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Biomedical subjects

Takashi Inenaga

Publications and source records attributed to Takashi Inenaga.

18 recordsLinked to original sources
PubMed2006

Renal function in patients with abdominal aortic aneurysm. Comparison with hypertensive patients.

AIMS: Renal dysfunction occurs occasionally after the repair of abdominal aortic aneurysm (AAA), and preoperative renal function is considered as one of the potential causes. The present study was designed to evaluate and compare renal function and risk factors of AAA patients with those of hypertensive patients. METHODS: We prospectively examined 95 patients with AAA and 72 patients with essential hypertension (HT) without other cardiovascular diseases (CVD). Renal function, urinary albumin excretion (UAE) and renal scintigraphy were compared. Kidney size was calculated using ultrasonography. RESULTS: Serum creatinine and creatinine clearance in AAA patients was worse than in HT patients. Smoking status was more apparent in AAA patients. Renal artery stenosis occurred in 8 patients with AAA. Renal scintigraphy showed normal function in 19%, hypofunction in 69% and severe dysfunction in 12% of the AAA patients, and normal function in 42% and hypofunction in 58% of the HT patients (p < 0.0001). Multivariate linear regression analysis showed that renal function was related to age, UAE, CVD, smoking status and kidney size for all patients, UAE, CVD, smoking status and kidney size for AAA patients, and age and kidney size for HT patients. CONCLUSION: Renal function of AAA patients was worse than HT patients without other CVD. The risk factors for renal dysfunction were different between AAA and HT patients. These preoperative conditions may relate to the postoperative renal dysfunction seen in AAA patients.

Aged↗
PubMed2006

Positive correlations between cerebral choline and renal dysfunction in chronic renal failure.

INTRODUCTION: Cerebral metabolism in chronic renal failure (CRF) patients has not been fully evaluated. This study examined cerebral metabolites in CRF, using proton magnetic resonance spectroscopy (MRS). METHODS: Subjects comprised 19 CRF patients and 21 healthy volunteers. Spectra were acquired from voxels of interest positioned in the parietal gray and white matter, and concentrations of the following cerebral metabolites were measured: N-acetyl group (NA), creatine + phosphocreatine (Cr), choline-containing compounds (Cho), myo-inositol and glutamate + glutamine. Among the 19 CRF patients, 9 who were started on hemodialysis (HD) underwent careful follow-up. Proton MRS was performed before and about 2 weeks after starting HD. In six patients in whom follow-up was possible, a third MRS was performed after about 18 months. RESULTS: The NA/Cr ratio was not significantly changed in CRF. However, elevations in the Cho/Cr ratio were found in both gray and white matter compared with controls. To the best of our knowledge, this is the first report of positive correlations between the Cho/Cr ratio in both regions and serum osmotic pressure. Compared with baseline data, no significant changes in cerebral metabolite ratios were found about 2 weeks after starting HD. About 18 months after starting HD, however, the elevated Cho/Cr ratio was significantly reduced in the gray matter and tended to be reduced in the white matter. CONCLUSIONS: Cho appear to play an important role in the regulation of cerebral metabolism to compensate for alterations in serum osmotic pressure in CRF, and HD may correct this abnormal cerebral metabolism.

Adult↗
PubMed2006

Masked hypertension and target organ damage in treated hypertensive patients.

BACKGROUND: Recent studies have shown that an elevated ambulatory or home blood pressure (BP) in the absence of office BP-a phenomenon called masked hypertension-is associated with poor cardiovascular prognosis. However, it remains to be elucidated how masked hypertension modifies target organ damage in treated hypertensive patients. METHODS: A total of 332 outpatients with chronically treated essential hypertension were enrolled in the present study. Patients were classified into four groups according to office (<140/90 or >or=140/90 mm Hg) and daytime ambulatory (<135/85 or >or=135/85 mm Hg) BP levels; ie, controlled hypertension (low office and ambulatory BP), white-coat hypertension (high office but low ambulatory BP), masked hypertension (low office but high ambulatory BP), and sustained hypertension (high office and ambulatory BP). Left ventricular mass index, carotid maximal intima-media thickness, and urinary albumin levels were determined in all subjects. RESULTS: Of the patients, 51 (15%), 65 (20%), 74 (22%), and 142 (43%) were identified as having controlled hypertension, white-coat hypertension, masked hypertension, and sustained hypertension, respectively. Left ventricular mass index, maximal intima-media thickness, and urinary albumin level in masked hypertension were significantly higher than in controlled hypertension and white-coat hypertension, and were similar to those in sustained hypertension. Multivariate regression analyses revealed that the presence of masked hypertension was one of the independent determinants of left ventricular hypertrophy, carotid atherosclerosis, and albuminuria. CONCLUSIONS: Our findings indicate that masked hypertension is associated with advanced target organ damage in treated hypertensive patients, comparable to that in cases of sustained hypertension.

