Autonomic blood pressure control in children and adolescents with type 1 diabetes mellitus

Introduction:  Increased daytime blood pressure and reduced nocturnal dipping can already be found in children with type 1 diabetes mellitus. We hypothesized that impaired baroreflex sensitivity can cause this abnormal blood pressure behavior in children and adolescents with type 1 diabetes, reflecting an early stage of diabetic autonomic neuropathy.
Methods:  In the present study, we monitored beat-to-beat blood pressure and pulse interval non-invasively with portapres© in 38 patients with type 1 diabetes (7–18 yr) and 14 non-diabetic subjects (5–17 yr). The Trigonometric Regressive Spectral Analysis was used to assign spontaneous oscillations of blood pressure and pulse interval to defined frequency bands between 0.003 and 1.0 Hz and to calculate baroreflex sensitivity. Correlations with diabetes-specific data like hemoglobin A1c (HbA1c) and with 24-h blood pressure measurements were calculated.
Results:  The diabetic subjects displayed significantly less variance of blood pressure and pulse interval in the high frequency (HF) bands and a lower BRS. BRS decreased with higher HbA1c and daily insulin dose. We also saw significant changes in spectral variance of blood pressure and pulse interval with these parameters. Patients with higher sympathetic activity (LF/HF-ratio) during daytime measurements displayed more nocturnal dipping.
Conclusion:  Our data evidence impaired baroreflex sensitivity in children and adolescents with type 1 diabetes mellitus. We suggest spectral analysis of spontaneous blood pressure and pulse interval oscillations during night sleep to further pursue the role of baroreflex sensitivity in the etiology of the non-dipping phenomenon in diabetic patients.     

Microalbuminuria and abnormal ambulatory blood pressure in adolescents with type 2 diabetes mellitus

OBJECTIVE: To determine whether risk factors for cardiovascular disease and diabetic nephropathy, as evidenced by abnormalities of ambulatory blood pressure (ABP), dyslipidemia, and microalbuminuria (MA), are present in adolescents with type 2 diabetes mellitus (T2DM). STUDY DESIGN: We enrolled 26 minority adolescents recently diagnosed with T2DM and 13 obese control subjects without diabetes mellitus. ABP monitoring was performed, and a 24-hour urine, a fasting lipid profile, blood urea nitrogen, creatinine, homocysteine, and hemoglobin A 1 c levels were obtained. The patients with T2DM underwent echocardiograms. RESULTS: Forty percent of the patients with T2DM had MA (> or = 30 mg of microalbumin/day), compared with none of the control subjects ( P < .05). There were no significant differences between patients with T2DM who had MA and patients with T2DM who didn't have MA in demographics, characteristics, casual BP, echocardiographic findings, and hemoglobin A 1 c levels. Average daytime systolic BP was greater in patients with T2DM with MA than patients without MA (129 versus 121 mm Hg, P = .03) and compared with the control subjects (113 mm Hg, P = .01). Patients with MA had an average daytime systolic BP load that was higher than patients without MA (37.1 versus 5.1%, P = .008) and compared with the control subjects (2.6%, P < .001). CONCLUSION: As in adults, adolescents with T2DM exhibit abnormalities of ABP, dyslipidemia, and microalbuminuria.     

Home blood pressure in children and adolescents: a comparison with office and ambulatory blood pressure measurements

