Genetic influence on blood pressure and lipid parameters in a sample of Polish twins.

We studied 76 healthy monozygotic (MZ) and same-sex dizygotic (DZ) twin pairs (mean age 35 +/- 8 years, body mass index, BMI, 23.6 +/- 3.9 kg/m2) to determine genetic and environmental contributions to systolic (SBP) and diastolic (DBP) blood pressure, heart rate (HR) and serum lipids [total cholesterol (TC), low-density lipoprotein cholesterol (LDL-chol), high-density lipoprotein cholesterol (HDL-chol) and triglycerides (TG)I. SBP, DBP and HR were measured clinically and by ambulatory blood pressure monitoring (ABPM). Parameters of the genetic models for age-, sex- and BMI-adjusted data were estimated by model fitting and path analysis technique using LISREL 8. We found significant genetic effect on SBP and DBP for both clinical and ABP measurements, ranging from 37% for night-time ambulatory DBP to 79% for daytime ambulatory SBP. Estimates of genetic effects were higher for daytime than night-time ABP values, and higher for ambulatory 24-h SBP than office SBP measurements, with the reverse true for DBP. Significant genetic effect on HR ranged from 59% for office measurements to 69% for 24-h mean values. In summary, we also found genetic effect on TC, LDL-chol and HDL-chol with estimates ranging from 36% to 64%, but not on TG. Furthermore, a shared environmental component for TG was found, estimated at 36%. We showed significant genetic effect on both office and ambulatory BP and HR, with stronger genetic effect on daytime than night-time BP. We also found genetic effect on TC and lipoprotein fractions, but no significant genetic effect on TG. Environmental factors influencing serum TG, such as alcohol consumption, may explain the apparent lack of genetic effect in this healthy, non-obese population.