Metabolic syndrome and weight gain in adulthood.

Background: The influence of long-term adult weight history on metabolic risk independent of attained body mass index (BMI) is unknown.

Methods: Using nationally representative data on adults aged 50-64 years from the 1999-2006 National Health and Nutrition Examination Surveys, we examined weight change for two periods of adulthood: prime age (age 25-10 years ago) and midlife (the last 10 years). Weight changes in each period were categorized as stable (gain <10 kg) or gain (gain >or=10 kg) to create weight history comparison groups: stable-stable, gain-stable (prime age gain), stable-gain (midlife gain), and gain-gain (continuous gain). Persons who lost weight were excluded. Logistic regression predicted odds of metabolic syndrome and its subcomponents based on weight history, adjusting for current BMI and covariates.

Results: Participants in the gain-stable group had 89% elevated odds of metabolic syndrome (odds ratio = 1.89, 95% CI: 1.19-3.01) relative to the stable-stable group, even after adjustment for current BMI. All weight gain groups had increased odds of low HDL and high triglycerides relative to participants with continuously stable weights. No significant associations were found between weight history and hypertension or high glucose.

Conclusions: Weight history confers information about metabolic risk factors above and beyond attained weight status. In particular, adult weight gain is related to risk of low HDL and high triglycerides. Weight history may contribute to our understanding of why some obese older persons are metabolically healthy but others are not.