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Impaired bone formation due to defective osteoblast function, as reflected in a decreased serum osteocalcin (OC) concentration in the patients with diabetes, has been implicated in the development of diabetic osteopenia. The role of hyperglycemia in this decrease in serum OC concentration was investigated. 1,25-dihydroxyvitamin D3 (1,25[OH]2D3), an active form of vitamin D3, stimulated OC secretion from the human osteosarcoma cell line MG-63 in a dose-dependent manner. Exposure of the cells to high concentrations of glucose for 7 days significantly impaired 1,25(OH)2D3-induced OC secretion as compared with that observed with cells maintained under normal glucose (5.5 mM) or high mannitol conditions. The inhibitory effect of glucose was in a dose-dependent manner up to 55 mM. High glucose (55 mM) also attenuated the 1,25(OH)2D3-induced increase in OC mRNA abundance in MG-63 cells, suggesting that the inhibition of the 1,25(OH)2D3-induced increase in OC secretion by exposure to a high concentration of glucose was, at least in part, mediated at the transcriptional level. High glucose significantly decreased the number of 1,25(OH)2D3 receptors in MG-63 cells, without any change in the dissociation constant for 1,25(OH)2D3; this effect was not mimicked by high mannitol, indicating specificity for glucose. These observations suggest that a high glucose concentration significantly impairs the ability of osteoblastic cells to synthesize OC in response to 1,25(OH)2D3 by reducing 1,25(OH)2D3 receptor number, and that impaired cell function caused by sustained exposure to high glucose contributes to the defect in bone formation observed in the patients with diabetic osteopenia.

Aims: The clinical implications of stiffness of the carotid artery (CA) have not been fully clarified in the prediction of coronary artery disease (CAD), although intima-media thickness (IMT) has been established as a surrogate marker. We examined the associations of stiffness parameter β (ST) and IMT with concurrent CAD.Methods: IMT and ST were measured by ultrasound in 439 nondiabetic subjects as a control and 1528 type 2 diabetic subjects (T2DM) with or without CAD in a cross-sectional study.Results: Both IMT and ST significantly increased with age and group category, in the order of control, T2DM without CAD, and T2DM with CAD (p&lt0.001). The area under the curve on ROC analysis of ST for concurrent CAD was comparable to that for IMT. On multivariate logistic regression analysis, High IMT (≥1.30 mm) and High stiffness (≥20.0) had significant odds ratios for concurrent CAD (2.205, p&lt0.001 and 1.548, p&lt0.05, respectively). The group with High IMT and High Stiffness exhibited a stronger multivariate odds ratio (3.115, p=0.0001).Conclusions: ST and IMT are associated with CAD and exhibited significant odds ratios for CAD. Our findings suggest that the combination of IMT and ST is a useful marker of atherosclerosis.

Although lipid-lowering therapy with 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) decreases the progression of coronary artery and aortic valve calcification, the mechanism of action of these drugs to inhibit the calcification process remains unclear. In this study, we investigated the effect of statins such as cerivastatin and atorvastatin on vascular calcification by utilizing an in vitro model of inflammatory vascular calcification. Cerivastatin and atorvastatin dose-dependently inhibited in vitro calcification of human vascular smooth muscle cells (HVSMCs) induced by the following inflammatory mediators (IM): interferon-gamma, 1alpha,25-dihydroxyvitamin D3, tumor necrosis factor-alpha, and oncostatin M. These statins also depressed expression of alkaline phosphatase (ALP) in HVSMCs induced by these factors. Mevalonate and geranylgeranylpyrophosphate reversed the inhibitory effect of cerivastatin on ALP expression in HVSMCs, while farnesylpyrophosphate showed no effect on the ALP activities inhibited by this drug, suggesting that inhibition of Rho and its downstream target, Rho kinase may mediate the inhibitory effect of cerivastatin. Cerivastatin prevented RhoA activation in HVSMCs induced by the IM. A specific inhibitor of Rho kinase (Y-27632) inhibited in vitro calcification and induction of ALP in HVSMCs. These findings provide a possible mechanism of statins to prevent the progression of calcification in inflammatory vascular diseases such as atherosclerosis and cardiac valvular calcification.

Arterial stiffness affects cardiac functions, peripheral circulation, and cardiovascular mortality. We examined whether arterial stiffness in different regions is equally affected by diabetes and other factors. The subjects were 161 patients with type 2 diabetes and 129 healthy subjects comparable in age and sex. Arterial stiffness was evaluated by measuring pulse wave velocity (PWV) in the heart-carotid, heart-brachial, heart-femoral, and femoral-ankle segments using an automatic device. The diabetic patients had greater PWV than the healthy subjects in the four arterial regions, and the effect of diabetes on PWV was greater in the heart-carotid and heart-femoral segments (central) than in the heart-brachial and femoral-ankle regions (peripheral). PWV increased with age in the four arterial regions, and the effect of age on PWV was greater in the central than in peripheral arteries. In multiple regression analysis, age and systolic blood pressure had significant impacts on PWV of the four regions, whereas diabetes was significantly associated only with PWV of the central arteries. In contrast, sex was associated with PWV of the peripheral arteries. Thus, type 2 diabetes had greater impact on PWV of the central arteries, and different factors were involved in PWV among different arterial regions.

Objectives— Platelet adherence and activation are associated with smooth muscle cell (SMC) proliferation and arterial restenosis. This study examined platelet-SMC interaction on fibrillar type I collagen and analyzed the role of thrombospondin (TSP)-1 in platelet-induced SMC proliferation. Methods and Results— When SMCs cultured on fibrillar collagen were treated with human platelets (5 preparations), 7.45±2.94% of the cells passed through S phase within 24 hours, as determined by bromodeoxyuridine nuclear labeling. The addition of platelets markedly induced SMC TSP-1 mRNA expression and cell surface protein accumulation, which colocalized with adhered platelets, as determined by α IIb integrin immunostaining. Direct interaction of platelets with SMCs was necessary for its effect on proliferation and TSP-1 accumulation, as determined in the transwell culture system. The anti–TSP-1 blocking antibody strongly inhibited platelet-induced SMC proliferation by ≈60%. Analysis of the receptors for TSP-1 accumulation on the SMC surface revealed that β 1 integrins are mainly involved. The anti–β 1 integrin blocking antibody, which potently suppressed TSP-1 accumulation on SMCs, also markedly inhibited platelet-stimulated SMC proliferation. Conclusions— TSP-1 and β 1 integrin interaction is involved in platelet-stimulated SMC proliferation. This in vitro coculture system could prove useful for examining the molecular mechanism underlying platelet-induced vascular remodeling and for studying the mechanism of a tested drug for restenosis.

