BACKGROUNDThe prevalence of metabolic syndrome (MetS) in hypertensive population in Chinese countryside is unknown. Firstly, this study compared the prevalence of MetS according to National Cholesterol Education Program (NCEP) ATPIII, revised NCEP and International Diabetes Federation (IDF) definitions. Secondly, it investigated the association between MetS, coronary heart disease (CHD) and stroke in patients with hypertension.

METHODSIn this cross sectional study, the cluster sampling method was used. Three MetS definitions were applied to 1418 normal subjects and 5348 hypertensive patients aged 40-75 years in rural areas in China. The agreement between different MetS definitions was estimated by kappa statistics. Logistic regression analyses determined the association between MetS defined by the three MetS definitions and CHD and stroke.

RESULTSIn subjects without hypertension, the prevalence of Mets was 4.1% by NCEP definition, 8.3% revised NCEP definition and 7.8% IDF definition. In hypertensive individuals, the prevalence was 14.0%, 32.9%, and 27.4% in men; 35.6%, 53.1%, and 50.2% in women by the same definitions, respectively. In hypertensive individuals, the agreement was 94.4% in men and 97.0% in women between revised NCEP and IDF definitions. The IDF defined MetS was more strongly associated with CHD than the NCEP or revised NCEP defined MetS (adjusted odds ratio: 1.92 compared with 1.85 and 1.69 in men; 1.64 compared with 1.48 and 1.60 in women).

CONCLUSIONSIn the patients with hypertension, the revised NCEP and IDF definitions identified more individuals than NCEP definition and their agreement is very high. The IDF defined MetS is more strongly associated with CHD than the NCEP or revised NCEP defined MetS, but weakly or not associated with stroke.