Abstract: SA-PO345
Factors Determining Timing of Onset of Hypertension in Premature Infants
Session Information
- Hypertension and CVD: Mechanisms
November 09, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Hypertension and CVD
- 1403 Hypertension and CVD: Mechanisms
Authors
- Jenkins, Randall, Oregon Health & Science University, Portland, Oregon, United States
- Farnbach, Katherine, Oregon Health & Science University, Portland, Oregon, United States
- Iragorri, Sandra, Oregon Health & Science University, Portland, Oregon, United States
- Al-Uzri, Amira, Oregon Health & Science University, Portland, Oregon, United States
- Rozansky, David J., Oregon Health & Science University, Portland, Oregon, United States
Background
We recently demonstrated that phthalate-exposed premature infants with unexplained hypertension (HTN) had evidence of inhibition of 11-BHSD2, and secondary activation of the mineralocorticoid receptor (MR). Neither HTN nor increased sodium transporter expression occurred until an adjusted age closer to term, despite phthalate exposure weeks earlier. We tested the hypothesis that other types of HTN in premature infants might also present with a similar timeframe.
Methods
We reviewed charts of all premature infants with HTN at two tertiary-care centers during the last 8 years, excluding infants with unknown phthalate exposures, and single case categories: neurology and renal vein thrombosis. Analyses included HTN incidence, time-course of HTN, and phthalate exposure.
Results
106 infants with 107 episodes of HTN were found. In both AKI and thromboembolism groups, HTN developed at an early chronological and postmenstrual age. Their phthalate exposure was small. In all other categories HTN presented near 40 weeks postmenstrual age, usually with low renin. Phthalate exposures were large in the pulmonary and medications groups, and moderate in the CAKUT group.
Conclusion
The development of HTN in premature infants from AKI and thromboembolism is unrelated to phthalate exposure and to sodium transporter maturation. Onset of HTN for phthalate-exposed infant categories (pulmonary, medications, and CAKUT) occurs closer to an adjusted term age - more in line with activation and maturation of MR-dependent sodium transporter processes such as we reported for infants with unexplained hypertension. Phthalate exposure may be a major factor in influencing the onset of HTN amongst these categories of infant hypertension.
Diagnostic, time-course, and phthalate exposures by category for premature infants with hypertension
| Categories | # | Plasma renin activity < 11.0 ng/ml/h #/n | Gestational age at birth weeks | DX of hypertension postmenstrual weeks | median IV fluid phthalate exposure ml (IQR) | Median respiratory phthalate exposure days (IQR) |
| Thrombolic | 2 | 1/2 | 33.1 +/- 3.9 | 34.1 +/- 3.7 | NR | 4 (2) |
| CAKUT | 8 | NR | 35.2+/- 0.8 | 41.8 +/- 6.7 | 235 (382) | 18 (22) |
| AKI | 4 | NR | 25.6 +/- 1.2 | 27.5 +/- 1.2 | 104 (160) | 17 (4) |
| Pulmonary | 84 | 73/74 | 27.6 +/- 2.7 | 39.5 +/- 2.7 | 21 (75) | 68 (48) |
| Medications | 9 | 5/5 | 29.9 +/- 4.6 | 43.7 +/- 5.9 | 181 (514) | 71 (32) |
NR, not reported; IQR, interquartile range; DX, diagnosis