Burden and prognostic importance of subclinical cardiovascular disease in overweight and obese individuals

Abstract

Background: The burden and prognostic importance of subclinical cardiovascular disease (CVD) in obesity has not been investigated systematically.

Methods and results: We examined prevalence of subclinical disease in 1938 Framingham Study participants (mean age, 57 years; 59% women) by use of 5 tests (electrocardiography, echocardiography, carotid ultrasound, ankle-brachial pressure, and urinary albumin excretion) and stratified by body mass index (BMI) (normal, < 25; overweight, 25 to < 30.0; obese, > or = 30 kg/m2) and waist circumference (WC) (increased, > or = 88 cm for women or > or = 102 cm for men). We investigated risk of overt CVD associated with adiposity according to presence versus absence of subclinical disease on any of the 5 tests. Prevalence of subclinical disease was higher in overweight (40.0%; adjusted odds ratio, 1.68) and obese individuals (49.7%; odds ratio, 2.82) compared with individuals with normal BMI (29.3%) and in individuals with increased WC (44.9%; odds ratio, 1.67) compared with normal WC (31.9%). On follow-up (mean 7.2 years), 139 participants had developed overt CVD. Presence of subclinical disease was associated with > 2-fold risk of overt CVD in all BMI and WC strata, with no evidence of an interaction between BMI and subclinical disease. CVD risk was attenuated in participants with obesity or increased WC but without subclinical disease (adjusted hazard ratio for obesity, 1.57; 95% confidence interval, 0.74 to 3.33; adjusted hazard ratio for increased WC, 1.22; 95% confidence interval, 0.69 to 2.15), compared with individuals with normal BMI or WC and no subclinical disease, respectively.

Conclusions: In our community-based sample, overweight and obesity were associated with high prevalence of subclinical disease, which partly contributed to the increased risk of overt CVD in these strata.