Usefulness of glucosemetabolism of psoas muscle on ¹⁸F-FDG PET/CT in the prediction of metabolic health impairment

Objectives: It is well known that skeletal muscle glucose utilization play important role in whole body insulin resistance and ¹⁸F-FDG PET/CT is a noninvasive functional molecular imaging modality for evaluating tissue glucose utilization. The purpose of this study was to assess the usefulness of glucose metabolism of psoas muscle on ¹⁸F-FDG PET/CT whether it could predict various clinical metabolic impairment including metabolic syndrome (MetS).

Methods: We retrospectively collected the data from 236 consecutive subjects (M/F=125/111, 52.7±8.7 years) who underwent regular health medical examinations including ¹⁸F-FDG PET/CT at their initial examination period. By reviewing their medical records and laboratory results, new-onset metabolic events of hypertension, hyperglycemia, hypertriglycemia, and low high-density lipoprotein-cholesterol (HDL-C) as well as MetS were assessed. The comparison of new-onset event-free interval between subgroups with low and high psoas muscle metabolism (SUVmax < 1.34 vs. ≥ 1.34) was made by Kaplan-Meier survival analysis and the log rank test.

Results: The mean duration of the follow up of this cohort was 1.8 ± 1.1 years. There was 40 (24.8%) new-onset hypertension out of 161 subjects, 22 (12.5%) new-onset hyperglycemia out of 176, 18 (10.2%) new-onset hypertriglycemia out of 176, 29 (17.0%) new-onset low HDL-C out of 171 and 30 (14.7%) new-onset MetS out of 204. The Kaplan-Meier curve predicted that the subgroup with high psoas muscle metabolism had increased risk for new-onset MetS than the subgroup with low psoas muscle metabolism (p < 0.001). Similar pattern was also seen in the prediction of other metabolic impairments (all, p < 0.001) and the event-free intervals between two subgroups were significantly different. After adjusted for age and sex, high psoas muscle metabolism observed to have significant increased risk for new-onset hypertension (HR, hazard ratio: 2.59, p = 0.027), hyperglycemia (HR: 3.29, p = 0.010), hypertriglycemia (HR: 3.64, p = 0.008), low HDL-C (HR: 5.28, p < 0.001), and MetS (HR: 3.27, p = 0.002).

Conclusions: The subgroup with high psoas muscle metabolism showed increased risk of new-onset event of metabolic impairments during their follow up period. The present data suggest that psoas muscle metabolism on ¹⁸F-FDG PET/CT seem useful for the prediction of metabolic health impairment in general population.