Casual blood pressure (CBP) is considered a reliable proxy for cardiovascular health. Although the auscultatory technique is the reference standard method for measuring CBP, oscillometric devices are increasingly being used in children. We sought to establish oscillometric CBP normative standards for Swedish children. Cross-sectional oscillometric CBP readings were obtained by the Welch Allyn Spot Vital Signs 420 monitor and measured according to the International Guidelines’ recommendations. Participants with elevated oscillometric CBP levels underwent verification by the auscultatory method. Ambulatory blood pressure monitoring (ABPM) was used to exclude casual hypertension. Data on 1,470 (772 males) apparently healthy Swedish schoolchildren aged 6–16 years were analyzed and sex-specific reference charts normalized to age or height were constructed. Systolic and diastolic CBP values were significantly higher with age, height, height standard deviation score (SDS), body mass index (BMI), and BMI SDS. Gender differences for systolic CBP were present starting from age of 15 years and revealed significantly higher values in boys than in girls, whereas for diastolic CBP, the differences were apparent at the age of 12 years, with higher values in girls. Increased BMI and BMI SDS were positively associated with CBP levels. Positive parental history of hypertension turned out to be a risk factor for higher systolic and diastolic CBP across all ages. Our normative standard for CBP can be used for blood pressure screening and control programs in Swedish children. The use of ABPM should be considered to confirm the diagnosis of casual hypertension.
Hypertension is a highly prevalent co-morbidity in pediatric kidney transplant recipients. Undertreated hypertension is associated with cardiovascular complications and negatively impacts renal graft survival. Thus, the accurate measurement of blood pressure is of the utmost importance for the correct diagnosis and subsequent management of post-renal transplant hypertension. Data derived from the general population, and to a lesser extent from the pediatric population, indicates that ambulatory blood pressure monitoring (ABPM) is superior to blood pressure measurements taken in the clinical setting for the evaluation of true mean blood pressure, identification of patients requiring antihypertensive treatment, and in the prediction of cardiovascular outcome. This Educational Review will discuss the clinical value of ABPM in the identification of individual blood pressure phenotypes, i.e., normotension, new-onset hypertension, white-coat hypertension, masked hypertension, controlled blood pressure, and undertreated/uncontrolled hypertension in pediatric kidney transplant recipients. Finally, we examine the utility of performing repeated ABPM for treatment monitoring of post-renal transplant hypertension and on surrogate markers related to relevant clinical cardiovascular outcomes. Taken together, our review highlights the clinical value of the routine use of ABPM as a tool for identifying and monitoring hypertension in pediatric kidney transplant recipients.
Nitric oxide (NO) contributes to maintaining normal cardiovascular and renal function. This bioactive signalling molecule is generally formed enzymatically by NO synthase in the vascular endothelium. NO bioactivity can also be attributed to dietary intake of inorganic nitrate, which is abundant in our diet, especially in green leafy vegetables and beets. Ingested nitrate is reduced to nitrite by oral commensal bacteria and further to NO systemically. Previous studies have shown that dialysis, by means of removing nitrate and nitrite from the body, can reduce NO bioactivity. Hence, dietary intervention approaches aimed to boost the nitrate–nitrite–NO pathway may be of benefit in dialysis patients. The purpose of this study was to examine the kinetics of plasma nitrate and nitrite after a single intake of nitrate-rich concentrated beetroot juice (BJ) in adult hemodialysis (HD) patients and in age-matched healthy volunteers (HV). Eight HD patients and seven HV participated in this single center, randomized, single-blind, placebo-controlled, crossover study. Each participant received a sequential single administration of active BJ (70 mL, 400 mg nitrate) and placebo BJ (70 mL, 0 mg nitrate) in a random order separated by a washout period of seven days. For the kinetic analysis, blood samples were collected at different time-points before and up to 44 h after BJ intake. Compared with placebo, active BJ significantly increased plasma nitrate and nitrite levels both in HD patients and HV. The area under the curve and the maximal concentration of plasma nitrate, but not of nitrite, were significantly higher in HD patients as compared with HV. In both groups, active BJ ingestion did not affect blood pressure or plasma potassium levels. Both BJs were well tolerated in all participants with no adverse events reported. Our data provide useful information in planning dietary nitrate supplementation efficacy studies in patients with reduced NO bioactivity.