Obesity, Insulin Resistance, and Nocturnal Systolic Blood Pressure

A n increasing prevalence of obesity is observed in all age and ethnicity groups and is increasingly being recognized as a serious health problem in children and adolescents.[1][2][3][4] Obesity is associated with a number of metabolic abnormalities, as well as increased risk for cardiovascular disease (CVD).3,4 In this issue of Hypertension, Lurbe et al 5 reported a relationship between insulin resistance, determined by the homeostatic model assessment technique, and nocturnal elevations of systolic blood pressure and heart rate in a large cohort of overweight and obese European children and adolescents.This relationship was present even after adjustment for age, sex, and height.Furthermore, waist circumference was strongly associated with insulin resistance, and both waist circumference and insulin resistance were associated with elevated nocturnal, but not daytime, blood pressures.These are important observations despite some limitations as to the methodology that the investigators used.One limitation of this report is the fact that sleep was not well documented, which limited the ability to strongly relate the nocturnal blood pressures and heart rate to circadian rhythmicity.Another potential limitation of this study relates to the fact that the children were recruited from an obesity clinic; therefore, the data may not be representative of the general population of children and adolescents.Finally, the results of this study are limited by the fact that it was a cross-sectional rather than a prospective longitudinal investigation.Nevertheless, the observations in this study are in concert with previous reports of a positive relationship between insulin resistance and hypertension in children and adolescents.6,7 As noted by the authors, the results of this cross-sectional study need to be validated in prospective longitudinal investigations in this population.Furthermore, the impact of weight reduction and other strategies to improve insulin sensitivity on elevated nocturnal blood pressures would be a potentially important avenue of investigation.Because both nocturnal elevation of blood pressure and insulin resistance are predictive of renal disease, 8,9 as well as CVD, the impact of insulin resistance and elevated nocturnal systolic blood pressure in children on blood pressure temporal trends, as well as the impact onThe opinions expressed in this editorial are not necessarily those of the editors or of the American Heart Association.