I am using thread to check a existing of data on sever this thread utilized 50 of CPU

Dim check As Thread
    Private Sub RunThread()
        Dim newThread1 As New ThreadStart(AddressOf Checkdata)
        check = New Thread(newThread1)
        check.Start()
    End Sub
    Private Sub Checkdata()
        Dim dt As Date
        Dim dset As DataSet
        Dim prr() As Object
        dt = Date.Now.AddMinutes(5)
        For i As Integer = 0 To 5
            If Date.Now > dt Then
                dt = Date.Now.AddMinutes(1)
                prr = {objBranch.BranchKey}
                Try
                    Dim objUIDataGetBranch As BranchSelectionFetch.UIDataWCFClient
                    objUIDataGetBranch = New BranchSelectionFetch.UIDataWCFClient("IndependentFetchDataEndPtHttp")
                    byteBranchSelectionData = objUIDataGetBranch.WCFAuxValuesByte(CRisMACEntity.ApplicationDown, prr)
                    objUIDataGetBranch.Close()
                    prr = Nothing
                    DecompressData(byteBranchSelectionData)
                    dset = ds
                Catch ex As Exception

                End Try

                If dset IsNot Nothing Then
                    If dset.Tables(0).Rows.Count > 0 Then                        
                                Application.ExitThread()
                                Application.Exit()
                                Application.DoEvents()
                                check.Abort()                       
                    End If
                End If
            End If
            i = 0
        Next
    End Sub