Background

Severe obesity is associated with fatigue, however, the effects of weight loss after bariatric surgery on particular dimensions of fatigue are unknown.In a secondary analysis of a prospective cohort study of women undergoing roux-en-y gastric bypass (RYGB) we explored relationships among multiple dimensions of fatigue and improving adiposity, insulin resistance and inflammation.

Methods

Before, and 1 and 6 months after RYBG, dimensions of fatigue were assessed using the validated, self-report, Multidimensional Fatigue Inventory.Total, abdominal visceral (VAT) and subcutaneous (SAT) adiposity, insulin sensitivity (Si and HOMA) and plasma concentrations of leptin, C-reactive protein (CRP) and interleukin-6 (Il-6) were measured using air displacement plethysmography, computed tomography, glucose tolerance testing and enzyme-linked immunoassay.Associations were assessed using Spearman correlations and linear regression.

Results

At baseline, the majority of our female participants (N=19, body mass index, 46.5 kg/m2, age 37.2 years) were experiencing elevated levels of fatigue.By 6 months, dimensions of physical (-43%), reduced activity (-43%), reduced motivation (-38%), general (-31%; all p < 0.005), and mental (-18%, p < 0.05) fatigue improved, concomitant with decreases in markers of adiposity, inflammation and insulin resistance.The decrease in VAT was associated with improvement in mental fatigue (beta, 0.447 ± 0.203, p = 0.045), independent of other indices of adiposity, IL-6 concentrations, or Si.

Conclusions

In the 6 months after RYGB, fatigue improved, especially physical fatigue. Decreases in mental fatigue were mediated by decreases in visceral adiposity. Nevertheless, the biologic mechanisms underlying changes in these specific fatigue dimensions remain undetermined.