1. Table 1: Demographics and Patient Characteristics
High Blood Pressure in Children with Chronic Kidney Disease (CKD) Correlates with 1,25(OH)2 Vitamin D and Not 25(OH) Vitamin D Bandana Paudyal, MD*1, Gail Prado MD*1, Morris Schoeneman MD*1, Hanan Tawadrous MD*1, Nataliya Chorny MD*1, Vaishali Bansilal MD*1, Valeriya Feygina MD*1, Ovidiu Galescu MD*1, Amrit Bhangoo, MD*2 and Anil K. Mongia, MD* Department of Pediatric Nephrology, SUNY, Brooklyn, NY; 2Peds Endocrinology, SUNY, Brooklyn, NY.
Abstract
Design/Methods
Results
BACKGROUND: Vitamin D deficiency is well known for its musculoskeletal complications in children and adults. In vitro studies have suggested 1, 25(OH)2Vit D (1,25 Vit D) as a vascular protective agent by its effect on the endothelium. However, limited studies are available looking at the effect of Vitamin D on blood pressure in children. HYPOTHESIS: 1,25 Vit D levels will negatively correlate with blood pressure. OBJECTIVE: To assess the effect of Vitamin D level on Blood Pressure, eGFR and PTH in children with Hypertension. DESIGN/METHODS: We enrolled 46 patients (25 patients with CKD, 9 primary hypertension (PH), and 12 Control (C). We collected data on age, sex, race, cause of kidney disease, eGFR, Ht, Wt, BMI, BP percentiles and z scores, electrolytes, calcium, 25 vit D, 1,25 vit D, PTH. Spearman coefficient was used to determine the correlation between Vitamin D, SBP z score, DBP z score, GFR, and PTH using SPSS version 2.0. RESULTS: SBP %'ile was significantly higher in pts with PH (87.7 ±17.6) and CKD (75.4 ±27,6) than C (43.5± 26.9) and DBP%'ile significantly higher in PH (90 ±10.6) and CKD (77 ±24.6) than
C (46.4±18.9). eGFR (ml/min/1.73m2) was significantly lower in patients with CKD (98±56.8) than
C (142.6±36). 86 % patients had Vitamin D level <30 ng/ml. Mean 25 Vit D level was 14 ±5.8 ng/dl. There was no correlation of 25 Vit D with SBP z-score( r=+0.083, p=0.721) and DBP z-score
(r=-0.030, p=0.897). 25 Vit D did not correlate with eGFR (r= , P=0.134) or PTH (r= , P=0.370). 1,25 Vit D level correlated negatively with SBP (r=-0.69, p=0.034) and DBP (r=-0.65, p=0.05) z scores.
CONCLUSIONS: Low 1, 25 Vitamin D levels may have deleterious effects on blood pressure in children. 1,25 Vitamin D levels should be measured and normalized in children with hypertension
We enrolled 46 patients [25 patients with Chronic Kidney disease (CKD), 9 primary hypertension (PH), and 12 Control (C)]. We collected data on age, sex, race, causes of kidney disease, eGFR, Height, Weight, BMI, SBP/DBP percentiles and z scores, calcium, phosphorus, 25(OH)2Vit D, 1,25(OH)2 Vit D, PTH. Patients stratified as obese, overweight, normal weight , malnourished as per BMI percentile chart for age and sex. eGFR was calculated using modified Schwartz formula.
Statistical analysis: Spearman coefficient was used to determine the correlation between Vitamin D, SBP z score, DBP z score, GFR, and PTH using SPSS version 2.0.
Results
Primary
Hypertension (N=9)
CKD (N=25)
Control (N=12)
Age ( yrs)
14 ± 4.7
13 ± 4.5
11.3 ± 3.4
Sex (M / F)
4 / 5
15 / 10
5 / 7
Ethnicity ( AA) 9 15 11
Causes Of CKD:
Hypodysplastic/Obstructive/FSGS/ Lupus/ others NA
4/2/6/3/10
BMI
>85%ile (Overweight)
>95%ile (Obese)
29.7 ± 8.9 1 6
23.2 ± 5.7 5
22.4 ± 7.6 3
Background
Primary physiological role of the Vitamin D is to regulate calcium homeostasis by regulating intestinal and renal calcium transport and bone mineralization.
Recent studies have shown broad-ranging activities of Vitamin D that extend beyond the regulation of calcium and phosphorus metabolism. These so-called non-calcemic activities include regulation of renal and cardiovascular functions and modulation of immune responses. Vitamin D insufficiency is associated with impaired vascular endothelial and smooth muscle function and hypertension in young rats.
1, 25(OH)2 D3 also functions as a negative endocrine regulator of the renin–angiotensin system (RAS) and thus plays an important role in the regulation of the renocardiovascular functions. In a cross sectional study on adolescents in the United States, low serum Vitamin D levels were associated with increased risk of hypertension, hyperglycemia, and the metabolic syndrome, even after controlling for race/ethnicity, BMI, socioeconomic status, and physical activity .
A significant association between Vitamin D and cardiovascular risk factors in youth would suggest that the successful repletion of Vitamin D has the potential to improve the cardiovascular risk profile during childhood.
Table 1: Demographics and Patient Characteristics
Primary
Hypertension
( N=9)
CKD (N=25)
Control (N=12)
p- value
SBP Z-Score
2.05 ± 1.6
0.85 ± 1.15
-0.15 ± 0.75
* * *0.006
DBP Z-Score
1.28 ± 1.16
1.17 ± 1.29
-0.19 ± 0.5
* * * 0.004
E GFR( ml/min)
86 ± 23
70.2 ± 37.6
106 ± 27.7
* * 0.03
PTH( pg/ml)
185 ± 166
222.6 ± 160 - NS
Calcium ( mg/dl)
9.7 ± 0.35
9.3 ± 0.7
9.7 ± 0.3
Phosphorus (mg/dl)
4.2 ± 0.58
4.5 ± 1.1
5.3
25 (OH) VitD
(32-110ng/ml)
14. 3± 4.3
21.8 ± 19.8
20.6 ± 10.2
1,25(OH)Vit D
(15-75 pg/ml) 29
65 ± 27
61 ± 14
P <0.05 between Primary Hypertension and CKD, * * P <0.05 between CKD and Control ,
* * * P <0.05 between primary hypertension and Control
Conclusions
Our conclusions from our study is Low 1, 25 vitamin D levels may have deleterious effects on blood pressure in children.
1,25 vitamin D levels should be measured and normalized in children with hypertension
References
Objectives
1)Y.C. Li, J. Kong, M. Wei, Z.F. Chen, S.Q. Liu, L.P. Cao. 1,25-Dihydroxyvitamin D(3) is a negative endocrine regulator of the renin–angiotensin system, J. Clin. Invest. 110 (2002) 229–238.
2)Sunil Nagpal et al. Noncalcemic Actions of Vitamin D Receptor Ligands Endocrine Reviews 26(5):662–687
3) Marianne Tare et al .Vitamin D insufficiency is associated with impaired vascular endothelial and Smooth muscle function and hypertension in young rats. . J Physiol (2011) pp 4777–4786
To assess the Prevalance of Hypertension among pediatric patients
To assess the effect of Vitamin D levels on blood pressure, eGFR, PTH in children with hypertension
Table 2: Comparison between Primary Hypertension, Chronic Kidney disease and Control.