Chronic fatigue syndrome is associated with metabolic syndrome: results from a case-control study in Georgia

We hypothesized that persons with chronic fatigue syndrome (CFS) would have a higher prevalence of metabolic syndrome compared with well controls, and that unwell persons with insufficient symptoms or fatigue for CFS (termed ISF) would have a prevalence of metabolic syndrome intermediate between those with CFS and the controls. We also sought to examine the relationship between metabolic syndrome and measures of functional impairment, fatigue, and other symptoms. Our analysis was based on a population-based case-control study conducted in metropolitan, urban, and rural areas of Georgia, United States, between September 2004 and July 2005. There were 111 persons with CFS, 259 with ISF, and 123 controls. Metabolic syndrome was determined based on having at least 3 of 5 standard risk components (abdominal obesity, high triglycerides, high blood pressure, elevated fasting glucose, and decreased high-density lipids) according to the National Cholesterol Education Program Adult Treatment Panel III definition. Persons with CFS were 2-fold as likely to have metabolic syndrome (odds ratio = 2.12, confidence interval = 1.06, 4.23) compared with the controls. There was a significant graded relationship between the number of metabolic syndrome factors and CFS; each additional factor was associated with a 37% increase in likelihood of having CFS. The association of ISF with metabolic syndrome was weaker (odds ratio = 1.72, confidence interval = 0.94-3.16). Among persons with CFS, the number of metabolic syndrome factors was significantly correlated with worse fatigue on a standardized summary measure of fatigue (r = 0.20, P = .04). In conclusion, CFS was associated with metabolic syndrome, which further exacerbated fatigue.