Association of In Vivo Adipose Tissue Cellular Kinetics With Markers of Metabolic Health in Humans.

Context: Adipose tissue (AT) expansion occurs by hypertrophy and hyperplasia. Impaired hyperplasia, or adipogenesis, has been associated with obesity-related diseases. Objective: We examined how in vivo adipogenesis in the subcutaneous abdominal (scABD) and femoral (scFEM) depots (via 8-week incorporation of deuterium) correlates with markers of metabolic health. Design: Data from 52 women with obesity [27 black and 25 white; 29.7 ± 5.5 years; body mass index (BMI) 32.2 ± 2.8 kg/m2; 44.3% ± 4.0% body fat] were analyzed at Pennington Biomedical Research Center. Main Outcomes: A linear repeated measure model was used to assess the fraction of new adipose cells and the associated covariates. Akaike information criterion determined the covariates that best described the data. Simple associations were examined using Spearman's correlation. Results: The covariates that were associated with adipose kinetics included BMI, visceral AT/total abdominal AT (VAT/TAT) ratio, and the Matsuda index. Simple correlations demonstrated that adipocyte and preadipocyte formation in scABD (P = 0.02 and P = 0.16, trend, respectively) and scFEM (P = 0.01 and P = 0.24, trend, respectively) depots correlated positively with VAT/TAT. Preadipocyte and adipocyte formation in the scABD (P < 0.0001 and P = 0.02, respectively) and scFEM (P = 0.0001 and P = 0.003, respectively) was negatively associated with insulin sensitivity. Conclusions: Our results challenge the AT expandability hypothesis and suggest that higher in vivo adipose cell turnover is positively associated with BMI and VAT/TAT and negatively associated with insulin sensitivity, all correlates of impaired metabolic health.