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Biomedical subjects

Toshihiko Inukai

Publications and source records attributed to Toshihiko Inukai.

24 records · Page 2Linked to original sources

Relationships of plasma interleukin-18 concentrations to hyperhomocysteinemia and carotid intimal-media wall thickness in patients with type 2 diabetes.

OBJECTIVE: We compared plasma interleukin (IL)-18 concentrations in patients with type 2 diabetes with those in age-matched control subjects and investigated whether plasma IL-18 was associated with plasma total homocysteine (tHcy) concentration or carotid intimal-media wall thickness (IMT), an early marker of atherosclerosis, in these patients. RESEARCH DESIGN AND METHODS: We measured plasma IL-18 in 103 type 2 diabetic patients and 45 age-matched control subjects. We also measured patients' plasma tHcy and serum high-sensitivity C-reactive protein (hs-CRP). IMT was evaluated for both common carotid arteries. RESULTS: Plasma IL-18 was significantly higher in diabetic patients than in control subjects (203 +/- 153 vs. 118 +/- 37 pg/ml, P < 0.001). High IL-18 was defined as equaling or exceeding the mean + 2 SD of plasma IL-18 in control subjects (192 pg/ml). Patients with high IL-18 showed a greater carotid IMT than those with normal IL-18. Carotid plaques were more numerous in diabetic patients with high IL-18 than in those with normal IL-18. Plasma tHcy concentrations were significantly higher in patients with high IL-18 than in those with normal IL-18. Univariate and multivariate analyses showed a strong independent association between tHcy and IL-18. Plasma IL-18 also correlated positively with serum hs-CRP. CONCLUSIONS: In patients with type 2 diabetes, plasma IL-18 concentrations are greater than in nondiabetic subjects. Plasma IL-18 is an independent determinant of plasma tHcy, which is linked independently with atherosclerotic carotid wall thickening.

Biomarkers↗

High glucose concentrations abolish the superoxide dismutase response of leukocytes to ascorbic acid or troglitazone in type 2 diabetes mellitus.

UNLABELLED: The hypoglycemic drug, troglitazone (TGZ) has antioxidant activity. Superoxide dismutase (SOD) removes superoxide produced by cells. We measured the response of SOD-like activity (deltaSOD) to ascorbic acid (AA) or TGZ using electron spin resonance at various glucose concentrations in polymorphonuclear leukocytes from 18 type 2 diabetic patients and 18 healthy controls. In control and diabetic subjects, ASOD in response to AA was dose-dependent (maximal effect at 100 ng/ml). Maximal response occurred 2 min after AA addition (50 ng/ml). In cells from diabetic patients, ASOD with 25 ng/ml AA was significantly less than for healthy controls. The deltaSOD with AA changed little at glucose concentration from 0 to 200 mg/dl. In patient and control cells, higher glucose concentrations (400 to 800 mg/dl) reduced ASOD with AA. Response patterns with TGZ resembled those with AA. deltaSOD with AA correlated positively with glycosylated hemoglobin A1c. CONCLUSIONS: The present data suggest that an amerioration of blood glucose on high levels in diabetic patients plays an important role in an antioxidant efficacy of TGZ and AA on leukocytes in patients.

Aged↗

Impaired fibrinolytic compensation for hypercoagulability in obese patients with type 2 diabetes: association with increased plasminogen activator inhibitor-1.

In patients with type 2 diabetes, fibrinolysis is considered impaired by increased plasma concentrations of plasminogen activator inhibitor (PAI)-1. However, several investigators found both coagulation and fibrinolysis to be activated in these patients. We further characterized the balance between coagulation and fibrinolysis in lean and obese patients with type 2 diabetes. We studied 112 type 2 diabetic patients (66 lean, 46 obese) and 69 age-matched healthy subjects (46 lean, 23 obese). We measured plasma concentrations of fibrinogen and prothrombin F1+2 (F1+2) as indicating coagulation activity and plasmin-antiplasmin complex (PAP) and D dimer as indicating fibrinolytic activity. Plasma PAI-1 concentrations also were determined. Plasma concentrations of F1+2, PAP, D dimer, and PAI-1 were higher in diabetic patients than in control subjects. Plasma fibrinogen and F1+2 were similar between lean and obese diabetic patients, but plasma PAP and D dimer were significantly lower in obese than lean diabetic patients (P <.0001, P =.0194, respectively). By multivariate analysis, plasma PAI-1 and body mass index (BMI) were independent factors in diabetic patients predicting PAP, while BMI and glycosylated hemoglobin (HbA(1c)) independently predicted D dimer. Plasma PAI-1 concentrations were significantly higher in obese than lean diabetic patients (P <.0001). In conclusions, both coagulation and fibrinolytic systems are enhanced in lean and obese type 2 diabetic patients compared with healthy subjects. Although the degree of activation of coagulation was similar between lean and obese diabetic patients, the fibrinolytic activity was lower in obese than lean patients. Fibrinolytic compensation for hypercoagulation is incomplete in obese patients with type 2 diabetes, partly because of elevated PAI-1 in the blood.

