Background: Increased incidence of hypertension, non-insulin dependent diabetes (NIDDM) and coronary heart disease often cluster in the same individuals and there have been speculations that a common mechanism may be responsible for all of these pathological conditions. This risk factor constellation, which is associated with an enhanced risk for cardiovascular disease, is sometimes referred to as the Insulin Resistance Syndrome , Syndrome X , or the Metabolic Syndrome .AIM: To find out the prevalence of Syndrome X in the population of patients coming to a preventive health check clinic at a tertiary care teaching hospital in a megacity of the developing world.Methods: A total of 270 patients, above the age of 40 years, who attended preventive health check clinics of 2 Family Physicians at the Aga Khan University from January 1996 to July 1997 were selected. Patients below 40 years were excluded from the study.Results: The prevalence of Syndrome X, defined as association of obesity, NIDDM, hypertension, raised LDL and raised triglycerides is 2.6% in patients above 40 years, who were screened in this study.CONCLUSION: The significant prevalence of Syndrome X is alarming and we need to strengthen our existing educational programs for prevention of obesity, increased physical activity and better control of hypertension. When drugs are selected for pharmacological treatment, priority should be given to those, which improve the insulin sensitivity index or are at least neutral in this respect
