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.4717.3p         miR.4709.3p        miR.20a.5p       miR.4763.5p        miR.30c.5p      miR.103a.2.5p        miR.4746.3p          miR.1253           miR.585    
RaceAfrAm               0.3244314045      2.180795508294 *    2.5506545222      2.2566952437 **   0.7435037673      0.03415366342      0.02144070089      0.3181524361      0.4675622727    
PovStatBelow           -0.4973172502      0.005091618549      1.0666323058     -0.2457787920      0.6045138430      0.17812544900     -0.32726978012     -0.3873396497      2.1651474005    
HypertenYes             0.3715293743     -0.067606528973     -1.3272628673      0.7963401754     -1.3974445659     -0.53805055267 *    0.20323605744      0.5502276830      2.1396281906    
RaceAfrAm:PovStatBelow  0.2377694899     -1.269972691291     -4.7176374884     -0.7378856023     -3.5121907794     -0.70876924315      0.10357705353      0.3429860593     -2.2073856869    
RaceAfrAm:HypertenYes  -1.4904263519     -2.973242990732 *    0.5820760748     -2.9657095106 **   2.3812231625      0.42533352162     -0.48996584068     -1.7822887698 *   -5.2088176504    

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.4717.3p        miR.4709.3p        miR.20a.5p       miR.4763.5p        miR.30c.5p     miR.103a.2.5p        miR.4746.3p          miR.1253            miR.585    
RaceAfrAm              0.3813985741      1.87652287137      1.3318651659      2.0799053021 **  -0.1216566301     -0.1356602925      0.04625671735      0.3930913749     -0.06130505515    
PovStatBelow          -0.3660564908     -0.69599740661     -1.3943895941     -0.6531288879     -1.2832464597     -0.2131509471     -0.27009001871     -0.1934286231      0.94655908751    
HypertenYes            0.3452772224      0.07261127606     -0.7821092393      0.8778101946     -1.0547760579     -0.4597952735      0.19180010516      0.5031414007      2.38334585323    
RaceAfrAm:HypertenYes -1.4694996365     -3.08501661246 *    0.3604433837     -3.0306527545 **   2.1537402586      0.3629528848     -0.48084975300     -1.7466926677 *   -5.40309544431    

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

                        miR.4717.3p        miR.4709.3p        miR.20a.5p      miR.4763.5p        miR.30c.5p     miR.103a.2.5p         miR.4746.3p          miR.1253           miR.585    
RaceAfrAm              0.3081872759      1.73732339005      1.0371546864      1.949279525 **  -0.3798387476     -0.1782904819     -0.007761286396      0.3521730539      0.1280067624    
HypertenYes            0.2720659242     -0.06658820526     -1.0507834690      0.747184417     -1.3199932566     -0.5024254629      0.137782101417      0.4615192894      2.5726576707    
RaceAfrAm:HypertenYes -1.3779855138     -2.91101726080 *    0.7701409963     -2.867370533 **   2.4932987597      0.4162406215     -0.413327248325     -1.6967307839     -5.6397352162