ambulatory BP monitoring, and discuss gaps in knowledge in usage of this technique in the management of pediatric hypertension.

Alterations in arterial pressure in patients with Type 1 diabetes are associated with long-term poor metabolic control and a more atherogenic lipid profile

AIM

To determine the prevalence of alterations in blood pressure (BP) in patients with Type 1 diabetes who are normoalbuminuric and normotensive; and to evaluate the association with genetic, clinical and metabolic factors. MATERIAL/ METHODS: Normoalbuminuric, normotensive Type 1 diabetic patients (no.=85) had their ambulatory blood pressure monitoring (ABPM) performed over 24 h, together with measurement of HbA1c and lipid profile, polymorphisms of the ACE gene, non-midriatic retinography, and the "historical HbA1c" calculated (mean of all the determinations available on the patient).

RESULTS

Of the 85 patients, a mean of 18.8% had pathologic values of BP over the 24 h, 31.8% during active periods and 22.4% during rest periods; in 42% there was a non-dipper pattern in BP. The patients with alterations of BP had higher body mass index (BMI), higher levels of glycemia and of triglycerides, and decreased levels of HDL cholesterol. The "historical HbA1c" was significantly higher in the patients with the non-dipper pattern (8.6 ± 1.4% vs 7.9 ± 1.4%; p=0.046). Pulse pressure was directly associated with male gender (p=0.006) and with BMI (p=0.001). No differences were detected in the distribution of the polymorphisms of the ACE gene as a function of the BP alterations.

CONCLUSIONS

An elevated number normoalbuminuric, normotensive, Type 1 diabetic patients have alterations in BP detected with ABPM over 24 h, and these are associated with a greater BMI, poor long-term metabolic control and a more atherogenic lipid profile.

Hypertension in adolescents

In adults, hypertension has long been perceived as a public health problem. By contrast, its impact in childhood is far less appreciated. In fact, quite often, high blood pressure in children is not even diagnosed. Blood pressure is a vital sign that is routinely obtained during a physical examination of adults, but only very seldom in children. The diagnosis of hypertension in children is complicated because 'normal' blood pressure values vary with age, sex and height. As a consequence, almost 75% of the cases of arterial hypertension and 90% of the cases of prehypertension in children and adolescents are currently undiagnosed. Furthermore, adolescence hypertension is increasing in prevalence as the prevalence of pediatric obesity has increased. Ambulatory blood pressure monitoring is a useful method for risk evaluation in adolescents. In addition to being viewed as an important cardiovascular risk factor in adolescents, elevated blood pressure should prompt a thorough search for other modifiable risk factors that, if treated, might reduce teenagers' risk of developing cardiovascular disease in adulthood. Thus, assessing blood pressure values in children represents one of the most important measurable markers of cardiovascular risk later in life and a major step in preventive medicine.

Arterial HTN in children with T1DM--frequent and not easy to diagnose

INTRODUCTION

To evaluate the diagnostic efficacy of the office blood pressure (OBP) and ambulatory blood pressure monitoring (ABPM) in the assessment of hypertension (HTN) in children with diabetes mellitus type 1 (T1DM).

METHODS

We analyzed OBP and ABPM measurements in 84 diabetic children (43 boys) obtained at a median age of 14.9 yr and 6.3 +/- 3.5 yr after diagnosis of T1DM. OBP and ABPM results were converted into standard deviation scores (SDS). In addition, we analyzed blood pressure loads and nighttime dipping. The comparison between OBP and ABPM was performed using kappa coefficient and receiver operator curve (ROC).

RESULTS

HTN was diagnosed in 43/84 (51%) patients using OBP (>95th percentile), and in 24/84 (29%) patients using ABPM ( > or = 95th percentile during 24 h, day or night). Both methods were in agreement in 33 ABPM normotensive and 16 ABPM hypertensive patients (most had nighttime HTN); 32% patients had white-coat HTN and 9.5% patients had masked HTN. The kappa coefficient was 0.175 (95% CI from -0.034 to 0.384) suggesting poor agreement between OBP and ABPM. Diastolic OBP was a better predictor of ABPM HTN (ROC area under the curve (AUC) = 0.71 +/- 0.06) than systolic OBP (AUC = 0.58 +/- 0.07). The percentage of non-dippers ranged from 7 to 23% in ABPM normotensive patients, and 21-42% in ABPM hypertensive patients who also had significantly higher BP loads (p < 0.0001).

