NA+/K+ INTAKE AND CV REACTIVITY IN BLACK ADOLESCENTS

原发性高血压（EH）在美国黑人中的患病率已达到 流行病的比例，是最高的任何种族群体中， 世界（1）。 由于EH的前体开始于儿童期（2），因此理想的 需要预防的人群是儿童和青少年。 以前的研究 研究表明，黑人儿童的心血管（CV） 反应性（血压（BP）对压力的增加）和更高的水平 与白色儿童相比， 鉴于 在黑人成年人中，EH的患病率较高，CV反应性增加， 睡眠时血压升高可能是重要的危险因素或标志物， 黑人儿童EH的早期发展。 许多研究者认为钠（Na+）敏感性 （血压变化改变Na+摄入量）也是BP的重要因素 调控 黑人更可能显示Na+敏感（SS）BP 白人（5-7）。 此外，饮食研究 干预措施表明，黑人，特别是显示减少， 低Na+饮食引起的偶发性BP（5-7）。 然而，遵守 低钠饮食在永久改变生活方式方面可能是 困难，尤其是对孩子。 最近，调查人员 增加膳食钾（K+）也可能有益于 对偶发血压的影响，尤其是在SS个体中（8-11）。 从理论上讲，坚持高K+饮食应该更容易， 低Na+饮食。 证据支持 高K+饮食对血压的有益作用来自动物研究 （8-10）和K+补充研究（11-15）。此外，校长 研究人员最近完成了一项试点研究（16）， 在一组黑人青少年中， 收缩压（S）和舒张压（D）的反应性从术前降低到 节食后 动态（A）血压与血压相关性的研究 模式和电解质排泄尚未证明 在一组清醒或睡眠时K+摄入量与ABP模式之间的关系， 黑人和白色儿童（17）;然而，进一步的研究是必要的， 确定增加膳食K+是否与ABP差异相关 SS与Na+抗性（SR）个体的模式。 的目的 目前的建议是确定高钾饮食的影响， 干预改变SS患者的CV反应性、ABP和偶发BP， SR血压正常的黑人青少年。

The prevalence of essential hypertension (EH) in U.S. blacks has reached epidemic proportions and is among the highest of any racial group in the world (1). Since the precursors of EH begin in childhood (2), the ideal population for prevention is children and adolescents. Previous research has demonstrated that black children show greater cardiovascular (CV) reactivity (increases in blood pressure (BP) to stress) and higher levels of BP while asleep as compared to white children (3-4). Given that the prevalence of EH is great among black adults, increased CV reactivity and elevated BP while asleep may be important risk factors or markers for the early development of EH in black children. A number of investigators have suggested that sodium (Na+) sensitivity (changes in BP to altering Na+ intake) is also an important factor in BP regulation. Blacks are more likely to show Na+ sensitive (SS) BP responses than whites (5-7). In addition, research on dietary interventions has indicated that blacks, in particular, show reductions in casual BP in response to low Na+ diets (5-7). However, compliance with low Na+ diets in terms of making permanent lifestyle changes may be difficult, especially for children. More recently, investigators have shown that increasing dietary potassium (K+) may also have beneficial effects on casual BP, especially in SS Individuals (8-11). Theoretically, adhering to a high K+ diet should be much easier for children than adhering to a low Na+ diet. Evidence supporting the beneficial effect of a high K+ diet on BP comes from both animal research (8-10) and K+ supplement studies (11-15). In addition, the Principal Investigator recently completed a pilot study (16) which demonstrated that Increasing dietary K+ in a group of black adolescents significantly decreased both systolic (S) and diastolic (D) BP reactivity from pre- to post-diet. Research on the relationship between ambulatory (A) BP patterns and electrolyte excretion has not demonstrated an association between K+ intake and ABP patterns while awake or asleep in a group of black and white children (17); however, further research Is warranted to determine if increasing dietary K+ is associated with differences in ABP patterns in SS versus Na+ resistant (SR) individuals. The purpose of the present proposal is to determine the effects of a high K+ dietary intervention on changing CV reactivity, ABP, and casual BP In SS versus SR black normotensive adolescents.