Evaluation of laboratory and bone mineral densitometry data in postmenopausal patients diagnosed with hypoparathyroidism

Aim: The aim of the study was to evaluate the bone mineral density, laboratory data, and osteoporotic fracture risk in postmenopausal women diagnosed with hypoparathyroidism and compare them with a control group. Materials and methods: This study is a retrospective study; 40 female patients in the hypoparathyroidism group and 40 female patients in the control group were included in our study. The sample of the study consists of patients diagnosed with hypoparathyroidism who applied to the Endocrinology outpatient clinic of Hitit University Erol Olçok Training and Research Hospital between February 2017 and September 2023 and postmenopausal female patients who underwent bone mineral density measurements for osteoporosis screening. The data of the case and control groups were retrospectively screened through hospital records, including anamnesis information, socio-demographic characteristics, physical examination findings, medical history, medications used, comorbidities, and laboratory and BMD measurements. Bone mineral density data were calculated from measurements obtained using Dual X-Ray Absorptiometry technique. The 10 year fracture risk assessed by the FRAX tool using femoral neck bone mineral density was calculated either. Patients with similar demographic characteristics who met the inclusion criteria for the case and control groups were selected. The data obtained were analyzed using the SPSS program. Results: Hip T-score, L1-L4 T-score, femur neck, femur total and L1-L4 bone mineral density measurements of the patient group were statistically significantly higher than the control group (p=0,002, p<0,001, p<0,001, p=0,001, p<0,001 respectively). Creatinine measurements of the patient group were statistically significantly higher than the control group (p=0,013). Parathormone, serum total calcium and corrected calcium values of the patient group were statistically significantly lower than the control group (p<0,001, p<0,001, p<0,001). The 25-hydroxy vitamin D and 24-hour urine calcium values of the patient group were statistically significantly higher than the control group (p= 0,011; p= 0,008). The patient group was divided into two groups according to 25-hydroxy vitamin D levels as 20 ng/dL and below and above 20 ng/dL. Bone mineral density measurements, fracture risk assessment scores and laboratory blood values were not statistically significantly different between the subgroups formed according to hydroxyvitamin D values. A negative statistically significant correlation was determined between the 25-hydroxyvitamin D values of all patients (n=80) in the patient and control groups and only the parathyroid hormone values (r=-0,371, p=0,001). No significant correlation was found between 25-hydroxyvitamin D values and other parameters (p>0,05 for all comparisons). Conclusions: Our study reveals important findings in postmenopausal women diagnosed with hypoparathyroidism. Particularly, when compared to the control group, we identified higher bone mineral density measurements and lower risk of major osteoporotic fractures in patients diagnosed with hypoparathyroidism. It was expected to find low levels of parathyroid hormone and high levels of calcium in 24-hour urine among the patient group. Upon reviewing the literature on hypoparathyroidism, our study stands out as the first in our country to investigate the impact of hypoparathyroidism on bone health. Globally, there are very few publications examining the effect of hypoparathyroidism on fracture risk. This underscores the international significance of your study and highlights its contribution to the literature. Key words: Bone Mineral Density, Hypoparathyroidism, Osteoporosis, Postmenopause