Aim: To compare BP measurements of children and adolescents using different methods office BP (OBP), ambulatory BP monitoring (ABPM) and home BP measurement (HBPM) and to study their correlations. Method: Individuals were evaluated between 5 and 15 years of age who had been referred because of a previous high BP. OBP was measured with the OMRON‐705CP. Three measurements were carried out at 5‐min intervals. HBPM were taken using the same device, two measurements at 5‐min intervals in the morning and in the evening during 7 days. ABPM was performed using the SpaceLabs 90207 monitors. Results: A total of 109 children and adolescents were evaluated (9.82 ± 2.63 years), 52.3% boys, 56.9% non‐white. The office systolic BP (SBP) was lower than in daytime ABPM (p < 0.001) but similar HBPM (p = 0.294), and the office diastolic BP (DBP) was lower than daytime ABPM (p < 0.001) and in HBPM (p = 0.035). The SBP and DBP at HBPM was lower than daytime ABPM (p < 0.001). Daytime ambulatory BP was more closely associated with home readings (SBP r = 0.731 and DBP r = 0.616) than with office’s readings (SBP r = 0.653 and DBP r = 0.394). Conclusion: The BP of children and adolescents varies depending on the place and manner of measurement. ABPM presents better correlation with HBPM than with the office measurements.     

Blood pressure response to melatonin in type 1 diabetes

HYPOTHESIS: Diminished decline of blood pressure at night has been associated with increased risk of cardiovascular disease. Exogenous melatonin given to healthy normotensive adults reduces blood pressure. We hypothesized that melatonin increases the decline of blood pressure during sleep in normotensive adolescents with type 1 diabetes. PATIENTS AND METHODS: Eleven normotensive normoalbuminuric patients with type 1 diabetes of 7.0 +/- 3.5 yr duration and 10 healthy controls aged 14-18 yr participated in a randomized placebo-controlled double-blind crossover study of 5 mg melatonin for 1 wk, with a 1-wk washout. Blood pressure was measured every 20 min for 24 h by an ambulatory device on the day before and on the last day of each treatment. Sleep measures were recorded by a diary and a wrist activity meter. Blood pressure measures were grouped by 24 h, sleep, and wake periods. Statistical analysis used sleep duration, number of awakenings, and treatment sequence as covariates for the blood pressure comparisons by treatment. RESULTS: In the patients with type 1 diabetes, the decline in diastolic blood pressure during sleep was significantly greater on melatonin (17.8 +/- 4.4 mmHg) than on placebo (16.0 +/- 3.0 mmHg, p < 0.01). No significant drug effect was present in the controls. No significant side effects were noted. CONCLUSION: Melatonin amplifies the nocturnal decline in diastolic blood pressure in patients with type 1 diabetes. We propose that dose-response studies of short- and long-acting preparations of melatonin be conducted and that melatonin be considered in trials of prevention of hypertension in type 1 diabetes.     

Accuracy of blood pressure measurement by the Dinamap monitor in infants and children

Indirect BPs measured by the Dinamap monitor, an oscillometric device, and the conventional auscultatory method were compared with the direct radial artery pressure in infants and children. There were 29 patients in the Dinamap group with a median age of 18 months (ranges 1 month to 16 years) and 20 patients in the auscultatory group with a median age of 3.5 years (ranges 3 months to 16 years). The direct radial artery pressures were recorded on a strip chart and the ranges of pressures were obtained for systolic, diastolic, and mean pressures. The range of the direct readings was converted to a weighted single reading, and comparisons were made between the direct and indirect readings. The linear regression equation between the direct (x) and the Dinamap (y) readings (with correlation coefficient) was y = 1.05x - 5.36 (r = .97) for systolic, y = 1.10x - 4.65 (r = .903) for diastolic, and y = 1.06x - 4.21 (r = .917) for mean pressures. The linear regression equation (with correlation coefficient) for the auscultatory pressure was y = 1.60x - 68.23 (r = .872) and y = 1.38x - 16.47 (r = .874) for diastolic pressures. The error was defined as the indirect reading minus the direct reading. The mean error +/- SD was -0.24 +/- 3.26 for systolic, 1.28 +/- 4.74 for diastolic, and 0.10 +/- 4.56 mm Hg for mean pressures by the Dinamap method. It was -1.65 +/- 6.68 for systolic, and 8.70 +/- 5.97 for diastolic pressures by the auscultatory method.(ABSTRACT TRUNCATED AT 250 WORDS)     

