The MetS is a cluster of cardiovascular risk factors including obesity, hypertension and dyslipidaemia that increases the risk of the development of type 2 diabetes mellitus and cardiovascular disease. The risk factors of MetS include obesity, aging, sedentary lifestyle, diabetes mellitus, coronary heart disease and lipodystrophy [14
]. It is estimated that t a large majority of patients with type 2 DM or impaired glucose tolerance have the metabolic syndrome[8
]. I note similar findings in this study and report the prevalence rate of Mets to be 86%. The prevalence rates of the Mets in both genders as noted in this report are comparable to that of a previous report on the Mets[16
]. The role of age as a risk factor of MetS cannot be overemphasized as age dependency of the syndrome's prevalence is seen in most populations around the world[6
]. In this report, the prevalence of MetS is noted to increase from 11% among participants aged 20 through 29 years to 89% in participants aged 70 through 79. Although this study showed that the mean age of men with MetS was significantly higher than that of women, the age specific prevalence of MetS however was similar in both genders except for ages 70-79 where the proportion of men with MetS was found to be almost twice that of females. These findings are contrary to those documented in a Seychelles'[17
] population where the greatest prevalence of MetS using the ATP definition was highest at age 45-54 for men. In a Finnish [18
] study on Mets, the prevalence of the MetS was found to increase with increasing age in women.
There are currently two major definitions for metabolic syndrome and these are provided by the International Diabetes Federation[16
] and the revised National Cholesterol Education Program [19
], respectively. In a bid to harmonize the different criteria for the definition of the Mets, several bodies have met and issued a joint statement making some alterations in the International Diabetes Federation (IDF) definition of the Mets. The main difference concerns the measure for central obesity which was proposed should no longer be an obligatory component for the diagnosis of the Mets although the waist measurement would continue to be a useful preliminary screening tool. The proposed blood glucose criterion as one of the defining parameters of the Mets is now 100 mg% or more[3
The components of the metabolic syndrome vary in their rates of occurrence. The Seychelles[16
] study reported high blood pressure and adiposity as the MetS defining criteria that occurred most commonly irrespective of the MetS definitions used. I however report central obesity and reduced HDL-cholesterol as the prevalent components of the Mets in our study subjects. The mean waist circumferences were comparable in both sexes with Mets but significantly lower HDL levels were noted in men than in women. Central obesity was found in 80% of the study subjects. This finding is not surprising given the observation that central obesity plays a central role in the development of the MetS and appears to precede the appearance of the other MetS components[20
]. It is however pertinent to note that although the specific role of central obesity in patients with the metabolic syndrome remains unexplained, active brown adipocytes which accumulate in central locations have been found to be metabolically active. In addition, many studies have confirmed the existence of a tighter correlation of central obesity with insulin resistance, dyslipidemia, hypertension, and atherosclerotic heart disease than for obesity without regard to pattern [21
]. Some researchers have report lower rates-25%- of occurrence of central obesity in the MetS[22
The pattern of lipid abnormalities in this study was such that LDL-C although not a component of MetS was the commonest documented lipid abnormality in subjects with the MetS. The occurrence of elevated LDL-C in people with the Mets has been noted to increase the magnitude of the risk for developing coronary artery disease[23
]. I report a gender difference in the pattern of lipid abnormality in subjects with the Mets. LDL-C and TCHOL were higher in women than in men with the MetS. The men with the MetS however had higher mean TG and lower HDL-C values than women with the MetS. This pattern of lipid abnormality was documented in a recent Nigerian study [7
Gender differences were also documented in the occurrence of hypertension in the metabolic syndrome. We report a prevalence rate of hypertension of 67%. This is similar to reports to reports from the Middle East[22
] and Nigerian reports[7
]. There were however significant gender differences in hypertension and females were found to have a significantly higher incidence rates of hypertension than men.
Although each of the components of the metabolic syndrome individually have been identified as risk factors for cardiovascular disease, an individual with three or more components is at particularly high risk. I report a comparable distribution of the components of the MetS in both sexes. A small proportion-5.8% -of our subjects with type 2 DM have all the components of the MetS. This is in contradistinction to the report by Fezeu et al[9
] who reported the absence of a combination of four component of the MetS in their study subjects. Potential factors that may have accounted in the gender differences in the distribution of the components of the MetS include an older age in men and significant smoking and alcohol histories.
A comparison of biochemical parameters other than those that define the MetS in both sexes showed that subjects with the MetS were significantly older, had higher body mass indices and higher low density cholesterol than those without the MetS.