Estimate levels of osteocalcin (OC) and bone-specific alkaline phosphatase (BAP) with the Genetic polymorphism of FTO in osteoporosis patients

Abstract

Osteoporosis is a systemic skeletal disorder marked by the degradation of bone microarchitecture, resulting in diminished bone mineral density (BMD) and an elevated risk of fractures. Aims of the study: the study aimed to evalute levels of osteocalcin and bone-specific alkaline phosphatase and the Genetic polymorphism of FTO in patients with osteoporosis. Methods: A study was conducted on 40 postmenopausal women with osteoporosis and 40 age-matched healthy controls from Salah al-Din Governorate, Iraq. Bone mineral density (BMD) was measured using DEXA, and osteoporosis was defined as a T-score ≤ –2.5. Serum levels of BAP and osteocalcin were quantified using ELISA. Genomic DNA was extracted and genotyped for FTO and MC4R polymorphisms using ARMS-PCR, with DNA quality confirmed by agarose gel electrophoresis and Nanodrop spectrophotometry.

Results: The results of the study showed a significant difference in mean level of osteocalcin (26.15 ± 5.42 ng/ml) and BAP levels (37.63 ± 10.36 U/L) in patient group compared with control (21.87 ± 4.95 ng/ml, 30.23 ± 7.21 U/L), respectively. While the study showed no significant differences in mean age and Body mass Index (BMI) in patients’ group (55.48 ± 11.53, 29.16 ± 5.31 kg/m²) compared with control (53.82 ± 9.59, 27.91 ± 6.47 kg/m²). The results of the analysis of the rs9939609 allele in the FTO gene indicate no significant differences when comparing the genotypes (TT, TA, and AA) between osteoporosis patients and healthy controls. In contrast, the allele analysis showed that the presence of the A allele was associated with a significantly increased risk of osteoporosis (OR=1.985, 95% CI=1.017–3.809, p=0.0414), suggesting that the A allele may represent a genetic factor contributing to susceptibility to this disease. the results of the analysis of the rs17817449 allele in the FTO gene indicate no significant differences when comparing the genotypes (TT, TA, and AA) between osteoporosis patients and healthy controls. The odds ratio (OR) and relative risk (RR) values ​​were not statistically significant (p>0.05), indicating that the TA and AA genotypes do not constitute an independent risk factor compared to the reference TT type. the allele analysis also showed no significant differences suggesting that the G allele may not represent a genetic factor contributing to susceptibility to this disease.

Conclusion: Osteoporosis patients had higher osteocalcin and BAP levels than controls, despite identical age and BMI. The A allele of the FTO gene's rs9939609 variant enhanced osteoporosis risk, while genotypes (TT, TA, AA) and the rs17817449 variant did not. These findings indicate that the A allele may be a genetic risk factor for osteoporosis