Abstract P294: Higher Obesity Duration and Severity are Associated with Progression to Metabolic Syndrome From Metabolically Healthy Obesity: Discrete Time Survival Evidence From the Multi-Ethnic Study of Atherosclerosis
While the health risks of obesity compared to normal weight have been well studied, the cumulative risk associated with chronic obesity remains unknown. Specifically, debate continues about the importance of recommending weight loss for those who have metabolically healthy obesity. We therefore hypothesized that longer duration of obesity combined with greater severity of obesity is associated with progression to incident metabolic syndrome.
We used complementary log-log models of discrete time survival to metabolic syndrome with clustered robust variance for time varying obesity severity and duration in 2,748 Multi-Ethnic Study of Atherosclerosis participants with obesity (BMI≥30kg/m2) at any visit. Participants who developed metabolic syndrome before obesity were excluded. We defined obesity duration as the number of visits with measured obesity and obesity severity as the WHO levels I-III based on BMI. We defined metabolic syndrome using Adult Treatment Panel III criteria modified to exclude waist circumference. We assessed whether participants exhibited individual heterogeneity in their risk for metabolic syndrome using a random effects complementary log-log model. We specified an a priori sensitivity analysis to determine if the results were similar in those younger or older than 70 years.
Higher obesity severity and duration were independently associated with incident metabolic syndrome (Table 1). Including random intercepts in the model, while statistically significant, did not attenuate other associations. Estimates for duration were stronger for those under 70 years when compared to those 70 and older (age interaction p=0.039).
While there is significant individual heterogeneity in risk, both duration and severity of obesity are associated with incident metabolic syndrome, suggesting that metabolically healthy obesity is a transient state in the pathway to metabolic risk. Weight loss should be recommended to all individuals with obesity, including those who are currently metabolically healthy.
Table 1. Metabolic syndrome hazard ratios and 95% confidence intervals from complementary log-log models of discrete time survival by obesity duration and severity in MESA participants with measured obesity at any visit (n=2,748)
* All models include age, gender, and race/ethnicity, and indicator variables for study visit (visits 1-5)
** All models, except for the random effects model, use robust variance clustered on participant ID
*** Metabolic syndrome is defined as 2 or more of the following:
1. Triglyceride level ≥150mg/dL
2. HDL cholesterol <40mg/dL in men and <50mg/dL in women
3. Systolic blood pressure ≥130mmHG or diastolic blood pressure ≥85mmHG or use of blood pressure medications
4. Fasting glucose ≥100mg/dL or use of medications for diabetes
Author Disclosures: M. Mongraw-Chaffin: None. M.C. Foster: None. R.R. Kalyani: None. D. Vaidya: None. G.L. Burke: None. M. Woodward: None. C.A.M. Anderson: None.
- © 2016 by American Heart Association, Inc.