Antidiabetic medication use and prevalence of chronic kidney disease among patients with type 2 diabetes mellitus in the United States

Abstract

Objectives: The aims of this study were to estimate the proportion of patients with type 2 diabetes mellitus (DM) in the United States with different stages of chronic kidney disease (CKD) and to describe glycemic control and antidiabetic drug use among them.

Methods: Using data from the Fourth National Health and Nutrition Examination Survey (NHANES IV) for the years 1999 through 2004, we performed a cross-sectional analysis of patients with type 2 DM aged >or=20 years at the time of the survey interview. CKD stages were categorized according to the classification system established by the National Kidney Foundation Kidney Disease Outcomes Quality Initiative. Anti-diabetic medication use among these patients was described using self-reported survey responses as well as survey medication files.

Results: A total of 1462 patients with type 2 DM were included in the analysis. Men and women constituted 48.3% and 51.7% of the study sample, respectively; 15.6% received a DM diagnosis <2 years ago, and 36.2% received their diagnosis >10 years ago. CKD was present in 39.7% of patients with DM. Mean (SE) glycosylated hemoglobin was lower in more advanced CKD stages, from stage 1 (8.35% [0.23%]) to combined stages 4 and 5 (6.63% [0.15%]). Based on the medication file data, the proportion of patients with CKD using 1 antidiabetic medication was higher as CKD progressed, from 36.3% at stage 1 to 62.9% at stages 4 and 5 (P = 0.007). By self-report, the proportion of patients with CKD using insulin alone was 6.7% at stage 1 and 38.8% at stages 4 and 5 (P < 0.001). The proportion of patients using oral antidiabetic agents alone was 69.0% at stage 1 and 43.4% at stages 4 and 5 (P < 0.001).

Conclusions: Our results indicate that 39.7% of adult patients with type 2 DM in the United States had some degree of CKD, as measured in NHANES IV for the years 1999 through 2004. This finding reinforces the need to screen patients with type 2 DM for CKD and to prevent the cascade of events leading to nephropathy by implementing adequate glycemic and blood pressure controls, especially in the early stages of CKD. Our data also reinforce the need for developing more oral antidiabetic therapies for patients with advanced CKD and type 2 DM, because treatment options for this group are limited.