Objective: To investigate the prevalence and identify the phenotype of individuals suspected to be metabolically obese but normal weight (MONW).
Design and subjects: Eight thousand nine hundred and eighty-seven nondiabetic subjects aged over 40 years were selected from the Chungju Metabolic disease Cohort study performed in 2003-2006 in Korea. Those within the highest quartile in the homeostasis model assessment of insulin resistance (HOMA-IR) with a normal body mass index (BMI) between 18·5 and 23 kg/m(2) were classified as MONW.
Measurements: Data on anthropometry, lipid profiles and HOMA-IR values were analysed.
Results: The prevalence of MONW was 14·2% for men and 12·9% for women amongst normal-weight subjects. Multiple logistic regression analysis showed that total cholesterol (TC) levels over 5·17 mm (odds ratio, OR = 1·481; 95% confidence intervals, CI 1·086-2·021), triglyceride (TG) levels over 1·69 mm (OR = 1·507; 95% CI 1·093-2·077) and high-density lipoprotein-cholesterol levels lower than 1·03 mm (OR = 1·580; 95% CI 1·053-2·371) independently had higher odds of diagnosing MONW amongst men. For women, a BMI over 21·5 kg/m(2) (OR = 1·405; 95% CI 1·034-1·909), TC levels over 5·17 mm (OR = 1·524; 95% CI 1·112-2·090) and TG levels over 1·69 mm (OR = 1·799; 95% CI 1·302-2·487) were independently associated with a diagnosis of MONW.
Conclusions: More than 10% of normal-weight subjects were classed as MONW in this cohort. Identification of these subjects based on lipid profiles could aid in the early detection of a high risk group of developing cardiometabolic diseases.
© 2011 Blackwell Publishing Ltd.