Men with average working hours longer than 60 h/week were found to have significantly increased risks for total CHD ( OR = 2.2 ) as compared to those with weekly working hours in 40-48 h , and those with daily hours of sleep fewer than 6 h were found to have increased risks for CHD ( OR = 3.0 ) as compared to those with sleeping hours in 6-9 h. Restriction to confirmed AMI yielded a greater risk and these associations remained consistent with adjustment of smoking status , body mass index and psychosocial work factors including job demands , job control , workplace justice , job insecurity and shift work .