Option Explicit
Sub DeleteBoldSentences()
Dim oSentence As Range
    For Each oSentence In ActiveDocument.Range.Sentences
        If Not IsInteger(Asc(oSentence.Characters(1))) Then
            Do While oSentence.Characters.Last = Chr(13)
                oSentence.End = oSentence.End - 1
            Loop
            If oSentence.Characters(1).Font.Bold Then oSentence.Delete
        End If
    Next oSentence
lbl_Exit:
    Set oSentence = Nothing
    Exit Sub
End Sub

Private Function IsInteger(ByVal i As String) As Boolean
    Select Case i
        Case 48 To 57
            IsInteger = True
        Case Else
            IsInteger = False
    End Select
lbl_Exit:
    Exit Function
End Function