Sung Yong Park

Importance: Among young adults, the association of the 2017 American College of Cardiology/American Heart Association (ACC/AHA) High Blood Pressure Clinical Practice Guidelines with risk of cardiovascular disease (CVD) later in life is uncertain. Objective: To determine the association of blood pressure categories before age 40 years with risk of CVD later in life. Design, Setting, and Participants: This population-based cohort study from the Korean National Health Insurance Service consisted of 2 488 101 adults aged 20 through 39 years with blood pressure measurements taken twice from 2002 through 2005. Starting from January 1, 2006, participants were followed up until the date of CVD diagnosis, death, or December 31, 2015. Exposures: Participants were categorized by blood pressure readings: normal (systolic, <120 mm Hg; diastolic, <80 mm Hg), elevated (sytolic, 120-129 mm Hg; diastolic, <80 mm Hg), stage 1 hypertension (systolic, 130-139 mm Hg; diastolic, 80-89 mm Hg), and stage 2 hypertension (systolic, ≥140 mm Hg; diastolic, ≥90 mm Hg). Main Outcomes and Measures: The primary outcome was CVD defined as 2 or more days of hospitalization due to CVD or death due to CVD. The secondary outcomes were coronary heart disease (CHD) and stroke. Results: The study population consisted of 2 488 101 participants (median age, 31 years [interquartile range, 27-36 years], 789 870 women [31.7%]). A total of 44 813 CVD events were observed during a median follow-up duration of 10 years. Men with baseline stage 1 hypertension compared with those with normal blood pressure had higher risk of CVD (incidence, 215 vs 164 per 100 000 person-years; difference, 51 per 100 000 person-years [95% CI, 48-55]; adjusted hazard ratio [HR], 1.25 [95% CI, 1.21-1.28]), CHD (incidence, 134 vs 103 per 100 000 person-years; difference, 31 per 100 000 person-years [95% CI, 28-33]; adjusted HR, 1.23 [95% CI, 1.19-1.27]), and stroke (incidence, 90 vs 67 per 100 000 person-years; difference, 23 per 100 000 person-years [95% CI, 21-26]; adjusted HR, 1.30 [95% CI, 1.25-1.36]). Women with baseline stage 1 hypertension compared with those with normal blood pressure had increased risk of CVD (incidence, 131 vs 91 per 100 000 person-years; difference, 40 per 100 000 person-years [95% CI, 35-45]; adjusted HR, 1.27 [95% CI, 1.21-1.34]), CHD (incidence, 56 vs 42 per 100 000 person-years; difference, 14 per 100 000 person-years [95% CI, 11-18]; adjusted HR, 1.16 [95% CI, 1.08-1.25]), and stroke (incidence, 79 vs 51 per 100 000 person-years; difference, 28 per 100 000 person-years [95% CI, 24-32]; adjusted HR [1.37, 95% CI, 1.29-1.46]). Results for state 2 hypertension were consistent. Conclusions and Relevance: Among Korean young adults, stage 1 and stage 2 hypertension, compared with normal blood pressure, were associated with increased risk of subsequent cardiovascular disease events. Young adults with hypertension, defined by the 2017 ACC/AHA criteria, may be at increased risk of cardiovascular disease.

We calculate the surface-plasmon dispersion relations for a periodic chain of spherical metallic nanoparticles in an isotropic host, including all multipole modes, in a generalized tight-binding approach. For sufficiently small particles $(kd\ensuremath{\ll}1,$ where k is the wave vector and d is the interparticle separation), the calculation is exact. The lowest bands differ only slightly from previous point-dipole calculations provided the particle radius $a\ensuremath{\lesssim}d/3,$ but differ substantially at smaller separation. We also calculate the dispersion relations for many higher bands, and estimate the group velocity ${v}_{g}$ and the exponential decay length ${\ensuremath{\xi}}_{D}$ for energy propagation for the lowest two bands due to single-grain damping. For $a/d=0.33,$ the result for ${\ensuremath{\xi}}_{D}$ is in qualitative agreement with experiments on gold nanoparticle chains, while for smaller separation, such as $a/d=0.45,$ ${v}_{g}$ and ${\ensuremath{\xi}}_{D}$ are expected to be strongly k dependent because of the multipole corrections. When the particles touch, we predict percolation effects in the spectrum, and find surprising symmetry in the plasmon band structure. Finally, we reformulate the band-structure equations for a Drude metal in the time domain, and suggest how to include localized driving electric fields in the equations of motion.