Aged↗
PubMed2005

Relationship between renal artery stenosis and intrarenal damage in autopsy subjects with stroke.

BACKGROUND: In patients with cardiovascular disease (CVD), renal dysfunction is a risk factor for the prognosis, but substantial evidence is still lacking about the relationship between clinical characteristics and renal histology. The aim of our study was to evaluate the relationship between the extent of renal parenchymal damage, renal artery stenosis (RAS) and clinical characteristics in autopsy subjects with stroke. METHODS: During the 17-year period 1980-1997, 2167 subjects were autopsied at the National Cardiovascular Center. We studied retrospectively all the autopsy cases aged 40 years and older who had a history of stroke. Thus, 346 subjects remained and they were classified into two groups. Thirty-six subjects had RAS (group A). Three hundred and ten subjects had no RAS, and we randomly chose 102 subjects among them (group B). We evaluated renal parenchymal damage using a semi-quantitative chronic damage score. RESULTS: The average overall chronic damage score was significantly higher in the stenosed kidneys of group A than in the non-stenosed kidneys of group B (9.0+/-2.6 vs 7.0+/-2.7). The contralateral kidneys of group A had a tendency to have milder renal damage than stenosed kidneys. Furthermore, the total score was higher in the subjects with hypertension, diabetes mellitus, proteinuria, renal insufficiency and CVD than in the subjects without such complications. The total score had a significant association with RAS, proteinuria, renal insufficiency, CVD and weight of the kidney. CONCLUSIONS: In autopsy subjects with stroke, we demonstrated that co-existing renal parenchymal damage was more severe in the subjects with RAS, hypertension, diabetes mellitus, proteinuria and renal insufficiency than those without such complications. The presence of RAS, impaired renal function and proteinuria was closely correlated with the severity of renal parenchymal damage.

Adult↗
PubMed2005

Asymptomatic renal infarction, due to fibromuscular dysplasia, in a young woman with 11 years of follow-up.

We report a 27-year-old woman with renovascular hypertension, renal infarction, and hepatic artery aneurysm due to fibromuscular dysplasia. The patient was first noted to have renal artery aneurysm and hepatic artery aneurysm at the age of 17. The renal infarction was asymptomatic and was incidentally detected by magnetic resonance imaging (MRI) examination. Because of the rather peripheral location of the aneurysms, percutaneous transluminal renal artery angioplasty was considered inappropriate. This case suggests the need for long-term and periodical follow-up of patients with fibromuscular dysplasia.

Adult↗
PubMed2005

QTc dispersion in haemodialysis patients with cardiac complications.

BACKGROUND AND AIMS: QTc dispersion (Maximum - Minimum QTc interval on a standard 12-lead electrocardiogram (ECG)) is a useful predictor of tachyarrhythmic events and related sudden cardiac death. Recent studies have reported that QTc dispersion is prolonged in patients receiving haemodialysis (HD), and it is often further prolonged following HD treatment. In the present study, we examine whether the patients who are susceptible to prolongation of QTc dispersion by HD are prone to life-threatening cardiovascular events and related deaths. METHODS: Forty-eight patients with cardiac symptoms such as chest pain (n = 32), arrhythmia (n = 2) or heart failure (n = 14) and receiving chronic HD treatment (40 males and eight females) were subjected to the present study. Twenty-six of a total 48 patients were given a diagnosis of ischaemic heart disease (IHD) by coronary angiography. Ten patients had cerebrovascular accidents and 11 patients had peripheral vascular disease. After the ECG recording, a prospective follow up was conducted for 37 +/- 24 months. RESULTS: During the follow-up period, 30 patients had cardiac events, and 23 including 18 cardiovascular deaths occurred as outcomes. Throughout the total period, patients who showed prolongation of QTc dispersion after HD had cardiovascular deaths with higher incidence than those did not show the prolongation. CONCLUSIONS: We consider that prolongation of QTc dispersion after HD treatment can predict the prognosis of patients with renal failure bearing cardiac complications. Great care is necessary for such patients if they show longer QTc dispersion and/or susceptibility for further prolongation after HD treatment.

