The obese without cardiometabolic risk factor clustering and the normal weight with cardiometabolic risk factor clustering: prevalence and correlates of 2 phenotypes among the US population (NHANES 1999-2004)

Arch Intern Med. 2008 Aug 11;168(15):1617-24. doi: 10.1001/archinte.168.15.1617.

Abstract

Background: The prevalence and correlates of obese individuals who are resistant to the development of the adiposity-associated cardiometabolic abnormalities and normal-weight individuals who display cardiometabolic risk factor clustering are not well known.

Methods: The prevalence and correlates of combined body mass index (normal weight, < 25.0; overweight, 25.0-29.9; and obese, > or = 30.0 [calculated as weight in kilograms divided by height in meters squared]) and cardiometabolic groups (metabolically healthy, 0 or 1 cardiometabolic abnormalities; and metabolically abnormal, > or = 2 cardiometabolic abnormalities) were assessed in a cross-sectional sample of 5440 participants of the National Health and Nutrition Examination Surveys 1999-2004. Cardiometabolic abnormalities included elevated blood pressure; elevated levels of triglycerides, fasting plasma glucose, and C-reactive protein; elevated homeostasis model assessment of insulin resistance value; and low high-density lipoprotein cholesterol level.

Results: Among US adults 20 years and older, 23.5% (approximately 16.3 million adults) of normal-weight adults were metabolically abnormal, whereas 51.3% (approximately 35.9 million adults) of overweight adults and 31.7% (approximately 19.5 million adults) of obese adults were metabolically healthy. The independent correlates of clustering of cardiometabolic abnormalities among normal-weight individuals were older age, lower physical activity levels, and larger waist circumference. The independent correlates of 0 or 1 cardiometabolic abnormalities among overweight and obese individuals were younger age, non-Hispanic black race/ethnicity, higher physical activity levels, and smaller waist circumference.

Conclusions: Among US adults, there is a high prevalence of clustering of cardiometabolic abnormalities among normal-weight individuals and a high prevalence of overweight and obese individuals who are metabolically healthy. Further study into the physiologic mechanisms underlying these different phenotypes and their impact on health is needed.

MeSH terms

  • Adult
  • Age Factors
  • Blood Glucose / analysis
  • Blood Pressure / physiology
  • Body Mass Index
  • C-Reactive Protein / analysis
  • Cholesterol, HDL / blood
  • Cluster Analysis
  • Continental Population Groups
  • Cross-Sectional Studies
  • Female
  • Health Surveys
  • Humans
  • Insulin Resistance / physiology
  • Male
  • Middle Aged
  • Motor Activity
  • Obesity / epidemiology*
  • Overweight / epidemiology
  • Phenotype
  • Risk Factors
  • Triglycerides / blood
  • United States / epidemiology
  • Waist-Hip Ratio

Substances

  • Blood Glucose
  • Cholesterol, HDL
  • Triglycerides
  • C-Reactive Protein