Increased plasma concentrations of osteoprotegerin in type 2 diabetic patients with microvascular complications.

OBJECTIVE: Osteoprotegerin (OPG) is a newly identified inhibitor of bone resorption. Recent studies indicate that OPG also acts as an important regulatory molecule in the vasculature. Plasma levels of OPG seem to be elevated in subjects with diabetes as well as in non-diabetic subjects with cardiovascular disease. The aim of the present study was to examine the association between plasma OPG levels and microvascular complications and glycemic control in patients with type 2 diabetes. DESIGN AND METHODS: Four groups of 20 subjects in each, individually matched for age and gender, were included in the study: (i) subjects with normal glucose tolerance (NGT); (ii) subjects with impaired glucose tolerance (IGT); (iii) type 2 diabetic patients without retinopathy; and (iv) type 2 diabetic patients with diabetic maculopathy (DMa). Plasma concentration of OPG was measured in duplicate by a sandwich ELISA method. Furthermore, fundus photography, flourescein angiography, and measurements of urinary albumin excretion rate (RIA) were performed. RESULTS: Plasma OPG was significantly higher in diabetic (iii+iv) than in NGT (i) subjects (3.04+/-0.15 vs 2.54+/-0.16 ng/ml, P<0.05). Plasma OPG was significantly higher in the DMa (iv) group than in the NGT (i) group (3.25+/-0.23 vs 2.54+/-0.16 ng/ml, P=0.01). Moreover, plasma OPG was significantly higher (3.61+/-0.36 ng/ml) in the group of diabetic subjects with both microalbuminuria and DMa (n=7) than in the NGT (i) (2.54+/-0.16 ng/ml, P<0.01), IGT (ii) (2.82+/-0.21 ng/ml, P<0.05), and no retinopathy (iii) groups (2.83+/-0.20 ng/ml, P<0.05). CONCLUSIONS: We found increased levels of OPG in plasma from diabetic patients with microvascular complications. This finding indicates that OPG may be involved in the development of vascular dysfunction in diabetes [corrected].

E-selectin-inducing activity in plasma from type 2 diabetic patients with maculopathy.

Diabetic maculopathy (DMa) is a leading cause of visual loss in the western world. We examined whether plasma from type 2 diabetic patients with DMa contains factor(s) capable of inducing expression of the adhesion molecules E-selectin and VCAM-1 or cellular proliferation in cultured endothelial cells. Four gender-, age-, and duration (diabetes groups)-matched groups of 20 subjects each participated: 1) subjects with normal glucose tolerance (NGT), 2) subjects with impaired glucose tolerance (IGT), 3) type 2 diabetic patients without retinopathy, and 4) type 2 diabetic patients with DMa. Fasting plasma was added to in vitro-grown human umbilical vein endothelial cells for 6 h, after which E-selectin and VCAM-1 expression was measured. Proliferation was evaluated by thymidine incorporation. The individuals were characterized by measurement of 24-h ambulatory blood pressure, urinary albumin excretion rate, Hb A(1c), and blood lipids. Plasma from type 2 diabetic patients with DMa induced a significantly higher expression of E-selectin in endothelial cells than did plasma from subjects with NGT (259 +/- 23 x 10(3) vs. 198 +/- 19 x 10(3); arbitrary absorbance units; P < 0.05). There were no significant differences in plasma stimulatory effects on VCAM-1 expression or on thymidine incorporation between groups. These findings suggest that plasma from type 2 diabetic patients with DMa contains factor(s) capable of inducing the expression of E-selectin in endothelial cells. Enhanced expression of E-selectin may contribute to the development of DMa in type 2 diabetes.

Insulin resistance is accompanied by increased von Willebrand factor levels in nondiabetic women: a study of offspring of type 2 diabetic subjects compared to offspring of nondiabetic subjects.

