Sex differences in cardiometabolic risk factors and in response to lifestyle intervention in prepubertal and pubertal subjects with obesity

Objectives: Childhood obesity is a growing health problem and requires a tailored treatment. This study explored the sex differences in cardiovascular risk factors in children/adolescents with obesity and in response to a weight loss intervention. Methods: Five hundred and thirty-three children/adolescents with obesity and their parents underwent to a 3 -months lifestyle intervention program. Tanner criteria were used to assess the pubertal stage. Before and after 3 months, anthropometric measurements, blood pressure (BP), and biochemical measurements were assessed. Results: Four hundred and forty five participants completed the treatment (age 12.4 +/- 2.7 years, males 45.8%, prepubertal 29.2%, BMI z score 2.3 +/- 0.2). In comparison to boys, prepubertal girls had higher values of BMI z score (2.4 +/- 02 vs. 2.3 +/- 0.2, p < 0.05), waist circumference z score (2.2 +/- 0.3 vs. 2.0 +/- 0.3, p < 0.05), HOMA-IR [2.9 (2.1-4.9) vs. 2.3(1.5-3.6), p < 0.01], prevalence of hypertransaminasemia (41.3% vs. 17.7%, p < 0.05) and lower levels of HDL cholesterol (46.2 +/- 9.8 vs. 51.2 +/- 10.5 mg/dl, p < 0.05). In the pubertal stage, boys had worse cardiometabolic risk profile than girls, including unfavourable measure of systolic BP (z score: 0.6 +/- 1.0 vs. 0.3 +/- 1.0, p < 0.01), fasting glucose (87.2 +/- 6.1 vs. 84.8 +/- 7.7 mg/dl, p < 0.01), ALT (26.9 +/- 21.5 vs. 20.2 +/- 10.6 U/L, p < 0.001) and uric acid (6.1 +/- 1.9 vs. 5.0 +/- 1.0 mg/dl, p < 0.001). After the lifestyle intervention, changes in BMI z score (p < 0.05) were higher in pubertal boys than pubertal girls. The systolic blood pressure decrease was greater in pubertal boys than in their female counterpart (Delta systolic BP: - 7.2 mmHg in boys vs. -3.6 mmHg in girls, p < 0.05; Delta systolic BP z score: - 0.6 in boys vs. -0.3 in girls, p < 0.05). LDL cholesterol showed an improvement only in boys, and ALT in the whole group. Conclusion: Our study showed that a short-term lifestyle intervention is more effective in reducing BMI z score and cardiovascular risk factors in pubertal boys than in their female counterparts. Further investigation is needed to deepen this gender difference, especially to develop a tailor-made intervention.