Clinical Significance of Urodynamic Study Parameters in Maintenance of Renal Function in Spinal Cord Injury Patients

OBJECTIVE: To analyze association between urodynamic study (UDS) parameters and renal function in spinal cord injured (SCI) patients with neurogenic detrusor overactivity. METHODS: Patients with a suprasacral SCI, who underwent UDS and radioisotope renogram at least twice between January 1, 2006 and January 31, 2013, were included. UDS (cystometric capacity, reflex volume, compliance, and maximal detrusor pressure) and radioisotope renogram (total effective renal plasma flow [ERPF] of both kidneys) data were collected. The following were conducted to reanalyze any association between reflex volume and ERPF: initial and follow-up results of consecutive evaluations were compared; a mixed-model regression analysis to account for clustered data was conducted to evaluate the association between UDS parameters and ERPF; and finally, a mixed-model analysis type 3 test with data pairs, of which the first evaluation showed involuntary detrusor contraction. RESULTS: A total of 150 patients underwent 390 evaluations which were arranged into 240 pairs of consecutive evaluations, of which 171 had first evaluations with observed involuntary detrusor contraction. The following results were obtained: cystometric capacity was significantly larger and maximal detrusor pressure was significantly lower on follow-up; on univariate analysis, reflex volume and maximal detrusor pressure were significant, and multivariate analysis using these two parameters showed that maximal detrusor pressure is significantly associated with total ERPF; and no significant differences were observed. CONCLUSION: Maximal detrusor pressure should be closely monitored in the urologic management of neurogenic detrusor overactivity in SCI patients. The results also may serve as a reference for regular UDS follow-up.

Serum Cystatin C for the Evaluation of Renal Function in the Spinal Cord Injured Patients

OBJECTIVE: To evaluate the renal function by investigating the relationship among serum cystatin C, serum creatinine, creatinine clearance and the average of bilateral ERPF (effective renal plasma flow) ratio of the MAG3 renal scan for the spinal cord injured patients. METHOD: Seventy-one spinal cord injured patients who admitted to our department were evaluated from January 2004 to October 2004. Blood samples and 24-hour urine of all the subjects were collected for measuring serum cystatin C, serum creatinine and creatinine clearance. MAG3 renal scan was done for 47 subjects. Regression analysis and Pearson's correlation methods were utilized for statistical analysis. RESULTS: There was significant correlation between 1/cystatin C and creatinine clearance (p<0.001) and the correlation coefficient between 1/cystatin C vs. creatinine clearance (R= 0.552) was bigger than that between 1/creatinine and creatinine clearance (R=0.329). The reciprocal of cystatin C was positively correlated with the average of bilateral ERPF ratio of MAG3 renal scan (p=0.01), while there was no significant correlation between 1/creatinine and the average of bilateral ERPF ratio. CONCLUSION: Measurement of serum cystatin C is a useful and convenient method for the evaluation of renal function in spinal cord injured patients.

Effects of Exogenous IGF-I on Endogenous IGF-I Production, Function and Hyperplasia/Hypertrophy of Kidney during Compensatory Renal Growth in Hypophysectomized Rats / 대한비뇨기과학회지

