P5.05 EXERCISE- INDUCED ALBUMINURIA IS A MANIFESTATION OF EXERCISE AORATIC RESERVOIR FUNCTION IN PATIENTS WITH TYPE 2 DIABETES MELLITUS

Abstract

Objectives: Patients with type 2 diabetes (T2DM) are susceptible to exercise-induced albuminuria even at submaximal exercise, but the mechanisms are unknown. Recent data indicates that T2DM patients have raised central blood pressure (BP) during submaximal exercise and this could contribute to renal dysfunction independent of upper arm BP. This study sought to determine the relationship between exercise central haemodynamics and exercise-induced albuminuria in T2DM. Methods: Forty T2DM patients (62±9 years; 50% male) and 40 healthy controls (53±9 years; 50% male) were examined at rest and during a 20-minute bout of light cycle exercise (40W; 50RPM). Haemodynamics recorded included, aortic reservoir function (excess pressure integral [xsP] and aortic reservoir pressure), aortic stiffness, augmented pressure (AP), brachial and central BP. Albuminuria was assessed by albumin/creatinine ratio (ACR) at rest and within 20 minutes after exercise. Results: There was no difference between groups in resting ACR (p>0.05). Exercise induced a significant ACR rise in T2DM patients but not controls (0.39±0.89 vs 1.05±1.38 mg/mol, p=0.017). All central haemodynamic variables indicative of systolic stress were significantly higher during exercise in T2DM participants (i.e. xsP, systolic BP and AP; p<0.01 all). For T2DM patients, exercise xsP was independently associated with increased ACR (β=0.003, p=0.001), independent of age, sex, body mass index, and 24-hour ambulatory SBP. Conclusions: Aortic reservoir function, as determined by excess pressure during submaximal exercise, is independently associated with exercise-induced albuminuria in T2DM patients. These novel findings suggest that aortic reservoir function could be important for appropriate renal function in patients with T2DM.