Mysql innodb lock struct(s)

[xula]

Hi bro,
I am using zabbix with mysql on debian.
I often get notification like:

=> Item values:

InnoDB lock structs (hostname:mysql.innodb_lock_structs): 91

i tried to use
Show innodb status\G;
and get

---TRANSACTION 0 277713068, ACTIVE 9 sec, process no 27807, OS thread id 140586878265088 starting index read
mysql tables in use 1, locked 1
LOCK WAIT 40 lock struct(s), heap size 6752, 209 row lock(s), undo log entries 208
MySQL thread id 48, query id 147607992 localhost zabbix Updating
update items set lastclock=1393995980,lastns=433229877,prevvalue=la stvalue,lastvalue='1' where itemid=47330
Trx read view will not see trx with id >= 0 277713069, sees < 0 277713024
------- TRX HAS BEEN WAITING 9 SEC FOR THIS LOCK TO BE GRANTED:
RECORD LOCKS space id 257 page no 791 n bits 128 index `PRIMARY` of table `zabbix`.`items` trx id 0 277713068 lock_mode X locks rec but not gap waiting
Record lock, heap no 19 PHYSICAL RECORD: n_fields 50; compact format; info bits 0

Have you met this problem, Do you know how to fix?
I also tried to optimize by some thread on internet, but not help
Please help, thank you in advanced!