ABPM vs office blood pressure to define blood pressure control in treated hypertensive paediatric renal transplant recipients

While 24-h ambulatory blood pressure monitoring (ABPM) is an established tool for monitoring antihypertensive therapy in adults, data in children are scarce. We retrospectively analysed whether office blood pressure (BP) is reliable for the diagnosis of BP control in 26 treated hypertensive paediatric renal transplants. Controlled office BP was defined as the mean of three replicate systolic and diastolic BP recordings less than or equal to the 95th age-, sex- and height-matched percentile on the three-outpatient visits closest to ABPM. Controlled ABPM was defined as systolic and diastolic daytime BP < or =95th distribution adjusted height- and sex-related percentile of the adapted ABPM reference. Eight recipients (30%) with controlled office BP were in fact categorized as having non-controlled BP by ABPM criteria. Overall, when office BP and ABPM were compared using the Bland and Altman method, the 95% limits of agreement between office and daytime values ranged from -12.6 to 34.1 mmHg for systolic and -23.9 to 31.7 mmHg for diastolic BP, and the mean difference was 10.7 and 3.9 mmHg respectively. Office readings miss a substantial number of recipients who are hypertensive by ABPM criteria. Undertreatment of hypertension could be avoided if ABPM is applied as an adjunct to office readings.     

Lipid profiles and blood pressure: are they risk factors for the development of early background retinopathy and incipient nephropathy in children with insulin-dependent diabetes mellitus?

The objective of this study is to examine the influence of lipid profiles and blood pressure on the development of microvascular complications in adolescents with insulin-dependent diabetes mellitus (IDDM) in a matched pairs study. Patients with early background retinopathy ( n = 21) or microalbuminuria ( n = 15) and their respective statistical twins participated in the study. Serum total cholesterol, high-density lipoprotein (HDL) cholesterol, fasting triglycerides, glycosylated haemoglobin A_lc (Hb A_lc.), and systolic and diastolic blood pressure during 3 years prior to the development of early background retinopathy or incipient nephropathy were examined. The multivariate discriminant analysis demonstrated glycaemic control and HDL cholesterol to be the most important variables related to the development of retinal lesions (84% correctness), and diastolic blood pressure to be associated with microalbuminuria (57% correctness). In addition to poor glycaemic control, different factors seem to be important for the early retinal or renal lesions of juvenile IDDM.     

Reference ranges for blood pressure in preschool Australians, obtained by oscillometry

OBJECTIVE: To derive reference centiles for blood pressure in children aged 1-6 years which seek to address shortcomings in available reference ranges. METHODS: Prospective cohort study of 2876 children in Perth, Western Australia, commenced in 1989 with serial blood pressure measurements through early childhood obtained by oscillometry under standardized conditions. RESULTS: Gender-specific reference centile charts for systolic and diastolic blood pressure, (i) across ages 1-6 years and (ii) across the range of corrected Body Mass Index values at ages 1, 3 and 6 years, were generated by fitting linear models with both fixed and random effects. CONCLUSIONS: Reference values for blood pressure for young children are of clinical use and may be of long-term predictive value.     

Reliability of the Dinamap non-invasive monitor in the measurement of blood pressure of ill Asian newborns

Four hundred thirty-one paired sets of readings of systolic and diastolic blood pressure and 438 paired sets of readings of mean arterial BP from 49 ill newborns, including 21 very low birth weight infants, were analyzed for the extent and pattern of agreement and the linear relationship between the Dinamap oscillometric monitor and the direct intraarterial blood pressure readings. Agreement between the two methods was measured by the intraclass correlation, whereas the linear relationship was assessed by the product-moment correlation. The intraclass correlations for systolic, diastolic and mean blood pressures were 0.696, 0.766, and 0.781, respectively. The product-moment correlations for systolic, diastolic and mean blood pressures were 0.706, 0.768, and 0.786, respectively. BP measurements by the Dinamap monitor showed reasonably close agreement to those obtained by the intraarterial mean arterial pressure ranges above 40 mmHg. For mean arterial pressure of 40 mmHg and lower, BP readings by the Dinamap monitor tended to be higher than those obtained by the intraarterial method. These findings appeared to be consistent regardless of the birth weight of the newborn.     

