Metabolic syndrome, obesity, and mortality: impact of cardiorespiratory fitness.
OBJECTIVE
To determine in normal weight, overweight, and obese men the risk of all-cause and cardiovascular disease (CVD) mortality associated with the metabolic syndrome (MetS) and the influence of cardiorespiratory fitness (CRF).


METHODS
This observational cohort study included 19,173 men who underwent a clinical examination, including a maximal exercise test. MetS was defined according to National Cholesterol Education Program guidelines.


RESULTS
At baseline 19.5% of the men had MetS. The ORs of the metabolic syndrome at baseline were 4.7 (95% CI 4.2-5.3) in overweight and 30.6 (26.7-35.0) in obese men compared with normal weight men. A total of 477 deaths (160 CVD) occurred in 10.2 years of follow-up. The risks of all-cause mortality were 1.11 (0.75-1.17) in normal weight, 1.09 (0.82-1.47) in overweight, and 1.55 (1.14-2.11) in obese men with MetS compared with normal weight healthy men. The corresponding risks for CVD mortality were 2.06 (0.92-4.63) in normal weight, 1.80 (1.10-2.97) in overweight, and 2.83 (1.70-4.72) in obese men with the MetS compared with normal weight healthy men. After the inclusion of CRF in the model, the risks associated with obesity and MetS were no longer significant.


CONCLUSIONS
Obesity and MetS are associated with an increased risk of all-cause and CVD mortality; however; these risks were largely explained by CRF.
Katzmarzyk
Peter T
PT
School of Physical and Health Education, Queen's University, Kingston, Ontario, Canada. katzmarz@post.queensu.ca
Church
Timothy S
TS
Janssen
Ian
I
Ross
Robert
R
Blair
Steven N
SN
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D005080:Exercise Test; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D024821:Metabolic Syndrome / Q000401:mortality*; D008875:Middle Aged; D009765:Obesity / Q000401:mortality*; D010809:Physical Fitness; D012307:Risk Factors