A gradual update method for simulating the steady-state solution of stiff differential equations in metabolic circuits.

Numerical simulation of differential equation systems plays a major role in the understanding of how metabolic network models generate particular cellular functions. On the other hand, the classical and technical problems for stiff differential equations still remain to be solved, while many elegant algorithms have been presented. To relax the stiffness problem, we propose new practical methods: the gradual update of differential-algebraic equations based on gradual application of the steady-state approximation to stiff differential equations, and the gradual update of the initial values in differential-algebraic equations. These empirical methods show a high efficiency for simulating the steady-state solutions for the stiff differential equations that existing solvers alone cannot solve. They are effective in extending the applicability of dynamic simulation to biochemical network models.

Relationship between serum bilirubin and albuminuria in patients with type 2 diabetes.

Previous studies showed that low serum bilirubin concentrations are associated with increased risk of cardiovascular disease. To explore this further, we evaluated the relationships between serum bilirubin concentrations and the degree of urinary albumin excretion and other markers of subclinical atherosclerosis in 633 consecutive patients with type 2 diabetes. Multiple regression analysis showed that the serum bilirubin concentration was an independent determinant of and had a significant inverse correlation to the log urinary albumin excretion. Serum bilirubin concentrations were significantly lower in patients with than in those without cardiovascular disease. A significant inverse correlation was found between the serum bilirubin concentration and pulse wave velocity, while a significant positive correlation was found to the ankle-brachial index in a subgroup of 386 patients. Our study shows that the serum bilirubin level is associated with microalbuminuria and subclinical atherosclerosis in patients with type 2 diabetes.

Serum uric acid is associated with microalbuminuria and subclinical atherosclerosis in men with type 2 diabetes mellitus.

Hyperuricemia has been reported to be associated with increased risk of renal insufficiency as well as cardiovascular events. The aim of this study was to evaluate the relationships between serum uric acid concentration and degree of urinary albumin excretion as well as markers of subclinical atherosclerosis in men with type 2 diabetes mellitus. Serum uric acid concentrations were measured in 343 men with type 2 diabetes mellitus. We then evaluated relationships of serum uric acid concentrations to degree of urinary albumin excretion as well as to major cardiovascular risk factors, including age, blood pressure, serum lipid concentration, and glycemic control (hemoglobin A1c). The relationships between serum uric acid concentration and pulse wave velocity or ankle-brachial index (n=236) and between serum uric acid concentration and carotid intima-media thickness or plaque score (n=125) were investigated additionally in a subgroup of patients. Serum uric acid concentration correlated positively with logarithm of urinary albumin excretion (r=0.302, P<.0001). Positive correlation was found between serum uric acid concentration and intima-media thickness (r=0.233, P=.0087), whereas inverse correlation was found between serum uric acid concentration and ankle-brachial index (r=-0.150, P=.0207). Multiple regression analysis demonstrated that serum uric acid concentration (beta=.281, P<.0001), duration of diabetes (beta=.253, P<.0001), hemoglobin A1c (beta=.166, P=.0034), serum triglyceride concentration (beta=.125, P=.0472), and systolic blood pressure (beta=.275, P=.0013) were independent determinants of logarithm of urinary albumin excretion. In conclusion, serum uric acid concentration is associated with microalbuminuria and subclinical atherosclerosis in men with type 2 diabetes mellitus.

The alpha-glucosidase inhibitor acarbose reduces the net electronegative charge of low-density lipoprotein in patients with newly diagnosed type 2 diabetes.

BACKGROUND: Several epidemiological studies have shown that postprandial hyperglycemia is associated with an increased risk of cardiovascular disease (CVD). The present study was conducted in order to compare the effects of acarbose and glimepiride treatment on serum lipoprotein profiles in patients with type 2 diabetes. METHODS: A total of 37 patients with newly diagnosed type 2 diabetes were studied. The patients were assigned randomly to treatment for 12 weeks with either acarbose (n=13, 100 mg x 3/day, group A), glimepiride (n=13, 2 mg/day, group G) or diet only (n=11, group D). Lipid and lipoprotein profiles before and after each treatment were evaluated. RESULTS: A significant reduction in the net electronegative charge of low-density lipoprotein (emLDL) was observed in group A (-1.8, P<0.01), whereas no significant change in emLDL was observed in groups G and D. In group A, small VLDL and very small LDL levels were also decreased significantly (P<0.05). The change in emLDL levels correlated significantly with changes in very small LDL (r=0.751, P<0.01) and oxidized LDL levels (r=0.623, P<0.05). CONCLUSION: These results suggest that measurement of serum emLDL may be a sensitive and clinically useful marker for determining qualitative lipoprotein abnormalities in diabetes, and that acarbose treatment lowers CVD risk by decreasing production of emLDL.

