Onset of puberty and cardiovascular risk factors in untreated obese children and adolescents: a 1-year follow-up study.

OBJECTIVE

To determine the course of obesity-associated nonalcoholic fatty liver disease (NAFLD) and the cardiovascular risk factors of hypertension, dyslipidemia, and disturbed glucose metabolism in untreated obese children.

DESIGN

Obese children were examined prospectively at baseline and 1 year later.

SETTING

Obesity clinic.

PARTICIPANTS

A total of 287 untreated obese children; 53.3% were girls, the mean age was 11.4 years, and the mean body mass index (calculated as weight in kilograms divided by height in meters squared) was 28.2.

MAIN OUTCOME MEASURES

Homeostasis model assessment of insulin resistance (HOMA-IR) values and prevalence of hypertension, dyslipidemia, impaired fasting glucose level, and NAFLD.

RESULTS

At baseline, 20.6% of obese children had hypertension, 22.3% had dyslipidemia, 4.9% had impaired fasting glucose levels, and 29.3% had NAFLD. These prevalences, as well as weight status, remained stable at the 1-year follow-up visit. Increases (SDs) in prevalence of hypertension (16.1% [51.8%]), hypertriglyceridemia (9.7% [59.3%]), and impaired fasting glucose level (8.1% [32.9%]), as well as mean HOMA-IR value (0.42 [1.22]), were observed in 62 children entering puberty. In contrast, mean decreases (SDs) in hypertension (-18.8% [53.2%]), hypertriglyceridemia (-12.5% [53.1%]), impaired fasting glucose level (-6.3% [38.1%]), and NAFLD prevalence (-18.8% [44.5%]), as well as mean HOMA-IR value (-0.83 [2.56]), were observed in 50 children entering late puberty (P < .01 for change of pubertal status in the multivariate model). Changes in HOMA-IR values were only weakly related to changes in prevalence of cardiovascular risk factors or transaminase levels (r < 0.2).

CONCLUSIONS

Cardiovascular risk factors worsened at onset of puberty and improved in late puberty in obese children whose weight status did not change. The weak correlation between HOMA-IR value and cardiovascular risk factors suggests that other characteristics may affect these disorders.