Inflammatory cells such as macrophages and T lymphocytes play an important role in vascular calcification associated with atherosclerosis and cardiac valvular disease. In particular, macrophages activated with cytokines derived from T lymphocytes such as interferon-γ (IFN-γ) may contribute to the development of vascular calcification. Moreover, we have shown the stimulatory effect of 1α,25-dihydroxyvitamin D 3 (1,25(OH) 2 D 3 ) on in vitro calcification through increasing the expression of alkaline phosphatase (ALP), an ectoenzyme indispensable for bone mineralization, in vascular smooth muscle cells. Therefore, we hypothesized that macrophages may induce calcifying phenotype, especially the expression of ALP in human vascular smooth muscle cells (HVSMCs) in the presence of IFN-γ and 1,25(OH) 2 D 3 . To test this hypothesis, we used cocultures of HVSMCs with human monocytic cell line (THP-1) or peripheral blood monocytes (PBMCs) in the presence of IFN-γ and 1,25(OH) 2 D 3 . THP-1 cells or PBMCs induced ALP activity and its gene expression in HVSMCs and the cells with high expression of ALP calcified their extracellular matrix by the addition of β-glycerophosphate. Thermostability and immunoassay showed that ALP induced in HVSMCs was bone-specific enzyme. We further identified tumor necrosis factor-α (TNF-α) and oncostatin M (OSM) as major factors inducing ALP in HVSMCs in the culture supernatants of THP-1 cells. TNF-α and OSM, only when applied together, increased ALP activities and in vitro calcification in HVSMCs in the presence of IFN-γ and 1,25(OH) 2 D 3 . These results suggest that macrophages may contribute to the development of vascular calcification through producing various inflammatory mediators, especially TNF-α and OSM.

Polymorphism of alpha2 integrin (C807T) is shown to be associated with an increased incidence of thrombotic cardiovascular events. However, it is not clear whether this polymorphism is associated with atherosclerotic arterial wall thickening. In this study, we examined the association of C807T polymorphism with arterial wall thickness in 265 control subjects and 272 patients with type 2 diabetes. In all subjects, intima-media thickness of the right carotid artery in the 807TT group (0.649 +/- 0.028 mm [SE]) was significantly (P = 0.0228, Scheffe's F test) less than in the 807CC group (0.767 +/- 0.033). This effect of polymorphism is gene dose dependent (P = 0.0227, ANOVA). The similar association was also observed in patients with diabetes but not in control subjects. Multiple regression analysis in all subjects revealed that the T allele was inversely (beta = -0.095, P = 0.021) associated with intima-media thickness independent of age, HbA(1c), and HDL cholesterol. Finally, an inverse relation between the occurrence of carotid plaque and the T allele was observed in patients with diabetes with an adjusted odds ratio of 0.487 (P = 0.031) in multiple logistic regression analyses. These results suggest that the number of 807T alleles in alpha2 integrin is protective against atherosclerotic arterial wall thickening and the occurrence of plaque in patients with type 2 diabetes.

Cardiovascular risk is increased in patients with diabetic nephropathy. The aim of this study was to examine the relative impacts of albuminuria and renal failure, the two important features of diabetic nephropathy, on potentially atherogenic lipoprotein changes in this condition. The subjects were 160 non-diabetic healthy controls and a total of 200 type 2 diabetes patients with various degrees of nephropathy. The diabetic patients were divided into four groups by urinary albumin/creatinine ratio (U-ACR) and serum creatinine (S-Cr) levels: DM-1 (U-ACR30 mg/g, N=85), DM-2 (U-ACR=30-300 mg/g, N=48), DM-3 (U-ACR300 mg/g, N=29) and DM-4 (S-Cr177 micromol/l or 2.0mg/dl, N=38). Lipids in very low (VLDL), intermediate (IDL), low (LDL), and high density (HDL) lipoproteins were measured following ultracentrifugation. VLDL-cholesterol (VLDL-C) was elevated (by 73-100%) in diabetic patients and it did not differ among the stages of nephropathy. IDL-C was higher as the nephropathy stage was advanced, and the elevation was significant in the DM-3 (by 75%) and DM-4 (by 131%) groups. LDL-C was not elevated in diabetic patients and was not different among the stages of nephropathy. Reduction of HDL-C was significant in DM-1, DM-2 and DM-3 (by 12-16%) and it was more exaggerated in DM-4 (by 35%). Multiple regression analyses indicated that elevated S-Cr, but not U-ACR, was an independent factor associated with raised IDL-C and lowered HDL-C in diabetic patients. These results indicate that diabetic patients with nephropathy show multiple lipoprotein changes, and that renal failure has greater impact than albuminuria on abnormalities in IDL and HDL. These lipoprotein alterations may contribute to an increased cardiovascular risk in diabetic nephropathy, especially in diabetic renal failure.

Abstract —Proliferation and α v β 3 integrin–dependent migration of vascular smooth muscle cells are suppressed on polymerized type I collagen. To identify genes specifically regulated in human smooth muscle cells by polymerized collagen, we used the suppressive subtraction hybridization technique. Compared with smooth muscle cells cultured on monomer collagen, polymerized collagen suppresses the following: (1) a number of other extracellular matrix proteins, including fibronectin, thrombospondin-1, tenascin-C, and cysteine-rich protein 61; (2) actin binding proteins including α-actinin; (3) signaling molecules; (4) protein synthesis–associated proteins; and (5) genes with unknown functions. Some of the identified genes, including cysteine-rich protein 61, show unique kinetics of mRNA regulation by monomer or polymerized collagen distinct from growth factors, suggesting extracellular matrix–specific gene modulation. Moreover, in vivo balloon catheter–mediated injury to the rat carotid artery induces many of the genes that are suppressed by polymerized collagen. Protein levels of thrombospondin-1 and fibronectin are also suppressed by polymerized collagen. Thrombospondin-1–mediated smooth muscle cell migration on vitronectin is significantly inhibited after culture on polymerized collagen for 24 hours, which is associated with decreased α-actinin accumulation at focal adhesions. Thus, polymerized type I collagen dynamically regulates gene expression, pericellular accumulation of extracellular matrix molecules, and the response to a given matrix molecule.

OBJECTIVE—To assess the impacts of insulin resistance and renal function on plasma total homocysteine (tHcy) levels in patients with type 2 diabetes with a wide range of nephropathy. RESEARCH DESIGN AND METHODS—Plasma tHcy levels were measured using the enzyme immunoassay method in 75 patients with type 2 diabetes and compared with those in 54 healthy control subjects. Insulin sensitivity indexes were assessed in patients with type 2 diabetes by hyperinsulinemic-euglycemic clamp using artificial pancreas. RESULTS—Plasma tHcy levels and their log-transformed values (log tHcy) were significantly higher in all patients with diabetes than in control subjects (tHcy, 12.0 ± 0.7 [SE] vs. 8.7 ± 0.3 μmol/l, P < 0.0001; log tHcy, 1.040 ± 0.021 vs. 0.920 ± 0.016 μmol/l, P < 0.0001). Plasma tHcy levels in patients with diabetes were significantly increased according to degree of nephropathy (P < 0.0001). On simple regression analyses, log tHcy correlated with insulin sensitivity indexes (r = –0.319, P = 0.005) as well as creatinine clearance (r = 0.634, P < 0.0001) in all patients with diabetes. Multiple regression analyses showed that insulin sensitivity indexes (β = –0.245) as well as creatinine clearance were independent contributors to log tHcy in all patients with diabetes (R2 = 0.750, P < 0.0001). For the 59 patients with diabetes with creatinine clearance >60 ml/min, insulin sensitivity indexes were also shown to be a significant contributor to log tHcy (β = –0.438, R2 = 0.561, P < 0.001). CONCLUSION—Insulin resistance and renal function are independent determinants of tHcy levels in patients with type 2 diabetes.

