c-peptide and Acute-Kidney-Injury

C-peptide has intrinsic biological activity and may be renoprotective. We conducted a systematic review to determine whether C-peptide had a beneficial effect on renal outcomes. MEDLINE, EMBASE, and the Cochrane Central Databases were searched for human and animal studies in which C-peptide was administered and renal endpoints were subsequently measured. We identified 4 human trials involving 74 patients as well as 18 animal studies involving 35 separate experiments with a total of 641 animals. In humans, the renal effects of exogenously delivered C-peptide were only studied in type 1 diabetics with either normal renal function or incipient nephropathy. Pooled analysis showed no difference in GFR (mean difference, -1.36 mL/min/1.73 m2, p = 0.72) in patients receiving C-peptide compared to a control group, but two studies reported a reduction in glomerular hyperfiltration (p<0.05). Reduction in albuminuria was also reported in the C-peptide group (p<0.05). In diabetic rodent models, C-peptide led to a reduction in GFR (mean difference, -0.62 mL/min, p<0.00001) reflecting a partial reduction in glomerular hyperfiltration. C-peptide also reduced proteinuria (mean difference, -186.25 mg/day, p = 0.05), glomerular volume (p<0.00001), and mesangial matrix area (p<0.00001) in diabetic animals without affecting blood pressure or plasma glucose. Most studies were relatively short-term in duration, ranging from 1 hour to 3 months. Human studies of sufficient sample size and duration are needed to determine if the beneficial effects of C-peptide seen in animal models translate into improved long-term clinical outcomes for patients with chronic kidney disease. (PROSPERO CRD42014007472).

Topics: Acute Kidney Injury; Animals; C-Peptide; Diabetes Mellitus, Experimental; Glomerular Filtration Rate; Humans; Kidney Diseases; Treatment Outcome

To study hormonal aspects of hemofiltration (HF) in acute renal failure (ARF).. Hydrocortisone (HC), thyroxine (T4), triiodothyronine (T3), TSH, thyrocalcitonine (TC), PTH, insulin (I), C-peptide (CP), STH, beta-endorphine (BE) were examined for plasma content, elimination with filtrate, sifting rate, filtration clearance in 29 patients with oliguric ARF (18 males and 11 females) aged 12-62 years. 19 patients underwent intermittent HF (rate 145.2 +/- 9.2/27-260/ml/min, volume 1.02 +/- 0.20/0.45-1.43/). 10 patients received continuous HF (rate 25.9 +/- 2.3 l/day or 0.36 +/- 0.05/0.17-0.95/). The hormones were measured with radioimmunoassay. The results were processed with variate statistics using Student's criterium.. Oliguria was associated with high plasma levels of HC, PTH, TC, I, CP; normal levels of TSH and STH, low ones of T4, T3 and BE. Intermittent HF led to an increased plasma concentrations of HC, T4, I, CP, decreased one of PTH, while TC, TSH, STH and T3 remained unchanged. The filtration rate of the hormones was different. The elimination was greatest for HC, T4, T3, BE. Concentration of the former three in the filtrate surpassed that in blood plasma.. Besides intensive elimination of the hormones with low molecular mass (HC, T4, T3), HF causes elimination of appreciable quantities of BE, PTH, I, CT and, probably, other peptide hormones. Plasma levels of hormones did not reflect their elimination with filtrate.

Topics: Acute Kidney Injury; Adolescent; Adult; beta-Endorphin; C-Peptide; Child; Data Interpretation, Statistical; Female; Hemofiltration; Hormones; Humans; Hydrocortisone; Male; Middle Aged; Parathyroid Hormone; Radioimmunoassay; Thyroid Hormones; Time Factors

Topics: Acute Kidney Injury; Adult; Aged; C-Peptide; Cholesterol; Female; Glucose; Hemofiltration; Humans; Insulin; Male; Middle Aged; Triglycerides

Human proinsulin connecting peptide (C-peptide) was measured by immunoassay in urine from 25 normal subjects, 18 patients with diabetes mellitus, and 34 patients with various degrees of renal insufficiency. Assay validation studies showed that pancreatic C-peptide was quantitatively recovered when added to urine. Fractionation of urine by gel filtration indicated that most endogenous C-peptide eluted in fractions that corresponded to the C-peptide standard. In 34 nondiabetic subjects with normal kidney function or various renal diseases, C-peptide clearance was independent of creatinine clearance over a range of 6 to 190 ml./min. Urine C-peptide clearance (5.1 +/- 0.6 ml./min.) is greater than that of insulin (1.1 +/- 0.2 ml./min.), and the total quantity of C-peptide excreted in the urine per day represents 5 per cent of pancreatic secretion, as against only 0.1 per cent of secreted insulin. Healthy subjects excreted 36 +/- 4 mug. C-peptide per 24 hours, while this value in juvenile-onset diabetics was only 1.1 +/- 0.5 mug. Adult-onset diabetics excreted 24 +/- 7 mug./24 hr., the range overlapping the excretory rates of both normal subjects and juvenile-onset diabetics. Two insulin-requiring adult-onset diabetics showed significant beta-cell reserve during the course of acute infections. These results suggest that urine C-peptide provides a useful means of assessing beta-cell secretory capacity over a period of time and is especially advantageous when frequent blood sampling is not feasible.

Topics: Acute Kidney Injury; C-Peptide; Chromatography, Gel; Creatinine; Diabetes Mellitus, Type 1; Humans; Immunoassay; Islets of Langerhans; Kidney; Peptides