Two eGFR paths emerge in diabetes with CKD and normoalbuminuria
Adults with diabetes and stage 3 chronic kidney disease will experience consistently lower estimated glomerular filtration rates over time despite having normal albuminuria status, according to findings published in Diabetes Care.
“A common assumption is that albuminuria is a necessary precursor for kidney loss,” Dorte Vistisen, PhD, senior researcher and team leader of clinical epidemiology at Steno Diabetes Center Copenhagen in Gentofte, Denmark, told Endocrine Today. “However, our study show[s] that if you have diabetes and moderate kidney loss you are likely on a progressive declining trajectory of kidney function, even if you have a normal urinary albumin excretion ratio.”
Vistisen and colleagues assessed how levels of eGFR changed in 935 adults with type 1 diabetes (mean age, 59.2 years; 51.1% women) and 1,984 adults with type 2 diabetes (mean age, 69.3 years; 42.4% women) after they presented with an eGFR of less than 60 mL/min/1.73 m2 — which was used to establish stage 3 CKD — at Steno Diabetes Center Copenhagen between 2001 and 2017. The median time of follow-up was 5.1 years for those with type 1 diabetes and 3.7 years for those with type 2 diabetes, according to the researchers.
In the group with type 1 diabetes, 427 had normoalbuminuria or a urinary albumin excretion ratio of less than 30 mg/g, and eGFR decreased by 1.9 mL/min/1.73 m2 on average during a 10-year period in this population. The researchers observed two different patterns of eGFR decline in this population. They wrote that 86% experienced a 1.6 mL/min/1.73 m2 spike in eGFR in the first year before a consistent decrease. In contrast, a “steep decline” in eGFR was followed by a plateauing in 14% of the population. Participants who experienced the sharper eGFR reduction had higher measures of cholesterol (P < .011), took fewer lipid-lowering medications (P = .039) and had more instances of severe retinopathy (P = .002) compared with those who increased eGFR initially.
In the group with type 2 diabetes, 942 had normoalbuminuria with the mean loss of eGFR across 10 years reaching a similar 1.9 mL/min/1.73 m2 measure as those with type 1 diabetes. The decline was preceded by rising eGFR levels in the first year in 90% of this population while a steep decline, followed by a slight increase, was noted in 10% of this population, the researchers wrote. Participants in this second group did not exercise as much as those with the initial increase (P = .002), and they also had lower measures of systolic blood pressure (P = .021) and lower diastolic BP (P = .002) and reduced use of renin-angiotensin system blockers (P = .021), antihypertensive treatment (P = .004) and lipid-lowering medication (P = .008), according to the researchers.
“Our results indicate that increased focus on the treatment of kidney disease is needed already in moderate renal impairment,” Vistisen said. “It is not enough to assess the risk of renal complications and ultimately the risk of chronic renal failure solely on the basis of increased excretion urinary albumin.” – by Phil Neuffer
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Dorte Vistisen, PhD, can be reached at firstname.lastname@example.org.
Disclosures: Vistisen reports she owns shares in Novo Nordisk. Please see the study for all other authors’ relevant financial disclosures.