CONCLUSION

Children with T1DM often suffer from nocturnal, white coat- and masked HTN, which can not be assessed and predicted by the OBP.

Ambulatory blood pressure measurements are related to albumin excretion and are predictive for risk of microalbuminuria in young people with type 1 diabetes

AIMS/HYPOTHESIS

The relationship between BP and microalbuminuria in young people with type 1 diabetes is not completely clear. As microalbuminuria is preceded by a gradual rise in albumin excretion within the normal range, we hypothesised that ambulatory BP (ABP) may be closely related to albumin excretion and progression to microalbuminuria.

METHODS

ABP monitoring (ABPM) was performed in 509 young people with type 1 diabetes (age median [range]: 15.7 [10.7-22.6] years) followed with annual assessments of three early morning urinary albumin:creatinine ratios (ACRs) and HbA(1c). Systolic BP (SBP) and diastolic BP (DBP) and the nocturnal fall in BP were analysed in relation to ACR.

RESULTS

All ABPM variables were significantly related to baseline log(10) ACR (p < 0.001). After the ABPM evaluation, 287 patients were followed for a median of 2.2 (1.0-5.5) years. ABP at baseline was independently related to mean ACR during follow-up. Nineteen initially normoalbuminuric patients developed microalbuminuria after 2.0 (0.2-4.0) years and their baseline daytime DBP was higher than in normoalbuminuric patients (p < 0.001). After adjusting for baseline ACR and HbA(1c), there was an 11% increased risk of microalbuminuria for each 1 mmHg increase in daytime DBP. Forty-eight per cent of patients were non-dippers for SBP and 60% for DBP; however, ACR was not different between dippers and non-dippers and there were no differences in the nocturnal fall in BP between normoalbuminuric and future microalbuminuric patients.

CONCLUSIONS/INTERPRETATION

In this cohort of young people with type 1 diabetes, ABP was significantly related to ACR, and daytime DBP was independently associated with progression to microalbuminuria. Increasing albumin excretion, even in the normal range, may be associated with parallel rises in BP.

Poor glycemic control in diabetes and the risk of incident chronic kidney disease even in the absence of albuminuria and retinopathy: Atherosclerosis Risk in Communities (ARIC) Study

BACKGROUND

Diabetic nephropathy is the leading cause of kidney failure in the United States. The extent to which an elevated glycated hemoglobin (HbA(1c)) concentration is associated with increased risk of chronic kidney disease (CKD) in the absence of albuminuria and retinopathy, the hallmarks of diabetic nephropathy, is uncertain.

METHODS

Glycated hemoglobin concentration was measured in 1871 adults with diabetes mellitus followed up for 11 years in the Atherosclerosis Risk in Communities (ARIC) Study. Incident CKD was defined as an estimated glomerular filtration rate less than 60 mL/min/1.73 m(2) after 6 years of follow-up or a kidney disease-related hospitalization. We categorized HbA(1c) concentrations into 4 clinically relevant categories. Albuminuria and retinopathy were measured midway through follow-up.

RESULTS

Higher HbA(1c) concentrations were strongly associated with risk of CKD in models adjusted for demographic data, baseline glomerular filtration rate, and cardiovascular risk factors. Compared with HbA(1c) concentrations less than 6%, HbA(1c) concentrations of 6% to 7%, 7% to 8%, and greater than 8% were associated with adjusted relative hazard ratios (95% confidence intervals) of 1.4 (0.97-1.91), 2.5 (1.70-3.66), and 3.7 (2.76-4.90), respectively. Risk of CKD was higher in individuals with albuminuria and retinopathy, and the association between HbA(1c) concentration and incident CKD was observed even in participants without either abnormality: adjusted relative hazards, 1.46 (95% confidence intervals, 0.80-2.65), 1.17 (0.43-3.19), and 3.51 (1.67-7.40), respectively; P(trend) = .004.

