OBJECTIVE: To assess, among
overweight non-hispanic black adolescents the relationship of changes in plasma
retinol binding protein 4 (
RBP4) over 3 years to changes in
insulin resistance (IR) and 4 associated cardiometabolic risks. STUDY DESIGN: Nested, retrospective study of 51
overweight, post-pubertal non-Hispanic black participants in the Princeton School District Study. Participants were in the top (worsening IR) or bottom (improved IR)
quartile for 3-year change in IR.
RBP4 was measured by quantitative
Western blot with frozen plasma. Regression analyses adjusted for age, sex, and
adiposity (baseline and change). Three measures of
adiposity were assessed (
waist circumference,
body mass index, and weight) in separate
regression models. RESULTS:
RBP4 increased in one third (n = 17). In
logistic regression analyses, increased
RBP4 was associated with significantly higher
odds of worsening as opposed to improved IR independent of age, sex, or
adiposity.
Odds ratios were 5.6 (weight, P = .024), 6.0 (BMI, P = .025) and 7.4 (
waist circumference, P = .015). Initial
RBP4 (beta = 0.81, P = .005) and change in
RBP4 (beta = 0.56, P = .046) also predicted change in
triglycerides, but not change in high-density lipoprotein-cholesterol, low-density lipoprotein-cholesterol, or
fibrinogen. CONCLUSION: This
retrospective cohort study provides evidence that
RBP4 may be a mechanism through which
obesity influences
insulin resistance and
hypertriglyceridemia in
overweight postpubertal black
youth and suggests
utility of
RBP4 as a biomarker of risk.
