Uric acid indicates a high cardiovascular risk profile but is not closely associated with insulin resistance in obese adolescents.

W e comment on a recent study by Dehghan et al. (1), who identified high serum uric acid as an independent risk factor for type 2 diabetes in adults. We investigated serum levels of uric acid in a large cohort of obese adolescents (n 355; mean SD age 13.1 4.1 years and age range 10–22 years) and normal-weight control subjects (n 200) of similar age and sex distribution (2). Uric acid levels were highly significantly increased in the obese adolescents (4.6 1.1 vs. 5.6 1.3 mg/dl, P 0.0001). Male probands had significantly higher uric acid serum levels (P 0.0001) in the obese and control groups. Interestingly, uric acid correlated highly significantly with systolic blood pressure (r 0.37, P 0.0001), increased intima-media thickness of common carotid arteries (r 0.33, P 0.0001), nuchal subcutaneous adipose tissue thickness (r 0.46, P 0.0001), measured by lipometry (3), and waist circumference (r 0.57, P 0.0001). A negative association was seen with the high molecular weight–to–total adiponectin ratio (r 0.35, P 0.01) (H. Mangge, G. Almer, H. Gruber, C. Mayer, M. Truschnig, N. Grandits, R. Möller, R. Horejsi, M. Borkenstein, S. Pilz, unpublished observations). In contrast to these strikingly significant correlations, identified as early as childhood, only weak correlations were seen between uric acid, homeostasis model assessment index (r 0.2, P 0.0001), and fasted insulin levels (r 0.2, P 0.0001). Fasted glucose levels and free fatty acids were not significantly associated with uric acid. Thus, in the earliest phases of the metabolic syndrome, as detected in obese adolescents aged 13 years, uric acid indicates a high cardiovascular risk profile. However, in contrast to the observations in subjects in late adulthood by Dehghan et al., obese adolescents show a stronger association between uric acid, early vascular abnormalities, trunk-weighted obesity, and hypertension compared with markers of insulin resistance such as fasted insulin and homeostasis model assessment index. HARALD MANGGE, MD STEFAN PILZ, MD SAMIH HAJ-YAHYA, MD GUNTER ALMER, MAG, MD