Calcification is almost invariably associated with atherosclerotic plaque lesions. Recent data suggest that plaque calcification is an active, regulated process similar to osteogenesis. In order to clarify the mechanism of plaque calcification, we developed an in vitro model of vascular calcification by utilizing bovine vascular smooth muscle cells (BVSMCs). This model is useful in that diffuse and massive calcification can be induced within 2 weeks and thereby biochemical analyses of vascular calcification can be performed. We have analyzed several aspects of vascular calcification by using this model and demonstrated as follows: 1) in vitro calcification of BVSMCs is regulated by calciotropic hormones and BVSMCs are equipped with a unique autocrine and/or paracrine system regulating calcium metabolism. 2) Sodium-dependent phosphate cotransport plays a crucial role in BVSMC calcification as well as in mineralization of skeletal tissues. 3) BVSMCs acquire osteoblastic phenotype under certain conditions. Finally, we discuss the roles of macrophages in the development of atherosclerotic calcification. Interferon-gamma (IFN-gamma) induces gene expression of 25-hydrovitamin D-1 alpha-hydroxylase (1 alpha OHase) and its activity in macrophages. Since 1 alpha OHase can locally convert 25-hydroxyvitamin D into 1 alpha, 25-dihydroxyvitamin D (1,25(OH)2D), an active metabolite of vitamin D, it is suggested that local production of 1,25(OH)2D by macrophages may promote atherosclerotic calcification. Moreover, macrophages may be involved in the phenotypic changes of vascular smooth muscle cells (VSMCs) to acquire calcifying capacity. Therefore, the phenotypic changes of VSMCs in atherosclerotic plaque may contribute to the development of atherosclerotic calcification.

OBJECTIVE We studied the relationship between vasoconstrictor changes in foot arteries (pedal, metatarsal, and digital arteries) and autonomic neuropathy in diabetic patients to estimate the degrees of sympathetic dysfunction. RESEARCH DESIGN AND METHODS Sixty-two patients and nineteen age-matched control subjects were studied. The resistance index (RI) and pulsatility index (PI) were measured as vascular hemodynamic parameters using Doppler sonography, and the increases in these hemodynamic parameters (%RI and %PI) from rest to a deep breath were measured as indexes of the degrees of sympathetic vasoconstrictor function. Cardiovascular autonomic function tests (AFTs) were performed and the score was compared to %RI and %PI values obtained. RESULTS Of the 62 diabetic patients, 51 had various degrees of autonomic neuropathy. Both %RI and %PI in the diabetic patients were significantly < those in the control subjects for all foot arteries tested (all P < 0.001). There were strongly inverse correlations between the %RI and %PI of foot arteries and the AFT score (r = −0.556 to −0.846, P < 0.0001). The %RI of the digital artery was the most strongly correlated with AFT score (r = −0.846, P < 0.0001) among foot arteries tested. The abnormality of sympathetic vasoconstriction was detectable in the majority of the diabetic patients with the early phase of autonomic neuropathy (%RI: 89.5%; %PI: 94.5%). CONCLUSIONS We conclude that the %RI of the digital artery is a useful and reliable sympathetic function test of early phase in diabetic patients.

To investigate the association between insulin resistance and diabetic nephropathy, peripheral insulin sensitivity indices (M/I values) were evaluated via euglycemic-hyperinsulinemic clamp in 45 non-obese, non-insulin-dependent diabetic (NIDDM) subjects. The patients were divided into four groups: 18 with normoalbuminuria (urinary albumin excretion rate [AER]30 mg/24 h, stage I), 10 with microalbuminuria (30or = AERor = 300 mg/24 h, stage II), seven with overt proteinuria (AER300 mg/24 h, stage III), and 10 with uremia (serum creatinine levels2.0 mg/dL, stage IV). There were no significant differences in age, body mass index (BMI), fasting plasma glucose, or hemoglobin A1c (HbA1c) among the four groups. No significant difference in M/I values was seen between stage I and stage II (6.30 +/- 0.73 and 5.95 +/- 0.85 mg/kg/(min per microU/mL) x 100, respectively). M/I values in the stage I and stage II groups were strongly correlated with BMI (r = -.790, P = .0001 and r = -.785, P = .007, respectively). M/I values in the stage III group (4.53 +/- 0.51) were lower than in the stage I group, although not significantly so. M/I values in the stage IV group (3.16 +/- 0.37) were significantly lower than in the stage I group (P = .025). In multiple regression analysis with a model in which age, sex, BMI, HbA1c, and creatinine clearance (Ccr) were included as independent variables, BMI and Ccr were demonstrated to be significant and independent contributors to insulin sensitivity indices as the dependent variable (beta = -0.716 and beta = 0.272, respectively, R2 = .564, P.0001). In conclusion, the present cross-sectional study demonstrated in non-obese NIDDM patients with nephropathy that microalbuminuria did not affect peripheral insulin resistance, but uremia did, as in nondiabetic patients, and that the peripheral insulin resistance was significantly contributed to by the degree of obesity and uremia.

OBJECTIVE Gastric myoelectrical activity was studied in diabetic patients using electrogastrography (EGG) to elucidate the relationship between glucose control, diabetic autonomic neuropathy (AN), and gastrointestinal motility. RESEARCH DESIGN AND METHODS Cutaneous EGG was recorded during 1 h of fasting and 1 h after the ingestion of a standard meal in 57 diabetic patients and 10 healthy subjects. EGG was measured in 12 diabetic patients after glycemic control for 4 weeks. Diabetic patients were also studied with respect to the presence of gastrointestinal symptoms and AN. RESULTS The percentage of dominant electrical frequency (DF) in normal range (the percentage ratio between the power at 2.4–3.6 cycles/min [cpm] and at 1–10 cpm) was significantly lower in patients with AN than in either the control subjects or the patients without AN (P < 0.01). The dominant frequency instability coefficient (DFIC) was significantly higher in patients with and without AN than in the control subjects (P < 0.01). The postprandial-to-fasting power ratio (PR) was the lowest in patients with AN (P < 0.01). Multiple regression analysis revealed that HbA1c levels were independently associated with the DFIC (R2 = 0.099, P = 0.0170) and that AN and HbA1c levels were independently associated with the PR (R2 = 0.378, P < 0.0001) in diabetic patients. The percentage of normal DF increased and the DFIC decreased significantly after glycemic control in 12 diabetic patients (P = 0.0409; P = 0.0096, respectively). CONCLUSIONS There appears to be an association between improvement in gastric myoelectrical activity and autonomic nerve function. Abnormalities of gastric myoelectrical activity may be partly ameliorated via the improvement of autonomic nerve function, which accompanies glycemic control.

