What is a normal estimated Glomerular Filtration Rate (eGFR) for an 80-year-old Caucasian woman?

From the Guidelines

A normal estimated Glomerular Filtration Rate (eGFR) for an 80-year-old Caucasian woman is typically between 45-59 mL/min/1.73m². This range reflects the natural decline in kidney function that occurs with aging, even in the absence of kidney disease. For context, a young healthy adult would have an eGFR of approximately 90-120 mL/min/1.73m². The lower eGFR in elderly individuals is due to the gradual loss of nephrons and reduced renal blood flow that occurs as part of normal aging 1. It's essential to consider that an eGFR in this range for an elderly person is not necessarily indicative of chronic kidney disease requiring intervention, but rather represents age-appropriate kidney function. When interpreting eGFR results in older adults, healthcare providers typically consider this age-related decline and focus more on stability of kidney function over time rather than comparing to values considered normal for younger adults 1. Some key points to consider include:

• The normal level of GFR varies according to age, sex, and body size 1.
• 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.
• Decreased GFR in the elderly is an independent predictor of adverse outcomes, such as death and cardiovascular disease (CVD) 1. Given the evidence, it is crucial to prioritize the stability of kidney function over time and adjust drug dosages accordingly to minimize potential complications in elderly patients with decreased eGFR 1.

From the Research

Normal eGFR Values for an 80-year-old Caucasian Woman

• The normal estimated Glomerular Filtration Rate (eGFR) for an 80-year-old Caucasian woman can vary based on different studies and equations used to estimate GFR.
• According to the study by 2, eGFR in women aged 75-85 ranges from 30 to 89 ml/min/1.73 m(2), which corresponds to stage 2-3 chronic kidney disease (CKD).
• Another study by 3 found that the mean GFR is approximately 107 ml/min/1.73 m(2) up to the age of 40 years, but renal decline begins beyond 40 years, with no evidence of difference between men and women in separate age groups.
• A study by 4 suggests that normal GFR values are largely over 60 mL/min/1.73 m(2) in healthy subjects, at least before the age of 70 years, but values below 60 mL/min/1.73 m(2) could be considered normal in adults older than 70 years.

eGFR Decline with Age

• The study by 2 found that women lost 22% of their eGFR during follow-up, with a mean loss per decade of 16.6 ml/min/1.73 m(2), and the decline accelerated between 80 and 85 years of age.
• The study by 3 supports the idea that renal decline begins beyond 40 years, with a continuous decline in GFR with age.

Association between eGFR and Cardiovascular Disease

• A study by 5 found that a higher eGFR, even in the normal or mildly impaired range, is associated with lesser incident cardiovascular disease (CVD) in men and women of all ages, including those over 60 years old.
• However, this study does not provide specific eGFR values for an 80-year-old Caucasian woman, but it suggests that maintaining a higher eGFR is associated with better cardiovascular health.