Illusion of knowledge: The greatest enemy of nephrology

The greatest enemy of nephrology is the illusion of knowledge rather than the serious complications of cardiorenal conditions, which highlights the importance of early recognition of albuminuria in at-risk patients, according to Professor Cheuk-Chun Szeto of the Department of Medicine & Therapeutics, Chinese University of Hong Kong, who spoke at AIM 2024.

Diabetes, kidneys, and beyond

Patients with diabetes are at risk of cardiorenal syndrome (CRS). CRS involves an interplay between the heart and kidneys, in which acute or chronic dysfunction in one organ may induce acute or chronic dysfunction in the other organ. The cardiorenal interactions are not limited to diabetes patients and can extend to patients with heart failure, chronic kidney disease (CKD), or atherosclerotic cardiovascular disease (CVD). [Circulation 2019;139:e840-e878]

“The greatest enemy of nephrology is not these serious comorbidities, as they can be treated fairly well nowadays,” said Szeto. With proper management (ie, blood pressure control, renin-angiotensin-aldosterone system [RAAS] inhibitors, sodium-glucose cotransporter-2 [SGLT2] Inhibitors, and nonsteroidal mineralocorticoid receptor antagonist [nsMRA]), patients with diabetic kidney disease can gain up to 15 years of dialysis-free survival. [Clin J Am Soc Nephrol 2021;16:1590-1600; Nat Rev Nephrol 2022;18:78-79]

“Instead, the greatest enemy of nephrology is the illusion of knowledge,” pointed out Szeto.

Patients’ and physicians’ illusion of knowledge

A survey in Hong Kong involving 303 diabetes patients revealed that 32 percent had moderate CKD. However, 40 percent of those with CKD were unaware of their kidney function and 15 percent even believed that they had normal kidney function. “The problem lies with healthcare providers, not with our patients,” commented Szeto. “While HbA_1c and creatinine were frequently checked in diabetes patients, approximately 40 percent of physicians had never checked urine albumin. This situation was observed across Hong Kong, the UK, and Europe.” [Szeto CC, AIM 2024]

Albuminuria (ie, elevated levels of urine albumin) is an early indicator of CKD. Of note, the 2024 Kidney Disease: Improving Global Outcomes (KDIGO) Clinical Practice Guideline recommends classifying CKD based on glomerular filtration rate (GFR) and degree of albuminuria (A1 [normal], <30 mg/g or <3 mg/mmol; A2 [microalbuminuria], 30-299 mg/g or 3-29 mg/mmol; A3 [macroalbuminuria], ≥300 mg/g or ≥30 mg/mmol). [Kidney Int 2024;105:S117-S314]

Primary care physicians as gatekeepers

“Early recognition and treatment of CKD require awareness as well as participation of specialists [eg, nephrologists, endocrinologists, cardiologists] and, most importantly, primary care physicians,” said Szeto. “Primary care physicians provide medical care to at-risk populations, including patients with diabetes, hypertension, and mild CVD. While some of these patients may not currently have CKD, they are likely to develop it a few years down the road.”

“CKD screening and risk stratification must include dual assessment of estimated GFR and albuminuria,” highlighted Szeto. “Importantly, the screening and monitoring should be serial instead of one-off.”

The gold standard for albuminuria assessment is urine albumin-to-creatinine ratio (UACR). [Kidney Int 2024;105:S117-S314] “While obtaining a urine sample from a patient and sending it to a laboratory in a hospital setting is a straightforward process, this can be more difficult in private practice settings,” commented Szeto. “Point-of-care urine protein-creatinine ratio [UPCR] test can be an acceptable alternative for albuminuria screening.”