CONCLUSIONS

We observed a positive association between HbA(1c) concentration and incident CKD that was strong, graded, independent of traditional risk factors, and present even in the absence of albuminuria and retinopathy. Hyperglycemia is an important indicator of risk of both diabetic nephropathy with albuminuria or retinopathy and of less specific forms of CKD.

Arterial hypertension determined by ambulatory blood pressure profiles: contribution to microalbuminuria risk in a multicenter investigation in 2,105 children and adolescents with type 1 diabetes

OBJECTIVE

Arterial hypertension is a key player in the development of diabetes complications. We used a nationwide database to study risk factors for abnormal 24-h blood pressure regulation and microalbuminuria in children and adolescents with type 1 diabetes.

RESEARCH DESIGN AND METHODS

Ambulatory blood pressure monitoring was performed in 2,105 children and adolescents from 195 pediatric diabetes centers in Germany and Austria. Individual least median squares (LMS)-SD scores were calculated for diurnal and nocturnal systolic (SBP), diastolic (DBP), and mean arterial (MAP) blood pressure according to normalized values of a reference population of 949 healthy German children. The nocturnal blood pressure reduction (dipping) was calculated for SBP as well as DBP.

RESULTS

In diabetic children, nocturnal blood pressure in particular was significantly elevated (SBP +0.51, DBP +0.58, MAP +0.80 LMS-SD) and dipping of SBP DBP, and MAP was significantly reduced (P < 0.0001). Age, diabetes duration, sex BMI, A1C, and insulin dose were related to altered blood pressure profiles; dipping, however, was only affected by age, female sex, and A1C. The presence of microalbuminuria was associated with nocturnal DBP (P < 0.0001) and diastolic dipping (P < 0.01).

CONCLUSIONS

Our observations revealed a clear link between the quality of metabolic control and altered blood pressure regulation even in pediatric patients with short diabetes duration. Nocturnal blood pressure in particular seems to mainly contribute to diabetes complications such as microalbuminuria.

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.

Early signs of left ventricular dysfunction in adolescents with type 1 diabetes mellitus: the importance of impaired circadian modulation of blood pressure and heart rate

Diabetic cardiomyopathy is a well-defined complication of diabetes that occurs in the absence of ischemic heart disease or hypertension. Moreover impaired circadian blood pressure (BP) variation has been associated with autonomic dysfunction. The aim of our study was to evaluate diurnal BP fluctuations and autonomic function and their association with left ventricular function in adolescents with Type 1 diabetes mellitus (T1DM). In 48 normotensive, normoalbuminuric diabetic adolescents, with a mean (+/-SD) age of 17.3 (+/-4.1) yr and a mean (+/-SD) diabetes duration of 8.5 (+/-3.3) yr, 24-h ambulatory BP was recorded. Moreover 24-h heart rate (HR) monitoring was performed. Myocardial structural parameters were studied by echocardiogram. Left ventricular end-diastolic (EDDLV) and end-systolic diameters (ESDLV) were estimated and left ventricular mass index (LVMI) was calculated using the Devereux formula. The patients were divided into 2 groups according to the absence of decrease (non-dippers) or the decrease (dippers) of nocturnal diastolic BP (DBP). The non-dippers showed, in comparison with the dippers, reduced mean 24-h HR (79.6 vs 84.0 beats/min, p=0.05) and reduced mean day-time HR (81.3 vs 86.0 beats/min, p=0.05). The nondippers also presented greater ESDLV (28.7 vs 25.9 mm, p=0.001) and EDDLV (47.8 vs 45.1 mm, p=0.040), and LVMI (90.2 vs 78.3 g/m2, p=0.044), in comparison with the dippers. During stepwise multiple regression, the most important variables affecting LVMI were mean HR (day): (b=-0.40, p=0.001), high frequency domain variable of HR variability (b=0.38, p=0.016) and glycosylated hemoglobin (b=0.67, p=0.001). In conclusion, we found that a group of normotensive diabetic adolescents with impaired nocturnal BP reduction, also had autonomic dysfunction, together with impaired left ventricular function. These findings suggest that there is a close relationship between autonomic function and left ventricular remodeling in patients with T1DM, which may be attributed to altered diurnal BP profile, autonomic neuropathy and poor glycemic control.

