在生命早期识别进展为高血压的危险因素对预防心血管疾病至关重要。美国学者对饮食中摄入钠钾盐和二者的比值对青少年血压的影响进行了一项前瞻性研究，结果表明，青春期少女摄钠≥3500 mg/d对血压水平无不良影响，饮食中摄入钾盐也可对收缩压和舒张压产生有益影响，这提示，在儿童期摄入较多含钾丰富的食物可能有助于抑制青少年期的血压升高。相关论文4月28日在线发表于《美国医学会杂志·儿科学》(JAMA Pediatr)。

        该美国心肺血液研究所的成长与健康研究是一项前瞻性队列研究，纳入了2185例初始年龄为9至10岁的黑人和白人女孩，有完整的青春期早期至中期的饮食和血压数据，对其随访10年。校正种族、身高、活动量、电视/视频观看时间、能量摄入和其他饮食因素后，利用纵向混合模型和协方差分析模型评估青春期和随访10年后的饮食中钠、钾和二者的比值对收缩压和舒张压的影响。主要转归指标为青春期和随访结束时(17至21岁)的平均收缩压和舒张压水平。

        结果研究者将钠摄入分为4类：<2500 mg/d(19.4%的受试者)、2500 mg/d-3000 mg/d(29.5%)、 3000 mg/d-4000 mg/d (41.4%)和≥4000 mg/d(9.7%)。钾摄入也分为4类：<1800 mg/d (36.0%)、1800 mg/d-2100 mg/d (26.2%)、2100 mg/d-2400 mg/d (18.8%)和≥2400 mg/d(19.0%)。

        无证据显示较多摄入钠(3000-4000 mg/d和≥4000 mg/d vs <2500 mg/d)对青少年血压有不良影响。纵向混合模型显示，与钠摄入2500 mg/d的个体相比，那些钠摄入≥3500 mg/d的受试者舒张压水平普遍较低(P = 0.18)。然而，在整个青春期和随访结束时，钾摄入较多与血压变化呈反相关关系(舒张压和舒张压的P值均<0 .001)(收缩压和舒张压的P值分别为 0.02和0 .05)。同时，钾/钠比值也与收缩压呈反相关关系( P=0.04))，与单独钾摄入的影响相比，这些影响通常较弱。

        参考文献：Justin R. Buendia, et al. JAMA Pediatr. Published online April 27, 2015. doi:10.1001/jamapediatrics.2015.0411

Longitudinal Effects of Dietary Sodium and Potassium on Blood Pressure in Adolescent GirlsONLINE FIRST
Justin R. Buendia, BS1; M. Loring Bradlee, MS1; Stephen R. Daniels, MD, PhD2,3; Martha R. Singer, MPH, RD1; Lynn L. Moore, DSc, MPH1
[+] Author Affiliations
1Department of Medicine, Boston University School of Medicine, Boston, Massachusetts
2Department of Pediatrics, University of Colorado School of Medicine, Aurora
3The Children’s Hospital, Aurora, Colorado
JAMA Pediatr. Published online April 27, 2015. doi:10.1001/jamapediatrics.2015.0411
ABSTRACT
ABSTRACT | INTRODUCTION | METHODS | RESULTS | DISCUSSION | CONCLUSIONS |ARTICLE INFORMATION | REFERENCES
Importance  Identification of risk factors early in life for the development of high blood pressure is critical to the prevention of cardiovascular disease.
Objective  To study prospectively the effect of dietary sodium, potassium, and the potassium to sodium ratio on adolescent blood pressure.
Design, Setting, and Participants  The National Heart, Lung, and Blood Institute’s Growth and Health Study is a prospective cohort study with sites in Richmond, California; Cincinnati, Ohio; and Washington, DC. Participants included 2185 black and white girls initially aged 9 to 10 years with complete data for early-adolescent to midadolescent diet and blood pressure who were followed up for 10 years. The first examination visits were from March 1987 through February 1988 and follow-up continued until February 1999. Longitudinal mixed models and analysis of covariance models were used to assess the effect of dietary sodium, potassium, and the potassium to sodium ratio on systolic and diastolic blood pressures throughout adolescence and after 10 years of follow-up, adjusting for race, height, activity, television/video time, energy intake, and other dietary factors.
Exposures  Mean dietary sodium and potassium intakes and the mean potassium to sodium ratio in individuals aged 9 to 17 years. To eliminate potential confounding by energy intake, energy-adjusted sodium and potassium residuals were estimated.
Main Outcomes and Measures  Mean systolic and diastolic blood pressures throughout adolescence and at the end of follow-up (individuals aged 17-21 years).
Results  Sodium intakes were classified as less than 2500 mg/d (19.4% of participants), 2500 mg/d to less than 3000 mg/d (29.5%), 3000 mg/d to less than 4000 mg/d (41.4%), and 4000 mg/d or more (9.7%). Potassium intakes ranged from less than 1800 mg/d (36.0% of participants) to 1800 mg/d to less than 2100 mg/d (26.2%), 2100 mg/d to less than 2400 mg/d (18.8%), and 2400 mg/d or more (19.0%). There was no evidence that higher sodium intakes (3000 to <4000 mg/d and ≥4000 mg/d vs <2500 mg/d) had an adverse effect on adolescent blood pressure and longitudinal mixed models showed that those consuming 3500 mg/d or more had generally lower diastolic blood pressures compared with individuals consuming less than 2500 mg/d (P = .18). However, higher potassium intakes were inversely associated with blood pressure change throughout adolescence (P < .001 for systolic and diastolic) and at the end of follow-up (P = .02 and P = .05 for systolic and diastolic, respectively). While the potassium to sodium ratio was also inversely associated with systolic blood pressure (P = .04), these effects were generally weaker compared with effects for potassium alone.
Conclusions and Relevance  In this study of adolescent girls, consumption of 3500 mg/d of sodium or more had no adverse effect on blood pressure. The beneficial effects of dietary potassium on both systolic and diastolic blood pressures suggest that consuming more potassium-rich foods during childhood may help suppress the adolescent increase in blood pressure.