BACKGROUND: Metabolic syndrome (MetS) is a collection of clinical conditions, 
including central obesity, hypertension, glucose intolerance and dyslipidemia. 
The long-term inflammatory and metabolic dysfunction associated with MetS may 
contribute to osteoarthritic processes leading up to total joint arthroplasty 
(TJA). The purpose of this study was to investigate levels of metabolic 
biomarkers and the prevalence of MetS in patients undergoing TJA.
METHODS: Under IRB approval, citrated plasma samples were collected from 41 
patients undergoing total hip and knee arthroplasty (THA/TKA) preoperatively and 
day 1 postoperatively. Control group consisted of 25 healthy human plasma 
samples (female and male, 18-35 years old) purchased from George King Biomedical 
Inc. (Overland Park, KS, USA). Samples were profiled for c-peptide, ferritin, 
IL-6, insulin, resistin, TNF-α, IL-1a, leptin, and PAI-1 using metabolic 
biochips purchased from RANDOX Co. (Antrim, Northern Ireland). NCEP/ATP III 
guidelines were used to evaluate which patients met MetS criteria.
RESULTS: Levels of IL-6, resistin, TNF-a, IL-1a, leptin, and PAI-1 were 
significantly elevated in patients undergoing TJA compared to normal. C-peptide 
and insulin were both decreased in TJA compared to normal. No significance was 
found when comparing TJA to normal for ferritin. TNFα was significantly lower in 
TJA+MetS compared to TJA-MetS, while other biomarkers showed no difference in 
TJA±MetS populations. Insulin & c-peptide both showed a significant decrease in 
TJA-MetS compared to normal, but levels in TJA+MetS patients were not 
significantly different from controls. Resistin showed significant increases in 
TJA+MetS vs. normal, but not in TJA-MetS vs. normal.
CONCLUSIONS: Overall, the differing metabolic profile seen in patients 
undergoing TJA suggest ongoing metabolic dysfunction. Insulin and c-peptide 
patterns among the different test groups hint toward a complex and dysfunctional 
metabolic process involved, with leptin and underlying insulin resistance 
playing a role. Increased resistin in TJA+MetS, but not in TJA-MetS, compared to 
normal, suggests that while elevated resistin levels may be associated with the 
osteoarthritic process, levels are further attenuated by MetS, which is highly 
prevalent in this population. Increased TNFα in TJA-MetS compared to TJA+MetS 
may be an artifact of differing sample populations or a true complication of the 
complex pathophysiology and medical regimen seen in patients with both OA and 
MetS. The lack of difference seen in the remaining biomarkers suggest that 
having MetS as a comorbidity does not contribute to the elevated levels seen in 
patients undergoing TJA.