why we van add these variables to confounding effect control in regression model

$$ Duration of oral antidiabetic drugs $($r$=-0\mathrm{.}127,$ p$-$value$=0\mathrm{.}005)$

$$ Age in years $($r$=-0\mathrm{.}144.$ p$-$value$=0\mathrm{.}001)$

$$ Duration of lipids drugs use $($r $=-0\mathrm{.}097,$ p$-$value$=0\mathrm{.}042)$

$$ Duration of antihypertensivedrugs $($r $=-0\mathrm{.}137.$ p$-$value$=0\mathrm{.}005)$

$$ Diastolic BP $($mmHg$)$ at baseline $($r $=0\mathrm{.}094.$ p$-$value $=0\mathrm{.}036)$

$$ Alkaline Phosphatase $($IU$/$L$)$ at baseline $($r $=0\mathrm{.}11.$ p$-$value$=0\mathrm{.}015)$c