Beneficial effect of gabexate mesilate on microscopic polyangiitis with renal dysfunction and pulmonary hemorrhage: A case report.

Corticosteroids and cyclophosphamide are the mainstay of the treatment of microscopic polyangiitis involving pulmonary hemorrhage or rapidly progressive glomerulonephritis. However, patients with advanced age are unable to tolerate this combined therapy, because of a relatively high incidence of side effects including infection, hemorrhagic cystitis, and bone marrow suppression. The authors encountered an 80-year-old patient with pulmonary hemorrhage and renal dysfunction ascribed to microscopic polyangiitis and achieved successful treatment by employing gabexate mesilate in addition to corticosteroids. The present case suggests that gabexate mesilate may be a therapeutic option for microscopic polyangiitis with progressive renal failure and pulmonary hemorrhage.

Hemoglobin concentration in men with type 2 diabetes mellitus.

Anemia is a common but often overlooked complication of diabetes. We investigated the relationship between hemoglobin concentration and various factors as well as markers of subclinical atherosclerosis in men with type 2 diabetes mellitus. Hemoglobin concentration was measured in 319 men with type 2 diabetes mellitus. We evaluated the relationship between hemoglobin concentration and various factors including age, body mass index, and glycemic control, as well as between hemoglobin concentration and pulse wave velocity or ankle-brachial index (n = 209) and between hemoglobin concentration and carotid intima-media thickness or plaque score (n = 125). Mean hemoglobin concentration was 14.2 +/- 0.80 g/dL. Body mass index (r = 0.340, P < .0001) and estimated glomerular filtration rate (r = 0.219, P = .0011) were positively associated with hemoglobin concentration, whereas age (r = -0.388, P < .0001), glycated albumin (r = -0.148, P = .0121), serum creatinine concentration (r = -0.206, P = .0019), and log (urinary albumin excretion) (r = -0.188, P = .0010) were negatively associated with hemoglobin concentration. Multiple regression analysis identified age (beta = -0.222, P = .0019), body mass index (beta = 0.145, P = .0432), systolic blood pressure (beta = 0.214, P = .0015), total cholesterol concentration (beta = 0.170, P = .0077), and serum creatinine concentration (beta = -0.181, P = .0045) as independent determinants of hemoglobin concentration. No significant association was observed between hemoglobin concentration and serum erythropoietin concentration (r = -0.079, P = .2980). Negative correlations were found between hemoglobin concentration and pulse wave velocity (r = -0.289, P < .0001) and between hemoglobin concentration and plaque score (r = -0.275, P = .0024). In conclusion, hemoglobin concentration was associated with various factors; and decreased hemoglobin concentration was associated with subclinical markers of atherosclerosis in men with type 2 diabetes mellitus.

Plasma serotonin is a predictor for deterioration of urinary albumin excretion in men with type 2 diabetes mellitus.

We performed an observational study to investigate if plasma 5-hydroxyindole-3-acetic acid (5-HIAA), a derivative end product of serotonin (5-hydroxytryptamine), concentration could be a predictor for deterioration of urinary albumin excretion. The relationship between baseline plasma 5-HIAA concentration and changes in urinary albumin excretion for 24 months was investigated in 162 male patients with type 2 diabetes mellitus. Patients were divided into tertiles according to plasma 5-HIAA concentration. Greater changes in urinary albumin excretion were seen in patients with high plasma 5-HIAA concentration (112.8 +/- 36.2 mg/g creatinine) than in patients with low plasma 5-HIAA concentration (7.6 +/- 8.0 mg/g creatinine, P = .0011) or in patients with intermediate plasma 5-HIAA concentration (25.6 +/- 15.0 mg/g creatinine, P = .0070) after adjustment for baseline values of urinary albumin excretion. A positive correlation was observed between log (plasma 5-HIAA concentration) and changes in urinary albumin excretion (r = 0.314, P < .0001). Multiple regression analysis demonstrated that log (plasma 5-HIAA concentration) (beta = .284, P = .0013) was an independent determinant of changes in urinary albumin excretion. In conclusion, plasma 5-HIAA concentration was positively correlated with changes in urinary albumin excretion, which may indicate causality in diabetic nephropathy in male patients with type 2 diabetes mellitus and high plasma 5-HIAA concentration.

