Associations Between Dietary Carbohydrate Intakes, Fatty Acid Oxidation Rates, and Sites of Ectopic Fat Deposition Over Two Years in Persons with Treated HIV.

Abstract

Background: Persons with HIV (PWH) on long-term antiretroviral therapy (ART) have exaggerated accumulation of ectopic fat and cardiometabolic disease risk.

Objective: To characterize longitudinal changes in habitual diet and macronutrient oxidation in relation to changes in abdominal adipose tissue and ectopic fat sites using MR and CT imaging.

Methods: A prospective cohort of 49 males with HIV had comprehensive assessments at baseline, 52 weeks (year 1), and 104 weeks (year 2). Linear mixed effects models accounted for the correlation structure in the data and estimated effects over time. Fixed effects included baseline value of the outcome, age, BMI, time since HIV diagnosis, and duration of ART.

Results: The consumption of simple carbohydrates decreased over time (total and added sugars, p = 0.03) concomitant with increased ratio of fatty acid to carbohydrate oxidation (p = 0.01). The amount of abdominal subcutaneous adipose tissue (SAT) decreased 15% (p < 0.0001) and the amount of visceral adipose tissue (VAT) decreased 7% (p = 0.009) simultaneously with improved SAT and VAT densities. Improvement in VAT density associated with reduced fat fraction of the liver (r = -0.28, p = 0.04) and thighs (r = -0.41, p = 0.03), indicating overall reduced ectopic fat accumulation. However, pancreas density decreased (p = 0.03), and no statistically significant change was observed in skeletal muscle density (p = 0.16), suggesting tissue-specific impacts.

Conclusions: These findings support the relationship between dietary carbohydrates intake, fat oxidation rate, and fat mobilization to reduce ectopic lipid deposition in PWH. While modest changes in dietary intakes show potential for improving metabolic flexibility and body composition among individuals on long-term ART, some organs and tissues may not respond in tandem with other depots of ectopic fat.