Factor analysis and defining the metabolic syndrome.
OBJECTIVE
The metabolic syndrome has been referred to as a number of metabolic or physiologic abnormalities that occur together more often than would be predicted by chance. Considerable controversy exists about the exact abnormalities that are a part of this syndrome. The aim of this study was to examine the interrelations between these abnormalities.


METHODS
National Health and Nutrition Examination Survey (1988-1994), a national cross-sectional health survey.


METHODS
United States.


METHODS
Persons aged > or = 20 years (N=6868).


METHODS
Factors composed of variables often associated with the metabolic syndrome derived from principal components analysis.


RESULTS
Depending on the subgroup studied, the analyses suggested that at least 2 or 3 components were needed to explain the majority of variance in a set of variables. Regardless of age group, sex, race or ethnicity, 4 variables (waist circumference, fasting insulin, triglycerides, and high-density lipoprotein cholesterol) consistently loaded together on the first component, which is consistent with a metabolic syndrome factor. Some differences in the number of factors and the loading patterns occurred among 3 age groups and among men and women. Relatively minimal race or ethnic variation was observed when the data were stratified by sex. A subanalysis that included leptin concentrations produced a similar set of factors as the analysis without leptin concentration. Furthermore, leptin concentration did not provide a unifying explanation for the set of factors.


CONCLUSIONS
Patterns of factors of variables, often associated with the metabolic syndrome, tended to be similar among Whites, African Americans, and Mexican Americans.
Ford
Earl S
ES
Division of Adult and Community Health, National Center for Chronic Disease Prevention and Health Promotion, Atlanta, Georgia, USA. esf2@cdc.gov
D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000886:Anthropometry; D044383:Black People; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008297:Male; D024821:Metabolic Syndrome / Q000097:blood / Q000453:epidemiology* / Q000208:ethnology; D017058:Mexican Americans; D008875:Middle Aged; D009749:Nutrition Surveys; D012737:Sex Factors; D014481:United States / Q000453:epidemiology; D001741:Black or African American