What is the significance of an abnormal microalbumin-to-creatinine ratio (MACR)?

From the Guidelines

An abnormal microalbumin-to-creatinine ratio (MACR) is a significant indicator of kidney damage and increased cardiovascular risk, with values above 30 mg/g signifying moderately increased albuminuria and values above 300 mg/g indicating severely increased albuminuria 1.

Key Points

• The albumin-to-creatinine ratio is a continuous marker for cardiovascular event risk at all levels of kidney function, with risk starting at values consistently above 30 mg/g 1.
• Microalbuminuria, defined as a MACR of 30-299 mg/g, is an early stage of diabetic nephropathy in type 1 diabetes and a marker for development of nephropathy in type 2 diabetes, and is also a well-established marker of increased cardiovascular disease (CVD) risk 1.
• Patients with macroalbuminuria, defined as a MACR of ≥300 mg/g, are likely to progress to end-stage renal disease (ESRD) over a period of years 1.
• The presence of albuminuria is a predictor of cardiovascular events, and even low levels of albuminuria can predict cardiovascular risk 1.
• Regular monitoring of kidney function, blood pressure, and electrolytes is essential in patients with abnormal MACR, and referral to a physician experienced in the care of kidney disease may be necessary for uncertainty about the etiology of kidney disease, difficult management issues, or advanced kidney disease 1.

Management

• Intensive diabetes management with the goal of achieving near normoglycemia has been shown to delay the onset of microalbuminuria and the progression of micro- to macroalbuminuria in patients with type 1 and type 2 diabetes 1.
• ACE inhibitors and ARBs have been shown to reduce the risk and slow the progression of renal disease, and are recommended for patients with elevated albuminuria 1.
• Monitoring of urine albumin excretion is recommended to assess both response to therapy and progression of disease 1.

From the Research

Significance of Abnormal Microalbumin-to-Creatinine Ratio (MACR)

• An abnormal microalbumin-to-creatinine ratio (MACR) is a significant indicator of kidney damage or disease, but the provided studies do not directly address the significance of MACR.
• The studies focus on the treatment of minimal change disease (MCD) and minimal change nephrotic syndrome (MCNS) in adults, including the efficacy of different steroid regimens and the use of rituximab 2, 3, 4, 5, 6.
• While the studies do not provide information on the significance of MACR, they do highlight the importance of monitoring kidney function and adjusting treatment regimens accordingly to minimize damage and prevent complications.

Treatment of Minimal Change Disease (MCD)

• The studies suggest that low-dose steroid regimens, combined with rituximab or other immunosuppressive agents, may be effective in treating MCD and preventing relapse 3, 5.
• A short-term steroid regimen may also be an effective treatment option for adult steroid-sensitive MCD patients, with lower steroid exposure 6.
• The optimal duration of initial steroid therapy for adult steroid-sensitive MCD remains unclear, but a 2-month short-term steroid regimen may be a viable option 6.

Monitoring and Adjusting Treatment Regimens

• Regular monitoring of kidney function, including MACR, is crucial in adjusting treatment regimens and minimizing damage to the kidneys.
• The studies emphasize the importance of individualized treatment approaches, taking into account the patient's response to treatment, relapse history, and potential side effects of steroid therapy 2, 3, 4, 5, 6.