Adult↗
PubMed2005

Adrenomedullin reflects cardiac dysfunction, excessive blood volume, and inflammation in hemodialysis patients.

BACKGROUND: Plasma adrenomedullin (AM) reflects cardiac dysfunction and predicts survival after myocardial infarction. The present study was designed to investigate whether the mature AM (mAM) reflects status of cardiac function, systemic blood volume, or inflammation in hemodialysis patients with cardiovascular disease, and whether mortality and additional cardiovascular morbidity can be predicted by mAM. METHODS: Plasma levels of mAM, atrial natriuretic peptide (ANP), B-type natriuretic peptide (BNP), norepinephrine (NE), and C-reactive protein (CRP) before hemodialysis were measured in 67 chronic hemodialysis patients with cardiovascular disease, along with 2-dimensional and Doppler echocardiographic variables. RESULTS: By univariate regression analysis, mAM correlated negatively with pulmonary venous flow velocity ratio and left ventricular (LV) ejection fraction and positively with LV inflow velocity ratio, LV end-diastolic, end-systolic volume indexes, plasma CRP level, and removal fluid volume by ultrafiltration. Multivariate stepwise regression analysis revealed that mAM reflected all variables better than log [ANP], log [BNP], and log [NE]. During a 1-year follow-up period, 7 patients died and 8 had additional cardiovascular events. Event-free Kaplan-Meier curves based on the median mAM (4.55 pmol/L) showed that patients with high plasma mAM levels had higher mortality and morbidity than those with low plasma mAM levels (P = 0.0056). By Cox multivariate proportional hazard analysis, mAM was related to mortality and morbidity [hazard ratio (HR) 4.55, 95% CI 1.2-16.8, P= 0.023). CONCLUSION: Plasma mAM reflects cardiac dysfunction, excessive blood volume, and inflammation better than ANP, BNP, and NE, resulting in a predictor of mortality and cardiovascular morbidity in hemodialysis patients with cardiovascular disease.

Adrenomedullin↗
PubMed2005

Life-threatening hyperkalemia during a combined therapy with the angiotensin receptor blocker candesartan and spironolactone.

We describe a hypertensive nephrosclerosis patient presenting with severe hyperkalemia due to a combination therapy of the angiotensin receptor blocker (ARB) candesartan and spironolactone despite mildly decreased renal function. Recently, ARBs are replacing the ACE inhibitors. The combined therapy with ARB and spironolactone will eventually become the standard regimen. The strict attention and close monitoring of serum potassium should be mandatory in combination therapy to prevent hyperkalemia. Assessment of trans-tubular potassium gradient (TTKG) and fractional excretion of potassium (FEK) before starting the therapy would help in identifying the patients at higher risk of developing hyperkalemia. Co-administration of thiazide or loop diuretics is recommended to reduce the risk of hyperkalemia.

Angiotensin II Type 1 Receptor Blockers↗
PubMed2004

Orthostatic hypotension at the introductory phase of haemodialysis predicts all-cause mortality.

