Albuminuria regression and all-cause mortality among insulin-treated patients with Type 2 diabetes: analysis of a large UK Primary Care cohort

Anyanwagu, U.; Donnelly, R.; Idris, I.

Abstract

Background: Overt albuminuria (urinary albumin-creatinine ratio (ACR) >300mg/g) is an established risk factor for progression of nephropathy and total mortality. However, whether, a reduction in ACR translates into a reduction in mortality and/or cardiovascular events among insulintreated patients with Type 2 diabetes (T2D) in routine practice is currently not known.
Methods We obtained data on a large cohort of insulin users with T2D and nephropathy (baseline ACR ≥ 300mg/g) from UK general practices between 2007 and 2014. Their corresponding ACR values after one year of follow up were thereafter categorised into: (1) less than 300mg/g (i.e. albuminuria regression) or (2) >300mg/g (i.e. non-regression of albuminuria), and the cohort was followed up for 5 years for all-cause mortality and cardiovascular events. Cox proportional hazard models were fitted to estimate the risk of all-cause death.
Results A total of 11,074 patients with insulin-treated T2D met the inclusion criteria. Their mean age was 62.3(13.6) years; mean HbA1c: 8.7(1.8) %; and 53% were male. 682 deaths occurred after a follow-up period of 43,393 person-years with a mortality rate of 16 per 1000 person-years. 5-year survival was markedly reduced in the group whose proteinuria persisted or progressed (91 vs 95%; log-rank p-value less than 0.001). Compared to patients whose ACR levels remained above 300mg/g, all-cause mortality and cardiovascular events were 31% and 27% lower in those whose albuminuria regressed to less than 300mg/g (aHR: 0.69; 95%CI: 0.52 to 0.91; p=0.008 and aHR: 0. 73; 95%CI: 0.54 to 0.98; p=0.041) respectively.
Conclusion: In patients with insulin-treated T2D and nephropathy in routine practice, a regression in albuminuria (e.g. via better BP or glycaemic control) is associated with a significant reduction in all-cause mortality. Thus, albuminuria is not simply a risk marker of renal and cardiovascular disease, but also an independent target for therapy. Albuminuria reduction should be viewed as a goal for renal and cardiovascular protection.

Citation

Anyanwagu, U., Donnelly, R., & Idris, I. (2019). Albuminuria regression and all-cause mortality among insulin-treated patients with Type 2 diabetes: analysis of a large UK Primary Care cohort. American Journal of Nephrology, 49(2), 146-155. https://doi.org/10.1159/000496276

• Journal Article Type: Article
• Acceptance Date: Aug 22, 2018
• Online Publication Date: Jan 25, 2019
• Publication Date: Jan 25, 2019
• Deposit Date: Sep 12, 2018
• Publicly Available Date: Jan 26, 2020
• Journal: American Journal of Nephrology
• Print ISSN: 0250-8095
• Electronic ISSN: 1421-9670
• Publisher: Karger Publishers
• Peer Reviewed: Peer Reviewed
• Volume: 49
• Issue: 2
• Pages: 146-155
• DOI: https://doi.org/10.1159/000496276
• Keywords: Nephrology
• Public URL: https://nottingham-repository.worktribe.com/output/1072469
• Publisher URL: https://www.karger.com/Article/Abstract/496276
• Contract Date: Sep 12, 2018