Twenty-four hour blood pressure monitoring in healthy children

Blood pressure and heart rate were measured every 20 min during the day and every 30 min during the night in 105 children (51 girls and 54 boys, aged 6–10 years) with a portable automated blood pressure monitor using an oscillometric principle of measurement. The monitor was well accepted by most of the children and the rate of invalid measurements was only 13%. Mean systolic and diastolic blood pressure was 114±7/72±5 by day and 99±7/56±6 by night. The corresponding heart rates were 93±8 and 72±9 beats/min. No significant differences were found between boys and girls. At night, systolic blood pressure dropped by 13%±4%, the diastolic value by 22%±7% and heart rate fell by 22%±6%. Mean systolic and diastolic blood pressure measurements correlated positively with the subject's height, whereas no correlation was found with age.     

Non-invasive oscillometric measurement of systolic,mean and diastolic blood pressure in infants with congenital heart defects after operation. A comparison with direct blood pressure measurements

The accuracy of indirect oscillometric blood pressure measurements has been evaluated in 32 infants up to 11 months of age undergoing heart surgery. In a number of 1029 simultaneous measurements the indirect blood pressure was compared with the direct value obtained from a radial artery catheter. Cuffs of different sizes were applied. The main results were as follows: (1) Regarding the ratio of cuff width to arm circumference, the best correlation between oscillometric and direct blood pressure measurements was obtained with a ratio of 0.38–0.41. (2) The value of indirect blood pressure measurements depends on the absolute height of the blood pressure. In low blood pressure there is a tendency to underestimate and in high blood pressure there is a tendency to overestimate by the oscillometric blood pressure measurement.By applying an appropriate cuff size and by using our diagrams it should be possible to derive a direct value for the blood pressure on the basis of indirect oscillometric blood pressure measurements.Abbreviations BP blood pressure - BPM blood pressure measurements - CW/ArmC cuff width to arm circumference ratio - DAP diastolic arterial pressure - MAP mean arterial pressure - SAP systolic arterial pressure - ME mean error - SD standard deviation Research fellow supported by the A. v. Humboldt Stiftung     

Self-monitoring of blood glucose in children and teens with diabetes

Improved metabolic control has unequivocally been demonstrated to delay the onset and slow the progression of microvascular complications in adolescents and adults with diabetes mellitus. Growing evidence also supports the association of tighter glucose control and more frequent blood glucose monitoring. Therefore, self-monitoring of blood glucose (SMBG) has become a fundamental part of diabetes care in children. Here, we review recent advances and ongoing trends in glucose monitoring in children with diabetes. Technologies have been developed to improve patient compliance with recommended monitoring, requiring less blood, involving less pain, and providing results more quickly. Alternate-site testing (AST) is also a potential means of improving patient compliance with SMBG by avoiding the sensitive fingertip area. The Continuous Glucose Monitoring System (CGMS) and the GlucoWatch Biographer are two recent tools that can track glucose levels continuously. However, inconsistency in their accuracy and precision remain challenges when using these technologies to guide management.     