Eosinophil count is positively correlated with albumin excretion rate in men with type 2 diabetes.

BACKGROUND AND OBJECTIVES: Patients with allergic disorders such as allergic rhinitis or asthma have been reported to be at increased risk for atherosclerosis. In this study, we evaluated the relationships between peripheral eosinophil count and degree of albumin excretion rate, which is a useful marker of cardiovascular mortality as well as diabetic nephropathy in patients with type 2 diabetes. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We evaluated relationships of peripheral eosinophil count to degree of albumin excretion rate as well as to major cardiovascular risk factors, including age, BP, serum lipid concentration, and glycemic control (glycosylated hemoglobin); body mass index; current treatment for diabetes; smoking status; and presence of cardiovascular disease in 783 patients (416 men and 367 women) with type 2 diabetes. RESULTS: Log(eosinophil count) was positively associated with systolic BP (r = 0.124, P = 0.0108), serum triglyceride concentration (r = 0.108, P = 0.0284), and log(albumin excretion rate) (r = 0.301, P < 0.0001) in men; however, no association was found between log(eosinophil count) and log(albumin excretion rate) (r = 0.085, P = 0.1050) in women. Multivariate linear regression analysis demonstrated that log(eosinophil count) (beta = 0.260, P < 0.0001), duration of diabetes (beta = 0.203, P = 0.0003), glycosylated hemoglobin (beta = 0.117, P = 0.0238), systolic BP (beta = 0.205, P = 0.0001), and serum triglyceride concentration (beta = 0.162, P = 0.0038) were independent determinants of log(albumin excretion rate) in men. CONCLUSIONS: Allergic disorders may be associated with microalbuminuria in men with type 2 diabetes.

Telmisartan, an angiotensin II type 1 receptor blocker, prevents the development of diabetes in male Spontaneously Diabetic Torii rats.

To assess the beneficial effects of the angiotensin II type 1 receptor blocker telmisartan on a non-obese animal model of reduced function and mass of islet beta-cells prior to the development of diabetes, Spontaneously Diabetic Torii (SDT) rats were treated with telmisartan at 8 weeks of age. At 24 weeks of age, the treatment with telmisartan dose-dependently ameliorated hyperglycemia and hypoinsulinemia, and high-dose (5 mg/kg/day) treated SDT rats did not developed diabetes. Real-time RT-PCR analysis revealed that treatment with high-dose telmisartan reduced mRNA expression of local renin-angiotensin system (RAS) components, components of NAD(P)H oxidase, transforming growth factor-beta1 and vascular endothelial growth factor in the pancreas of male SDT rats. Immunohistochemical and Western blot analyses revealed that treatment with telmisartan also reduced expression of p47(phox). These results suggest that treatment with telmisartan reduces oxidative stress by local RAS activation and protects against islet beta-cell damage and dysfunction. These findings provide at least a partial explanation for the reduced incidence of new-onset diabetes that has been observed in several clinical trials involving angiotensin II type 1 receptor blockers and ACE inhibitors.

Bone stiffness in men with type 2 diabetes mellitus.

Osteoporosis in elderly men as well as women is increasingly recognized, and patients with type 2 diabetes mellitus have higher risk of fracture than nondiabetic subjects. The aim of the present study was to investigate the relationship between bone stiffness and serum testosterone concentration as well as other variables in men with type 2 diabetes mellitus. The relationships between bone stiffness and serum bioavailable testosterone concentrations as well as other variables including age, duration of diabetes, glycemic control (hemoglobin A(1c)), or body mass index were evaluated in 294 men with type 2 diabetes mellitus. An inverse correlation was found between stiffness index and age. A positive correlation was found between stiffness index and serum bioavailable testosterone concentration (r = 0.231, P = .0005). Stiffness index was significantly less in current smokers (81.6 +/- 17.7) than in past smokers (86.6 +/- 17.8, P = .0396) or nonsmokers (87.7 +/- 15.2, P = .0426). Multiple regression analysis demonstrated that serum bioavailable testosterone concentration (beta = .271, P = .0006) and smoking status (beta = -0.147, P = .0408) were independent determinants of stiffness index. In conclusion, bone stiffness was associated with serum bioavailable testosterone concentration but not associated with hemoglobin A(1c) or duration of diabetes in men with type 2 diabetes mellitus.