Central obesity is associated with reduced peripheral wave reflection in Indigenous Australians irrespective of diabetes status

OBJECTIVETo determine the influence of central obesity and type 2 diabetes on peripheral wave reflection in Indigenous Australians. DESIGN AND METHODSA cross-sectional study of remote Indigenous Australians with (n = 43) and without (n = 54) type 2 diabetes of similar age (47 years) and sex; using anthropometric and bioelectrical impedance measures of obesity and applanation tonometry to determine the aortic augmentation index (AI) as an index of peripheral wave relfection. RESULTSIndices of obesity were significantly higher in the diabetic than non-diabetic participants [body mass index (BMI)27.3 versus 24.6 kg/m, P = 0.018; waist circumferencewomen 101 versus 94 cm, P = 0.008, men 102 versus 91 cm, P = 0.039]. AI was negatively related to obesityBMI (r = −0.35, P = 0.0003), weight (r = −0.44, P < 0.0005), waist circumference (r = −0.34, P = 0.0003) and fat mass (r = −0.35, P < 0.0005). There was no significant difference in AI between the groups with and without diabetes. On multiple regression analysis, 66% of the variance in AI was explained with the following significant predictorsage, heart rate, male gender, fat mass and mean arterial pressure. Similar results were obtained when weight, waist circumference or BMI were substituted for fat mass. CONCLUSIONWhen compared with Indigenous Australians without diabetes, those with type 2 diabetes do not have greater aortic pressure augmentation from peripheral wave reflection. However, obesity, irrespective of the index used, was related to lower peripheral wave reflection in both those with and without type 2 diabetes.