Epidemiology and factor analysis of obesity, type II diabetes, hypertension, and dyslipidemia (syndrome X) on the Island of Kosrae, Federated States of Micronesia

Objectives: Obesity, type II diabetes, hypertension, and dyslipidemia are m ajor causes of morbidity and mortality throughout the world. Though these d isorders often cluster in individuals and families and are collectively kno wn as syndrome X, the basis for this aggregation is not well understood. To further understand the pathogenesis of syndrome X, a comprehensive epidemi ological study was undertaken on the Pacific Island of Kosrae, Federated St ates of Micronesia (FSM). Methods: The entire adult (>20 years of age) popu lation of Kosrae underwent a clinical evaluation that included a questionna ire that noted the participants' sex, family data including listing of biol ogical parents, siblings, and children, smoking status, village of residenc e, age and health status. The medical evaluation included: anthropometric m easures (weight, height, waist, hip), serum chemistries (leptin, fasting bl ood sugar (FBS), insulin, total cholesterol (TC), triglycerides (TG), and a polipoproteins B and A-I (apo B and apo A-I) and blood pressure (BP) measur ements. Results: Obesity (BMI greater than or equal to 35) was found in 24% , diabetes (FBS greater than or equal to 126 or 2-hour oral glucose toleran ce test greater than or equal to 200) in 12%, hypertension (SBP greater tha n or equal to 140 or DBP greater than or equal to 90) in 17%, and dyslipide mia (TC greater than or equal to 240 or TG greater than or equal to 200 or apo B greater than or equal to 120 or apo A-I less than or equal to 88) in 20% of the population. Significant covariate effects after multivariate ana lysis were as follows: sex affected the frequency of all four disorders, pa rity affected the frequency of dyslipidemia, smoking affected the frequency of obesity and diabetes, village of residence affected the frequency of ob esity, hypertension, a nd dyslipidemia, and age affected the frequency of a ll four disorders. Factor analysis identified four independent factors that explained 73% of the total variance of the entire data set: factor 1 (weig ht, waist, leptin, insulin, and TG), factor 2 (TC, TG, apo B, apo A-I, and insulin), factor 3 (systolic and diastolic BP, FBS, waist and weight), and factor 4 (apo A-I, TG, leptin, and weight). Conclusions: This population-ba sed study on the Island of Kosrae suggests that syndrome X is a composite o f 4 independent factors: obesity with diabetes and hypertriglyceridemia, co mbined hyperlipidemia with diabetes, hypertension with obesity and diabetes , and increased HDL-low TG with thinness and high leptin. Further studies t o identify the genetic components of these factors as well as the individua l traits are under way. Copyright (C) 2000 S. Karger AG. Basel.