Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD), previously known as Non-Alcoholic Fatty Liver Disease (NAFLD), is a rapidly growing public health concern.
A notable study that analyzed data from the Canadian Longitudinal Study on Aging between 2012 and 2018 estimates that MASLD afflicts 35 per cent of Canadians. Globally, it affects approximately 38 per cent of adults, with prevalence rising to 65 per cent among patients with Type 2 Diabetes Mellitus (T2DM).
MASLD is commonly recognized as an hepatic manifestation of metabolic syndrome and is characterized by the buildup of fat (steatosis) in greater than 5 per cent of hepatocytes, alongside at least one cardiometabolic risk factor (CMRF), and the exclusion of other likely causes including alcohol.
Despite its prevalence, MASLD is routinely diagnosed incidentally in primary care practices. Abnormal liver enzymes or bilirubin levels identified through routine blood tests often lead to further work up, namely a liver ultrasound.
Yet, though liver ultrasound is the most common modality for MASLD diagnosis, it can only reliably detect hepatocyte steatosis levels greater than 20 per cent, and results are subject to inter-operator variability. As such, it is conceivable that an even larger percentage of Canadians are affected by MASLD and remain undiagnosed.
Once diagnosed, patients are stratified based on existing diagnoses of any other CMRFs, such as hypertension. Otherwise healthy patients may undergo assessment of fibrosis levels every three-four years, while those with CMRFs may be assessed for the same every two-three years. Fibrosis can be measured using transient elastography (Fibroscan), which is a more sensitive and specific diagnostic approach when compared with ultrasound.
While a subset of patients with high levels of hepatic fibrosis are referred to hepatology, most patients do not meet this threshold and are managed in primary care clinics. Management strategies implemented for these patients include watchful waiting, counselling about diet and lifestyle modifications and pharmacological management of CMRFs.
Although substantial evidence supports the role of lifestyle interventions for managing CMRFs in patients with metabolic syndrome and T2DM, parallel data specifically for patients with MASLD remain limited.
While it is important to acknowledge that lifestyle modifications have demonstrated effectiveness in reducing levels of hepatic steatosis, this approach often falls short as counselling on weight loss, diet and exercise in primary care has been shown to be inconsistent. Several studies point to health-care providers utilizing a more monitoring-based approach to MASLD management as opposed to active management due to limited tools and knowledge to facilitate behavioural change.
Further, surveyed patients have indicated feeling uninformed about the seriousness of the condition, being told that MASLD is “fairly common” and “not something to worry about.” After receiving minimal guidance on ways to adapt their diet and exercise, they reported feeling inadequately supported. Notably, primary care clinicians have noted that patients were often underdiagnosed and under treated. They attributed these patterns to lack of MASLD-specific treatments and minimal implications for management resulting from further workup.
Ultimately, primary care clinicians have described constraints within the health-care system as decreasing their ability to engage in active management approaches and call for more patient-directed solutions.
Therein lies the disconnect. While clinicians face barriers in active management of patients with MASLD, those patients simultaneously feel lost with regards to their care. Though the risk of progression to complications such as cirrhosis is low, MASLD is the second-highest risk factor for non-alcohol related liver transplants. As such, addressing this disconnect is paramount given that the prevalence of MASLD continues to rise.
When searching for new tools and approaches to management, it is important to make sure that a patient-centred focus can be implemented within the constraints of an already resource-limited primary care environment. Continuous glucose monitors (CGMs) show promise as a potential solution.
A cross-sectional study found that increased mean glucose, glycemic variability and mean of daily differences, all of which were identified using CGMs, were linked with a higher degree of hepatic steatosis. Another study of children with NAFLD found an association between glucose profile derangement, as detected through CGMs, and hepatic fibrosis severity.
While data connecting MASLD and CGM use in clinical contexts is sparse, CGMs have been implemented extensively within the context of diabetes, another related metabolic condition. In this setting, CGMs have been shown to serve as a powerful driver of lifestyle change, providing patients with insight regarding their blood glucose levels and how their body responds to lifestyle changes like diet and exercise. One study identified an association between CGM use and increased exercise time per week, reduced BMI, reduced post-prandial glucose and reduced HbA1C after 12 weeks. Another study looking at CGMs and diet coaching showed participants changed their behaviour based on CGM data, stating after the study that they would work to maintain their new habits. While they did not decide to use the CGMs continually, they were open to resuming use if they deviated from their goals.
The key value proposition of CGMs is that they are a patient-centred tool that can empower patients that otherwise feel lost in their care. At the same time, CGMS can be implemented within the constraints of our health-care system and can provide a means of connecting clinicians and patients through active disease management. Importantly, more data is needed on CGM-derived metrics and subsequent changes in steatosis levels in MASLD patients.
If proven efficacious, CGMs have the potential to represent a transformative approach to the management of MASLD.
