OBJECTIVES The relationship between the renin-angiotensin system (RAS) and diabetes has been studied for many years. However, studies that assessed RAS components comprehensively were limited. We hypothesized that serum RAS components, especially the effector peptide angiotensin-II, might be closely associated with glucose metabolism status and diabetic complications.

METHODS We investigated the association of individual RAS component with albuminuria in 407 subjects with normal glucose metabolism (NGM), prediabetes, or type 2 diabetes mellitus (T2DM). Anthropometric and biochemical parameters, including glucose homeostasis, albuminuria, and RAS-related parameters such as plasma renin activity (PRA), aldosterone, angiotensin-converting enzyme (ACE), and angiotensin-II levels, were measured.

RESULTS The mean±standard deviation (SD) age and body mass index were 57.1±11.1years and 24.7±3.3kg/m², respectively. There were 54 subjects with NGM, 102 with prediabetes, and 251 with T2DM. The mean±SD angiotensin-II levels in these groups were 9.32±6.89, 12.89±10.39, and 17.00±15.28pg/mL, and the respective urinary albumin-to-creatinine ratios (ACRs) were 8.1±5.3, 13.3±17.3, and 30.7±51.9mg/g, which were significantly different among the groups. The serum angiotensin-II levels were correlated with levels of PRA, insulin resistance, C-reactive protein, and urinary ACR. Among RAS-related parameters, only the angiotensin-II level was significantly associated with urinary ACR after adjusting for relevant risk factors.

CONCLUSIONS Angiotensin-II may play an important role in the development of albuminuria, particularly in subjects with impaired glucose metabolism.