We examined the association between the polymorphism of the apolipoprotein E (apoE) and the ACE genes and the intima-media thickness (IMT) of the carotid and femoral arteries measured using ultrasonography. The values of IMT of each artery were significantly higher in NIDDM patients (n = 356) than in control subjects (n = 235). The E4 allele or the D allele did not affect clinical characteristics, including age, fasting plasma glucose, total cholesterol, HDL cholesterol, LDL cholesterol, or blood pressure, in NIDDM or control subjects. No difference in the carotid IMT value was noted among the apoE genotypes in control or diabetic subjects. The carotid IMT was significantly higher in diabetic patients with the DD genotype (1.200 ± 0.586 mm) than in those with the II genotypes (0.990 ± 0.364 mm). Neither the E4 allele nor the D allele affected the femoral IMT in control or diabetic subjects. Multiple regression analysis demonstrated that the carotid IMT of NIDDM patients was associated with age, the D allele, and LDL cholesterol but not with the E4 allele, whereas that of control subjects was associated with age, sex, systolic blood pressure, LDL cholesterol, and HDL cholesterol, inversely. These results suggested that the E4 allele was not associated with the carotid or femoral IMTs, but that the D allele was statistically associated with carotid IMT in NIDDM patients but not control subjects. However, since the association was weak (2.3% explanatory power), its biological significance remains to be determined.

To elucidate the relationship between diabetic autonomic neuropathy and gastrointestinal motility, antroduodenal motility was studied in patients with diabetes using duplex sonography.Antroduodenal motility, transpyloric fluid movement, and velocity curves of fluid flow were studied using duplex sonography in 32 patients with diabetes and 10 healthy subjects after their ingestion of a meat soup.The frequency of antroduodenal coordination was significantly reduced in patients with diabetes with both early and definite autonomic neuropathy compared with healthy subjects (P0.05 and P0.01, respectively). The frequency and duration of end-cycle reflux episodes were also significantly reduced in patients with early and definite autonomic neuropathy compared with healthy subjects (P0.05 and P0.01, respectively). The frequency of end-cycle reflux episodes was closely correlated with the frequency of antroduodenal coordination in both healthy subjects (r = 0.859; P = 0.002) and patients with diabetes (r = 0.929; P = 0.0001). There was a significant correlation between fasting plasma glucose concentrations and the frequency of antroduodenal coordination in patients with diabetes (r = -0.361; P = 0.039).These findings suggest that reduced frequency and duration of end-cycle reflux episodes may be an early indicator of diabetic gastroparesis that may be related mainly to autonomic neuropathy but also in part to acute hyperglycemia.

Aim: Atherosclerosis and arteriosclerosis are mainly caused by the dysfunction of arterial components, namely, vascular endothelial cells, smooth muscle cells, and the extracellular matrix. Endothelial dysfunction is well established as a predictive surrogate marker of cardiovascular events; however, little is known regarding the clinical implications of vascular smooth muscle dysfunction for cardiovascular disease and microangiopathy. In the present study, we aimed to clarify the association of arterial dysfunction with micro-/macroangiopathy and conventional cardiovascular risk factors in 181 type 2 diabetic patients (T2DM; age±SD, 64±10 years; duration of diabetes, 12±10 years). Methods: Flow-mediated dilatation (FMD) and nitroglycerin-mediated dilatation (NMD) were assessed to evaluate endothelial dysfunction and vascular smooth muscle dysfunction, respectively, by using a novel ultrasound device, UNEXEF18G (Unex Co. Ltd., Japan).Results: The FMD and NMD were 6.4±3.9% and 13.4±6.6%, respectively. No significant differences in FMD were noted between T2DM with and without micro- or macroangiopathy; however, NMD in T2DM patients with micro- and macroangiopathy was significantly lower than that in T2DM patients without angiopathy. NMD decreased with the progression of chronic kidney disease (CKD) stage (p= 0.005), but not FMD (p= 0.071). On multiple regression analysis, significant independent contributors to FMD were age, smoking, systolic blood pressure, glycosylated hemoglobin, and serum total cholesterol, while those for NMD were age, systolic blood pressure, and waist circumference.Conclusion: The relationship of vascular complications and cardiovascular risk factors with NMD is different from that with FMD in type 2 diabetic patients.

In order to study whether or not exogenous and/or endogenous glucocorticoids affect the glucose transport rate in human cells, we examined the transport rate of a non-metabolizable hexose analogue, 3-O-methyl-D-glucose, in polymorphonuclear leukocytes from patients with hypercortisolism. The mean glucose transport rate was prominently decreased in 5 patients with Cushing's syndrome compared with 29 healthy controls (5.4 +/- 1.8 vs 10.4 +/- 2.5 fl/cell.sec, mean +/- SD, p < 0.001) and the transport rate returned to normal range after adenoma resection in 2 of them. In 10 patients with nephrotic syndrome treated with prednisolone, a significant negative correlation was found between transport rates and daily prednisolone doses. When prednisolone of 40 mg/day was administered to a diabetic patient and the dose was gradually reduced, glucose transport rate was transiently decreased during the initial period. In an in vitro study, a synthetic glucocorticoid, dexamethasone, directly inhibited glucose transport rate in those cells in time- and concentration-dependent manners by mainly reducing Vmax. These results suggest that either exogenous or endogenous hypercortisolism in humans is associated with a decrease in glucose transport rate in polymorphonuclear leukocytes, and that the direct effect of glucocorticoids accounts at least in part for the decreased glucose transport rates found in those cells.

Gut transit using radiopaque markers was assessed in 5 healthy subjects and 24 diabetic patients. In the diabetics, various parameters including duration of the disease and diabetic complications, such as neuropathy, retinopathy and nephropathy, were determined, and the relationships between gut transit times and these complications were evaluated. The effect of cisapride on gut transit was studied in 10 diabetic patients. Large intestinal, descending colon, distal colon, and whole gut transit times were delayed in diabetics with autonomic neuropathy compared to controls and to diabetics without autonomic neuropathy (P less than 0.01). There was no difference in proximal colon transit times among them. An inverse correlation was observed between CVRR and the transit times for descending colon, distal colon, large intestine and whole gut. Large intestinal and whole-gut transit times were delayed in diabetics with retinopathy or with nephropathy compared to diabetics without those complications (P less than 0.01). In the diabetics, oral administration of 7.5 mg/day of cisapride for 2 weeks significantly accelerated descending colon transit (P less than 0.05) and partially accelerated distal colon, large intestinal and whole-gut transit. It is concluded that diabetics with autonomic neuropathy have delayed transits for the whole gut and that this finding is apparent to some extent in the distal colon but not in the proximal colon. Chronic oral administration of cisapride, a gastrointestinal prokinetic drug, was effective to improve these gastrointestinal motility disorders in diabetics with autonomic neuropathy.

We studied the transport rate of a non-metabolizable hexose analogue, 3-O-methyl-D-glucose, in polymorphonuclear leukocytes (insulin-insensitive cells) from patients with untreated non-insulin-dependent diabetes mellitus. The mean glucose transport rate was significantly elevated in the diabetic patients compared with healthy controls (13.3 +/- 3.7 vs 10.4 +/- 2.5 fl/cell.sec, mean +/- SD, p less than 0.01). In the diabetic subjects, glucose transport rates were positively correlated with HbA1c levels (r = 0.563, p less than 0.01) but had no relations with ambient plasma glucose concentrations. Short-term incubation with 20 mM D-glucose had no effect on glucose transport in those cells. When glucose transport rates, HbA1c and fasting plasma glucose levels were simultaneously measured at weekly intervals over a four-week period in three diabetic subjects, the alterations in transport rates generally paralleled the changes observed in HbA1c levels rather than plasma glucose concentrations. It can be concluded that unlike insulin-sensitive cells such as adipocytes and muscle, glucose transport in human polymorphonuclear leukocytes, which are insulin insensitive cells, is increased in patients with non-insulin-dependent diabetes mellitus. Long-term, not short-term, derangement of glucose metabolism seems to be associated with increased glucose transport rate found in those patients.

