The association between serum activin A levels and albuminuria among community-dwelling middle-aged and older adults in Taiwan

Activin A, a cytokine belonging to the transforming growth factor-β family, has been shown to play pivotal roles in tissue remodeling after renal injury and is present in elevated levels in diabetic patients. However, the association between activin A and albuminuria remains unclear. We aimed to evaluate their association by using cross-sectional data from community-dwelling middle-aged and older adults in Taiwan. We assessed 466 participants (67% male; mean age 71 ± 13 years) from the I-Lan Longitudinal Aging study for whom data pertaining to serum activin A level and urine albumin-to-creatinine ratio (UACR) were available. Of these, 323 (69%) had normal albuminuria, 123 (26%) had microalbuminuria, and 20 (4%) had overt albuminuria. Patients with overt albuminuria and microalbuminuria had significantly higher activin A concentrations than those in the normal albuminuria group (p < 0.001). Circulating activin A was significantly correlated with multiple risk factors, including higher systolic blood pressure and higher UACR. Univariate and multivariate results indicated that activin A level was an independent variable for albuminuria. The cutoff value of 602 pg/mL of activin A demonstrated a sensitivity of 70.6% and specificity of 75.7% (AUC 0.774) in diagnosing overt albuminuria. In conclusion, middle-aged and older adults with elevated activin A levels were associated with a higher incidence of albuminuria.

Abstract 3781: A Reduction in Urinary Albumin Excretion is Associated with a Decrease in 10-year Cardiovascular Mortality in Hypertensive Type 2 Diabetic Patients

Urinary albumin excretion (UAE) is one of the strongest predictors of both adverse renal and cardiovascular outcomes in patients with type 2 diabetes. Although measurement of UAE is widely recommended, there is little available data to suggest that reducing UAE translates into a reduction in cardiovascular mortality. We assessed whether an early reduction in UAE is associated with improved long-term cardiovascular mortality in hypertensive type 2 diabetic patients with normo, micro, or overt albuminuria at baseline. The study is a 10-year longitudinal analysis of a prospective, randomized study- the Appropriate Blood Pressure Control in Diabetes (ABCD) trial including 393 type 2 diabetic patients with hypertension. We evaluated the association between the change in UAE from baseline to 1-year with the incidence of all cause and cardiovascular mortality over a ten year period. Our results revealed that a reduction in log UAE achieved at one-year was one of the strongest predictors of reduced cardiovascular mortality in a multivariable model that adjusted for multiple cardiovascular risk factors (HR1.42, 95% CI 1.06 – 1.92). This association was at all levels of UAE, normo, micro and overt albuminuria. In conclusion, an early reduction in UAE even at the normoalbuminuria level is associated with improvements in long-term cardiovascular mortality. Our data support current guideline recommendations to screen for UAE in all type 2 diabetic patients, but also suggest that serial UAE measurements after initiation of therapy may have clinical value. Prospective studies addressing this approach to care are needed prior to widespread adoption in practice.