Cholecystectomy Is Linked With Lower Respiratory Exchange Ratio and Higher Lipid Oxidation and Sleep Energy Expenditure.

OBJECTIVE

Cholecystectomy (GBX) may alter energy metabolism, but human evidence is limited. We examined whether GBX alters energy expenditure (EE), respiratory exchange ratio (RER), and substrate oxidation.

METHODS

A total of 384 healthy Southwestern Indigenous American adults (222 males, age 28 ± 6 years) were studied, including individuals with a history of gallbladder surgery [GBX(+), n = 39] and without surgery [GBX(-), n = 345]. In addition, 24-h energy metabolism was measured in a respiratory chamber. General linear models were adjusted for age, sex, body composition, and glucose regulation. RER and macronutrient oxidation rates were further adjusted for energy balance.

RESULTS

GBX(+) participants were older (31 ± 7 vs. 27 ± 6 years, p = 0.0002) and mostly female (95% vs. 36%, p < 0.0001), and they had higher body fat (40% ± 5% vs. 32% ± 8%, p < 0.0001), although body composition differences were sex related. Adjusted models showed lower RER (β = -0.01, p = 0.01), higher lipid oxidation (β = 79 kcal/day, p = 0.03), and higher sleep EE (β = 78 kcal/day, p = 0.006) in the GBX(+) group. Other EE variables and macronutrient oxidation rates were not significantly associated with GBX history (all p's > 0.1).

CONCLUSIONS

Independent of obesity, an absent gallbladder is associated with decreased RER and increased lipid oxidation and sleep EE rates, indicating that the gallbladder may have a role in metabolic fuel selection that has implications for metabolic health.

TRIAL REGISTRATION: ClinicalTrials.gov identifiers: NCT00339482, NCT00340132.