Calcium metabolism was studied in patients with diabetes mellitus. Information on the dietary intake of major nutrients was gathered from 23 non-insulin-dependent diabetic patients, 42 insulin-dependent diabetic patients and 245 nondiabetic patients under hemodialysis through a questionnaire. A calcium absorption test was performed, using an isotopic technique, in 11 non-insulin-dependent diabetic patients and 4 age-matched healthy subjects. Parathyroid function was examined, using oral phosphate loading, in 6 diabetic patients and 6 age-matched control subjects. The daily dietary intake of calcium in the non-insulin-dependent diabetic patients (602 +/- 52 mg) was up to the average daily nutritional requirement (600 mg). The calcium absorption rate in these patients (54.4 +/- 13.9%) was similar to that in the healthy subjects (50.1 +/- 5.4%). The response of parathyroid hormone to phosphate loading was significantly reduced in the diabetic patients compared to the control subjects. The results suggest that calcium homeostasis in diabetic patients with normal renal function is almost conserved, despite the decreased response of parathyroid hormone to phosphate loading.

Increased arterial stiffness is an independent predictor of death from cardiovascular disease, and aortic stiffness is more predictive than stiffness of other arterial regions. Because little is known about the effect of chronic kidney disease (CKD) on regional arterial stiffness, pulse wave velocity (PWV) of four different arterial segments was measured in patients who had type 2 diabetes with and without various stages of CKD. A total of 434 patients had type 2 diabetes, and there were 192 healthy control subjects who were comparable in age and gender. GFR was estimated by the abbreviated Modification of Diet in Renal Disease equation. The patients with diabetes were classified into CKD stages by the definition of the Kidney Disease Outcomes Quality Initiative guidelines. PWV was measured in the heart-femoral, heart-carotid, heart-brachial, and femoral-ankle segments simultaneously using an automatic pulse wave analyzer. PWV of each arterial region was increased in patients who had diabetes without kidney damage and was increased further in a stepwise manner with the advanced stages of CKD. The increase in PWV was greater in the heart-femoral and heart-carotid regions than in the heart-brachial and femoral-ankle segments. However, after adjustment for age, BP, and other confounding factors using a multiple regression model, decreased GFR was independently associated with increased PWV of the heart-femoral region but not with PWV of other arterial segments. In type 2 diabetes, CKD was associated with increased stiffness of arteries, particularly of the aorta. The cross-sectional result may explain the increased risk for cardiovascular disease in CKD, although longitudinal studies are needed to confirm it.

It is difficult to predict the hypoglycemic effect of pioglitazone (a thiazolidinedione) as an insulin sensitizer. The purpose of the present study was to investigate whether insulin resistance index, homeostasis model assessment index (HOMA-IR) is a useful predictor of hypoglycemic effect of pioglitazone in comparison with body mass index (BMI).Thirty-four type 2 diabetic patients (14 men and 20 women, mean age 60 +/- 14 years) were treated with pioglitazone, 15 mg per day for 3 months. Eighteen subjects showed a decrease of 0.5% or more in HbA1C after treatment and were considered responders while 16 subjects were non-responders. A receiver operating characteristic (ROC) analysis was performed to determine HOMA-IR and BMI sensitivity and the false positive rate (1-specificity) for discriminating responders from non-responders.Although there was no significant difference in age, sex, fasting plasma glucose, HbA1C and BMI between responders and non-responders, fasting insulin levels and HOMA-IR prior to treatment were significantly higher in the responders than in the non-responders. In ROC analysis, the sensitivity, false positive rate, and efficiency for HOMA-IR at the cut-off value, 4.6, with the highest efficiency were 81.2%, 22.2%, and 79.4%, respectively, and those for BMI at the cut-off value, 29.1, were 87.5%, 53.3%, and 67.7%, respectively.HOMA-IR is a useful predictor of pioglitazone treatment in type 2 diabetic patients.

OBJECTIVE—To investigate whether the quantitative insulin sensitivity check index (QUICKI) and the reciprocal index of homeostasis model assessment (1/HOMA-IR) derived from fasting plasma glucose and insulin level are excellent surrogate indices of insulin resistance in both normal range-weight and moderately obese type 2 diabetic and healthy subjects. RESEARCH DESIGN AND METHODS—The association between QUICKI or 1/HOMA-IR and insulin resistance index assessed by euglycemic-hyperinsulinemic clamp (clamp-IR) was investigated in 121 type 2 diabetic and 29 healthy subjects recruited from among 120 (age 55 ± 11, 48 ± 15, and 52 ± 15 years [means ± SD], respectively). Type 2 diabetic subjects were divided into groups of 76 normal range-weight and 45 moderately obese subjects (BMI 21.4 ± 2.3 vs. 27.2 ± 2.2 kg/m2, P < 0.0001). RESULTS—QUICKI and 1/HOMA-IR were significantly lower in the moderately obese group than in the normal range-weight type 2 diabetic and healthy groups (n = 120) (QUICKI, 0.338 ± 0.030, 0.371 ± 0.037, and 0.389 ± 0.041, respectively, P < 0.0001; 1/HOMA-IR, 0.50 ± 0.33, 0.92 ± 0.55, and 1.24 ± 0.82, P < 0.0001). QUICKI was strongly correlated with clamp-IR in normal range-weight, moderately obese type 2 diabetic, and healthy subjects (r = 0.641, 0.570, and 0.502, respectively; all subjects, r = 0.608, P < 0.01) and 1/HOMA-IR exhibited correlations comparable to those of QUICKI with clamp-IR (r = 0.637, 0.530, and 0.461, respectively; all subjects, r = 0.589, P < 0.001). In multiple regression models including QUICKI or 1/HOMA-IR as an independent variable, the estimation formula accounted for 55% of the variability of clamp-IR for the group of all type 2 diabetic subjects (R2 = 0.547 and 0.551, respectively, P ≤ 0.0001). CONCLUSIONS—QUICKI and 1/HOMA-IR were highly correlated with clamp-IR, with comparable coefficients in both normal range-weight and moderately obese type 2 diabetic patients and nondiabetic subjects. The latter can probably be applied clinically in view of its convenience.

Elevated intermediate-density lipoprotein (IDL), a remnant lipoprotein, is an independent risk factor for atherosclerosis in patients with end-stage renal disease (ESRD). Since the presence of diabetes mellitus further increases the risk of cardiovascular mortality in ESRD, we examined the effect of diabetes on IDL among ESRD patients. The subjects were 330 healthy control subjects and 287 patients with end-stage renal disease including 80 patients with type 2 diabetes. As compared with the healthy subjects, the nondiabetic ESRD patients had increased plasma triglyceride and IDL cholesterol. Diabetic patients with ESRD showed a further increase in plasma triglyceride and IDL cholesterol compared with the nondiabetic group. However, the difference in IDL levels between the ESRD groups was no longer significant when subjects were stratified by plasma triglyceride. Plasma triglyceride was correlated with IDL cholesterol. Increased hemoglobin A(1c) was significantly associated with IDL cholesterol in a multiple regression model including age, gender, and the presence of ESRD. Such an association was no longer significant in another model including plasma triglyceride as an additional covariate. Further analysis indicated the positive effects of diabetes and hyperglycemia on plasma triglyceride. These results indicate that increased IDL in ESRD is further deteriorated in the presence of diabetes, and that the adverse effect is accounted for at least partly by hypertriglyceridemia associated with chronic hyperglycemia.

