Objective: The risk factor pattern underlying a parental history of myocardial infarction (MI) is incompletely understood. We examined whether a parental history of clinically verified early MI may promote development of insulin resistance, obesity and the metabolic syndrome (MetS).
Methods: One hundred and seventy-four offspring to patients with clinically verified MI before 60 years of age in the population-based prospective Malmo Diet and Cancer (MDC) study were recruited (positive parental history). As controls, we included 174 offspring of MDC participants without MI during 14 years of follow-up in the MDC (negative parental history). MetS was defined according to the National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) guidelines, obesity as BMI greater than 30 kg/m and insulin resistance as the top quartile of homeostasis model assessment index in the 348 included offspring (mean age 44 years, 49% women).
Results: The odds ratio, 95% confidence interval, for MetS in positive parental history as compared with negative parental history was 2.05, 1.06-4.00 (P = 0.034) after adjustment for age, sex, low-density lipoprotein cholesterol (LDL) and smoking. positive parental history was also independently associated with obesity 2.50, 1.34-4.66 (P = 0.003), abdominal obesity 2.01, 1.21-3.33 (P = 0.007) and insulin resistance 1.97, 1.14-3.40 (P = 0.014), whereas there was no association with LDL and smoking. All of these relationships were stronger in men than in women.
Conclusion: Parental history of clinically verified early MI is associated with MetS, obesity and insulin resistance rather than with traditional cardiovascular disease risk factors such as LDL and smoking, suggesting that primary preventive interventions targeted at weight reduction and improvement of insulin sensitivity may be particularly beneficial in this subset of the population.