BACKGROUND: Since the predictive value of orthostatic hypotension (OH) at the introductory phase of haemodialysis (HD) is unknown, we examined the association between OH and all-cause death in patients who started HD between 1987 and 2001. METHODS: More than three consecutive blood pressure measurements before HD treatments (pre-HD BP) were made on each of 304 patients who had recently been started on HD and were in a stable condition. OH was defined as a drop in systolic BP of >20 mmHg or in diastolic BP of >10 mmHg after standing. RESULTS: Of 304 patients, 42% had OH. OH was significantly associated with pre-HD supine systolic BP; its severity was significantly associated with a past history of cerebrovascular disease and pre-HD supine systolic BP. During a mean follow-up of 4.0+/-3.0 years (range 0.1-13.2 years), 136 deaths were recorded. A multivariate Cox proportional hazards model analysis demonstrated that OH and a past history of cerebrovascular disease were independent predictors of all-cause death. The comparison by Kaplan-Meier analysis of the overall survival of patients with and without OH was significant. CONCLUSIONS: Our findings validate OH at the introductory phase of HD as a novel independent predictor of all-cause mortality among HD patients.

Aged↗
PubMed2004

The thiazide-sensitive Na(+)-Cl(-) cotransporter gene, C1784T, and adrenergic receptor-beta3 gene, T727C, may be gene polymorphisms susceptible to the antihypertensive effect of thiazide diuretics.

The response of blood pressure to thiazide diuretics (TZDs) differs among individuals. The prediction of the antihypertensive effect of TZDs is important for realizing individualized therapy in the management of hypertension. The aim of this study was to identify the single nucleotide polymorphisms (SNPs) susceptible to the antihypertensive effect of TZDs, particularly focusing on genes related to water-electrolyte absorption in the kidney. Seventy-six outpatients (mean age, 65.4+/-9.0 years) with essential hypertension (EHT) taking TZDs were retrospectively assessed. We defined as responders (R) those whose mean blood pressure was lowered by more than 5 mmHg after the use of TZDs. Forty-eight SNPs in 17 genes (ADD1, GNB3, TSC [SLC12A3], MLR [NR3C2], NCX1 [SLC8A1], WNK1, WNK4, AGT, ACE, AT1 [AGTR1], CYP11B2, ADRB1, ADRB2, ADRB3, ADRA1A, ADRA1B, ADRA2A) were genotyped in the 76 patients. The SNPs in TSC, MLR, NCX1, WNK1, and WNK4 were identified by direct sequencing and those with minor frequencies of greater than 5% were genotyped in this study. The comparison of polymorphism prevalence between R and non-responders (NR) showed significant differences in TSC C1784T (C allele vs. T allele, odds ratio (OR)=3.81, p =0.016, confidence interval (CI): 1.25-11.63) and ADRB3 T727C (Trp64Arg) (T allele vs. C allele, OR=4.59, p =0.005, CI: 1.54-13.68). The blood pressure (BP) in patients homozygous for the major alleles of both TSC C1784T and ADRB3 T727C were significantly reduced by TZD treatment; however, the BP in those homozygous for the minor allele and heterozygous (TSC C1784T: TT+CT; ADRB3 T727C: CC+CT) for both SNPs were not significantly changed after TZD treatment. Both newly detected TSC C1784T and ADRB3 T727C are gene polymorphisms susceptible to the antihypertensive effect of TZDs in patients with EHT. Thus, the prediction of BP reduction by TZDs may be possible by evaluating these two SNPs.

Benzothiadiazines↗
PubMed2004

Diagnostic and prognostic value of plasma brain natriuretic peptide in non-dialysis-dependent CRF.

BACKGROUND: Brain natriuretic peptide (BNP) is useful for the evaluation of ventricular dysfunction in patients with various cardiac diseases. However, its diagnostic value has been considered to be limited in patients with chronic renal failure (CRF) because renal dysfunction itself may affect BNP levels. This study is designed to clarify the diagnostic and prognostic value of plasma BNP level in patients with CRF. METHODS: In 103 non-dialysis-dependent patients with CRF without heart failure and 60 hypertensive patients with normal renal function, echocardiographic examinations and BNP measurements were performed. RESULTS: Plasma BNP level was much greater in patients with CRF than in hypertensive controls; however, multiple regression analysis showed that left ventricular (LV) end-diastolic volume (EDV) index (LVEDVI) and the difference in mitral and pulmonary venous atrial wave duration (Ad-PVad), a marker of LV end-diastolic pressure, were independent determinants of plasma BNP levels in patients with CRF. The influence of LV overload (LVEDVI > or = 75 mL/m 2 and/or Ad-PVad < 0 milliseconds) on plasma BNP levels in subjects with CRF was independent of the severity of renal dysfunction. From Kaplan-Meier event-free curves (mean follow-up, 13 months), the incidence of heart failure was much greater in patients with a plasma BNP level of 150 pg/mL or greater ( P < 0.001). By means of multivariate Cox regression analysis, high plasma BNP level was the strongest predictor for heart failure events (hazard ratio, 6.31; P < 0.001). CONCLUSION: These findings support plasma BNP level as a reliable marker of LV overload, even in nondialysis patients with CRF. Also, a high BNP level (> or =150 pg/mL) may have powerful predictive potential for heart failure in these patients.