Ambulatory blood pressure monitoring (ABPM) in normotensive adolescents with type 1 diabetes

Abstract: Objective: To evaluate 24‐h ambulatory blood pressure monitoring (ABPM) for early detection of hypertension in adolescents with type 1 diabetes mellitus (DM1). Design: Patients underwent fundoscopy, albuminuria determinations, two repeated autonomic cardiovascular tests, heart rate (HR) variation during deep breathing and blood pressure (BP) variation during sustained handgrip. Twenty‐four hour BP measurements were taken automatically by an oscillometric portable monitor. Setting: A specialty pediatric diabetes clinic and subjects' homes. Participants: Eighteen children aged 10–17 yr with 2+ yr of DM1, without long‐term complications, and 34 controls. Results: Higher ambulatory HR during the day than at night did not differ between DM1 subjects and controls. Mean systolic (s) and diastolic (d) BP in patients during the daytime were not significantly different from the control values. During the night, both sBP and dBP mean values in patients differed from those of controls. Statistical analysis of day and night HR and BP measurements were not different in both groups. The percentage decrease during the night in sBP and dBP was significantly smaller in patients than in controls. There were no differences by gender or duration of diabetes > or < 5 yr or by HbA1 above and below 10%. No difference in nocturnal sBP or dBP decline was observed between patients with or without abnormal autonomic test results. Conclusion: ABPM is more reliable than casual BP measurement in detecting early BP alterations during the night, before the appearance of microalbuminuria, in young patients with DM1.     

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目的调查四川省藏族儿童青少年肥胖指标体重指数(BMI)、腰围(WC)、腰臀比(WHR)、腰围身高比(WhtR)与血压、血脂,并对其相关性进行分析。方法采用多阶段、分层、整群随机抽样的方法,选取2007年10月调查的四川省阿坝自治州松潘县藏族儿童青少年818名资料完整者进行数据分析。测量计算BMI、WC、WHR、WhtR,并分别检测收缩压(SBP)、舒张压(DBP)、总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白(HDL-C)以及低密度脂蛋白(LDL-C)的血清浓度,并进行相关性分析。结果女童超重肥胖率(12.78%)高于男童(3.30%),男童和女童超重肥胖组的血压、血脂与同性别BMI正常组相比差异有统计学意义。对血压、血脂与年龄、肥胖指标进行不同性别单因素相关性分析显示,男童和女童的BMI和WC均与SBP、DBP呈正相关。血脂四项与肥胖指标有不同程度的相关性。结论四川省藏族儿童青少年的BMI、WC、WHR、WhtR和血压、血脂存在不同程度的性别、年龄差异,尤其体现在16～17岁年龄组。监测儿童青少年期的BMI、WC和WhtR对于血压和血脂的控制和维持具有重要意义。     

动态血压在儿科的应用

动态血压监测能真实反映患者24h血压的平均水平、日常生活的血压变化和昼夜节律变化,较传统的血压监测有明显的优势.研究已经确定其在识别儿童白大衣性高血压及隐匿性高血压、预测靶器官损害、评价降压药物疗效、鉴别原发性高血压及继发性高血压等方面有一定价值.该文简述动态血压监测在儿科的临床应用.     

A longitudinal study of blood pressure,cholesterol and left ventricular muscle volume in children: The Shimane Heart Study

Three hundred and forty-four healthy schoolchildren living in Izumo City, Shimane Prefecture, Japan, were assessed at 3 year intervals from 6 to 15 years, starting in 1978 (Cohort 1) or 1981 (Cohort 2). Tracking indices (Ti) were calculated as follows: Ti = (2x + y - z)/N/0.89, where x, y and z refer to the total number in the same, adjacent and remote trisections, respectively, and N = x + y + z. If Ti > 1, there is positive tracking. For systolic blood pressure (SBP) measurements (except at 6 years old) and serum cholesterol levels, all Ti were greater than 1.0 regardless of the time when tracking was commenced. Tracking indices were slightly greater in the serum cholesterol levels than in the SBP measurements. Left ventricular muscle volume indices (LVMVI) were calculated by echocardiographic measurements. In girls, the LVMVI was larger only in the above-median SBP group at the age of 12 years (P < 0.01), but the LVMVI of the higher SBP (above median) group was larger than in the lower (below median) group at every age in boys; the difference was statistically significant (P < 0.05) at 12 and 15 years of age. Left ventricular mass enlargement may occur in the prehypertensive stage in humans as well as in rats.