A team of researchers from the Indian Institute of Technology-Madras has discovered a genetic variation that causes an increased risk of hypertension (high blood pressure) in people.
The team studied the genetic profile of persons with hypertension and healthy control individuals and showed that four alterations in the DNA building block of a gene called MMPS could increase the risk of hypertension.
Nitish R. Mahapatra, professor in the Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences on the institute premises, led the research that included researchers from Translational Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad; Department of Experimental Medicine and Biotechnology, PGIMER, Chandigarh; and the Institute of Cardiovascular Disease, Madras Medical Mission, Chennai.
The results of their work were published in the Journal of Hypertension.
Mr. Mahaptra said: “The genetic cause of high BP is complex and many genes contribute to it. Hypertension contributes the largest to the burden of disease and mortality in India, with an estimated 1.6 million annual deaths due to ischemic heart disease and stroke caused by it.”
Hypertension causes stiffness of blood vessel walls and arterial stiffness due to accumulation of excess collagen on the walls. Collagen is a type of protein generated in the body.
Normally excess collagen is broken down by an enzyme called “matrix metalloproteinase 8” (MMP8) preventing accumulation. However, a dysfunction or imbalance of the enzyme could result in the collagen not being broken down and it settles on artery walls.
Earlier studies have correlated changes in MMP8 amounts in blood to several cardiovascular diseases. MMP8 enzyme abnormalities are associated with hypertension and chronic kidney disease.
The research team has established the relationship between MMP8 gene variations and enzyme level changes. The team recruited 1,432 patients with hypertension and 1,133 healthy volunteers at MMM hospital and PGIMER, Chandigarh. It amplified the DNA samples from the participants and a certain portion of the gene was extracted, cloned and transferred live into experimental living cells.
The researchers found specific genetic variations (MMP8 Hap3 genotype) that result in reduced blood MMP8 levels. Individuals having this specific genetic variation in their DNA have enhanced risk of collagen deposition in arteries and consequently higher risk of hypertension and other cardiovascular diseases, they concluded. The genetic variations are, in effect, a predictor of hypertension.
Such people can adopt lifestyle changes from early on to avoid this malady, the researchers said.