Renal response to an acute protein challenge in pregnant women with borderline hypertension

Abstract

Mid-term borderline HP failed to increase CCr as much as NP did after a protein challenge, suggesting altered functional response of the nephron or lessened sensitivity of renal vasculature to additional vasodilator stimuli. These results support the interest of additional prospective studies with a larger number of patients to confirm these findings and evaluate the value of RR tests as predictors of outcome of pregnancies at risk.

Is renal hyperfiltration protective in chronic kidney disease‐stage 1 pregnancies? A step forward unravelling the mystery of the effect of stage 1 chronic kidney disease on pregnancy outcomes

“…The main result in this non‐diabetic, non‐obese, normotensive, non nephrotic population affected by CKD 1 is the lack of difference in pregnancy‐related outcomes between the ‘hyperfiltrating’ patients and ‘non‐hyperfiltrating’ patients (Tables ). This result is in contrast with a few previous suggestions, indicating that an intact renal functional reserve, defined as the capacity to develop a hyperfiltration response after a challenge (high‐protein meal or amino acid infusion), may be relevant in pregnancy‐related outcomes, as well as in long‐term prognosis in non‐pregnant patients …”

“…For this purpose, a highly selected cohort of CKD stage 1 patients was analyzed: these patients were referred early, and had no known risk and progression factors (hypertension, diabetes, obesity, relevant proteinuria) at the start of pregnancy (Table ). The discriminating agent selected for the analysis was one of the most ‘physiological’, although elusive ones: the hyperfiltration response, that could be observed during early stages of ‘healthy’ pregnancies . The lack of response was correlated in previous studies with poorer pregnancy related outcomes in pregnant women with hypertension or collagen diseases …”

“…This discrepancy can, at least partly, be explained by different study designs: our study, dealing with a larger prospective historical cohort, was based on GFR observed at the end of the first trimester, while the studies by Ronco and Heguilen used protein‐rich meals . Since the GFR observed in our study did not represent a ‘maximal challenge’, other studies may have recorded different degrees of adaptation to different stimuli.…”

“…The central role of the kidney in the hypertensive disorders of pregnancy led to try to quantify the renal functional reserve in pregnant women or in experimental models by means of protein‐rich meals or amino acid infusion; the results suggest that the lack of hyperfiltration may herald adverse pregnancy‐related outcomes …”

“…[8][9][10][11][12][13][14][15] The central role of the kidney in the hypertensive disorders of pregnancy led to try to quantify the renal functional reserve in pregnant women or in experimental models by means of protein-rich meals or amino acid infusion; the results suggest that the lack of hyperfiltration may herald adverse pregnancy-related outcomes. [16][17][18][19][20][21] In spite of the theoretical interest, there are no studies to our knowledge that have assessed whether the 'spontaneous' hyperfiltration induced by pregnancy can be considered a marker of materno-foetal outcomes in the first stages of CKD, when kidney damage is known to exist but renal function is still normal.…”