Metabolic syndrome & Framingham Risk Score: observations from a coronary angiographic study in Indian patients

Abstract

Background & objectives: Metabolic syndrome (MS) is an important determinant of cardiovascular (CV) risk. Framingham Risk Scores (FRS) often underestimate the CV risk in Asians, younger patients and those with MS. Asians often develop coronary artery disease (CAD) at a younger age and also have a high prevalence of MS. Only limited data are available on the relationship between MS and FRS in such patients and the present study was undertaken to report on this aspect in an Indian patient population with angiographically documented CAD.

Methods: Two hundred patients undergoing coronary angiography during a three months study period were included. Diagnosis of MS was based on modified south Asian guidelines.

Results: Of the 200 patients (age 56.5 ± 8.6 yr) undergoing coronary angiography, MS was diagnosed in 77 per cent n=154; abdominal obesity, low HDL and hypertension were the commonest of the diagnostic criteria of MS, being present in >70 per cent cases. Patients with MS had significantly higher mean FRS than those without MS (15.1 vs 8.65, P<0.0001). Most patients with MS (74%, n=148) had an intermediate to high 10-year CV risk (>10%) as estimated by FRS. The proportion of patients with MS progressively increased in those with low, intermediate and high FRS (61, 87 and 92%, respectively). Though the prevalence of MS was uniformly similar (74-84%) in all age groups (<45, 45-55, 55-65 and > 65 yr, respectively), amongst those <45 yr, none of the patients could be categorized as having high CV risk as estimated by FRS despite having angiographic CAD, highlighting the limitation of age dependence of FRS.

Interpretation & conclusions: MS is common in Indian patients with angiographically documented CAD; most patients with MS have 10-year risk of >10 per cent as estimated by FRS. Though MS is uniformly prevalent across all age groups, using the FRS may underestimate the CV risk in Indian patients despite documented CAD. These findings have significant implications for Asian patients with CAD in whom onset of CAD is often at a younger age than their Western counterparts. There should be continued health care emphasis on detection of MS and intensification of targeted preventive strategies.

Fig. 1

Proportion of patients in the low, intermediate and high FRS groups having MS (P value <0.05 for comparison between low and intermediate as well as low and high FRS groups).

Fig. 2

Prevalence of metabolic syndrome in different age quartiles in patients with CAD (P value ns for all distribution of MS across all age groups demonstrating that MS was common across all age quartiles).