#3011 INCIDENT CHRONIC KIDNEY DISEASE IN NEWLY DIAGNOSED DIABETES MELLITUS
Authors: Fong Jie Ming Nigel , Kog Zheng XI , Yang Xu , Teo Pek Siang Edmund , Poh Cheng Boon , Tay Hui Boon , Choo Jason , Tan Ngiap Chuan , Bee Yong Mong , Kwek Jia Liang 
Published: June 2023

Abstract

Background and Aims
Singapore has the world's 3rd highest rate of incident end-stage kidney disease (ESKD) on dialysis. Diabetes mellitus (DM) was the cause of ESKD in 68% of patients initiating dialysis in 2020. We explored the rate of incident CKD in newly diagnosed DM, and risk factors associated with the development of incident CKD.

Method
This is a retrospective cohort of patients newly diagnosed with DM in 2014-2020, in primary care and specialist clinics across Singapore's largest health system. Patients were excluded if they had known CKD, were not screened for CKD, or were diagnosed with CKD at the first screening (which may reflect pre-existing CKD). CKD was defined as a CKD-EPI glomerular filtration rate (GFR) &lt;60 ml/min/1.73 m2, and/or urine albumin-creatinine ratio (UACR) &gt;3 mg/mmol. Two readings ≥3 months apart were required for diagnosis. Demographic and laboratory data was retrieved from electronic records, and analysed using Pearson's Chi-square, Wilcoxon rank-sum test, and Cox regression evaluating time to onset of incident CKD.

Results
Of 25714 patients with newly-diagnosed DM and no known CKD, 3963 (15.4%) were not screened for CKD, and 2019 (7.9%) were diagnosed with CKD at the first screening; both groups were excluded. The remainder 19732 patients (76.7%) formed the study cohort. This included 14175 Chinese (71.8%), 3085 Malay (15.6%), 1658 Indian (8.4%), and 814 patients of other ethnicities (4.1%). Baseline mean (SD) GFR was 90.7 (17.6) ml/min/1.73 m2. Over a mean follow up of 2.28 (1.98) years, 5929 patients (30.0%) developed incident CKD after a mean of 1.35 (1.09) years. Of patients who developed CKD, 869 (14.7%) met the GFR criteria, 4847 (81.8%) developed albuminuria, and 213 (3.6%) met both criteria. GFR declined more rapidly in patients who developed CKD (−2.8 (4.4) ml/min/1.73 m2/year), than in patients who did not (−1.7 (5.7) ml/min/1.73 m2/year, p&lt;0.001). GFR decline began in the first year. Baseline characteristics associated with incident CKD on bivariate analysis (Table 1) included older age (61 (11) vs 59 (12) years, p&lt;0.001), female gender (p&lt;0.001), lower GFR (89 (19) vs 91 (17) ml/min/1.73 m2, p&lt;0.001), higher systolic blood pressure (136 (17) vs 135 (17) mmHg, p&lt;0.001), and ischemic heart disease (p&lt;0.001). On multivariate Cox regression exploring characteristics associated with time to incident CKD, independent risk factors include female gender (HR 1.30, 95%CI 1.23-1.39), lower GFR (per 10ml/min/1.73 m2 lower GFR, HR 1.10, 95%CI 1.08-1.11), higher systolic blood pressure (per 10mmHg rise, HR 1.06, 95%CI 1.04-1.08), higher HbA1c (per 1% rise, HR 1.06, 95%CI 1.05-1.08), cerebrovascular accident (HR 1.16, 95%CI 1.02-1.31) and gout (HR 1.16, 95%CI 1.01-1.32). Despite a prevalence of hypertension of 85%, only 5440 (28%) of the cohort with incident CKD received an angiotensin converting enzyme inhibitor (ACE) or angiotensin receptor blocker (ARB) (as at 6 months after diagnosis of DM). 498 patients (2.5%) received a sodium-glucose cotransporter-2 inhibitor, which was not widely available during the period of this study.

Conclusion
Incident CKD was frequent in early DM; the risk factors above may identify higher-risk patients who benefit from enhanced screening. The relatively low rate of ACE/ARB prescription may require further review.