OBJECTIVES: To examine whether levels of von Willebrand factor (vWF), fibrinogen and fibronectin are related to a parental history of type 2 diabetes and to determine possible explanatory factors for high versus low vWF and fibrinogen. DESIGN: Cross-sectional study. SUBJECTS, MAIN OUTCOME MEASURES: We compared vWF, fibrinogen and fibronectin in 88 nondiabetic offspring of type 2 diabetic subjects (relatives) and 103 offspring of nondiabetic subjects (controls). Other measurements included urinary albumin excretion rate, blood pressure, lipid profile and insulin resistance using homeostasis model assessment (HOMAIR). RESULTS: There were no significant differences in vWF (1.12 vs. 1.06 IU x mL(-1), P = 0.296), fibrinogen (3.2 vs. 3.1 g x L(-1); P = 0.263) or fibronectin (0.39 vs. 0.40 g x L(-1), P = 0.448) between relatives and controls. With multiple logistic regression we determined explanatory factors for high versus low vWF and fibrinogen. Age (P < 0.01), urinary albumin excretion rate (P < 0.05), ischaemic heart disease (IHD) (P < 0.05) were found to be significant explanatory factors for vWF above the median (1.10 IU x mL(-1)). Interaction between insulin resistance and sex was found. Odds ratio for high versus low insulin resistance was 18.39 (P < 0.001) for women and 1.92 (P = 0.32) for men. Body mass index (BMI) (P < 0.05), sex (P < 0.01), smoking status (P < 0.05) and IHD (P < 0.01) were significant explanatory factors for fibrinogen above the median (3.1 g x L(-1)). CONCLUSIONS: Levels of vWF, fibrinogen and fibronectin were not influenced by a parental history of type 2 diabetes. Insulin resistance was found to be a significant risk indicator for high vWF only in women. This may indicate that insulin resistance is a higher risk factor for women than for men, when the outcome is endothelial dysfunction possibly resulting in overt cardiovascular disease.

Autonomic neuropathy in nondiabetic offspring of type 2 diabetic subjects is associated with urinary albumin excretion rate and 24-h ambulatory blood pressure: the Fredericia Study.

The aim of this study was to examine the impact of parental type 2 diabetes on the autonomic nervous system and to determine whether autonomic neuropathy is present and associated with changes in 24-h ambulatory blood pressure (AMBP) and urinary albumin excretion rate (UAER) in nondiabetic subjects with parental type 2 diabetes. We examined 223 nondiabetic offspring of type 2 diabetic subjects and a control group of 258 offspring of nondiabetic subjects. The autonomic nervous system was assessed by three cardiovascular reflex tests, 24-h AMBP was measured with an oscillometric recorder (90207; Spacelabs, Redmond, WA), and UAER was determined through three overnight urine samples. The subjects with parental type 2 diabetes had significantly lower heart rate variation in all three bedside tests (P < 0.01) than subjects without parental diabetes. The prevalence of autonomic neuropathy in the nondiabetic offspring with parental type 2 diabetes (6.7%) was significantly (P < 0.01) higher compared with the control group (1.6%). Autonomic neuropathy was associated with a higher fasting insulin level (P < 0.05), higher UAER (P < 0.001), higher 24-h mean AMBP (P < 0.01), and reduced diurnal blood pressure variation (P < 0.001) after adjustment for age, sex, and BMI. In conclusion, parental type 2 diabetes was found to be associated with alterations in the autonomic nervous system in nondiabetic subjects. The presence of autonomic neuropathy in subjects with parental type 2 diabetes was associated with higher UAER, fasting insulin level, and 24-h AMBP and a reduced diurnal blood pressure variation. This study indicates that parental type 2 diabetes has an impact on the cardiac autonomic function in nondiabetic subjects.

Normal blood pressure and preserved diurnal variation in offspring of type 2 diabetic patients characterized by features of the metabolic syndrome: the Fredericia Study.

OBJECTIVE: To examine whether an elevated blood pressure (BP) level and an impaired reduction in nocturnal BP are already present in nondiabetic first-degree relatives of type 2 diabetic patients. RESEARCH DESIGN AND METHODS: We examined 253 offspring of type 2 diabetic patients using ambulatory BP monitoring and compared the BP level and profile with 275 offspring of nondiabetic subjects. Anthropometric measures and cholesterol, fasting blood glucose, and insulin levels were also compared between groups. RESULTS: No significant differences in BP level (P > 0.05) or diurnal BP profile were evident between the nondiabetic glucose-tolerant offspring of type 2 diabetic subjects and the offspring of nondiabetic subjects. BMI (P < 0.05 and P < 0.01, male vs. female), waist-to-hip ratio (P < 0.05), fasting blood glucose (P < 0.01), C-peptide (P < 0.05 and P < 0.01, male vs. female), insulin resistance index (P < 0.05 and P < 0.01, male vs. female), triglycerides (P < 0.05), apolipoprotein B (apoB) (P < 0.01 and P < 0.05, male vs. female), and apoA1/apoB (P < 0.01) were significantly higher in the nondiabetic offspring of type 2 diabetic subjects than in the offspring of nondiabetic subjects. CONCLUSIONS: This study shows a preserved diurnal BP profile and a normal BP level in the nondiabetic glucose-tolerant offspring of type 2 diabetic subjects compared with the offspring of nondiabetic subjects, although the offspring of diabetic patients are characterized by features of the metabolic syndrome.