What are the next steps for maintaining kidney health with normal kidney function?

Maintaining Kidney Health with Normal Kidney Function

If your kidney function is truly normal, continue annual screening with both eGFR and urine albumin-to-creatinine ratio (UACR), optimize blood pressure and glucose control if you have diabetes, and adopt lifestyle modifications including regular physical activity and dietary sodium restriction. 1

Annual Screening Requirements

• Measure both estimated glomerular filtration rate (eGFR) and urinary albumin-to-creatinine ratio (UACR) at least once yearly to detect early kidney damage before symptoms appear, as CKD in early stages is completely asymptomatic 1, 2, 3
• For patients with type 1 diabetes of ≥5 years duration or any patient with type 2 diabetes, annual screening is mandatory regardless of current kidney function 1
• Testing should include serum creatinine to calculate eGFR and a random spot urine sample for UACR 1, 4

Blood Pressure and Glucose Optimization

• Target blood pressure <130/80 mmHg to prevent future kidney damage, as uncontrolled hypertension is one of the leading causes of CKD and can accelerate GFR decline by 4-8 mL/min per year 1, 4
• If you have diabetes or prediabetes, optimize glucose control to A1C <7% (or individualized target) to reduce risk of developing diabetic kidney disease, which affects 20-40% of patients with diabetes 1, 4
• Do not use ACE inhibitors or ARBs for primary prevention if you have normal blood pressure and normal UACR (<30 mg/g), as these medications are not recommended in this setting 1

Lifestyle Modifications

Physical Activity

• Undertake moderate-intensity physical activity for at least 150 minutes per week or to a level compatible with your cardiovascular tolerance 1
• Avoid sedentary behavior and incorporate both aerobic and resistance exercises 1

Dietary Recommendations

• Limit sodium intake to <2 g per day (equivalent to <5 g of sodium chloride or <90 mmol sodium daily) 1
• Maintain protein intake at approximately 0.8 g/kg body weight per day (the recommended daily allowance), and avoid high protein intake >1.3 g/kg/day as this increases risk of albuminuria and kidney function decline 1
• Adopt a diet with higher consumption of plant-based foods compared to animal-based foods and lower consumption of ultra-processed foods 1
• Achieve and maintain optimal body mass index through healthy dietary patterns 1

Tobacco and Nephrotoxin Avoidance

• Do not use any tobacco products, as smoking accelerates kidney disease progression 1, 4
• Minimize exposure to nephrotoxic agents including nonsteroidal anti-inflammatory drugs (NSAIDs), which can cause kidney damage even with normal baseline function 1, 4

Risk Factor Assessment

• Evaluate for diabetes or prediabetes, as these significantly increase risk of developing CKD, with screening particularly important if you have family history of kidney disease, hypertension, obesity, or age >50 years 4, 2
• Monitor for metabolic syndrome components (hypertension, prediabetes, dyslipidemia, obesity) as their combination dramatically accelerates CKD development 4

Common Pitfalls to Avoid

• Do not assume normal kidney function means no monitoring is needed - early CKD is asymptomatic and can only be detected through laboratory testing 2, 3, 5
• Do not rely on serum creatinine alone - always calculate eGFR using validated equations and measure UACR, as these provide independent prognostic information 4
• Do not skip UACR testing - albuminuria can be the first sign of kidney damage even when eGFR remains normal (CKD stages 1-2) 1, 4
• Avoid combining multiple nephrotoxic medications, as this significantly increases kidney injury risk even with initially normal function 6
• Do not discontinue screening if you develop diabetes, hypertension, or other risk factors - increase monitoring frequency to twice yearly in these situations 1