Renal function deterioration in adult patients with type-2 diabetes

Abstract

Background: To explore, in a large group of patients with type-2 diabetes (T2DM), renal function decline in terms of the slope of the estimated glomerular filtration rate (eGFR) over time, and to find out how classical risk factors, such as the presence of hypertension, dyslipidemia and microalbuminuria, affect the renal function.

Methods: The analysis included 32,492 adult T2DM patients from the DIVE/DPV registries who had serial eGFR determinations and information on the presence of microalbuminuria, hypertension and dyslipidemia available.

Results: Patients had a mean age of 66.3 years, 52.6% were male with a mean BMI of 31.7 kg/m². The mean eGFR was 78.4 ± 21.4 mL/min/1.73m². The results showed that the prevalence of renal function impairment understood as chronic kidney disease (CKD) is considerable (53.0%) in a population of patients with T2DM and has a high incidence rate of 6.6% within a year. Serial determinations of the eGFR are, however, infrequent (7.8% of all patients) and these patients are characterised by the presence of a high-risk profile for CKD, such as hypertension (88.1%) and dyslipidemia (66.1%). Over a three-year time period, 30.9% of the patients had an eGFR slope of -12 mL/min/1.73m² or more; and more than a doubled proportion of patients with an eGFR < 30 mL/min/1.73 m² (3.8% vs. 1.8%; p < 0.001). Hypertension and albuminuria contributed to renal function decline while dyslipidemia did not negatively affect the slope.

Conclusion: CKD is highly prevalent in patients with T2DM. Serial surveillance of the glomerular filtration rate is, however, not established in clinical practice, which would be necessary as indicated by a doubling of patients with an eGFR < 30 mL/min/1.73 m² within 3 years. Moreover, the use of renin-angiotensin blocking agents was low, pointing at considerable room for improvement. Taken together we conclude that a closer surveillance of patients with diabetes based on the presence of further risk factors is mandatory combined with a mandatory prescription of RAS blocking agents once microalbuminuria and / or renal function deterioration develops.

Keywords: Chronic kidney disease; Dyslipidemia; Hypertension; Type 2 diabetes; eGFR slope.

Fig. 1

Chronic Kidney Disease prevalence by eGFR and albuminuria (based on [2, 12]). Green, low risk (if no other markers of kidney disease, no CKD); yellow, moderately increased risk; orange, high risk; red, very high risk

Fig. 2

Chronic Kidney Disease incidence by eGFR and albuminuria (based on [2, 12]). Green, low risk (if no other markers of kidney disease, no CKD); yellow, moderately increased risk; orange, high risk; red, very high risk. *There were 27,201 patients with incident CKD during one year. For 9245 of these patients we were not able to group them into risk classes