Impact of kidney function and urinary protein excretion on intima–media thickness in Japanese patients with type 2 diabetes

Background Carotid echo indexes [intima–media thickness (IMT)] are commonly used surrogate markers for cardiovascular disease; however, the impacts of chronic kidney disease (CKD) on changes in IMT are unclear. We examined associations between CKD and IMT in participants with and without type 2 diabetes through longitudinal analysis. Methods In total, 424 subjects were enrolled in this study. IMT was measured as per carotid echo indexes. Relationships between IMT and risk factors were analyzed using multiple linear regression analysis, in which we defined IMT as the dependent variable and atherosclerosis-related factors (age, sex, systolic pressure, total cholesterol, body mass index, estimated glomerular filtration rate (eGFR), uric acid, smoking index, number of antihypertensive drugs, statin use, urinary protein levels, past cardiovascular event, glycated hemoglobin, and diabetes duration) as independent variables. Results The study population was composed of 70.3 % male subjects. Participants with diabetes accounted for 64.4 % of the total population. The mean follow-up duration was 2.2 ± 1.5 years. Alterations in IMT tended to be associated with systolic blood pressure (+10 mmHg) ( β = −0.0084, p = 0.09) and eGFR (+10 mL/min/1.73 m 2 ) ( β = −0.0049, p = 0.06) in all participants. In participants without diabetes, alterations in IMT were associated with eGFR (+10 mL/min/1.73 m 2 ) ( β = −0.0104, p = 0.03) and tended to be associated with systolic blood pressure (+10 mmHg) ( β = 0.0094, p = 0.06). No significant relationships were found in participants with diabetes. Conclusion Low eGFR was associated with progression of carotid thickness independent of common cardiovascular risk factors in non-diabetic participants.