Administration, Oral↗

Myotonic dystrophy associated with variable circadian rhythms of serum cortisol and isolated thyrotropin deficiency.

We describe a case of myotonic dystrophy presenting with a disturbed circadian rhythm of the serum cortisol and an isolated thyrotropin deficiency. The diagnosis of myotonic dystrophy was based on clinical characteristics, positive electromyographic findings, and increased number of CTG repeats in the dystrophia myotonica protein kinase (DMPK) gene. The patient presented with a variable circadian rhythm of the serum cortisol, increased excretion of urinary free cortisol, and a high adrenocorticotropin hormone responses to corticotropin-releasing hormone. The basal serum thyrotropin concentration was low and did not increase after thyrotropin-releasing hormone stimulation. The protein encoded by the DMPK gene may act as a second messenger in signal transduction, like a protein kinase. The present patient had a diverse pattern of disturbances in the hypothalamus-pituitary-endocrine organ axis, probably mediated by differences in the action or expression of the gene products in each endocrine cell.

Adrenocorticotropic Hormone↗

Small low-density lipoprotein and small low-density lipoprotein/total low-density lipoprotein are closely associated with intima-media thickness of the carotid artery in Type 2 diabetic patients.

BACKGROUND: The intima-media thickness (IMT) of the carotid artery, as determined by ultrasonography, is useful for reflecting the extent of subclinical atherosclerosis. We investigated the relationship between IMT and the serum concentrations of small low-density lipoprotein (LDL) in diabetic patients. METHODS: The study was conducted with 27 Type 2 diabetic patients (14 males and 13 females; mean age=62.6+/-8.3 years) and 12 age-matched healthy controls. The LDL subfraction was measured using a polyacrylamide gel electrophoresis method. Vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF) concentrations were measured by an enzyme immunoassay. The IMT was expressed as the maximum IMT (Max-IMT) and average IMT (Ave-IMT) of the carotid artery, measured by ultrasonography. RESULTS: Both the IMT and the small LDL concentrations were significantly increased in the diabetic patients compared with the healthy participants. The IMTs were significantly correlated with small LDL concentration and small LDL/total LDL more than LDL concentrations by multivariate analysis. The IMTs were not significantly correlated with the serum VEGF or PDGF concentrations. The patients with a larger IMT had a significantly higher prevalence of hypertension or ischemic heart disease than did the patients with a normal IMT. CONCLUSIONS: The increased small LDL concentrations and small LDL/total LDL, in addition to total LDL concentrations, in Type 2 diabetic patients are closely associated with increased IMT of the carotid artery.

Arteriosclerosis↗

Association between circulating monocyte chemoattractant protein-1 and urinary albumin excretion in nonobese Type 2 diabetic patients.

In 70 nonobese inpatients with Type 2 diabetes [body mass index (BMI): 24.0+/-4.4 kg/m(2)], we examined circulating monocyte chemoattractant protein (MCP) -1 as a candidate marker of atherosclerosis by comparison with established markers: serum high-sensitivity C-reactive protein (hsCRP), plasma fibrinogen, and combined carotid artery intimal-medial thickness (IMT). In addition, an association was sought between circulating MCP-1 and urinary albumin excretion (UAE), reflecting diabetic renal microangiopathy. Serum MCP-1 was determined by enzyme-linked immunosorbent assay (ELISA). Patients were grouped by UAE: normoalbuminuria, below 30 mg/g of creatinine (Cr); microalbuminuria, 30 to 300 mg/g Cr; or macroalbuminuria, over 300 mg/g Cr. Serum MCP-1 for all participants, men, and women was 280.0+/-78.9, 269.0+/-68.8, and 294.9+/-87.9 pg/ml, respectively, showing no difference between genders. No correlation was noted between MCP-1 and hsCRP, fibrinogen, or carotid artery IMT. No correlation of MCP-1 was observed with age, duration of diabetes, fasting plasma glucose (FPG), hemoglobin (Hb) A(1C), BMI, diastolic blood pressure (DBP), or serum lipid concentrations, but significant correlations were found with systolic blood pressure (SBP; R=.2723, P=.0225) and with log(10)-transformed (log) UAE (R=.3343, P=.0047). Patients with macroalbuminuria had significant higher circulating MCP-1 than did those with normo- or microalbuminuria (P=.0063 and P=.0188, respectively). By stepwise regression analysis, only log UAE independently predicted serum MCP-1 (beta=.3700, P=.0020). Thus, in nonobese Type 2 diabetic patients, MCP-1 might not be a marker of atherosclerosis and might be influenced significantly by diabetic nephropathy.

Albuminuria↗