Union Home Minister Rajnath Singh called on Samajwadi Party patriarch Mulayam Singh Yadav late on Saturday evening to inquire about his health.Mulayam Singh had been admitted to the SGPGI here for about two hours after he complained of weakness. An official release said that the veteran leader had fluctuating sugar levels.Rajnath Singh went to Mulayam Singh's private residence at Shaheed Path and stayed there for about 30 minutes. The two leaders, both former Uttar Pradesh Chief Ministers, are known to share a warm rapport.Rajnath Singh, who is contesting again from the Lucknow Lok Sabha constituency, faces the party's Poonam Sinha, the wife of actor-politician Shatrughan Sinha, in the contest.