Determinants of muscle function and health-related quality of life in patients with endogenous hypercortisolism: a cross-sectional study

OBJECTIVE

Prospective data on determinants of muscle strength impairment and quality of life in patients with various subtypes and severity of endogenous hypercortisolism are lacking.

DESIGN

Single-center cross-sectional study, 2019 to 2022.

METHODS

Patients with Cushing syndrome (CS) and mild autonomous cortisol secretion (MACS) were assessed with clinical and biochemical severity scores, muscle function (nondominant hand grip strength and sit-to-stand test), and quality of life (Short Form-36 [SF36] and CushingQoL). Referent subjects were recruited from the local population undergoing abdominal imaging for reasons other than suspected adrenal disorder.

RESULTS

Of 164 patients, 81 (49%) had MACS, 14 (9%) had adrenal CS, 60 (37%) had pituitary CS, and 9 (5%) had ectopic CS. Median age was 53 years (interquartile range: 42-63 years), and 126 (77%) were women. The SF36 mental component score was similarly low in patients with MACS vs CS, but physical component score was lower in CS when compared to MACS (mean of 34.0 vs 40.5, P = .001). Compared to MACS, patients with CS had lower scores on the standardized CushingQoL (mean of 47.1 vs 34.2, P < .001). Compared to referent subjects, patients with MACS demonstrated reduced muscle strength, similar to patients with CS (mean sit to stand Z-score of -0.47 vs -0.54, P = .822). Clinical severity (r = -0.22, P = .004) but not biochemical severity was associated with sit-to-stand test performance.

CONCLUSIONS

Both patients with overt CS and MACS demonstrate reduced muscle strength and low quality of life. The clinical severity score utilized is associated with both physical and psychosocial components of CushingQoL and with the physical component of SF36.

High Intensity Jump Exercise Preserves Posture Control, Gait, and Functional Mobility During 60 Days of Bed-Rest: An RCT Including 90 Days of Follow-Up

Physical inactivity causes a deconditioning of the human body. Concerns due to chronic bed-rest include deficits in posture and gait control, predisposing individuals to an increased fall and injury risk. This study assessed the efficiency of a high-load jump exercise (JUMP) as a countermeasure to prevent detrimental effects on gait, posture control and functional mobility. In an RCT (23 males), the effect of 60 days bed-rest without training was compared to JUMP. JUMP is characterized by plyometric executed as a high intensity interval training. Typical trainings session consisted of 4 × 10 countermovement jumps and 2 × 10 hops in a sledge jump system. We assessed sway path and muscle activity in monopedal stance, spatiotemporal, kinematic, and variability characteristics in gait, functional mobility with repeated chair-rises and Timed Up and Go (TUG). Results revealed: The JUMP group showed no significant changes after bed-rest, whereas the control group exhibited substantial deteriorations: an increased sway path (+104%, p < 0.05) was accompanied by increased co-contractions of antagonistic muscles encompassing the ankle (+32%, p < 0.05) and knee joint (45%, p < 0.05). A reduced locomotor speed (−22%, p < 0.05) was found concomitant with pathological gait rhythmicity (p < 0.05), reduced joint excursions (ankle −8%, knee −29%, p < 0.05) and an increased gait variability (p < 0.05). Chair-rising was slowed (+28%, p < 0.05) with reduced peak power (+18%, p < 0.05), and more time was needed to accomplish TUG (+39%, p < 0.05). The effects persisted for a period of 1 month after bed-rest. Increases in sway path were correlated to decreases in gait speed. The JUMP effectively preserved the neuromuscular system's ability to safely control postural equilibrium and perform complex locomotor movements, including fast bipedal gait with turns and rises. We therefore recommend JUMP as an appropriate strategy combatting functional deconditioning.