It is surprising how many people suffer ... .
= The large number of people who suffer ... is surprising.
= A surprisingly large number of people suffer ...
= So many people suffer ... that it is surprising.
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The same applies to how much.
It is surprising how much money is required to meet expenses these days.
= The great amount of money that is required ... is surprising.
= A surprisingly great amount of money is required ...
= So much money is required ... that it is surprising.
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And in fact the same applies to how in general with any adjective or adverb.
It is surprising how vindictive people can be.
= People can be surprisingly vindictive.
= People can be so vindictive that it is surprising.
It is surprising how carefully you have to move when balancing a basket on your head.
= You have to move surprisingly carefully when ...
= You have to move so carefully when ... that it is surprising.
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And you can substitute other words for surprising.
It is amazing how ...
It is astonishing how ...
It is embarrassing how ...
It is disgusting how ...
It is laughable how ...
It is worrisome how ...
CJ