The peroxisome proliferator-activated receptor (PPAR) gamma is an important regulator of adipocyte differentiation and a modulator of intracellular insulin-signaling events. We examined the roles of the Pro12Ala variant of PPAR gamma2 in obesity and insulin resistance in 402 Japanese patients with type 2 diabetes and 116 control subjects. Among the diabetes subjects, the Pro12Pro homozygotes showed significantly higher body mass index (BMI) than those with the Pro12Ala variant (p = 0.020), while there was no association between genotype and BMI in the controls. Furthermore, diabetic subjects with Pro12Pro showed significantly higher fat body mass index (FBMI) than those with Pro12Ala (p = 0.016), while no association between genotype and lean body mass index (LBMI) was observed. Regarding insulin resistance, there was no difference in the HOMA index or in clamp index between Pro12Ala and Pro12Pro variants. These data suggest that the Pro12Ala polymorphism of PPAR gamma2 does not influence insulin resistance but body composition in Japanese diabetic subjects.

Monckeberg's medial sclerosis (MMS) is one of the characteristic calcified lesions of uremic artery disease and often exhibits osseous metaplasia. Although its pathogenic mechanism is largely unknown, MMS may contain two different pathologic processes: degenerative process leading to apoptosis or necrosis of medial smooth muscle cells and osteogenic process leading to formation of bone-like structures. It has long been known that calcification follows necrosis. Apoptotic/necrotic cells often release matrix vesicles or membranous cellular degradation products resulting from disintegration of the cells that frequently serve as the nidus of calcification. On the other hand, vascular cells may exhibit osteoblastic phenotype in vitro, and some of the markers for osteoblastic differentiation and noncollagenous proteins regulating mineralization have been demonstrated in calcified arterial lesions. As a possible etiologic factor inducing these two responses, hyperphosphatemia among various metabolic disturbances recognized in uremia may play an important role in the development of MMS in uremia.

Stiffening and thickening of arterial wall are two important components of atherosclerosis. The purpose of this study was to evaluate the effects of femoral artery wall stiffness on clinical manifestation of peripheral vascular disease (PVD) in type 2 diabetes mellitus. The subjects were 315 patients with type 2 diabetes. Presence of intermittent claudication and/or leg pain at rest and reduced ankle-brachial blood pressure index (ABI

Abstract —Oxidation of LDLs plays an important role in atherosclerosis, and immune response to oxidized LDL (oxLDL) may modulate atherogenesis. Although immunization with oxLDL is shown to suppress atherogenesis in animal models, the role of the immune response to oxLDL is not well established in humans. We investigated the relationship between the titer of anti-oxLDL antibody (oxLDL Ab) and arterial wall thickness in a healthy population with no clinical signs of atherosclerosis. Intima-media thickness of the carotid arteries (CA-IMT) was measured by high-resolution B-mode ultrasonography in 446 healthy subjects. The titer of IgG-class oxLDL Ab was measured by a solid-phase ELISA. In univariate analysis, CA-IMT correlated positively with age, systolic blood pressure, total cholesterol, triglyceride, LDL cholesterol, body mass index, and waist-to-hip ratio, whereas it correlated negatively with HDL cholesterol and oxLDL Ab titer. The inverse association between oxLDL Ab titer and CA-IMT remained significant in multiple regression analysis, which took other confounding variables into account. These results indicate an independent inverse relationship between oxLDL Ab titer and CA-IMT in healthy subjects, supporting the hypothesis that immune response to oxLDL may have a protective role at an early stage of human atherosclerosis.

Abstract —Endothelial dysfunction has been implicated in the pathogenesis of diabetic microangiopathies such as retinopathy and nephropathy as well as macrovascular diseases. The aim of the current study was to determine whether endothelial function in the retinal and renal arteries is impaired in type 2 diabetes mellitus. We examined the effects of an intravenous infusion of l -arginine and a sublingual administration of nitroglycerin on the brachial, retinal, and interlobar arterial hemodynamics in 20 type 2 diabetic patients (10 with normoalbuminuria and 10 with microalbuminuria) and 10 aged-matched control subjects. Despite no difference in the nitroglycerin-induced vascular response of the brachial or retinal artery among the 3 groups, the l -arginine–induced vascular response of each artery was significantly lower in both the normoalbuminuric and microalbuminuric patients than in the control subjects and the microalbuminuric patients showed the lowest value among the 3 groups ( P l -arginine–induced vascular response of each artery was significantly correlated with HbA1c levels (brachial artery, r =0.617, P =0.0003; retinal artery, r =0.599, P =0.0005; interlobar artery, r =0.636, P =0.0002). In addition, stepwise multiple regression analysis of all subjects showed that HbA1c level was an independent determinant for the l -arginine–induced vascular response of each artery. The results showed that the endothelium-dependent vascular responses of the retinal and intrarenal arteries as well as the brachial artery were impaired in diabetic patients before the clinical manifestation of diabetic nephropathy, and suggest that endothelial dysfunction in these arteries is associated with hyperglycemia in these patients.

OBJECTIVE: To investigate whether the insulin resistance index (IR) assessed by homeostasis model assessment (HOMA) is associated with the insulin resistance index assessed by euglycemic-hyperinsulinemic clamp (clamp IR) in type 2 diabetic patients who received sulfonylureas (SUs), as well as in those treated by diet alone. RESEARCH DESIGN AND METHODS: Retrospectively, the association between HOMA IR and clamp IR was analyzed in 80 type 2 diabetic subjects (53 subjects treated with SUs and 27 subjects treated with diet alone). The 80 subjects, selected because they had not received insulin therapy, were among 111 diabetic participants in a clamp study for evaluation of insulin resistance from May 1993 to December 1997 in Osaka City University Hospital. RESULTS: The HOMA IR showed a hyperbolic relationship with clamp IR. The log-transformed HOMA IR (all subjects, r = -0.725, P < 0.0001; SU group, r = -0.727, P < 0.0001; diet group, r = -0.747, P < 0.0001) correlated more strongly with clamp IR than did HOMA IR per se (all subjects, r = -0.594, P < 0.0001; SU group, r = -0.640, P < 0.0001; diet group, r = -0.632, P = 0.0004). The univariate regression line between log-transformed HOMA IR and clamp IR in the SU group did not differ from that in the diet group (slope, -6.866 vs. -5.120, P > 0.05; intercept, 6.566 vs. 5.478, P > 0.05). Stepwise multiple regression analyses demonstrated that the log-transformed HOMA IR was the strongest independent contributor to clamp IR (R2 = 0.640, P < 0.0001). CONCLUSIONS: The HOMA IR strongly correlated with the clamp IR in type 2 diabetic patients treated with SUs as well as in those treated with diet alone.

