Metabolic Syndrome: Comparison of Occurrence Using Three Definitions in Hypertensive Patients

Objective To compare the frequency of occurrence of metabolic syndrome (MetS) using three international definitions and to study the distribution of cardiovascular risk factors among newly-diagnosed hypertensive Nigerian subjects.

Design Cross sectional study.

Settings Cardiology unit of LAUTECH Teaching Hospital, Osogbo, Nigeria.

Participants One hundred forty newly-diagnosed hypertensive Nigerian subjects and 70 age- and sex-matched normotensive controls were used for this study.

Methods Clinical history and relevant laboratory investigations were performed on all study participants. The definition of MetS was based on three international definitions (World Health Organization [WHO], International Diabetes Federation [IDF], and National Cholesterol Education Program Adult Treatment Panel III [NCEP ATP III]). Ethical approval was obtained for the study. Statistical analyses were performed using SPSS 16.0.

Results There was no difference in age and gender distribution between the hypertensive subjects and controls. (55.14 ± 10.83 years, females 53.6% vs. 54.67 ± 10.89 years, females 52.9% respectively, P>0.05). The frequency of occurrence of MetS among hypertensives was 34.5% according to WHO, 35.0% according to NCEP ATP III, and 42.5% according to the IDF criteria. Visceral obesity and reduced high-density-lipoprotein (HDL) were the other common cardiovascular risk factors among newly-diagnosed hypertensive subjects. Female hypertensives had a higher prevalence of visceral obesity and low HDL.

Conclusion Frequency of occurrence of metabolic syndrome was similar using the NCEP ATP III and WHO definitions. However, the IDF definition resulted in a higher frequency because of the lower cut off for waist circumference used for identification of visceral obesity. Metabolic syndrome is present in a significant proportion of newly-diagnosed hypertensive subjects. Appropriate screening and treatment are therefore required.