Abstract 17763: Hypertension and Dyslipidemia, but Not Fasting Blood Glucose, Dissociate From Central Obesity and Insulin Resistance With Advancing Age
Background and aims: Obesity is a strong cardio-vascular (CV) risk factor. However its association with CV mortality markedly declines with age. This may be due to weakening associations with the other components of the metabolic syndrome (MS). In the present study we examined the prevalence and the cross-sectional relations between central obesity and MS components according to age in a large population of hypertensive patients.
Materials and methods: The study cohort comprised 5712 consecutive, non-diabetic hypertensive patients (50.1 % males, age range: 40-95 years) who visited our outpatient hypertension clinic. The total population was divided in five age groups (40-49, 50-59, 60-69, 70-79, >80 years old). BP was evaluated by both office and 24-hour ambulatory (ABPM) measurements. All patients underwent a biochemical evaluation of glucose metabolism and inflammation parameters at drug free baseline. The diagnosis of the MS was based on the ATP-III definition.
Results: The prevalence of the MS remained stable with age. However, we noted a progressive decrease in the associations between Waist Circumference (WC) and the ABPM systolic BP (r2 from 9.9% to 1%, p<0.001), WC and HDL-cholesterol (r2 from 21% to 4.9% p=0.002) and between WC and triglycerides levels (r2 from 17.5% to 1.9%, p<0.001). In contrast we observed a stable or increased association between WC and HOMA-IR (r2 from 24% to 29%, p=NS) and FBG (r2 from 6.8% to 13.4% p=0.02). High sensitivity C-reactive protein (hs-CRP) was highly correlated with aSBP, HDL-cholesterol, triglycerides and FBG in all age groups (p<0.001 for all). In multiple linear regression analysis, hsCRP remained among the most significant predictors for aSBP (p<0.001) and HDL-cholesterol (p<0.05) in patients >80 years old.
Conclusion: The association between central obesity, insulin resistance and FBG persists in old age. However, central obesity is no longer associated with high blood pressure or dyslipidemia. These data suggest that with aging BP and dyslipidemia are increasingly determined by factors distinct from central obesity and insulin resistance, in particular inflammation. The weakening associations between MS components may underlie the weakening of obesity as a CV risk factor in the elderly.
- © 2010 by American Heart Association, Inc.