Nutrients
Phase Angle, Skeletal Muscle Function, and Molecular Phenotype in HFpEF: A Subanalysis of the SAUNA-HFpEF Study
By Ammar Abo Hwach, Aysenur Dasdemir, Doerte Ahrens and 10 others.
Abstract
Background
The phase angle (PhA) derived from bioelectrical impedance analysis (BIA) is a non-invasive marker of cellular integrity that has been associated with nutritional status, functional status and prognosis in heart failure (HF). Whether PhA is related to the skeletal muscle molecular phenotype in HF with preserved ejection fraction (HFpEF) remains unknown.
Methods
In this exploratory subanalysis of the SAUNA-HFpEF trial, 17 patients with HFpEF underwent BIA with assessment of body composition, cardiopulmonary exercise testing, isokinetic assessment of quadriceps muscle strength, and measurement of circulating growth differentiation factor-15 (GDF-15), as well as nutrition-related and metabolic laboratory parameters before and after a 10-week sauna intervention. Paired vastus lateralis biopsies (n = 12) were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR) for catabolic (FBXO32, GSK-3β), fatty acid metabolism (ACADL, CPT1B, CD36), and anabolic (mTOR, IGF-1) markers. Associations with PhA were assessed using Spearman correlation and repeated-measures correlation (rmcorr), with false discovery rate (FDR) correction for multiple testing.