Renoprotection with vitamin D: specific for diabetic nephropathy?

Zhang and co-workers report on the renoprotective role of the vitamin D receptor (VDR) in diabetic nephropathy using the method of streptozotocin-induced hyperglycemia in wild-type and VDR(-/-) mice. Also, experiments with cultured mesangial cells and podocytes confirm the effect of the active vitamin D metabolite 1,25(OH)(2)D(3) on inhibition of the renin-angiotensin system (RAS) in vitro. The authors conclude that the higher activation of the intrarenal RAS is the key factor to induce more severe diabetic nephropathy in VDR(-/-) mice.

QT interval prolongation in association with impaired circadian variation of blood pressure and heart rate in adolescents with Type 1 diabetes

AIMS

The aim of our study was to assess diurnal blood pressure (BP) and heart rate variability and their possible relationship to the duration of the QT interval in adolescents with Type 1 diabetes.

METHODS

In 48 normotensive, normoalbuminuric diabetic adolescents, with a mean (+/- sd) age of 17.3 (+/- 4.1) years and a mean (+/- sd) diabetes duration of 8.5 (+/- 3.3) years, 24-h ambulatory BP was recorded. In addition, 24-h heart rate (HR) monitoring was performed and QT and corrected QT (QTc) intervals were estimated as indices of autonomic function. The patients were divided into two groups according to the absence of a decrease (non-dippers) or the presence of a decrease (dippers) in nocturnal diastolic BP (DBP).

RESULTS

In comparison with the dippers, the non-dippers showed reduced mean 24-h HR (79.6 vs. 84.0 beats/min, P = 0.05) and reduced mean daytime HR (81.3 vs. 86.0 beats/min, P = 0.05). The QT interval was prolonged in the non-dippers (366.3 vs. 347.5 ms, P = 0.015), and end systolic (28.7 vs. 25.9 mm, P = 0.004) and end diastolic left ventricular diameters (47.8 vs. 45.5 mm, P = 0.037) were greater. In stepwise multiple regression, HR variables were the most important factors affecting DBP ratio or the duration of the QT interval.

CONCLUSIONS

In conclusion, normotensive diabetic adolescents with impaired nocturnal BP reduction also have impaired autonomic function tests, in association with prolonged QT interval and increased left ventricular diameters. These findings suggest that diabetic adolescents who have the 'non-dipper' phenomenon may need close follow-up for the possible development of vascular complications, such as cardiac arrhythmias and left-ventricular hypertrophy.

Ambulatory blood pressure monitoring and renal functions in children with a solitary kidney

The aim of this study is to investigate the blood pressure (BP) profile, microalbuminuria, renal functions, and relations with remaining normal kidney size in children with unilateral functioning solitary kidney (UFSK). Sixty-six children with UFSK were equally divided into three groups: unilateral renal agenesis (URA), unilateral atrophic kidney (UAK), and unilateral nephrectomy (UNP). Twenty-two age-, weight-, and height-matched healthy children were considered as a control group. The serum creatinine level and first-morning urine microalbumin and creatinine concentrations were determined by the standard methods. Also, the BP profile was determined by ambulatory blood pressure monitoring (ABPM). We found that the serum creatinine level was higher and creatinine clearance was lower in each patient groups compared to those of the control group (p < 0.05). Compared with the controls, each group of patients had mean office, 24-h, daytime, and night-time systolic and diastolic BP values similar to those of the controls (p > 0.05). An inverse correlation was found between the renal size standard deviation scores (SDS) of normal kidneys and 24-h systolic and diastolic BP load SDS in all of the patients (p < 0.05; r = -0.372, r = -0.295, respectively). The observed relationship between renal size SDS and 24-h mean arterial pressure (MAP), systolic and diastolic BP load SDS suggests that children with UFSK should be evaluated by using ABPM for the risk of hypertension.