If don't know if you want to use javascript, but in case you want, here is what you have to do:
$( document ).ready(function() {
var height = $('#inputEmail3').parent().prev().height();
var dif = height - $('#inputEmail3').height();
var margin = dif / 2;
$('#inputEmail3').css('margin-top', margin);
});
And here is the example. By the way, i don't recomand you use col-sm-2 class on the label insted of a div.
If you want this script to be universal, just use this:
$( document ).ready(function() {
$(".form-control").each(function() {
var height = $(this).parent().prev().height();
var dif = height - $(this).height();
var margin = dif / 2;
$(this).css('margin-top', margin);
});
});
And the result is here