The Relationship of Retinol Binding Protein 4 to Changes in Insulin Resistance and Cardiometabolic Risk in Overweight Black Adolescents

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 (β = 0.81, P = .005) and change in RBP4 (β = 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.

Abbreviations: BMI, Body mass index, Δ, Change in, HDL, High-density lipoprotein, LDL, Low-density lipoprotein, IR, Insulin resistance, HOMA-IR, Homeostasis model of insulin resistance, RBP4, Retinol binding protein 4