Comparison of the Estimated Glomerular Filtration Rate (eGFR) in Diabetic Patients, Non-Diabetic Patients and Living Kidney Donors

&lt;b&gt;&lt;i&gt;Background/Aims: &lt;/i&gt;&lt;/b&gt;We have reported that the eGFR overestimates renal function when glycemic control is poor. It has been reported that eGFR calculated by serum creatinine underestimates GFR in living kidney donors. We compared the utility of the eGFR in diabetic patients, non-diabetic patients and living kidney donors. Forty diabetic patients, 40 non-diabetic patients, and 40 living kidney donors were enrolled. &lt;b&gt;&lt;i&gt;Methods: &lt;/i&gt;&lt;/b&gt;GFR was measured by inulin clearance (C&lt;sub&gt;in&lt;/sub&gt;). eGFR was calculated based on serum creatinine (eGFR&lt;sub&gt;cr&lt;/sub&gt;) or serum cystatin C (eGFR&lt;sub&gt;cys&lt;/sub&gt;). We compared the agreements between each of the eGFR and C&lt;sub&gt;in&lt;/sub&gt; in each group. &lt;b&gt;&lt;i&gt;Results: &lt;/i&gt;&lt;/b&gt;There were significant and positive correlations between each eGFR and C&lt;sub&gt;in&lt;/sub&gt; in diabetic patients and non-diabetic patients. However, the intraclass correlation coefficients (ICC) between each eGFR and C&lt;sub&gt;in&lt;/sub&gt; in diabetic patients (ICC: eGFR&lt;sub&gt;cr&lt;/sub&gt; 0.699, eGFR&lt;sub&gt;cys&lt;/sub&gt; 0.604) were weaker than those in non-diabetic patients (ICC: eGFR&lt;sub&gt;cr&lt;/sub&gt; 0.865, eGFR&lt;sub&gt;cys&lt;/sub&gt; 0.803). The correlation coefficients between each eGFR and C&lt;sub&gt;in&lt;/sub&gt; (eGFR&lt;sub&gt;cr&lt;/sub&gt;; r = 0.422, p = 0.0067 and eGFR&lt;sub&gt;cys&lt;/sub&gt;; r = 0.358, p = 0.0522) in living kidney donors were significantly weaker than those in non-diabetic patients. The ICCs between each eGFR and C&lt;sub&gt;in&lt;/sub&gt; (ICC: eGFR&lt;sub&gt;cr&lt;/sub&gt; 0.340, eGFR&lt;sub&gt;cys&lt;/sub&gt; 0.345) in living kidney donors were significantly weaker than those in non-diabetic patients. &lt;b&gt;&lt;i&gt;Conclusions: &lt;/i&gt;&lt;/b&gt;Based on C&lt;sub&gt;in&lt;/sub&gt;, eGFR was accurate in non-diabetic patients. However, eGFR was inaccurate in living kidney donors and relatively inaccurate in diabetic patients.</jats:p

Increased Glomerular Hydrostatic Pressure is Associated with Tubular Creatinine Reabsorption in Healthy Subjects

