What is the significance of elevated creatinine (Creatinine) levels of 1.39 mg/dL, above the high normal range of 0.76-1.27 mg/dL, and an estimated glomerular filtration rate (eGFR) of 56 mL/min/1.73m², which is below the low normal range of >59 mL/min/1.73m², indicating Impaired renal function?

From the Guidelines

Your creatinine level of 1.39 mg/dL is elevated above the normal range (0.76-1.27 mg/dL), and your estimated glomerular filtration rate (eGFR) of 56 mL/min/1.73m² is below the normal threshold of >59, indicating mild kidney function impairment, which is a significant concern as a GFR level less than 60 mL/min per 1.73 m2 represents loss of half or more of the adult level of normal kidney function 1.

Key Points to Consider

• The normal level of GFR varies according to age, sex, and body size, with normal GFR in young adults being approximately 120 to 130 mL/min per 1.73 m2, and it declines with age 1.
• A decreased GFR in the elderly is an independent predictor of adverse outcomes, such as death and cardiovascular disease (CVD), and requires adjustment in drug dosages 1.
• The definition of chronic kidney disease is the same, regardless of age, and is defined as either kidney damage or decreased kidney function (decreased GFR) for 3 or more months 1.

Recommendations

• I strongly recommend scheduling a follow-up appointment with your healthcare provider within the next 2-4 weeks to discuss these results and determine if further evaluation is needed.
• In the meantime, it is crucial to stay well-hydrated with 2-3 liters of water daily, avoid excessive use of NSAIDs like ibuprofen, and inform your doctor about all medications you're taking, as some may affect kidney function.
• If you have diabetes or hypertension, ensure these conditions are well-controlled as they can impact kidney health.
• These laboratory values suggest Stage 3a chronic kidney disease, but a single abnormal result doesn't confirm chronic kidney disease - your doctor will need to assess whether this is a temporary change or represents a persistent condition 1.

From the FDA Drug Label

In patients with severe congestive heart failure whose renal function may depend on the activity of the renin-angiotensin-aldosterone system, treatment with angiotensin converting enzyme inhibitors, including lisinopril, may be associated with oliguria and/or progressive azotemia and rarely with acute renal failure and/or death In hypertensive patients with unilateral or bilateral renal artery stenosis, increases in blood urea nitrogen and serum creatinine may occur. The usual dose of lisinopril tablets, USP (10 mg) is recommended for patients with creatinine clearance > 30 mL/min (serum creatinine of up to approximately 3 mg/dL). For patients with creatinine clearance ≥ 10 mL/min ≤ 30 mL/min (serum creatinine ≥ 3 mg/dL), the first dose is 5 mg once daily In patients with heart failure who have hyponatremia (serum sodium < 130 mEq/L) or moderate to severe renal impairment (creatinine clearance ≤ 30 mL/min or serum creatinine > 3 mg/dL), therapy with lisinopril tablets, USP should be initiated at a dose of 2.5 mg once a day under close medical supervision.

The patient has a creatinine level of 1.39 mg/dL, which is above the normal range, and an eGFR of 56 mL/min/1.73, which is below the normal range.

• The patient's renal function is impaired, but not severely.
• Dose adjustment may be necessary, but the exact dose is not specified in the provided text for this particular scenario.
• Close medical supervision is recommended when initiating therapy with lisinopril in patients with renal impairment.
• Caution should be exercised when using lisinopril in patients with renal impairment, as it may worsen renal function. 2 2

From the Research

Creatinine and eGFR Levels

• The provided creatinine level is 1.39 mg/dL, which is above the high normal range of 0.76-1.27 mg/dL 3.
• The eGFR level is 56 mL/min/1.73, which is below the low normal range of >59 mL/min/1.73 4.

Association with Kidney Disease

• Chronic kidney disease (CKD) is characterized by damage to the renal glomeruli, vascular supply, and/or tubulointerstitium, and can be detected incidentally via urinalysis or blood test results showing an elevated creatinine level 4.
• The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation is the most accurate creatinine-based method for estimating glomerular filtration rate (GFR) in routine practice 4.

Treatment with ACE Inhibitors

• Angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) are commonly used in patients with early CKD, but their value in advanced CKD is unknown 5.
• Studies suggest that combination renin-angiotensin-aldosterone system (RAAS)-inhibiting therapy provides additive benefit in diabetic nephropathy, but may be associated with a reduction in GFR and an increase in serum creatinine 6.
• The use of high doses of ACEI/ARB and their up-titration in patients with CHF and CKD III/IV may be appropriate provided that the patient is adequately monitored 7.

Monitoring and Management

• Patients with CKD should be monitored regularly for changes in renal function, worsening CHF, and hyperkalemia 7.
• Management goals include mitigation of CKD risk factors to slow disease progression, including optimizing management of underlying conditions such as hypertension and diabetes 4.