After accounting for matching normotensive and hypertensive African Americans and whites by age and fitting several models with higher order terms, here's what appears after eliminating nonsignificant higher order terms:

                       miR.20a.5p     miR.4763.5p     miR.30c.5p     miR.103a.2.5p     miR.4746.3p     miR.1253     miR.585    
RaceAfrAm                  2.5507          2.2567 **      0.7435           0.03415         0.02144       0.3182      0.4676    
PovStatBelow               1.0666         -0.2458         0.6045           0.17813        -0.32727      -0.3873      2.1651    
HypertenYes               -1.3273          0.7963        -1.3974          -0.53805 *       0.20324       0.5502      2.1396    
RaceAfrAm:PovStatBelow    -4.7176         -0.7379        -3.5122          -0.70877         0.10358       0.3430     -2.2074    
RaceAfrAm:HypertenYes      0.5821         -2.9657 **      2.3812           0.42533        -0.48997      -1.7823 *   -5.2088    

Plotting the effects for just outcomes with significant effects:

The finding for miR.103a.2.5p may be spurious because there are no significant effects after poverty status × race is removed:

                      miR.20a.5p     miR.4763.5p     miR.30c.5p     miR.103a.2.5p     miR.4746.3p     miR.1253      miR.585    
RaceAfrAm                 1.3319          2.0799 **     -0.1217           -0.1357         0.04626       0.3931     -0.06131    
PovStatBelow             -1.3944         -0.6531        -1.2832           -0.2132        -0.27009      -0.1934      0.94656    
HypertenYes              -0.7821          0.8778        -1.0548           -0.4598         0.19180       0.5031      2.38335    
RaceAfrAm:HypertenYes     0.3604         -3.0307 **      2.1537            0.3630        -0.48085      -1.7467 *   -5.40310    

Also, the finding for miR.1253 may be spurious because there are no significant effects after removing poverty status:

                      miR.20a.5p     miR.4763.5p     miR.30c.5p     miR.103a.2.5p     miR.4746.3p     miR.1253     miR.585    
RaceAfrAm                 1.0372          1.9493 **     -0.3798           -0.1783       -0.007761       0.3522       0.128    
HypertenYes              -1.0508          0.7472        -1.3200           -0.5024        0.137782       0.4615       2.573    
RaceAfrAm:HypertenYes     0.7701         -2.8674 **      2.4933            0.4162       -0.413327      -1.6967      -5.640