Cardiovascular risk factors in portuguese obese children and adolescents: impact of small reductions in body mass index imposed by lifestyle modifications.
OBJECTIVE
Evaluate cardiovascular risk factors in Portuguese obese children and adolescents and the long-term effects of lifestyle modifications on such risk factors.


METHODS
Transversal cohort study and longitudinal study.


METHODS
University Hospital S. João and Children's Hospital Maria Pia, Porto.


METHODS
148 obese children and adolescents [81 females (54.7%); mean age of 11.0 years] and 33 controls (sex and age matched) participated in a cross-sectional study. Sixty obese patients agreed to participate in an one year longitudinal study after medical and nutritionist appointments to improve lifestyle modification; a substantial body mass index (BMI) reduction was defined by a decrease in BMI z-score (BMI z-sc) of 0.3 or more over the studied period.


METHODS
Lipid profile (triglycerides, cholesterol, HDLc, LDLc, lipoprotein (a), apolipoproteins A and B) and circulating levels of C-reactive protein (CRP), adiponectin, glucose, and insulin.


RESULTS
Compared with the lean children, obese patients demonstrated statistically significantly higher insulin resistance index [Homeostasis model assessment (HOMA)], and triglycerides, LDLc, apolipoprotein (apo) B, insulin and CRP concentrations, whereas their HDLc and apo A levels were significantly lower (cross-sectional study). In the longitudinal study (n=60), a substantial BMI reduction occurred in 17 (28.3%) obese patients which led to a significant reduction in triglycerides, cholesterol, LDLc, apo B, glucose and insulin levels and in HOMA. The ΔBMI values over the studied period correlated inversely and significantly with BMI (P<0.001) and HOMA (P=0.026) values observed at baseline. In multiple linear regression analysis, BMI at baseline remained associated to changes in BMI over the studied period (standardised Beta: -0.271, P=0.05).


CONCLUSIONS
Our data demonstrates that small reductions in BMI-zc, imposed by lifestyle modifications in obese children and adolescents, improve the cardiovascular risk profile of such patients. Furthermore, patients with higher BMI and/or insulin resistance seem to experience a greater relative reduction in their BMI after lifestyle improvements.
Departamento de Bioquímica, Faculdade de Farmácia, Universidade do Porto, 4050-047 Porto, Portugal.
Henrique
H
Nascimento
Elísio
E
Costa
Petronila
P
Rocha-Pereira
Carla
C
Rego
Helena Ferreira
HF
Mansilha
Alexandre
A
Quintanilha
Alice
A
Santos-Silva
Luís
L
Belo