Gain-of-Function R990G Polymorphism of the Calcium-Sensing Receptor Gene: Gender-Related Effects in Patients with Coronary Heart Disease

Background: Activating the calcium-sensing receptor (CaSR), which regulates extracellular calcium, has been suggested to possibly decrease renin expression, thus playing a role in regulating the blood pressure via the renin-angiotensin-aldosterone system. Objectives: Considering this hypothesis, the aim of this study was to find the relationship between the gain-of-function variation of the CaSR gene, R990G (A < G), and coronary heart disease (CHD) risk factors and complications. Methods: The study sample consisted of 121 CHD patients and 105 healthy people from Turkish population. R990G function-gain mutation of the CaSR gene was analyzed by the real-time PCR method. Results: The AA genotype of CaSR R990G variation was associated with higher LDL-C, SBP, DBP and lower HDL-C in the CHD group compared to controls (P < 0.001). The comparison by gender in theCHDgroup revealed increased systolic blood pressure inwomen with common AA genotype as compared to men (P = 0.008) whereas in the control group, higher HDL-C and lower serum LDL-C (P < 0.001 and 0.031, respectively) were observed in women with AA versus men with AA. Higher blood pressure levels in women were not sustained in G allele carriers compared to men with G allele (P > 0.05). Conclusions: The common AA genotype of CaSR R990G was found to be related to hypertension in CHD patients while showing a higher association with hypertension, especially in women. We also suggest that the CaSR R990G AA genotype may have diverse effects on serum lipids and that the genetic effect could differ by gender.