OBJECTIVE: We assessed the effects of atherosclerosis on the glomerular filtration rate (GFR) in patients with type 2 diabetes and who had micro- or normoalbuminuria. RESEARCH DESIGN AND METHODS: A total of 61 Japanese patients with type 2 diabetes were recruited from inpatients of Osaka City University Hospital. They ranged in age from 40 to 69 years (28 men and 33 women). Each subject collected a 24-h urine sample for quantitative analysis of albumin. Absence of albuminuria was defined as a urinary albumin excretion level of

OBJECTIVE To investigate the association between arterial wall stiffness indexes β of the common carotid artery (CCA) and the femoral artery (FA) and insulin resistance in NIDDM subjects in a cross-sectional study. RESEARCH DESIGN AND METHODS We evaluated the arterial stiffness indexes β of CCA and FA using an ultrasonic phase-locked echo-tracking system in 60 NIDDM subjects attending the diabetes center in Osaka City University Hospital, compared with 120 ageand sex-matched control subjects. Insulin sensitivity indexes were evaluated using a euglycemic-hyperinsulinemic clamp. RESULTS Stiffness indexes β of both CCA and FA were significantly higher in NIDDM subjects than in control subjects (CCA 18.1 ± 0.9 vs. 11.7 ± 0.3, respectively, P < 0.001; FA 35.7 ± 2.3 vs. 23.7 ± 0.8, respectively, P < 0.001). The mean insulin sensitivity index in NIDDM subjects was 4.69 ± 0.29 mg · kg−1 · min−1 · mU−1 · 1. The stiffness indexes β of both CCA and FA were inversely correlated with insulin sensitivity indexes (CCA r = −0.393, P = 0.002; FA r = −0.329, P = 0.010), as well as with age, duration of diabetes, and mean blood pressure. In stepwise multiple regression analyses, insulin sensitivity index and duration of diabetes were identified as significant independent variables for stiffness indexes 3 in both CCA and FA (CCA R2 = 0.249, P = 0.0003; FA R2 = 0.336, P < 0.0001). CONCLUSIONS Arterial stiffness indexes β of CCA and FA were associated with insulin resistance in NIDDM subjects.

OBJECTIVE The purpose of the study was to examine the relationship between gastric emptying and the efficacy of an α-glucosidase inhibitor in NIDDM patients. RESEARCH DESIGN AND METHODS Sixteen NIDDM patients (4 patients treated with diet therapy alone and 12 receiving a sulfonylurea) were given 0.6 mg of voglibose daily for 4 weeks. The efficacy of voglibose was assessed by measurement of HbA1c, fasting plasma glucose, and 45- and 120-min postprandial plasma glucose (PPG) and serum insulin concentrations before and after the 4 weeks of voglibose therapy. Gastric emptying was evaluated using the proportional cumulative area under the absorption curve (% AUC) of plasma acetaminophen concentration at 60 min after ingestion of a liquid test meal containing 20 mg/kg of acetaminophen. These measurements were also taken before and after the therapy. RESULTS The change in the 45-min PPG levels from the fasting state correlated significantly with the % AUC of the plasma acetaminophen concentrations (r = 0.625, P = 0.0096) before the voglibose administrations. The mean 45-min and 2-h PPG levels were reduced significantly after 4 weeks of voglibose (P < 0.05 and P < 0.01, respectively). Two-hour postprandial serum insulin concentrations were also significantly reduced at the end of the treatment period (P < 0.05). The changes in the PPG levels between pre- and posttreatment periods correlated significantly with the % AUC of the plasma acetaminophen concentrations before the treatment period (r = 0.499, P = 0.0490; r = 0.713, P = 0.0019, respectively). There was no significant difference in the plasma acetaminophen concentrations between pre- and posttreatment periods. CONCLUSIONS The rate of gastric emptying affects the efficacy of voglibose therapy in NIDDM patients. Voglibose did not however alter the rate of gastric emptying.

Plasma leptin level is known to correlate with the degree of obesity. To determine the influences of renal fuction and insulin resistance on plasma leptin concentrations, we measured plasma leptin concentrations and performed the euglycaemic hyperinsulinaemic clamp studies in 57 patients with non-insulin-dependent diabetes mellitus with a wide range of renal function. In simple regression analyses, plasma leptin concentration showed significant positive correlations with percentage of body fat measured by dual energy X-ray absorptiometry, body mass index, waist to hip ratio and fasting plasma insulin. Leptin level was higher in females than males. Multiple regression analyses indicated that percent body fat, waist to hip ratio, plasma insulin, gender and renal function (1/creatinine), but not insulin sensitivity, were significant and independent determinants of plasma leptin level. These results suggest that plasma leptin level is regulated or affected by multiple factors including renal function. Insulin resistance appeared to increase leptin levels indirectly by raising plasma insulin. [Diabetologia (1997) 40: 676–679]

Background The insertion/deletion ( I/D ) polymorphism of the ACE gene has been shown to be associated with cardiovascular disease in healthy subjects as well as in patients with non–insulin-dependent diabetes mellitus (NIDDM). We investigated the relationship between the ACE gene polymorphism and the wall thickness of both carotid and femoral arteries in NIDDM patients. Methods and Results We measured the intimal plus medial thickness (IMT) of both carotid and femoral arteries using high-resolution B-mode ultrasonography in 288 Japanese NIDDM patients (160 men, 128 women). No significant differences among the three genotypes were found with respect to age, sex, duration of diabetes, body mass index, blood pressure, plasma glucose, hemoglobin A 1C , total cholesterol, triglycerides, HDL cholesterol, or cigarette-years. Plasma ACE levels were strongly associated with I/D polymorphism, with an additive effect of the D alleles. The carotid IMT of the patients carrying the D allele ( DD+ID genotype) was significantly higher than that of the patients not carrying the D allele ( II genotype) ( P =.037), whereas the femoral IMT was not affected by the I/D polymorphism. Multiple regression analysis demonstrated that the risk factors for carotid IMT of patients with NIDDM were age, non-HDL cholesterol, and D allele of the ACE gene ( R 2 =.155, P Conclusions The D allele of the ACE gene may be a risk factor for the development of wall thickening of the carotid but not the femoral artery in NIDDM patients.

A generalized hypersensitivity reaction against human insulin was demonstrated in a non-insulin dependent diabetic man treated with only human insulin. The patient had no history of previous insulin exposure or atopy. Because of negative reactions to intracutaneous tests of constituents of the formulation and the presence of insulin-specific IgE antibody, this generalized allergic reaction seems to have been caused by the human insulin itself. Although desensitization was not effective, this allergic reaction was improved both by the treatment with oral antihistamines and desensitization. Cases of generalized and primary allergy against human insulin have been rarely reported making this a very rare case.

