METHODS: Twelve Sprague-Dawley rats received either 20% fructose solution [FFR] or tap water [C] to drink ad libitum for 8 weeks. The renal vasoconstrictor response to noradrenaline (NA), phenylephrine (PE), methoxamine (ME) and Ang II was determined in the presence and absence of 5-methylurapidil (5-MU) (α1A-adrenoceptor antagonist) in a three-phase experiment (pre-drug, low- and high-dose 5-MU). Data, mean ± SEM were analysed by ANOVA or Student's unpaired t-test with significance at P < 0.05.
RESULTS: FFR exhibited insulin resistance (HOMA index), hypertension and significant increases in plasma levels of glucose and insulin. All agonists caused dose-related reductions in cortical blood perfusion that were larger in C than in FFR while the magnitudes of the responses were progressively reduced with increasing doses of 5-MU in both C and FFR. The degree of 5-MU attenuation of the renal cortical vasoconstriction due to NA, ME and Ang II was significantly greater in the FFR compared to C.
CONCLUSIONS: Fructose intake for 8 weeks results in smaller vascular response to adrenergic agonists and Ang II. The α1A-adrenoceptor subtype is the functional subtype that mediates renal cortical vasoconstriction in control rats, and this contribution becomes higher due to fructose feeding.
METHODOLOGY: A prospective observational study was conducted by inviting pre-dialysis CKD patients. Fluid overload was assessed by BIS.
RESULTS: A total of 312 CKD patients with mean eGFR 24.5 ± 11.2 ml/min/1.73 m2were enrolled. Based on OH value ≥7 %, 135 (43.3 %) patients were hypervolemic while euvolemia was observed in 177 (56.7 %) patients. Patients were categorized in different regions of hydration reference plot (HRP) generated by BIS i.e., 5.1 % in region-N (normal BP and fluid status), 20.5 % in region I (hypertensive with severe fluid overload), 29.5 % in region I-II (hypertensive with mild fluid overload), 22 % in region II (hypertensive with normohydration), 10.2 % in region III (underhydration with normal/low BP) and 12.5 % in region IV (normal BP with severe fluid overload). A total of 144 (46 %) patients received diuretics on basis of physician assessment of BP and edema. Maximum diuretics 100 (69.4 %) were prescribed in patients belonging to regions I and I-II of HRP. Interestingly, a similar number of diuretic prescriptions were observed in region II (13 %) and region IV (12 %). Surprisingly, 7 (4.9 %) of patients in region III who were neither hypervolemic nor hypertensive were also prescribed with diuretics.
CONCLUSION: BIS can aid clinicians to categorize CKD patients on basis of their fluid status and provide individualized pharmacotherapy to manage hypertensive CKD patients.