Mitochondrial tRNAMet mutation is associated with clinical and biochemical characteristics in primary hypertension

Abstract

Mitochondrial DNA mutations have been increasingly associated with various diseases. An association between the mitochondrial tRNA gene mutation, tRNAMet, and primary hypertension has been suggested. In the present study, the association between the tRNAMet mutation and the development of primary hypertension was investigated by assessing clinical and biological indicators in 800 patients with primary hypertension. General [gender, age, age of onset, body mass index (BMI) and family history] and clinical data (routine blood counts, blood biochemistry profiles and color Doppler echocardiography) were obtained. Venous blood samples were drawn from all the subjects for the separation of white blood cells (WBCs) and DNA extraction. Mitochondrial tRNAMet was amplified using PCR, purified and sequenced; samples identified to have a mutation were sequenced in triplicate for validation. Comparisons were made between 7 hypertensive patients with mutations (0.875%) and 10 age-, gender- and medication‑matched hypertensive patients without mutations (controls). A maternal history of hypertension was present in 57.1% of patients with tRNAMet mutations and only 20.0% of patients without mutations. Notably, tRNAMet mutations were associated with a significantly earlier age of hypertension onset, decreased red blood cell (RBC) counts and hemoglobin (Hb) levels and increased total cholesterol (TC), triacylglycerol (TG), high‑density lipoprotein cholesterol (HDL-C) and glucose levels (all P<0.05). Heart structure and function differences were also assessed between the two groups. In conclusion, mitochondrial tRNAMet mutations may induce changes in tRNA structure and function, which contributes to the pathogenesis of primary hypertension by disturbing blood lipid metabolism, the steady state of blood cells and cardiac structure and function.