Trajectories of kidney function and associated factors among community-dwelling older Japanese: a 16-year...

No study has reported trajectories of kidney function in later life. This long-term prospective study attempted to classify trajectories of estimated glomerular filtration rate (eGFR) and identify factors associated with these trajectories.

We collected data from annual geriatric health checkups conducted during 2002-2017 in Kusatsu Town, Gunma Prefecture, Japan. The participants were 1990 adults aged 65-90 years (mean [SD] age, 71.0 [5.7] years; 57.0% women), and the total number of observations was 9291. Data were analyzed with a group-based semiparametric mixture model and age-adjusted univariable cumulative logit models.

Trajectory of kidney function, as determined by eGFR, was classified as low, middle, and high (4.8%, 38.9%, and 56.3% of men, respectively, and 5.2%, 31.5%, and 63.3% of women). Among men and women in the low trajectory group, chronic kidney disease (CKD) stage worsened from stage G3a (51.8 ml/min/1.73 m² in men and 53.6 in women) at age 65 years to stage G4 (28.0 ml/min/1.73 m² in men and 28.5 in women) by age 85 years. A history of hypertension (men and women) and heart disease (men) were more likely in the low trajectory group than in the middle and high trajectory groups.

About 5% of community-dwelling older adults had an eGFR < 30 later in life. Our findings suggest that those with stage G3a CKD at age 65 years should be managed intensively, to control risk factors for CKD progression.