PURPOSE: Compensatory renal hypertrophy(CRH) after loss of considerable renal volume is essential process for recovery and maintenance of renal function, but on the other hand CRH induces glomerulosclerosis, eventually renal failure. Recently, the considerable studies reveal that insulin-like growth factor-I(IGF-I) is an important molecule relating to renal hypertrophy. This study investigates the possibility of IGF-I as a therapeutic agent, it should be proved whether external IGF-I affects renal function and glomerulosclerosis or does not affect in devoid state of growth hormone(GH) effect. MATERIALS AND METHODS: 100?150g Sprague-Dawley male rats were hypophysectomized by transpharyngeal approach and hypophysectomy were confirmed by daily monitoring of body weight for 3weeks. The left kidney were removed in the rats of UNX group(uninephrectomy) and UNX+IGF-I group(IGF-I treated after uninephrectomy), and sham operation were done in the other rats of control group and IGF-I group(IGF-I treated). Recombinant IGF-I were administered via Alzet osmotic minipump for 5 days in rats of IGF-I group and UNX+IGF-I group. At the 5th day after uninephrectomy, the glomerular filtration rate(GFR) and the effective renal plasma flow(ERPF) were investigated by measuring recovery of 99mTc-DTPA and 125I-hippurate, and then the rats were sacrificed and the kidneys were removed. The wet kidney weights were measured in removed kidneys, renal IGF-I concentrations were measured by RIA, and cellular proliferation were evaluated by flow-cytometry. RESULTS: 1. The wet kidney weight per body weight significantly increased after uninephrectomy, and had not been affected by IGF-I treatment regardless of uninephrectomy. 2. Renal IGF-I tended to increase after uninephrecromy, and significantly increased with IGF-I treatment in both IGF-I and UNX+IGF-I. The level of renal IGF-I of UNX+IGF-I group was significantly higher than that of IGF-I group. 3. Total GFR tended to decreased after uninephrectomy and were significantly increased by IGF-I treatment regardless of uninephrectomy. 4. The GFR per g wet kidney weight significantly increased after uninephrectomy, and were significantly increased by IGF-I treatment regardless of uninephrectomy. 5. Total ERPF were not significantly changed after uninephrectomy and significantly increased by IGF-I treatment in sham operation group but did not changed by IGF-I treatment in uninephrectomy group. 6. The ERPF per g wet weight significantly increased after uninephrectomy, and significantly increased by IGF-I treatment in sham operation group but did not changed by IGF-I treatment in uninephrectomy group. 7. The mean % of S1 phase cells were 33.6% in UNX+IGF-I group, 23.5% in IGF-I group, 19.96% in UNX group, and 10.4% in control group. The mean % of G2+M phase cells were 2.5% in UNX+IGF-I group, 1.95% in IGF-I group, 1.73% in UNX group, and 1.2% in control group. CONCLUSIONS: GH non-dependent IGF-I participate in CRH, and only IGF-I without GH increases renal function. IGF-I treatment during CRH might increase GFR by changing glomerular efferent arteriol of filtration fraction.

The Effects of Recombinant IGF-I on Function and Nitric Oxide Synthase Activity of Kidney during Compensatory Hypertrophy / 대한비뇨기과학회지

PURPOSE: Among renotropic agents, a growth hormone(GH) independent insulin-like growth factor I(IGF-I) improves renal function without inducing glomerulosclerosis and its potential for treating renal disease is increasing. To elucidate the effect of externally administered IGF-I toward enhancing renal function, the change in renal function and renal nitric oxide synthase(NOS) activity were investigated in the presence of the GH-IGF-I axis. MATERIALS AND METHODS: 100?150g Sprague-Dawley male rats were classified four groups according to experimental methods. The left kidney were removed in the rats of UNx group(uninephrectomy) and UNx+IGF-I group(IGF-I treated after uninephrectomy), and sham operation were done in the other rats of control group and Sham+IGF-I group(IGF-I treated after sham operation). The UNx+IGF-I group and Sham+IGF-I group were treated with 300microgram of recombinant IGF-I(rhIGF-I) daily for 5days after operation. The NOS activity were determined in the contralateral kidney tissues and the glomerular filtration rate(GFR) and effective renal plasma flow(ERPF) were determined in the serum. RESULTS: The GFR, ERPF and NOS activity significantly increased compared to control after uninephrectomy(p<0.05). The GFR, ERPF and NOS activity were significantly different between UNx+IGF-I group and UNx group(p<0.05), but there was no significant difference between Sham+IGF-I group and Sham group after the administration of rhIGF-I. CONCLUSIONS: Externally administered rhIGF-I increases GFR and ERPF via increasing NOS activity. We suggest that it is especially effective in improving the renal function of damaged kidneys.

The Evaluation of Renal Function in Spinal Cord Injury Patients Using Radioisotope Renography

OBJECTIVE: The purposes of this study were to determine the renal function by radioisotope renography and to compare the findings of radioisotope renography in the spinal cord injured patients to the clinical presentations and findings of other conventional urologic examinations. METHOD: Intravenous pyelogram(IVP), voiding cystourethrogram(VCUG) and urodynamic study were performed in twenty-five spinal cord injured patients along with serum BUN/Creatinine levels and 24 hour creatinine clearance tests. Technetium-99 m mercaptoacetyltriglycine was used for the radioisotope renography. RESULTS: One abnormal radioisotope renography finding was noted among 22 normal findings by IVP and VCUG studies, while no abnormal finding by IVP and VCUG studies was noted among the subjects with a normal radioisotope renography. Effective renal plasma flow(ERPF) was significantly lower in patients with lower creatinine clearance. ERPF, cortical retention and creatinine clearance values for hyperreflexic bladders were significantly different from areflexic bladders. ERPF was significantly higher in a clean intermittent catheterization group than in a percussion and Cred method group for the hyperreflexic bladders. CONCLUSION: The study proves that the radioisotope renography is a sensitive and valuable study to evaluate the renal dysfunction in the spinal cord injured patients.