Chronic kidney disease in type 2 diabetes: trends in prevalence, clinical phenotypes and outcomes

Type 2 diabetes mellitus (T2DM) is one of the leading causes of chronic kidney disease (CKD). This review analyzes the results of studies assessing the prevalence, clinical phenotypes, and outcomes of CKD in T2DM. Over the past 20–30 years, there has been a global trend toward an increase in the number of patients with T2DM and CKD. At the same time, the prevalence of CKD among patients with T2DM appears to remain stable and averages 25–30%. Studies from different countries demonstrate both upward and downward trends in the prevalence of CKD among patients with T2DM. This may be explained by differences in study design and completeness of CKD screening, as well as true differences in the prevalence of CKD in different populations. In patients with T2DM, CKD is heterogeneous in morphological and clinical characteristics, course, and outcomes. An obvious trend in the epidemiology of CKD in patients with type 2 diabetes is the increasing prevalence of renal function decline in the absence of albuminuria. Female gender, older age, optimal glycemic and hypertension control, use of renin-angiotensin system blockers, and the absence of diabetic retinopathy are associated with non-albuminuric CKD in type 2 diabetes. Patients with type 2 diabetes and the albuminuric phenotype of CKD appear to have a higher risk of developing end-stage renal disease and major adverse cardiovascular events compared with patients with type 2 diabetes and non-albuminuric CKD. The reported incidence of end-stage renal disease in patients with type 2 diabetes varies widely, from 0.41 to 6.9 cases per 1000 patient-years. The diversity of data can be explained by differences in baseline patient characteristics and different duration of follow-up. The heterogeneity of the design of studies conducted to date, the small number of prospective studies on large samples make it difficult to objectively assess the dynamics of the prevalence and incidence of CKD in patients with type 2 diabetes. Studies of the epidemiology of CKD in patients with type 2 diabetes in real clinical practice are urgently needed.