Sexual Dimorphism in Masked Hypertensive Youth (page 410)
Masked hypertension, elevated ambulatory blood pressure in the presence of normal conventional blood pressure, is a condition that, in adults, has been associated with organ damage and cardiovascular risk, similar to that for sustained hypertension (both conventional and ambulatory hypertension). If an elevation in ambulatory blood pressure precedes the development of sustained hypertension, further knowledge of the risk factors associated with this blood pressure increase can be valuable in the management of hypertension in children and adolescents. The present study, the first to analyze the long-term prognostic value of masked hypertension to progress to hypertension in youths, has established that masked hypertension is a precursor of sustained hypertension. Moreover, the risk of developing sustained hypertension is higher in masked hypertensive boys when compared with masked hypertensive girls. The findings of the present study have important implications for the diagnosis and treatment of hypertension in children and adolescents and for future research. The presence of the masked condition warrants follow-up, especially in this age group, one that frequently does not receive continuous medical attention. Once the persistence of masked hypertension is established, left ventricular mass should be assessed, and if left ventricular hypertrophy is detected, blood pressure–lowering therapy should be started in youth. The fact that masked hypertension is not prognostically innocent increases the importance of the diagnosis at an early age.
Metabolomics and Incident Hypertension (page 398)
The human metabolome represents the outcome of multiple physiological and metabolic processes, as well as the ultimate expression of interaction between gene and environment, by which blood pressure is regulated and hypertension is controlled. Blacks have greater prevalence and severity of hypertension than whites, and are, thus, prime candidates for primary prevention efforts. In this issue of Hypertension, findings from 896 blacks from the Atherosclerosis Risk in Communities (ARIC) Study with a follow-up of ≈10 years suggest that serum metabolic pathways are dysregulated in the development of hypertension. Using untargeted metabolomic technologies, this study identified 1 metabolite, 4-hydroxyhippurate, and 1 metabolomic pattern, sex steroids, which were significantly associated with incident hypertension. The mechanism of action of 4-hydroxyhippurate on blood pressure regulation is speculated to be through gut microbial fermentation and suggests that gut microbes and oxidative stress may contribute to the development of hypertension. The association with a sex steroid pattern was consistent in men and women, implying a role for sex hormones in blood pressure regulation in both sexes. The study concludes that metabolomic studies improve our understanding of the underlying pathophysiology of hypertension, which may help target individuals at high risk for hypertension and indicate earlier therapeutic interventions to them, when necessary.
Risk Factors for High Blood Pressure in Children (page 247)
The childhood obesity epidemic raises concern about obesity-associated risk factors in children, as well as concern on potential long-term consequences in premature cardiovascular and metabolic disease. In this study, childhood data from the National Health and Nutrition Examination Survey (NHANES) III (1988–1994) and continuous NHANES (1999–2008) were examined to determine secular trends in childhood blood pressure (BP) level and prevalence of high blood pressure (HBP). In this report, the prevalence of HBP was defined as prehypertension and hypertension combined. To obtain the most rigorous child reference BP data, the BP percentile norms were based on BP levels in normal weight children, thus excluding overweight and obese. Analysis on these 2 NHANES data periods demonstrated a significant increase in HBP from 15.8% to 19.2% in boys, and from 8.2% to 12.6% in girls (P=0.007). In addition to the expected significant increase in BMI that was associated with HBP increase, there were other findings of clinical importance. The study results also documented a significant and independent association of both waist circumference and dietary sodium intake with HBP in children (see Figure). There has been a population-wide increase in sodium intake among children and adults. The increase in dietary sodium intake is largely because of consumption of processed food products, fast foods, and restaurant meals. The results of this study support benefit in both clinical and public health strategies that reduce high dietary sodium consumption in addition to preventing childhood obesity.
- © 2013 American Heart Association, Inc.