Lower Serum Adiponectin Levels in African‐American Boys

Abstract

DEGAWA-YAMAUCHI, MIKAKO, JASON R. DILTS, JASON E. BOVENKERK, CHANDAN SAHA, J. HOWARD PRATT, AND ROBERT V. CONSIDINE. Lower serum adiponectin levels in African-American boys. Obes Res. 2003;11:1384 -1390. Objective: To examine adiponectin, an adipocyte-secreted hormone with anti-inflammatory and insulin-sensitizing effects, in relation to race or gender in younger subjects. Research Methods and Procedures:The relationship of adiponectin, quantitated by radioimmunoassay, to anthropometric and metabolic factors (fasting insulin, glucose, and leptin) and reproductive hormones was examined in 46 healthy African Americans (25 girls/21 boys) and 40 whites (20 girls/20 boys) ranging in age from 12 to 21 years. Results: There was no statistical difference in BMI or in BMI percentile among the four groups. Sums of skinfolds, but not skinfold percentile, were significantly lower in boys than girls (p ϭ 0.001 and p ϭ 0.896, respectively), whereas there was no difference between racial groups. Leptin was significantly greater in girls (p ϭ 0.0002). There was no difference in fasting serum glucose, insulin, or homeostasis model assessment score among any of the groups. There was a significant negative univariate relationship between serum adiponectin and both BMI and BMI percentile for the entire group (p ϭ 0.006 and p ϭ 0.005). In a multivariate model, BMI percentile (p ϭ 0.005) and the interaction between race and gender (p ϭ 0.026) were significant predictors of serum adiponectin. In this model, AfricanAmerican boys had the lowest serum adiponectin level, 37% less than white boys, who had the highest adiponectin levels. Discussion: Serum adiponectin levels are reduced in young obese subjects (African Americans and whites) and are lower in African-American boys than white boys. A lower adiponectin level in African-American boys may predispose this group to a greater risk of diabetes and cardiovascular disease.

Adiponectin Is Lower Among African Americans and Is Independently Related to Insulin Sensitivity in Children and Adolescents

“…Because African Americans enter puberty at an earlier age and because previous studies have found a relationship between increased testosterone and decreased adiponectin concentrations (37,38), we reasoned that higher testosterone among African-American males may account for the lower adiponectin previously reported in this sex-ethnic subgroup (20). However, we did not observe a significant relationship between adiponectin and either Tanner stage or testosterone concentration.…”

“…Recently, it was shown that adiponectin was lower among African-American versus Caucasian females, but only among nonobese subjects (19). Another study found that African-American males had the lowest adiponectin concentrations among a group of African-American and Caucasian males and females aged 12-21 years (20). In this study, no relationship was observed between adiponectin and estimated S i (estimated using the homeostasis model), after controlling for BMI or BMI percentile (20).…”

“…Another study found that African-American males had the lowest adiponectin concentrations among a group of African-American and Caucasian males and females aged 12-21 years (20). In this study, no relationship was observed between adiponectin and estimated S i (estimated using the homeostasis model), after controlling for BMI or BMI percentile (20). The relationship between adiponectin and S i among AfricanAmerican and Caucasian children has not been examined using robust measures of S i .…”

Adiponectin and the Development of Type 2 Diabetes

“…A previous report (32) of similar levels among obese African-American and white women in a much smaller sample may have resulted from selection bias, as this finding was not replicated here. An additional small study (33) showed lower adiponectin levels in African-American, compared with white, boys. The lower levels we found among African Americans, especially if present from childhood, could explain in part their higher diabetes risk.…”

Systemic Adiponectin Malfunction as a Risk Factor for Cardiovascular Disease

“…High plasma Ad concentrations are associated with a lower risk of MI in men (17,30,49). Ethnic disparities in Ad levels might explain predilection in African Americans and those of South Asian descent for increased type-2 diabetes and coronary artery disease (13,26,51). Persistently, low plasma Ad concentration after acute myocardial infarction is predictive of future adverse cardiac events (3).…”