Plasma uric acid and renal haemodynamics in type 2 diabetes patients

Abstract

Aim Increased plasma uric acid (PUA) concentrations are associated with chronic kidney disease in type 2 diabetes (T2D) patients. The mechanisms involved remain unclear. We investigated the relation between PUA and (intra)renal haemodynamics in T2D patients without overt kidney disease. Methods Eighty‐eight white men and women with T2D were included (age 64 (58–68) years; body mass index 30.9 (28.3–33.6) kg/m2; glycated haemoglobin 7.1 (6.8–7.6)%). Plasma UA and fractional excretion of UA were measured, while glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were assessed by inulin and PAH‐clearance techniques, respectively. Effective renal vascular resistance was calculated (ERVR). Renal afferent and efferent arteriolar resistances and glomerular hydrostatic pressure were estimated. Relationships between PUA and fractional excretion of UA and (intra)renal haemodynamic parameters were evaluated by multivariable linear regression analyses. Results Plasma UA concentrations were at the higher end of the normal range in most participants: 342 ± 68 μmol/L or 5.7 ± 1.1 mg/dL (mean ± SD). In multivariable analyses, PUA concentrations were negatively associated with GFR (r = −0.471; P = 0.001), ERPF (r = −0.436; P = 0.003) and glomerular hydrostatic pressure (r = −0.427; P = 0.003). In contrast, PUA concentrations had a positive correlation with ERVR (r = 0.474; P = 0.001), but not with efferent vascular resistance. Fractional excretion of UA was not related to renal haemodynamics. Conclusion Plasma UA was negatively associated to GFR, ERPF but positively related to ERVR in T2D patients without overt renal impairment. Plasma UA‐related increase in ERVR may be related to increased arterial afferent tone, which may put the kidney at risk for renal damage through ischaemia.

Protein intake and risk of urolithiasis and kidney diseases: an umbrella review of systematic reviews for the evidence-based guideline of the German Nutrition Society

“…Since elevation of serum urea above the upper limit of the normal range primarily depends on functional GFR reduction [ 72 ] and further confounders like hydration status, circulating urea rather represents an insensitive indicator of kidney function [ 72 ]. Next, serum uric acid shows varying interdependences with protein ingestion [ 73 ], purine intake, hydration status [ 74 ], and GFR [ 75 ], as well as with metabolic syndrome [ 76 ] and diabetes mellitus type 2 [ 77 ]. Thus, irrespective of the rating of the overall certainty of evidence as ‘probable’ or ‘insufficient’ for effects due to increases in protein intake, the utilisation of serum urea and uric acid, respectively, for the assessment of potential influences of HPI on kidney health appears to be a less specific approach.…”

Role of Diabetes Mellitus and Hypertension in the Progression of Chronic Kidney Disease A Systematic Review

“…None of the studies reviewed shows the mechanism of progression. Some studies also show that serum plasma uric acid levels are higher in patients with diabetes [16].…”

“…The short duration of diabetes, lower glycated hemoglobin, absent DR, and active urinary sediment were independent predictors of nondiabetic renal disease on univariate analysis. 16 Suijk DLS et al [16] 2020 Cross sectional Plasma uric acid was negatively associated with GFR, and effective renal plasma flow but positively related to effective renal vascular resistance in T2D patients without overt renal impairment. 17 Takamatsu K et al [17] Crosssectional…”

“…Obesity, hyperglycemia, hypertension, and dyslipidemia are only a few renal risk factors that can be successfully treated [16]. The high frequency of chronic kidney disease (CKD), microalbuminuria, and macroangiopathy, including coronary heart disease (CHD), and rapid deterioration in renal function have been described in senior diabetic individuals [17].…”