DUBAI, Jan 20 (Reuters) - Here are some factors that may affect Middle East stock markets on Tuesday. Reuters has not verified the press reports and does not vouch of their accuracy.INTERNATIONAL/REGIONAL* GLOBAL MARKETS-Asia on edge, braces for China growth data MKTS/GLOB* Oil markets open cautiously ahead of China GDP data O/R* MIDEAST STOCKS-Gulf soft as oil slips; poor results weigh on Saudi I