Type 2 diabetes strengthens the association between pulse pressure and chronic kidney disease: The AusDiab study

Objective: Chronic kidney disease (CKD) is a serious disorder with significant public health impact. Identification of factors associated with risk of progression of kidney disease may help in earlier intervention in high-risk groups. We investigated whether brachial pulse pressure (PP) was associated with 5-year changes in estimated glomerular filtration rate (eGFR) and incident CKD and whether type 2 diabetes modified these associations. Methods: In the population-based Australian Diabetes, Obesity and Lifestyle Study (AusDiab) 5554 individuals (5.8% with type 2 diabetes) who took part in the 5-year follow-up and had no CKD or microalbuminuria at baseline were included. Results: After adjusting for baseline age, sex, eGFR and use of blood pressure-lowering medication, each baseline SD higher PP was associated with a decline in eGFR of 0.32 ml/min (P = 0.006) and an odds ratio (OR) for CKD of 1.29 [95% confidence interval (CI) 1.09-1.53] in individuals without type 2 diabetes. In individuals with type 2 diabetes, eGFR declined by 1.10 ml/min (P = 0.011) and the OR for incident CKD was 1.94 (1.14-3.29). Similar associations with eGFR decline were observed with systolic blood pressure and incident CKD in individuals without type 2 diabetes. In individuals with type 2 diabetes, higher systolic blood pressure was only significantly associated with eGFR decline if the diastolic blood pressure was 70 mmHg or less (P for interaction between systolic and diastolic blood pressure: 0.033). CONCLUSIONS: PP is an important risk factor for eGFR decline and incident CKD over a 5-year period, especially in individuals with type 2 diabetes.