Sarcopenia Is an Independent Risk Factor for the Decline in Anal Sphincter Function and Increased Levator Laxity in Women.

Introduction: Pelvic floor disorders are prevalent in women. Sarcopenia, or age-related muscle mass loss, may be a contributing factor. We aimed to investigate the association between sarcopenia, as measured by the psoas muscle index (PMI), and pelvic floor and anal sphincter function in women with evacuation disorders.

Methods: We conducted a retrospective analysis of data from women who underwent magnetic resonance defecography and high-resolution anorectal manometry. As an indicator of overall muscle mass measurement, PMI was computed at the L4 level.

Results: Women with evacuation disorders who had magnetic resonance imaging diagnosis of sarcopenia (98/264; 37.1%), were older and had lower body mass index ( P < 0.001), with comparable rates of parity and pelvic surgery. There was a significant association between diminished PMI and decreased anal resting ( P < 0.001) and squeeze ( P < 0.001) pressures, as well as increased levator hiatus length ( P = 0.004), descent ( P = 0.01), and anorectal angle ( P = 0.002). Patients with sarcopenia were more likely to have anal hypotension and hypocontractility ( P < 0.001), and increased levator hiatus laxity measurements ( P < 0.05), associated with lower obstructive defecation scores (9 vs 11, P = 0.003), and higher Wexner fecal incontinence scores (8 vs 4, P = 0.03). Sarcopenia was an independent risk factor of anal hypotension and hypocontractility, levator enlargement, and exaggerated levator hiatus descent.

Discussion: Sarcopenia significantly affects anal sphincter function and pelvic floor dynamics in women with evacuation disorders, serving as a risk factor of anal hypotension/hypocontractility and levator laxity. These findings highlight the need for integrated approaches in managing pelvic floor disorders, taking into account the role of muscle mass and strength in treatment strategies.