Association between family history and essential hypertension in Han population in Shanghai China

Backgrounds Genetic factor is one of important influencing factors of essential hypertension, and family history (FH) is an important marker of genetic factors. Objective To explore the association between family history and essential hypertension in Han population in Shanghai China. Methods The method of case-control study was used，342 cases of hypertension and 342 controls were selected and investigate their nuclear family members in the both study groups. The diagnostic information of hypertension in all relatives of these two groups was investigated. The method of genetic epidemiology research was used to explore the effect of family history. Results The average prevalence of hypertension was 23.32%. The prevalence of hypertension of first-degree relatives was 33.99%; the prevalence of second- degree relatives was 17.60%; the prevalence of third-degree relatives was 13.51%. All prevalence of hypertension of case group relatives was significantly higher than that of control group relatives. The average onset age in population with positive FH was 48.74±11.16 years old, and the average onset age in population with negative FH was 54.38±9.87 years old. The difference about two FH groups showed statistically significant (t=4.589, P<0.001). The average onset age of offspring with father, mother, grandpa, grandma, maternal grandpa or maternal grandma positive was respectively 48.42, 49.16, 39.55, 39.88, 43.67 or 43.64 years old; and the average onset age of children with father, mother, grandpa, grandma, maternal grandpa or maternal grandma negative was respectively 51.90, 51.17, 51.07, 51.08, 50.50 or 50.57 years old. The difference about two groups showed statistically significant. Conclusion Family history had a positive effect on the occurrence of hypertension, and led to earlier age of onset of offspring. The effects were different among parent and grandparent in Han in Shanghai China.