Objectives: To prospectively examine the independent and combined effect of occupational physical activity and metabolic syndrome on all-cause and cardiovascular mortality in a large population-based cohort.
Methods: Data on 37 300 men and women participating in the Norwegian HUNT Study (1995-1997) were linked with the Cause of Death Registry at Statistics Norway. Cox proportional HR with 95% CI were estimated.
Results: During a median follow-up of 12.4 years, a total of 1168 persons died. Of these, 278 died from cardiovascular disease. Persons with metabolic syndrome and much walking/lifting at work had a HR of 1.79 (95% CI 1.20 to 2.66) for cardiovascular death referencing persons without metabolic syndrome and much walking/lifting. Using the same reference, persons with metabolic syndrome and sedentary work had a HR of 2.74 (95% CI 1.82 to 4.12) while persons with metabolic syndrome and heavy physical work had a HR of 3.02 (95% CI 1.93 to 4.75). Associations with all-cause mortality were somewhat weaker, and were largely due to deaths from cardiovascular disease.
Conclusions: The association between metabolic syndrome and cardiovascular mortality is stronger for persons with sedentary work and with physically heavy work than for persons with much walking/lifting at work.