Fatty Liver Disease (FLD) is defined by the accumulation of excess fat (steatosis) within liver cells. This buildup is driven by metabolic dysfunction, leading to the newer terminology: Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD), formerly known as NAFLD. MASLD represents a spectrum of liver injury, ranging from simple fat accumulation to inflammation and scarring, and its prevalence increases substantially with age.
Prevalence of Fatty Liver in Later Life
Fatty liver disease is common among older adults, a trend supported by numerous global studies. In the United States, the prevalence affects approximately 40% of individuals aged 60 to 74, with similar rates in those 75 years and older.
MASLD is rapidly becoming the leading cause of chronic liver disease worldwide, particularly impacting older populations. While prevalence may peak in the sixth and seventh decades of life, the risk of progression to a more severe form, such as metabolic dysfunction-associated steatohepatitis (MASH), also increases with age. Older adults with MASLD are therefore at higher risk for advanced fibrosis and related complications.
Age-Related Factors Increasing Susceptibility
Several physiological changes associated with aging make older adults more vulnerable to developing fatty liver disease. A significant factor is the shift in fat storage patterns toward visceral adiposity, which is the accumulation of fat around internal organs, including the liver. Even if an older person’s overall body mass index (BMI) remains stable, the proportion of metabolically harmful visceral fat tends to increase with age.
Aging also contributes to a higher baseline level of insulin resistance, meaning the body’s cells are less responsive to insulin. This resistance leads to increased fat breakdown and the delivery of excessive free fatty acids to the liver, fueling the steatosis process. Furthermore, many older adults experience “inflammaging,” a state of chronic, low-grade inflammation that contributes to metabolic dysfunction and accelerates liver damage.
Changes in the gut microbiota also play a part, as the bacterial composition in the digestive tract shifts with age. These alterations affect the gut-liver axis, influencing nutrient absorption and metabolism in a way that promotes fat accumulation. These age-specific mechanisms drive the condition’s high prevalence and severity in the elderly.
Identifying and Monitoring the Condition
Diagnosing fatty liver disease in older adults can be challenging because the condition is often asymptomatic. Routine blood tests may reveal elevated liver enzymes, such as alanine transaminase (ALT), but these levels are often less reliable in the elderly. They can remain normal despite significant liver damage, so diagnosis is often first suspected when imaging performed for other reasons detects fat in the liver.
Initial detection frequently involves non-invasive imaging techniques like abdominal ultrasound to visualize fat accumulation. More advanced imaging, such as magnetic resonance imaging (MRI) or computerized tomography (CT), can provide greater detail about the extent of steatosis. After diagnosis, the focus shifts to monitoring the progression of scarring, or fibrosis, which is the strongest predictor of long-term liver outcomes.
Non-invasive tools like transient elastography (FibroScan) are used to measure liver stiffness, which correlates directly with the amount of fibrosis present. This monitoring is particularly important in older patients, where advanced fibrosis and cirrhosis are concerns. Blood-based scoring systems can also estimate the degree of liver scarring without requiring an invasive liver biopsy.
Targeted Management Strategies
Management for older adults with MASLD must be tailored to account for age-related considerations like frailty and multiple existing health conditions. Lifestyle modification remains the cornerstone of treatment, focusing on gradual weight loss. Achieving a modest weight reduction of 5% can improve simple steatosis, while a 7–10% loss is often necessary to reverse steatohepatitis and fibrosis.
Dietary changes should emphasize a balanced, nutrient-dense eating plan, such as the Mediterranean diet, which is rich in vegetables, healthy fats, and fiber. Exercise should include a combination of aerobic activity and resistance training to maintain muscle mass. Physicians must clear any new exercise regimen to ensure safety and prevent injury in individuals with physical limitations.
A necessary step in managing MASLD is a thorough review of all medications, known as polypharmacy, which is common in this age group. Many prescription and over-the-counter drugs are metabolized by the liver and can potentially exacerbate liver stress. While lifestyle changes are the primary intervention, pharmaceutical options are emerging for advanced MASH, including new drugs like Resmetirom and Semaglutide.