You should be able to do it using variable variables, so first assign Con-1
to a variable and then substitute this variable for the name in the assignment...
$var = 'Con-1';
$statement->execute(
array(
':name' => $data->$var[$i]->name,
':address' => $data->$var[$i]->address,
':gender' => $data->$var[$i]->gender,
':designation' => $data->$var[$i]->designation,
':age' => $data->$var[$i]->age
)
);