Importance: Albuminuria, as measured by single urine albumin-to-creatinine ratio (UACR) levels, is associated with cardiac remodeling and adverse clinical outcomes. The longitudinal patterns of change in UACR through young adulthood and their associations with myocardial structure and function later in life remain unclear.
Objective: To describe the trajectory of albuminuria as measured by UACR across a 20-year span and evaluate the association of albuminuria trajectory with echocardiographic indices of structure and function in middle age.
Design, setting, and participants: In the Coronary Artery Risk Development in Young Adults (CARDIA) study, a prospective cohort of black and white participants aged 18 to 30 years at baseline (March 1985 to June 1986) were evaluated over 30 years. Participants underwent evaluations at 4 urban US sites. Data were collected from March 1985 to May 2016, and data were analyzed from September 2018 to April 2019.
Exposures: Trajectories of UACR from the year 10 examination to the year 30 examination as determined by latent class modeling.
Main outcomes and measures: Echocardiographic indices of myocardial structure, systolic function, and diastolic function at the year 30 examination.
Results: Of the 2647 included participants, 1441 (54.4%) were white, 1206 (45.6%) were black, and the mean (SD) age was 35.2 (3.6) years. A total of 5 trajectory groups of UACR were identified, including 1718 participants (64.9%) in the low-stable group, 682 (25.8%) in the moderate-stable group, 116 (4.4%) in the high-stable group, 88 (3.3%) in the moderate-increasing group, and 43 (1.6%) in the high-increasing group. Apart from the high-increasing cohort, the remaining 4 groups had median baseline UACR levels less than 30 mg/g. Male sex, current smoking, diabetes, and elevated blood pressure were more common in the moderate-increasing and high-increasing UACR groups. After adjustment for clinical variables and baseline UACR levels, there were significant differences in left ventricular (LV) mass by trajectory group (mean [SE] LV mass: high-increasing, 98.4 [3.4] g/m2; moderate-increasing, 91.7 [2.2] g/m2; high-stable, 86.0 [2.1] g/m2; moderate-stable, 82.3 [0.8] g/m2; low-stable, 78.6 [0.5] g/m2; P < .001). Significant differences by trajectory group were also noted in LV longitudinal strain, e' tissue velocities, and estimated LV filling pressures, even after adjustment for clinical variables and baseline UACR level. The association of trajectory group with indices of myocardial structure and function remained significant after adjustment for clinical variables and cumulative UACR from the year 10 to year 25 examinations.
Conclusions and relevance: There are distinct patterns of change in albuminuria among young adults over a 20-year span, and these trajectory groups cannot be identified by baseline UACR level alone. Dynamic changes in albuminuria are independently associated with adverse alterations to cardiac structure, LV systolic function, and LV diastolic function.