Serum levels of galactose-deficient IgA are elevated in patients with IgA nephropathy but do not correlate to disease activity or progression.

INTRODUCTION: IgA nephropathy (IgAN) is the most common glomerulonephritis globally. Because of the heterogeneity of the disease prognostic biomarkers are highly needed. AIM: To investigate associations between galactose-deficient IgA1 (Gd-IgA1) concentrations in plasma and urine and disease activity and progression in patients with IgAN. METHODS: Serum and urine samples were collected at the time of kidney biopsy (baseline) in patients with IgAN (n = 40) and analysed for Gd-IgA1. Patients with chronic kidney disease (CKD) without IgAN (n = 21) and healthy controls (n = 19) were examined as controls. In 19 patients with IgAN, analyses of Gd-IgA1 were repeated after a median follow up time of approximately 10 years. RESULTS: Serum Gd-IgA1 and Gd-IgA1:IgA were significantly elevated at the time of kidney biopsy in patients with IgAN compared to patients with non-IgAN CKD and healthy controls (p < 0.001). Urinary Gd-IgA1:creatinine was significantly elevated in patients with IgAN compared to patients with non-IgAN CKD. Neither serum Gd-IgA1, nor serum Gd-IgA1:IgA, correlated significantly to estimated GFR, urine albumin:creatinine (UACR), or blood pressure, at baseline. Serum Gd-IgA1 and Gd-IgA1:IgA at time of biopsy did not correlate significantly to annual changes in eGFR or UACR during follow up. In patients with IgAN, serum Gd-IgA1 decreased significantly over time during approximately 10 years of follow up (Δ-20 ± 85%, p = 0.027). Urinary Gd-IgA1:creatinine showed a strong positive correlation to UACR in patients with IgAN and likely reflected unspecific glomerular barrier injury. CONCLUSION: Although serum Gd-IgA1 and the Gd-IgA1:IgA ratio were significantly elevated in patients with IgAN at the time of kidney biopsy they were not related to disease activity or progression in this patient cohort.

Comparison of aneroid and oscillometric blood pressure measurements in children.

Limited data exist on the comparison of blood pressure (BP) measurements using aneroid and oscillometric devices. The purpose of the study was to investigate the difference in BP obtained using oscillometric and aneroid BP monitors in 9- to 10-year-old children. A total of 979 children were divided into group O, which underwent two oscillometric BP readings followed by two aneroid readings, and group A, which had BP measured in the reverse order. No significant difference was found between the mean (±standard deviation) of the two systolic BP readings obtained using the oscillometric and aneroid devices (111.5±8.6 vs 111.3±8.1 mm Hg; P=.39), whereas the mean diastolic BP was lower with the oscillometric monitor (61.5±8.0 vs 64.5±6.8 mm Hg; P<.001). A significant downward trend in BP was observed with each consecutive measurement, and agreement between the two monitors was limited. Multiple BP measurements are, therefore, recommended before the diagnosis of elevated BP or hypertension is made with either method.

The relationship between birth weight and blood pressure in childhood: a population-based study.

BACKGROUND: Low birth weight has been associated with increased risk of hypertension later in life. The aim of this study was to evaluate the association between birth weight and blood pressure (BP) in healthy 9- to 10-year-old Icelandic children. METHODS: Each child underwent 4 seated BP measurements, and the BP percentile was calculated from the mean of the 4 measurements. Height and weight were measured and birth weight retrieved from the Icelandic Birth Registry. Birth measures and anthropometric data were correlated with BP and BP percentiles. Multivariable linear regression was employed to examine the association between BP and birth measures. RESULTS: Of 857 children with complete data, 445 were female (51.9%). The mean BP was 112/64 mm Hg in males and 111/63 mm Hg in females. The mean birth weight was 3714 ± 620 g. No correlation was found between birth weight and absolute BP values. A significant negative correlation between birth weight and both systolic (r = -0.09, P = 0.005) and diastolic (r = -0.08, P = 0.014) BP percentiles was observed. Gestational age did not correlate with BP. CONCLUSION: In contrast to many previous studies, we found no association between birth weight and absolute BP in children. However, we observed a statistically significant negative correlation between birth weight and BP percentiles. The lack of standardized BP values may partly explain the conflicting results of previous studies in children, and we suggest that BP percentiles be examined more thoroughly in association with birth weight.

Birth weight and childhood blood pressure.

A large body of literature suggests an inverse relationship between birth weight and blood pressure in children, adolescents and adults. The most persistent findings have been observed in children with a history of low birth weight or intrauterine growth restriction, while a large number of studies carried out in populations with normally distributed birth weight have shown conflicting results. A recently reported strong direct association between high birth weight and blood pressure, and the significant positive effect of postnatal growth on blood pressure suggests that the fetal origins of adult disease hypothesis should be expanded to include the role of excessive fetal and postnatal growth. In this paper, we review recent studies on the relationship between birth weight and blood pressure in childhood, with a focus on confounding variables that may explain the conflicting results of published work in this field.

Prevalence of hypertension in 9- to 10-year-old Icelandic school children.

The purpose of the study was to investigate blood pressure (BP) distribution, prevalence of hypertension, and correlation between BP and body mass index (BMI) in 9- to 10-year-old Icelandic children. Two manual and two automated BP measurements were performed in 1071 Icelandic children. Children with elevated BP underwent a second BP screening, and a third screening was performed if the BP was elevated at the second visit. Hypertension was defined as BP ≥95th percentile at all three visits. White-coat hypertension was diagnosed in hypertensive children with normal 24-hour ambulatory BP. Of 970 children with complete data, 489 were girls (50.4%). The mean BP was 111/63 mm Hg in girls and 112/64 mm Hg in boys (P<.001). The prevalence of elevated BP was 13.1%, 6.0%, and 3.1% after the first, second, and third screen, respectively. The prevalence of sustained hypertension was 2.5% and an additional 0.6% had white-coat hypertension. A significant correlation between BMI and BP was observed (r=0.338, P<.001) and 8.6% of the obese children had hypertension. The prevalence of hypertension in 9- to 10-year-old Icelandic children is lower than indicated in recent reports and is associated with obesity.