Relationship between plasminogen activator inhibitor-1 antigen, leptin, and fat mass in obese children and adolescents

Hyperleptinemia may be associated with cardiovascular risk and is linked wi th parameters of fibrinolytic processes in adults. We studied whether body fatness, leptin, and insulin interact with plasminogen activator inhibitor- 1 antigen (PAI-1-Ag) and tissue-type plasminogen activator antigen (tPA-Ag) in obese children and adolescents. Twenty-three boys (mean +/- SD: age, 10 .7 +/- 3.3 years; body mass index [BMI], 28.7 +/- 5.4 Kg/m(2)) and 19 girls (age, 11.9 +/- 2.7 years; BMI, 29.4 +/- 4.8 Kg/m(2)) were investigated. Bo dy fat mass (FM) in the children was calculated by bioelectrical impedance analysis, and blood samples were obtained for leptin, insulin, C-peptide. P AI-1-Ag, and tPA-Ag, The children were divided into 3 subgroups according t o maturation. Maturity was associated with greater adiposity and higher lev ers of leptin and C-peptide, but insulin and PAI-1-Ag were not different be tween prepubertal, pubertal, and late/postpubertal children. PAI-1-Ag was a ssociated with leptin and insulin, but not after adjustment for fatness. PA I-1-Ag was independently associated with tPA-Ag (r = .36, P < .02). Multipl e regression analysis showed that tPA-Ag failed to reach the level of signi ficance (P = .07), but FM contributed to the variation in PAI-1-Ag (adjuste d R-2 = .29). The BMI was the main determinant for the variation in leptin (adjusted R-2 = .386) and in insulin (adjusted R-2 = .60, all P < .001). Ne ither gender, maturation, chronological age, or leptin contributed signific antly to the variation in either PAI-1-Ag or tPA-Ag. Our data suggest that adiposity and other variables contribute to higher levels of PAI-1-Ag. Lept in seems not to be independently linked with fibrinolytic parameters, but a n unfavorable metabolic and fibrinolytic risk profile might emanate from th e obese pubertal stage. Copyright (C) 2000 by W.B. Saunders Company.