Metabolic associated fatty liver disease (MAFLD) is associated with multiple metabolic-vascular disorders and is now viewed as an independent risk factor for cardiovascular disease [1]. A high prevalence of hepatic steatosis has been reported with T1DM based on ultrasonographic characteristics [2], however when the technique of 1H-MRS was used, a lower rate of steatosis was seen in T1DM compared with controls [3]. Part of this inconsistency may be related to liver glycogen, which has a similar ultrasonographic appearance to fat [3].
Proton magnetic resonance spectroscopy (1H-MRS) was used to examine liver fat and glycogen content in five clinical groups defined based on metabolic and liver disease phenotypes, each containing five participants: 1. type 1 diabetes (T1DM) with glycogenic hepatopathy, 2. satisfactorily controlled T1DM with no liver disease, 3. suboptimally controlled T1DM without liver disease, 4. a control group of BMI- and age-matched individuals without diabetes or liver disease, and 5. no diabetes but hepatic steatosis (biopsy-proven), unmatched for BMI or age.
Fat content was highest in the hepatic steatosis group (median 15.4%, IQR 10.0-19.3). Compared with the control group (median 1.0%, IQR 0.7-1.1), fat content was much higher in the individuals with glycogenic hepatopathy (median 6.5%, IQR 4.5-9.1), lower in the T1DM with satisfactory control (median 0.3%, IQR 0.2-0.6), and not significantly different in the group of T1DM with suboptimal control without liver disease (median 1.1%, IQR 0.9-1.1).
1H-MRS glycogen content could not be interpreted in the majority of those with glycogenic hepatopathy because of interference from the fat signal.
The findings from this pilot study confirm and extend current evidence suggesting that the hyperechoic ultrasonographic liver changes seen in T1DM are often termed “fatty liver”, but may relate to glycogen accumulation and not fat, however in cases diagnosed with glycogenic hepatopathy there may be significant concomitant fat accumulation.