To elucidate the association of glomerular filtration rate (GFR) at baseline with subsequent progression of albuminuria in individuals with type 2 diabetes.
This was a single-center retrospective cohort study of 6,618 Japanese adults with type 2 diabetes and urinary albumin-to-creatinine ratio of <300 mg/g, comprising 2,459 women and 4,159 men with a mean (± SD) age of 60 ± 12 years. The exposure was baseline estimated GFR (eGFR) (mL/min/1.73 m2), treated as a categorical variable and classified into five categories: ≥90, 75–90, 60–75, 45–60, and <45, as well as a continuous variable. The outcome was progression of albuminuria category (i.e., from normoalbuminuria to micro- or macroalbuminuria or from micro- to macroalbuminuria). Hazard ratios (HRs) for the outcome were estimated using the multivariable Cox proportional hazards model. In the analysis treating baseline eGFR as a continuous variable, the multivariable-adjusted restricted cubic spline model was used.
During the median follow-up period of 6.3 years, 1,190 individuals reached the outcome. When those with a baseline eGFR of 75–90 mL/min/1.73 m2 were considered the reference group, HRs (95% CIs) for the outcome in those with a baseline eGFR of ≥90, 60–75, 45–60, or <45 mL/min/1.73 m2 were 1.38 (1.14–1.66), 1.34 (1.14–1.58), 1.81 (1.50–2.20), or 2.37 (1.84–3.05), respectively. Furthermore, the inverse J-shaped curve was more clearly shown by the spline model.
This study of Japanese adults with type 2 diabetes suggests that both high and low GFRs are implicated in the pathogenesis of albuminuria progression.
Glomerular hyperfiltration may induce kidney damage.
We asked whether glomerular filtration rate (GFR) is associated with subsequent development and progression of albuminuria in people with diabetes.
This retrospective cohort study of 6,618 adults with type 2 diabetes has shown that both an estimated GFR (eGFR) ≥90 mL/min/1.73m2 and an eGFR <75 mL/min/1.73m2 at baseline were risk factors for the subsequent category progression of albuminuria.
This study suggests that both a high and low GFR are implicated in the pathogenesis of albuminuria development and progression in people with diabetes.
This article contains supplementary material online at https://doi.org/10.2337/figshare.21399495.