Differentiation between obesity and insulin resistance in the association with C-reactive protein.
BACKGROUND
Plasma C-reactive protein (CRP) concentrations are increased in obese and/or hyperinsulinemic individuals. The goal of this study was to determine if the relation between insulin resistance and CRP was independent of obesity.


RESULTS
Plasma CRP concentrations were measured before and after 3 months of calorie restriction in 38 healthy, obese women. Steady-state plasma glucose (SSPG) concentration during a 180-minute infusion of octreotide, glucose, and insulin was used to stratify participants into insulin-resistant (IR, n=20) or insulin-sensitive (n=18) groups, similar in terms of mean age (46+/-2 versus 44+/-2 years), body mass index (32.0+/-0.4 versus 31.4+/-0.3 kg/m2), and waist circumference (96+/-2 versus 95+/-2 cm). Mean CRP (0.39+/-0.08 versus 0.12+/-0.03 mg/dL, P=0.003) concentrations were higher in the IR group, as were day-long plasma glucose and insulin responses (P<0.001). There was a significant correlation at baseline between CRP and day-long plasma integrated insulin response (r=0.47, P=0.001) but not between CRP and body mass index (r=0.14) or waist circumference (r=0.10). Weight loss was similar in the two groups (8.7+/-0.9 versus 8.4+/-0.8 kg) but was associated with significant (P<0.001) decreases in SSPG and CRP concentrations in the IR group only. Regression analysis showed that SSPG and day-long plasma insulin response were the only significant predictors of CRP concentration.


CONCLUSIONS
CRP concentrations are elevated predominantly in obese individuals who are also insulin resistant and fall in parallel with weight loss-associated improvements in insulin resistance. The relation between CRP concentrations and insulin resistance is independent of obesity.
McLaughlin
Tracey
T
Stanford University School of Medicine, Stanford, Calif, USA.
Abbasi
Fahim
F
Lamendola
Cindy
C
Liang
Lynn
L
Reaven
Gerald
G
Schaaf
Patricia
P
Reaven
Peter
P
D000328:Adult; D001786:Blood Glucose; D001823:Body Composition; D002097:C-Reactive Protein / Q000032:analysis / Q000378:metabolism*; D031204:Caloric Restriction; D003937:Diagnosis, Differential; D005260:Female; D015309:Glucose Clamp Technique; D005951:Glucose Tolerance Test; D006801:Humans; D006946:Hyperinsulinism / Q000097:blood / Q000175:diagnosis; D007328:Insulin / Q000097:blood / Q000494:pharmacology; D007333:Insulin Resistance / Q000502:physiology; D008875:Middle Aged; D009765:Obesity / Q000097:blood* / Q000175:diagnosis* / Q000178:diet therapy; D012044:Regression Analysis; D012307:Risk Factors; D013997:Time Factors; D015431:Weight Loss / Q000502:physiology
D001786:Blood Glucose; D007328:Insulin; D002097:C-Reactive Protein