Adipose tissue mass and location affect circulating adiponectin levels

Abstract

Aims/hypothesis: Plasma levels of adiponectin are inversely associated with body mass. We hypothesised that adipose tissue distribution and body composition influences adiponectin levels.

Methods: We assessed plasma adiponectin concentrations and dual-energy X-ray absorptiometry (DEXA) measurements of body composition among 2,820 participants from the Dallas Heart Study.

Results: Among both women and men, adiponectin levels were higher in whites than in either Hispanics or African-Americans (for women: median 9.99 μg/ml [25th,75th percentile 7.11, 13.77] vs 7.56 μg/ml [5.05, 9.98] vs 6.39 μg/ml [4.37, 9.41], respectively, p < 0.0001; for men: 6.43 μg/ml [4.66, 9.19] vs 5.55 μg/ml [3.64, 7.50] vs 5.03 μg/ml [3.39, 7.28], p < 0.0001). In univariate analysis, each individual component of body mass was inversely associated with adiponectin. After multivariate analysis, adiponectin levels were found to be positively associated with lower extremity fat, whether expressed in absolute mass (for women: β = 0.055, p < 0.0001; for men: β = 0.061, p < 0.0001), or as a relative proportion (for women: β = 0.035, p < 0.0001; for men: β = 0.034, p < 0.0001). This association was consistent across ethnicities. Conversely, adiponectin was negatively correlated with truncal fat, both in absolute (for women: β = -0.039, p < 0.0001; for men: β = -0.044, p < 0.0001) and relative terms (for women: β = -0.027, p < 0.0001; for men β = -0.033, p < 0.0001). At the extreme of body mass, higher degrees of lower extremity and truncal adiposity were associated with higher levels of adiponectin.

Conclusions/interpretation: These data suggest that the location of adipose depots differentially influences circulating adiponectin concentrations-a finding observed across ethnicity and sex. Gross measures of body mass alone do not adequately account for adiponectin levels. This supports a role of adiponectin as a mediator of the positive effects of lower extremity adiposity on improvements in insulin sensitivity.

Fig. 1

Adiponectin levels for (a) men and (b) women in the Dallas Heart Study, stratified by ethnicity. Median (25th,75th percentile) values (μg/ml) are: women, black 6.39 (4.37, 9.41), white 9.99 (7.11, 13.77), Hispanic 7.56 (5.05, 9.98); men, black 5.03 (3.39, 7.28), white 6.43 (4.66, 9.19), Hispanic 5.55 (3.64, 7.50). The tenth and 90th percentiles are displayed as whiskers

Fig. 2

Median adiponectin concentrations by sex- and ethnicity-stratified quartiles of total body fat (%) and (a) truncal or (b) lower extremity fat (%). Increasing lower extremity adiposity is associated with higher adiponectin levels across quartiles of total body fat. The opposite finding is seen for truncal fat

Fig. 3

Median adiponectin levels stratified by quartiles of adiposity in the lower extremities (a, c) and trunk (b, d) among (a, b) women and (c, d) men at the upper tenth percentile extreme of BMI for the study population. p values refer to non-parametric ANOVA for differences between groups: (a) p=0.0001; (b) p=0.033; (c) p=0.002; (d) p<0.002. Higher degrees of adiposity appeared to be related to greater adiponectin levels, particularly among men