OBJECTIVES: To estimate the age-adjusted prevalence and severity of CKD in US adults with diagnosed diabetes, undiagnosed diabetes, prediabetes, and no diabetes.

METHODS: Adult patients (≥20 years) with self-reported diabetes were identified from the National Health and Nutrition Examination Survey between 2009-2016. Participants without the necessary information (serum creatinine, age, gender, and/or race) to determine estimated glomerular filtration rate (eGFR) by the CKD Epidemiology Collaboration (CKD-EPI) equation were excluded. Pregnant participants were also excluded from the study due to the possible bias in their eGFR values. The population was categorized into four sub-groups (diagnosed diabetes, undiagnosed diabetes, pre-diabetes and no diabetes) based on self-reporting and Fasting Blood Glucose (FPG) diagnostic criteria. Stages of CKD was defined as per Kidney Disease: Improving Global Outcomes (KDIGO) 2012 guidelines using the CKD-EPI equation.

RESULTS: There were 2793 patients with diagnosed diabetes, 444 patients with undiagnosed diabetes, 3472 patients with prediabetes, and 4595 patients with no diabetes. The demographical characteristics such as gender, ethnicity, education level and annual household income etc. varied significantly across the four sub-groups. The mean (SD) age of patients with diagnosed diabetes (i.e. 61.47 (13.00)) or undiagnosed diabetes (i.e. 57.53 (15.55)) was higher and these sub-groups had higher FPG, glycohemoglobin and albumin-creatinine ratio than the patients in the prediabetes or no diabetes sub-groups. 70.28% of the diagnosed diabetes group reported hypertension, followed by 49.77% of undiagnosed diabetes, 39% pre-diabetes and 24.22% in no diabetes. The age-adjusted prevalence of CKD varied across the four subgroups (diagnosed diabetes; 55.53%, undiagnosed diabetes; 50.99 %, pre-diabetes; 49.54 % and no diabetes; 46.04%).

CONCLUSIONS: The demographical characteristics differed significantly among four sub-groups. CKD prevalence is high among people with diagnosed, undiagnosed diabetes and pre-diabetes.