Higher Glycemic Control Associated with Lower Albuminuria

Worldwide, the leading cause of chronic kidney disease (CKD) is diabetes mellitus. According to data from the National Health and Nutrition Examination Survey (NHANES), the prevalence of kidney disease in patients with diabetes overall has not changed over time. However, there have been changes in the prevalence of the independent defining features of kidney disease.

Albuminuria (albumin creatinine ratio [ACR], ≥30 mg/g) has declined over time, while the prevalence of estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2 has increased. There are few available data on whether the prevalence of those features is associated with glycemic control (defined by hemoglobin A1c).

Mitra Mosslemi and colleagues at the University of California, Irvine, conducted a study to examine the association of glycemic control level with clinical manifestation of CKD among patients with diagnosed diabetes. The researchers reported results in a presentation during the NKF Spring Clinical Meetings. The presentation was titled Association of Glycemic Control Level with the Clinical Manifestation of Kidney Injury among Patients with Diagnosed Diabetes.

The cross-sectional study analyzed NHANES data from 1999 through 2016. Diagnosed diabetes cases where those who reported being diagnosed by a physician or using glucose-lowering medications (n=5647). The researchers characterized the proportion of any CKD (ACR ≥30 or eGFR <60), albuminuria only (ACR ≥30 and eGFR ≥60), reduced eGFR only (ACR <30 and eGFR <60), and both albuminuria and reduced eGFR (ACR ≥30 and eGFR <60) among patients with diagnosed diabetes with good (a1c <7%), intermediate (7% ≤ A1c <9%), and poor glycemic control (A1c >9%).

The study also examined the prevalence of patients with hyperfiltration (defined by eGFR >120) across glycemic control groups. The association between eGFR and ACR with A1c was assessed using univariate and multivariable linear regression models.

Proportions of any CKD in the study population were similar across glycemic control groups: good, 51%; intermediate, 50%; and poor, 54%. The proportion of patients with reduced eGFR only was highest in the good glycemic control group, and the albuminuria only status was highest in the group with poor glycemic control.

In univariate analyses, there were significant associations between A1c and ACR and between A1c and eGFR. Following adjustment for age, sex, race, and age at diagnosis of diabetes, the association remained significant only for ACR. In the poor glycemic control group compared with the other two groups, the percentage of hyperfiltration (relatively higher eGFR) was higher: 8.5% versus intermediate, 4% and good, 3.2%.

“This study demonstrated that among patients with diabetes, better glycemic control is associated with lower albuminuria, but not higher eGFR level. Further studies should examine the risk factors of eGFR decline in patients with diabetes,” the researchers said.

Source: Mosslemi M, Wenziger C, Hsiung J-T, et al. Association of glycemic control level with the clinical manifestation of kidney injury among patients with diagnosed diabetes. Abstract of a presentation at the National Kidney Foundation 2020 Spring Clinical Meetings; abstract #311.