The patient, a 69-year-old woman, was admitted to Osaka City University Hospital on July 25, 1992, for severe hypercalcemia. Laboratory data on admission revealed severe hypercalcemia of 14.9 mg/dl and renal dysfunction with serum creatinine of 2.9 mg/dl. As reflected by increased urinary excretions of pyridinoline and deoxypyridinoline and suppressed serum levels of parathyroid hormone (PTH) and 1,25-dihydroxyvitamin D, increased bone resorption seemed to be a main factor for the development of hypercalcemia. The development of hypercalcemia seemed to be acute because of (i) her severe symptoms caused by hypercalcemia and (ii) impaired renal function which improved after normalization of serum calcium. Following combination therapy of saline infusion and furosemide, there was a gradual decrease and later normalization of serum calcium together with serum creatinine. Even 8 months after discontinuation of the therapy for hypercalcemia, the serum calcium level has remained within the normal range. Measurement of serum factors which have hypercalcemia effects such as PTH, parathyroid hormone-related peptide and cytokines (interleukin-1 alpha, interleukin-1 beta, interleukin-2, interleukin-6 and tumor necrosis factor-alpha) were all within the normal range. In summary, hypercalcemia in this patient was regarded as a kind of disequilibrium hypercalcemia due to a combination of increased bone resorption and decreased renal capacity to excrete calcium. Furthermore, since it was temporary and has not recurred despite no treatment, her hypercalcemia developed due to imbalance in calcium regulation but not due to any organic disease.

Total body bone mineral content and bone mineral content in various body sites were measured by dual-photon absorptiometry in 103 patients with non-insulin-dependent diabetes mellitus (NIDDM) and the findings were compared with those for 214 non-diabetic control subjects matched for age and body weight. Neither total body bone mineral content (TBBM) nor the bone mineral density of the third lumbar vertebra (L3 BMD) in the diabetic subjects differed from the values in control subjects of either sex, but the values were significantly decreased in patients diseased for at least five years when compared with control subjects. Regional bone mineral measurement showed prominent bone loss in the truncal site, but no reduction in bone mass was found in the head, pelvis, arms, or legs in either male or female patients. These results suggest that reduced TBBM and L3 BMD are associated with duration of the disease and that a site-specific bone defect is present in NIDDM.

OBJECTIVE To determine whether hemodynamic changes in retinal arteries precede clinical manifestations of diabetic retinopathy and to examine the effects of control of hyperglycemia on retinal artery blood flow. RESEARCH DESIGN AND METHODS We assessed blood flow in bilateral central retinal arteries in 50 insulin-dependent diabetes mellitus (IDDM) patients without retinopathy and 20 sex- and age-matched control subjects using duplex Doppler sonography. We determined the peak systolic velocity (PSV), end-diastolic velocity (EDV), time-averaged velocity (TAV), resistance index (RI), and pulsatility index (PI). RESULTS PSV, EDV, and TAV were significantly lower in IDDM patients than in control subjects (P < 0.05, P < 0.01, and P < 0.01, respectively). The RI was significantly higher in IDDM patients than in control subjects (P < 0.01) and was significantly correlated with plasma levels of glucose in IDDM patients (r = 0.0.310, P = 0.0248). Multiple regression analysis identified the plasma levels of glucose as a significant determination of RI in IDDM patients. After 14 days of intensive insulin therapy in 7 IDDM patients, the RI and plasma levels of glucose showed significant decreases (P = 0.018, P = 0.001, respectively). CONCLUSIONS Our results showed that changes in retinal hemodynamics were present before the clinical detection of overt diabetic retinopathy and suggest that the presence of short-term hyperglycemia partly contributes to impaired retinal circulation.

In a 19-year-old Japanese male (case 1) with thyrotoxic periodic paralysis (TPP), an increase of plasma glucose concentration together with abnormally high levels of serum immunoreactive insulin (IRI) was observed preceding a spontaneous attack of paralysis. Therefore, the plasma glucose, glucagon, epinephrine, norepinephrine, serum IRI, growth hormone and cortisol levels, and the erythrocyte insulin receptors were measured in case 1 and a 40-year-old Japanese male (case 2) with TPP during attacks of paralysis induced by prolonged glucose loading. In case 1, the serum IRI concentration was elevated to the extraordinarily high level of 655.0 microU/ml at the beginning of paralysis, and at that time, the plasma glucose concentration was 147 mg/dl. However, when paralysis was not induced by a similar glucose loading during methimazole treatment, the serum IRI and plasma glucose levels at the corresponding time after glucose loading were 20.9 microU/ml and 87 mg/dl, respectively. Furthermore, the affinity of the erythrocyte insulin receptors was decreased during the attack. In case 2, plasma glucose and serum IRI concentrations were increased in accordance with the initiation of paralysis although the blood levels of hormones counteracting insulin were not significantly changed. These findings suggest that there is something interacting with the normal action of the insulin in the early phase of paralysis.

Transport of the nonmetabolizable glucose analogue, 3-O-methylglucose, was assessed in human polymorphonuclear leucocytes with or without the chemotactic peptide N-formylmethionylleucylphenylalanine(fMet-Leu-Phe). The peptide increased entry of labelled 3-O-methylglucose about 5-fold and the intracellular distribution space about 70%. The half-time of equilibration was 3 s in the treated cells. Similar effects were observed with zymosan-treated serum (containing the chemotactic factor C5a), with arachidonic acid, calcium ionophore A23187 and phorbol myristate acetate. However, the chemtotactic protein, thrombin, had no effect, even though binding to high-affinity receptors was demonstrated. Km for zero-trans entry of 3-O-methylglucose was about 1 mM and fMet-Leu-Phe increased Vmax from 5 to about 25 amol · s−1 · cell−1. Similar values were obtained from incubations for a few seconds with glucose and 2-deoxyglucose. The rate of 2-deoxyglucose uptake (8 min incubations) was limited by the transport step at substrate concentrations lower than approx. 0.1 mM, whereas the phosphorylation step became rate-limiting at higher concentrations. Thus, 2-deoxyglucose uptake can only be taken as a measure of transport at a tracer concentration. It is concluded that chemotactic factors can, but do not necessarily, increase the maximal transport velocity of hexoses entering the polymorphonuclear leucocyte via the glucose transporter.

Transport of the non-metabolizable hexose analogue 3-O-methyl-D-glucose (3OMG) was measured at 37 degrees C, pH 7.4, in human polymorphonuclear leukocytes (PMNLs) obtained from 15 ml of fresh venous blood. In the study, 0.05 mM of 3OMG was equilibrated with a half-time of about 10 s, and the rate constant was 0.074/s in PMNLs from a healthy subject (male, 38 years). The coefficient of variation of values assayed on different days was about 7% and the intra-assay variation was about 2%. The transport rate did not differ between the two sexes or between subjects of different ages (23-63 years), but was significantly higher in 23 patients with non-insulin-dependent diabetes than in 29 normal controls (13.3 +/- 3.7 vs. 10.4 +/- 2.5 fl/cell.s, mean +/- SD). In conclusion, the measurement of transport of 3OMG in PMNLs may be useful for the study of glucose transport in clinical investigations.

Transport of the nonmetabolizable hexose analogue 3-O-methyl-D-glucose (30MG) was measured in human polymorphonuclear leukocytes at 37 degrees C, pH 7.4. 3OMG at very low concentration (0.05 mM) equilibrated with the intracellular water with a rate constant of about 0.08 s-1. Transport of 3OMG in the presence of 20 microM cytochalasin B and transport of L-glucose were insignificant. Countertransport of 14C-labelled 3OMG was demonstrated. Exchange of 3OMG between the extracellular and intracellular water showed saturation with a Km of about 4 mM. Thus, the transport of 3OMG is mediated almost exclusively by facilitated diffusion.