Aged↗
PubMed2003

Efficacy of screening for primary aldosteronism by adrenocortical scintigraphy without discontinuing antihypertensive medication.

BACKGROUND: Recently, it has been proposed that discontinuation of antihypertensive medications is not necessarily essential for the measurement of plasma aldosterone-to-renin ratios. We examined the efficacy of adrenocortical scintigraphy performed without modification of antihypertensive medications. METHODS: A retrospective study was conducted on 119 patients, in whom functional tests, anatomic studies, and adrenocortical scintigraphy were replete. Interrelationship among these was studied. The patients tested were being treated with antihypertensive medications from several classes including angiotensin-converting enzyme inhibitors, calcium antagonists, beta-blockers, diuretics, and spironolactone. RESULTS: Significantly higher percentage of scintigraphy positive patients had plasma aldosterone-to-renin ratio of greater than 25:1. Positive rate for adrenal nodules by anatomic studies was significantly higher in the scintigraphy positive patients than in the scintigraphy negative patients. Finally, the percentage of patients who underwent adrenalectomy was higher in the scintigraphy positive patients than in the scintigraphy negative patients. CONCLUSIONS: We conclude that adrenocortical scintigraphy is a valid evaluation tool for primary aldosteronism and that the discontinuation of antihypertensive medications is not a requirement for this test.

Adult↗
PubMed2003

Microalbuminuria and cardiovascular events in elderly hypertensive patients without previous cardiovascular complications.

To assist in the development of better treatments for elderly hypertensive patients, we studied the degree to which the baseline values of urinary albumin excretion (UAE) and other cardiovascular risk factors were predictive of cardiovascular complications in a cohort of elderly hypertensive patients. In 1994, we adopted 144 elderly hypertensive patients, who had been treated for more than 6 years at various clinics and more than 1 year at the National Cardiovascular Center, Osaka, Japan. They were divided into 2 groups: a NA group (n=111) with normoalbuminuria (UAE<30mg/day) and an MA group (n=33) with microalbuminuria (UAE 30-300 mg/day). At baseline, the two groups were similar with respect to systolic and diastolic blood pressure (SBP/DBP), pulse pressure (PP), age, ratio of males to females, serum creatinine, uric acid, total cholesterol, fasting plasma glucose (FPG), and creatinine clearance (CCr). PP was calculated as SBP minus DBP. The efficacy of blood pressure (BP) control was similar in both groups during the 8-year follow up period; however, a total of 14 cardiovascular events occurred in the MA (6/33) and NA (8/111) groups, with the MA group showing the higher incidence rate by multiple logistic regression analysis (p<0.05). At 8 years of follow-up, PP and age were correlated with UAE (p<0.05, p<0.001). At the same time point, CCr was correlated with UAE at baseline (p<0.05). The results indicated that, in elderly hypertensive patients without previous cardiovascular complications, microalbuminuria can be a predictor of cardiovascular events irrespective of conventional BP control.

Aged↗
PubMed2002

Effects of the creation of arteriovenous fistula for hemodialysis on cardiac function and natriuretic peptide levels in CRF.