&lt;b&gt;&lt;i&gt;Background:&lt;/i&gt;&lt;/b&gt; Cr is secreted by the proximal tubules and thus Cr clearance (&lt;i&gt;C&lt;/i&gt;&lt;sub&gt;cr&lt;/sub&gt;) can overestimate inulin clearance (&lt;i&gt;C&lt;/i&gt;&lt;sub&gt;in&lt;/sub&gt;). However, in some cases, &lt;i&gt;C&lt;/i&gt;&lt;sub&gt;cr&lt;/sub&gt; can even underestimate &lt;i&gt;C&lt;/i&gt;&lt;sub&gt;in&lt;/sub&gt;. This suggests that Cr could be reabsorbed in the tubuli. We examined the clinical parameters that are associated with tubular Cr reabsorption. &lt;b&gt;&lt;i&gt;Methods:&lt;/i&gt;&lt;/b&gt; In 80 kidney donor candidates (53.9 ± 13.2 years, 29 males), &lt;i&gt;C&lt;/i&gt;&lt;sub&gt;in&lt;/sub&gt; and para-aminohippuric acid clearance were measured simultaneously. Intrarenal hemodynamic parameters were calculated by Gomez’s formulae. To quantify the secretory component of &lt;i&gt;C&lt;/i&gt;&lt;sub&gt;cr&lt;/sub&gt; (SF&lt;sub&gt;cr&lt;/sub&gt;), it was calculated as follows: SF&lt;sub&gt;cr&lt;/sub&gt; = (&lt;i&gt;C&lt;/i&gt;&lt;sub&gt;cr&lt;/sub&gt; − &lt;i&gt;C&lt;/i&gt;&lt;sub&gt;in&lt;/sub&gt;)/&lt;i&gt;C&lt;/i&gt;&lt;sub&gt;cr&lt;/sub&gt;. &lt;b&gt;&lt;i&gt;Results:&lt;/i&gt;&lt;/b&gt; Twenty-five subjects (31.3%) showed SF&lt;sub&gt;cr&lt;/sub&gt; values &amp;#x3c;0. SF&lt;sub&gt;cr&lt;/sub&gt; that correlated significantly and negatively with efferent arteriolar resistance (&lt;i&gt;R&lt;/i&gt;&lt;sub&gt;e&lt;/sub&gt;) and glomerular hydrostatic pressure (&lt;i&gt;P&lt;/i&gt;&lt;sub&gt;glo&lt;/sub&gt;) (&lt;i&gt;R&lt;/i&gt;&lt;sub&gt;e&lt;/sub&gt;: &lt;i&gt;r&lt;/i&gt; = −0.30, &lt;i&gt;p&lt;/i&gt; = 0.008; &lt;i&gt;P&lt;/i&gt;&lt;sub&gt;glo&lt;/sub&gt;: &lt;i&gt;r&lt;/i&gt; = −0.28, &lt;i&gt;p&lt;/i&gt; = 0.025). In multiple regression analyses, &lt;i&gt;R&lt;/i&gt;&lt;sub&gt;e&lt;/sub&gt; and &lt;i&gt;P&lt;/i&gt;&lt;sub&gt;glo&lt;/sub&gt; were significantly and negatively associated with SF&lt;sub&gt;cr&lt;/sub&gt; after adjustment for other confounders. &lt;b&gt;&lt;i&gt;Conclusions:&lt;/i&gt;&lt;/b&gt; These findings suggest that tubular reabsorption of Cr can occur in some cases. Intrarenal glomerular hemodynamic burden may be related to tubular creatinine reabsorption, which possibly leads to lower &lt;i&gt;C&lt;/i&gt;&lt;sub&gt;cr&lt;/sub&gt; values. </jats:p

Influence of protein intake on the changes in skeletal muscle mass after kidney transplantation

Clinical Nutrition. 2022, 41 (9), P.1881-188

Relationship Between Serum Uric Acid Levels and Intrarenal Hemodynamic Parameters

Background/Aims: Hyperuricemia has been reported to affect renal hemodynamics in rat models. We evaluate the relationship between serum uric acid and intrarenal hemodynamic parameters in humans, utilizing the plasma clearance of para-aminohippurate (CPAH ) and inulin (Cin). Methods: Renal and glomerular hemodynamics were assessed by simultaneous measurement of CPAH and Cin in 58 subjects. Of these, 19 subjects were planned to provide a kidney for transplantation; 26 had diabetes without proteinuria; and 13 had mild proteinuria. Renal and glomerular hemodynamics were calculated using Gomez`s formulae. Results: Cin was more than 60 ml/min/1.73m2 in all subjects. Serum uric acid levels correlated significantly with vascular resistance at the afferent arteriole (Ra) (r = 0.354, p = 0.006) but not with that of the efferent arteriole (Re). Serum uric acid levels (β = 0.581, p = a after adjustment for several confounders (R2 = 0.518, p = Conclusions: These findings suggest, for the first time in humans, that higher serum uric acid levels are associated significantly with Ra in subjects with Cin > 60 ml/min/1.73m2. The increase in Ra in subjects with higher uric acid levels may be related to dysfunction of glomerular perfusion