Fat-free mass accounts for most of the variance in alcohol elimination rate in women

Neda Seyedsadjadi; Vijay A Ramchandani; Martin H Plawecki; Ann E K Kosobud; Sean O'Connor; Blair Rowitz; Marta Yanina Pepino

doi:10.1111/acer.15047

Fat-free mass accounts for most of the variance in alcohol elimination rate in women

Alcohol Clin Exp Res (Hoboken). 2023 May;47(5):848-855. doi: 10.1111/acer.15047. Epub 2023 Mar 14.

Authors

Neda Seyedsadjadi¹, Vijay A Ramchandani², Martin H Plawecki³, Ann E K Kosobud³, Sean O'Connor³, Blair Rowitz^{4

5

6}, Marta Yanina Pepino^{1

4

5}

Affiliations

¹ Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.
² Human Psychopharmacology Laboratory, Division of Intramural Clinical and Biological Research, National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland, USA.
³ Department of Psychiatry, Indiana University School of Medicine, Indianapolis, Indiana, USA.
⁴ Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.
⁵ Carle Illinois College of Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.
⁶ Department of Surgery, Carle Foundation Hospital, Urbana, Illinois, USA.

PMID: 36871954
DOI: 10.1111/acer.15047

Abstract

Background: Understanding how blood alcohol concentrations (BAC) achieved after drinking are determined is critical to predicting alcohol exposure to the brain and other organs and alcohol's effects. However, predicting end-organ exposures is challenging, as there is wide variation in BAC achieved after drinking a specified volume of alcohol. This variation is partly due to differences in body composition and alcohol elimination rates (AER), but there are limited data on how obesity affects AER. Here, we assess associations between obesity, fat-free mass (FFM), and AER in women and examine whether bariatric surgeries, which are linked to an increased risk of alcohol misuse, affect these associations.

Methods: We analyzed data from three studies that used similar intravenous alcohol clamping procedures to estimate AER in 143 women (21 to 64 years old) with a wide range of body mass index (BMI; 18.5 to 48.4 kg/m² ). Body composition was measured in a subgroup using dual-energy X-ray absorptiometry (n = 42) or Bioimpedance (n = 60), and 19 of the women underwent bariatric surgery 2.1 ± 0.3 years before participation. We analyzed data using multiple linear regression analyses.

Results: Obesity and older age were associated with a faster AER (BMI: r_s = 0.70 and age: r_s = 0.61, both p < 0.001). Compared to women with normal weight, AER was 52% faster (95% Confidence Interval: 42% to 61%) in women with obesity. However, BMI lost predictive value when adding fat-free mass (FFM) to the regression model. Age, FFM, and its interaction explained 72% of individual variance in AER (F (4, 97) = 64.3, p < 0.001). AER was faster in women with higher FFM, particularly women in the top tertile of age. After controlling for FFM and age, bariatric surgery was not associated with differences in AER (p = 0.74).

Conclusions: Obesity is associated with a faster AER, but this association is mediated by an obesity-related increase in FFM, particularly in older women. Previous findings of a reduced alcohol clearance following bariatric surgery compared with prior to surgery are likely explained by a reduction in FFM post-surgery.

Keywords: BMI; alcohol elimination rate; bariatric surgery; fat-free mass; obesity.

Abstract

Grants and funding