BACKGROUND: Cardiac failure occasionally is caused by the creation of vascular access for hemodialysis. However, the influence of an arteriovenous (AV) fistula on cardiac function has not been fully elucidated. The present study investigated serial changes in cardiac function and hormonal levels after the AV fistula operation. METHODS: Sixteen patients with chronic renal failure underwent echocardiographic studies before and 3, 7, and 14 days after the AV fistula operation. Plasma atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) concentrations were measured before and 1, 3, 6, 10, and 14 days after the operation. RESULTS: Creation of an AV fistula produced significant elevations in left ventricular (LV) end-diastolic diameter (+4%), fractional shortening (+8%), and cardiac output (CO; +15%). In LV inflow velocities measured by Doppler echocardiography, deceleration time of the early diastolic filling wave shortened (-12%) and the ratio of the peak velocity of early diastolic to atrial filling (E-A ratio) increased (+18%). The difference in duration of LV inflow and pulmonary venous flow at atrial contraction, a marker of LV end-diastolic pressure, significantly shortened day 14 after the operation (-37%). That is, creation of an AV fistula induced LV diastolic dysfunction toward a restrictive filling pattern. Both ANP and BNP levels increased after the operation, and maximal percentages of increase were observed after 10 days (ANP, +48%; BNP, +68%). In the relationship between cardiac function and hormonal response, the increase in CO was associated with elevation of ANP levels (r = 0.61; P = 0.01), but not BNP levels. Conversely, the increase in E-A ratio correlated only with BNP level elevation (r = 0.60; P = 0.01). CONCLUSION: Our observations indicate that creation of an AV fistula has significant effects on cardiac systolic and diastolic performance, and ANP release is induced by volume loading, but BNP release is stimulated by LV diastolic dysfunction.

Adult↗
PubMed2002

Left ventricular hypertrophy is a risk factor independent of hypertension in survival of hemodialyzed patients.

Hemodialysis patients have low 5-year survival rates of approximately 60%, and the most common cause of death is cardiovascular diseases. Their population may be considered, therefore, as an accelerated model in analyzing the risk factors for cardiovascular diseases. We previously reported the role of blood pressure, one of the most important risk factors for cardiovascular diseases, in determining the prognosis of hemodialysis patients. In this study, we examined the effect of cardiomegaly detected on chest roentgenogram or electrocardiogram before initiating hemodialysis therapy on survival after introduction to maintenance hemodialysis. One hundred and sixty hemodialysis patients who had no history of ischemic heart disease or arrhythmia were followed up for 88.9 +/- 4.0 months, among whom 69 died. Heart enlargement, defined on chest roentgenogram, was detected in 104 patients, and left ventricular hypertrophy, defined on electrocardiogram, was detected in 105 patients. The presence of either finding shortened their survival. However, Cox's proportional hazards model and logistic multiple regression analysis identified only left ventricular hypertrophy as one of the significant determinants for survival, but heart enlargement was not independent. Correction of systolic hypertension on the maintenance phase had no significant favorable effect on survival in patients with left ventricular hypertrophy, while it improved in those with heart enlargement. This finding, together with those above from Cox's model and logistic analysis strongly suggests that risk from left ventricular hypertrophy is independent of, but one from heart enlargement is dependent on hypertension.

Cardiovascular Diseases↗
PubMedDate not supplied

Clinical characteristics and survival in end-stage renal disease patients with arteriosclerosis obliterans.

BACKGROUND: Atherosclerotic disease (ASO) is considered a serious problem in dialysis patients. We tried to clarify the characteristics of ASO and to evaluate its impact on survival. METHODS: Between January 1990 and December 1999, 525 patients with end-stage renal disease were admitted to our hospital. Among these patients, 71 (59 male and 12 female) had ASO. Blood pressure and blood samples were measured before and after hemodialysis, and were compared with the hemodialysis patients without any cardiovascular diseases. Mortality findings were collected until April 30, 2000. RESULTS: Patients with ASO contained a larger percentage of males, hypertension, hyperlipidemia, diabetes mellitus, nephrosclerosis and smoking status. Their serum calcium, serum phosphate, triglyceride and C-reactive protein levels were also higher. During the follow-up period (2.8 +/- 0.2 years), the mortality rate of the patients with ASO was higher than the hemodialysis patients without any cardiovascular diseases. Among the patients with ASO, the significant covariates concerning the cardiovascular mortality rate were age, hyperlipidemia and smoking status according to the Cox Proportional Hazards regression analysis. CONCLUSIONS: Hemodialysis patients with ASO had many traditional risk factors and uremic risk factors. Their survival rate was poorer and dependent on these risk factors.

Adult↗