Skeletal muscle microvascular exchange capacity is associated with hyperglycaemia in subjects with central obesity

• Published in: Diabetic medicine Vol. 26; no. 11; pp. 1112 - 1119
• Main Authors: Turzyniecka, M., Wild, S. H., Krentz, A. J., Chipperfield, A. J., Gamble, J., Clough, G. F., Byrne, C. D.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.11.2009; Blackwell
• Subjects: Biological and medical sciences; Diabetes Mellitus, Type 2 - etiology; Diabetes Mellitus, Type 2 - physiopathology; Diabetes. Impaired glucose tolerance; Endocrine pancreas. Apud cells (diseases); Endocrinopathies; Etiopathogenesis. Screening. Investigations. Target tissue resistance; Feeding. Feeding behavior; Female; Fundamental and applied biological sciences. Psychology; glycated haemoglobin; Glycated Hemoglobin A - metabolism; HbA1c; Humans; Hyperglycemia - etiology; Hyperglycemia - physiopathology; insulin sensitivity; Male; Medical sciences; microcirculation; Microcirculation - physiology; Middle Aged; Muscle, Skeletal - metabolism; Muscle, Skeletal - physiopathology; obesity; Obesity, Abdominal - complications; Obesity, Abdominal - physiopathology; Plethysmography; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Vertebrates: endocrinology; Endocrinopathy; Exchange capacity; Human; Obesity; Pancreatic hormone; Nutrition; Insulin sensitivity; Diabetes mellitus; HbA; Nutrition disorder; Metabolic diseases; Hemoglobin A1; Striated muscle; Insulin; Microcirculation; Hyperglycemia; Association; Hemoglobin A1c; Glycated hemoglobin; glycated haemoglobin; Endocrinology; Nutritional status
• ISSN: 0742-3071; 1464-5491; 1464-5491
• DOI: 10.1111/j.1464-5491.2009.02822.x

Aims  Poor glycaemic control is associated with increased risk of microvascular disease in various organs including the eye and kidney, but the relationship between glycated haemoglobin (HbA1c) and microvascular function in skeletal muscle has not been described. We tested the association between HbA1c and a measure of microvascular exchange capacity (Kf) in skeletal muscle in people with central obesity at risk of developing Type 2 diabetes. Methods  Microvascular function was measured in 28 women and 19 men [mean (± sd) age 51 ± 9 years] with central obesity who did not have diabetes. We estimated insulin sensitivity by hyperinsulinaemic–euglycaemic clamp, visceral and total fatness by magnetic resonance imaging, fitness (VO2 max by treadmill testing), physical activity energy expenditure [metabolic equivalents of tasks (METS) by use of the SenseWear Pro armband] and skeletal muscle microvascular exchange capacity (Kf) by venous occlusion plethysmography. Results  In regression modelling, age, sex and fasting plasma glucose accounted for 30.5% of the variance in HbA1c (r2 = 0.31, P = 0.001). Adding Kf to this model explained an additional 26.5% of the variance in HbA1c (r2 = 0.57, P = 0.0001 and Kf was strongly and independently associated with HbA1c (standardized B coefficient −0.45 (95% confidence interval −0.19, −0.06), P = 0.001). Conclusions  We found a strong negative independent association between a measure of skeletal muscle microvascular exchange capacity (Kf) and HbA1c. Kf was associated with almost as much of the variance in HbA1c as fasting plasma glucose.